| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Stephen Boyd | 7010 | 38.81% | 73 | 26.16% |
| Jerome Brunet | 2083 | 11.53% | 22 | 7.89% |
| Dong Aisheng | 1690 | 9.36% | 7 | 2.51% |
| Michael Turquette | 1685 | 9.33% | 16 | 5.73% |
| Tomeu Vizoso | 440 | 2.44% | 4 | 1.43% |
| Grant C. Likely | 437 | 2.42% | 1 | 0.36% |
| Sylwester Nawrocki | 396 | 2.19% | 7 | 2.51% |
| Marek Szyprowski | 337 | 1.87% | 2 | 0.72% |
| Geert Uytterhoeven | 320 | 1.77% | 12 | 4.30% |
| James Hogan | 294 | 1.63% | 5 | 1.79% |
| Boris Brezillon | 268 | 1.48% | 3 | 1.08% |
| Leonard Crestez | 263 | 1.46% | 4 | 1.43% |
| Russ Dill | 222 | 1.23% | 1 | 0.36% |
| Gregory CLEMENT | 208 | 1.15% | 1 | 0.36% |
| Maxime Ripard | 191 | 1.06% | 10 | 3.58% |
| Sam Protsenko | 180 | 1.00% | 1 | 0.36% |
| Heiko Stübner | 147 | 0.81% | 2 | 0.72% |
| Mike Tipton | 137 | 0.76% | 2 | 0.72% |
| Peter 'p2' De Schrijver | 127 | 0.70% | 2 | 0.72% |
| Prashant Gaikwad | 119 | 0.66% | 3 | 1.08% |
| Chen-Yu Tsai | 118 | 0.65% | 2 | 0.72% |
| Masahiro Yamada | 101 | 0.56% | 14 | 5.02% |
| Lee Jones | 93 | 0.51% | 2 | 0.72% |
| Saravana Kannan | 89 | 0.49% | 3 | 1.08% |
| Matti Vaittinen | 88 | 0.49% | 2 | 0.72% |
| Ulf Hansson | 83 | 0.46% | 7 | 2.51% |
| Shawn Guo | 81 | 0.45% | 4 | 1.43% |
| Ben Dooks | 65 | 0.36% | 1 | 0.36% |
| Dinh Nguyen | 60 | 0.33% | 1 | 0.36% |
| Dmitry Osipenko | 56 | 0.31% | 1 | 0.36% |
| Derek Basehore | 53 | 0.29% | 1 | 0.36% |
| Sowjanya Komatineni | 51 | 0.28% | 1 | 0.36% |
| Fabio Estevam | 49 | 0.27% | 1 | 0.36% |
| J Keerthy | 41 | 0.23% | 1 | 0.36% |
| Nico Pitre | 38 | 0.21% | 1 | 0.36% |
| Shawn Lin | 33 | 0.18% | 2 | 0.72% |
| Tudor-Dan Ambarus | 32 | 0.18% | 2 | 0.72% |
| Neil Armstrong | 32 | 0.18% | 1 | 0.36% |
| Thierry Reding | 24 | 0.13% | 1 | 0.36% |
| Olof Johansson | 22 | 0.12% | 2 | 0.72% |
| Julia Lawall | 22 | 0.12% | 1 | 0.36% |
| David Lechner | 20 | 0.11% | 1 | 0.36% |
| Guenter Roeck | 17 | 0.09% | 1 | 0.36% |
| Andy Shevchenko | 16 | 0.09% | 2 | 0.72% |
| Greg Kroah-Hartman | 16 | 0.09% | 1 | 0.36% |
| Mark Brown | 15 | 0.08% | 1 | 0.36% |
| SF Markus Elfring | 15 | 0.08% | 3 | 1.08% |
| Marc Zyngier | 12 | 0.07% | 1 | 0.36% |
| Taniya Das | 10 | 0.06% | 1 | 0.36% |
| Joachim Eastwood | 10 | 0.06% | 1 | 0.36% |
| Ricardo Ribalda Delgado | 10 | 0.06% | 1 | 0.36% |
| Miquel Raynal | 10 | 0.06% | 1 | 0.36% |
| Martin Blumenstingl | 9 | 0.05% | 1 | 0.36% |
| Claudiu Beznea | 9 | 0.05% | 1 | 0.36% |
| Alex Elder | 9 | 0.05% | 1 | 0.36% |
| Lai Jiangshan | 8 | 0.04% | 1 | 0.36% |
| Lukasz Bartosik | 8 | 0.04% | 2 | 0.72% |
| Krzysztof Kozlowski | 7 | 0.04% | 1 | 0.36% |
| Rajendra Nayak | 7 | 0.04% | 2 | 0.72% |
| Rasmus Villemoes | 7 | 0.04% | 2 | 0.72% |
| Insu Yun | 5 | 0.03% | 1 | 0.36% |
| Kishon Vijay Abraham I | 5 | 0.03% | 1 | 0.36% |
| Andrew F. Davis | 5 | 0.03% | 1 | 0.36% |
| Tomasz Figa | 5 | 0.03% | 2 | 0.72% |
| Yisheng Xie | 5 | 0.03% | 1 | 0.36% |
| Rafael J. Wysocki | 5 | 0.03% | 1 | 0.36% |
| Maxime Coquelin | 4 | 0.02% | 1 | 0.36% |
| Joe Perches | 4 | 0.02% | 1 | 0.36% |
| Andrzej Hajda | 3 | 0.02% | 1 | 0.36% |
| Stefan Wahren | 3 | 0.02% | 1 | 0.36% |
| Tero Kristo | 2 | 0.01% | 2 | 0.72% |
| Rob Herring | 2 | 0.01% | 1 | 0.36% |
| Felipe Balbi | 2 | 0.01% | 1 | 0.36% |
| Viresh Kumar | 2 | 0.01% | 1 | 0.36% |
| Chi Minghao | 2 | 0.01% | 1 | 0.36% |
| Peng Fan | 1 | 0.01% | 1 | 0.36% |
| Kuninori Morimoto | 1 | 0.01% | 1 | 0.36% |
| Mauro Carvalho Chehab | 1 | 0.01% | 1 | 0.36% |
| Lubomir Rintel | 1 | 0.01% | 1 | 0.36% |
| Martin Fuzzey | 1 | 0.01% | 1 | 0.36% |
| Sarang Mairal | 1 | 0.01% | 1 | 0.36% |
| Rishi Gupta | 1 | 0.01% | 1 | 0.36% |
| Jean-François Moine | 1 | 0.01% | 1 | 0.36% |
| Total | 18062 | 279 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> * * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst */ #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/clk/clk-conf.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/err.h> #include <linux/list.h> #include <linux/slab.h> #include <linux/of.h> #include <linux/device.h> #include <linux/init.h> #include <linux/pm_runtime.h> #include <linux/sched.h> #include <linux/clkdev.h> #include "clk.h" static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); static struct task_struct *prepare_owner; static struct task_struct *enable_owner; static int prepare_refcnt; static int enable_refcnt; static HLIST_HEAD(clk_root_list); static HLIST_HEAD(clk_orphan_list); static LIST_HEAD(clk_notifier_list); static const struct hlist_head *all_lists[] = { &clk_root_list, &clk_orphan_list, NULL, }; /*** private data structures ***/ struct clk_parent_map { const struct clk_hw *hw; struct clk_core *core; const char *fw_name; const char *name; int index; }; struct clk_core { const char *name; const struct clk_ops *ops; struct clk_hw *hw; struct module *owner; struct device *dev; struct device_node *of_node; struct clk_core *parent; struct clk_parent_map *parents; u8 num_parents; u8 new_parent_index; unsigned long rate; unsigned long req_rate; unsigned long new_rate; struct clk_core *new_parent; struct clk_core *new_child; unsigned long flags; bool orphan; bool rpm_enabled; unsigned int enable_count; unsigned int prepare_count; unsigned int protect_count; unsigned long min_rate; unsigned long max_rate; unsigned long accuracy; int phase; struct clk_duty duty; struct hlist_head children; struct hlist_node child_node; struct hlist_head clks; unsigned int notifier_count; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; struct hlist_node debug_node; #endif struct kref ref; }; #define CREATE_TRACE_POINTS #include <trace/events/clk.h> struct clk { struct clk_core *core; struct device *dev; const char *dev_id; const char *con_id; unsigned long min_rate; unsigned long max_rate; unsigned int exclusive_count; struct hlist_node clks_node; }; /*** runtime pm ***/ static int clk_pm_runtime_get(struct clk_core *core) { if (!core->rpm_enabled) return 0; return pm_runtime_resume_and_get(core->dev); } static void clk_pm_runtime_put(struct clk_core *core) { if (!core->rpm_enabled) return; pm_runtime_put_sync(core->dev); } /*** locking ***/ static void clk_prepare_lock(void) { if (!mutex_trylock(&prepare_lock)) { if (prepare_owner == current) { prepare_refcnt++; return; } mutex_lock(&prepare_lock); } WARN_ON_ONCE(prepare_owner != NULL); WARN_ON_ONCE(prepare_refcnt != 0); prepare_owner = current; prepare_refcnt = 1; } static void clk_prepare_unlock(void) { WARN_ON_ONCE(prepare_owner != current); WARN_ON_ONCE(prepare_refcnt == 0); if (--prepare_refcnt) return; prepare_owner = NULL; mutex_unlock(&prepare_lock); } static unsigned long clk_enable_lock(void) __acquires(enable_lock) { unsigned long flags; /* * On UP systems, spin_trylock_irqsave() always returns true, even if * we already hold the lock. So, in that case, we rely only on * reference counting. */ if (!IS_ENABLED(CONFIG_SMP) || !spin_trylock_irqsave(&enable_lock, flags)) { if (enable_owner == current) { enable_refcnt++; __acquire(enable_lock); if (!IS_ENABLED(CONFIG_SMP)) local_save_flags(flags); return flags; } spin_lock_irqsave(&enable_lock, flags); } WARN_ON_ONCE(enable_owner != NULL); WARN_ON_ONCE(enable_refcnt != 0); enable_owner = current; enable_refcnt = 1; return flags; } static void clk_enable_unlock(unsigned long flags) __releases(enable_lock) { WARN_ON_ONCE(enable_owner != current); WARN_ON_ONCE(enable_refcnt == 0); if (--enable_refcnt) { __release(enable_lock); return; } enable_owner = NULL; spin_unlock_irqrestore(&enable_lock, flags); } static bool clk_core_rate_is_protected(struct clk_core *core) { return core->protect_count; } static bool clk_core_is_prepared(struct clk_core *core) { bool ret = false; /* * .is_prepared is optional for clocks that can prepare * fall back to software usage counter if it is missing */ if (!core->ops->is_prepared) return core->prepare_count; if (!clk_pm_runtime_get(core)) { ret = core->ops->is_prepared(core->hw); clk_pm_runtime_put(core); } return ret; } static bool clk_core_is_enabled(struct clk_core *core) { bool ret = false; /* * .is_enabled is only mandatory for clocks that gate * fall back to software usage counter if .is_enabled is missing */ if (!core->ops->is_enabled) return core->enable_count; /* * Check if clock controller's device is runtime active before * calling .is_enabled callback. If not, assume that clock is * disabled, because we might be called from atomic context, from * which pm_runtime_get() is not allowed. * This function is called mainly from clk_disable_unused_subtree, * which ensures proper runtime pm activation of controller before * taking enable spinlock, but the below check is needed if one tries * to call it from other places. */ if (core->rpm_enabled) { pm_runtime_get_noresume(core->dev); if (!pm_runtime_active(core->dev)) { ret = false; goto done; } } ret = core->ops->is_enabled(core->hw); done: if (core->rpm_enabled) pm_runtime_put(core->dev); return ret; } /*** helper functions ***/ const char *__clk_get_name(const struct clk *clk) { return !clk ? NULL : clk->core->name; } EXPORT_SYMBOL_GPL(__clk_get_name); const char *clk_hw_get_name(const struct clk_hw *hw) { return hw->core->name; } EXPORT_SYMBOL_GPL(clk_hw_get_name); struct clk_hw *__clk_get_hw(struct clk *clk) { return !clk ? NULL : clk->core->hw; } EXPORT_SYMBOL_GPL(__clk_get_hw); unsigned int clk_hw_get_num_parents(const struct clk_hw *hw) { return hw->core->num_parents; } EXPORT_SYMBOL_GPL(clk_hw_get_num_parents); struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw) { return hw->core->parent ? hw->core->parent->hw : NULL; } EXPORT_SYMBOL_GPL(clk_hw_get_parent); static struct clk_core *__clk_lookup_subtree(const char *name, struct clk_core *core) { struct clk_core *child; struct clk_core *ret; if (!strcmp(core->name, name)) return core; hlist_for_each_entry(child, &core->children, child_node) { ret = __clk_lookup_subtree(name, child); if (ret) return ret; } return NULL; } static struct clk_core *clk_core_lookup(const char *name) { struct clk_core *root_clk; struct clk_core *ret; if (!name) return NULL; /* search the 'proper' clk tree first */ hlist_for_each_entry(root_clk, &clk_root_list, child_node) { ret = __clk_lookup_subtree(name, root_clk); if (ret) return ret; } /* if not found, then search the orphan tree */ hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { ret = __clk_lookup_subtree(name, root_clk); if (ret) return ret; } return NULL; } #ifdef CONFIG_OF static int of_parse_clkspec(const struct device_node *np, int index, const char *name, struct of_phandle_args *out_args); static struct clk_hw * of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec); #else static inline int of_parse_clkspec(const struct device_node *np, int index, const char *name, struct of_phandle_args *out_args) { return -ENOENT; } static inline struct clk_hw * of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) { return ERR_PTR(-ENOENT); } #endif /** * clk_core_get - Find the clk_core parent of a clk * @core: clk to find parent of * @p_index: parent index to search for * * This is the preferred method for clk providers to find the parent of a * clk when that parent is external to the clk controller. The parent_names * array is indexed and treated as a local name matching a string in the device * node's 'clock-names' property or as the 'con_id' matching the device's * dev_name() in a clk_lookup. This allows clk providers to use their own * namespace instead of looking for a globally unique parent string. * * For example the following DT snippet would allow a clock registered by the * clock-controller@c001 that has a clk_init_data::parent_data array * with 'xtal' in the 'name' member to find the clock provided by the * clock-controller@f00abcd without needing to get the globally unique name of * the xtal clk. * * parent: clock-controller@f00abcd { * reg = <0xf00abcd 0xabcd>; * #clock-cells = <0>; * }; * * clock-controller@c001 { * reg = <0xc001 0xf00d>; * clocks = <&parent>; * clock-names = "xtal"; * #clock-cells = <1>; * }; * * Returns: -ENOENT when the provider can't be found or the clk doesn't * exist in the provider or the name can't be found in the DT node or * in a clkdev lookup. NULL when the provider knows about the clk but it * isn't provided on this system. * A valid clk_core pointer when the clk can be found in the provider. */ static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index) { const char *name = core->parents[p_index].fw_name; int index = core->parents[p_index].index; struct clk_hw *hw = ERR_PTR(-ENOENT); struct device *dev = core->dev; const char *dev_id = dev ? dev_name(dev) : NULL; struct device_node *np = core->of_node; struct of_phandle_args clkspec; if (np && (name || index >= 0) && !of_parse_clkspec(np, index, name, &clkspec)) { hw = of_clk_get_hw_from_clkspec(&clkspec); of_node_put(clkspec.np); } else if (name) { /* * If the DT search above couldn't find the provider fallback to * looking up via clkdev based clk_lookups. */ hw = clk_find_hw(dev_id, name); } if (IS_ERR(hw)) return ERR_CAST(hw); return hw->core; } static void clk_core_fill_parent_index(struct clk_core *core, u8 index) { struct clk_parent_map *entry = &core->parents[index]; struct clk_core *parent; if (entry->hw) { parent = entry->hw->core; } else { parent = clk_core_get(core, index); if (PTR_ERR(parent) == -ENOENT && entry->name) parent = clk_core_lookup(entry->name); } /* * We have a direct reference but it isn't registered yet? * Orphan it and let clk_reparent() update the orphan status * when the parent is registered. */ if (!parent) parent = ERR_PTR(-EPROBE_DEFER); /* Only cache it if it's not an error */ if (!IS_ERR(parent)) entry->core = parent; } static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core, u8 index) { if (!core || index >= core->num_parents || !core->parents) return NULL; if (!core->parents[index].core) clk_core_fill_parent_index(core, index); return core->parents[index].core; } struct clk_hw * clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index) { struct clk_core *parent; parent = clk_core_get_parent_by_index(hw->core, index); return !parent ? NULL : parent->hw; } EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index); unsigned int __clk_get_enable_count(struct clk *clk) { return !clk ? 0 : clk->core->enable_count; } static unsigned long clk_core_get_rate_nolock(struct clk_core *core) { if (!core) return 0; if (!core->num_parents || core->parent) return core->rate; /* * Clk must have a parent because num_parents > 0 but the parent isn't * known yet. Best to return 0 as the rate of this clk until we can * properly recalc the rate based on the parent's rate. */ return 0; } unsigned long clk_hw_get_rate(const struct clk_hw *hw) { return clk_core_get_rate_nolock(hw->core); } EXPORT_SYMBOL_GPL(clk_hw_get_rate); static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core) { if (!core) return 0; return core->accuracy; } unsigned long clk_hw_get_flags(const struct clk_hw *hw) { return hw->core->flags; } EXPORT_SYMBOL_GPL(clk_hw_get_flags); bool clk_hw_is_prepared(const struct clk_hw *hw) { return clk_core_is_prepared(hw->core); } EXPORT_SYMBOL_GPL(clk_hw_is_prepared); bool clk_hw_rate_is_protected(const struct clk_hw *hw) { return clk_core_rate_is_protected(hw->core); } EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected); bool clk_hw_is_enabled(const struct clk_hw *hw) { return clk_core_is_enabled(hw->core); } EXPORT_SYMBOL_GPL(clk_hw_is_enabled); bool __clk_is_enabled(struct clk *clk) { if (!clk) return false; return clk_core_is_enabled(clk->core); } EXPORT_SYMBOL_GPL(__clk_is_enabled); static bool mux_is_better_rate(unsigned long rate, unsigned long now, unsigned long best, unsigned long flags) { if (flags & CLK_MUX_ROUND_CLOSEST) return abs(now - rate) < abs(best - rate); return now <= rate && now > best; } int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, unsigned long flags) { struct clk_core *core = hw->core, *parent, *best_parent = NULL; int i, num_parents, ret; unsigned long best = 0; struct clk_rate_request parent_req = *req; /* if NO_REPARENT flag set, pass through to current parent */ if (core->flags & CLK_SET_RATE_NO_REPARENT) { parent = core->parent; if (core->flags & CLK_SET_RATE_PARENT) { ret = __clk_determine_rate(parent ? parent->hw : NULL, &parent_req); if (ret) return ret; best = parent_req.rate; } else if (parent) { best = clk_core_get_rate_nolock(parent); } else { best = clk_core_get_rate_nolock(core); } goto out; } /* find the parent that can provide the fastest rate <= rate */ num_parents = core->num_parents; for (i = 0; i < num_parents; i++) { parent = clk_core_get_parent_by_index(core, i); if (!parent) continue; if (core->flags & CLK_SET_RATE_PARENT) { parent_req = *req; ret = __clk_determine_rate(parent->hw, &parent_req); if (ret) continue; } else { parent_req.rate = clk_core_get_rate_nolock(parent); } if (mux_is_better_rate(req->rate, parent_req.rate, best, flags)) { best_parent = parent; best = parent_req.rate; } } if (!best_parent) return -EINVAL; out: if (best_parent) req->best_parent_hw = best_parent->hw; req->best_parent_rate = best; req->rate = best; return 0; } EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags); struct clk *__clk_lookup(const char *name) { struct clk_core *core = clk_core_lookup(name); return !core ? NULL : core->hw->clk; } static void clk_core_get_boundaries(struct clk_core *core, unsigned long *min_rate, unsigned long *max_rate) { struct clk *clk_user; lockdep_assert_held(&prepare_lock); *min_rate = core->min_rate; *max_rate = core->max_rate; hlist_for_each_entry(clk_user, &core->clks, clks_node) *min_rate = max(*min_rate, clk_user->min_rate); hlist_for_each_entry(clk_user, &core->clks, clks_node) *max_rate = min(*max_rate, clk_user->max_rate); } static bool clk_core_check_boundaries(struct clk_core *core, unsigned long min_rate, unsigned long max_rate) { struct clk *user; lockdep_assert_held(&prepare_lock); if (min_rate > core->max_rate || max_rate < core->min_rate) return false; hlist_for_each_entry(user, &core->clks, clks_node) if (min_rate > user->max_rate || max_rate < user->min_rate) return false; return true; } void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, unsigned long max_rate) { hw->core->min_rate = min_rate; hw->core->max_rate = max_rate; } EXPORT_SYMBOL_GPL(clk_hw_set_rate_range); /* * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk * @hw: mux type clk to determine rate on * @req: rate request, also used to return preferred parent and frequencies * * Helper for finding best parent to provide a given frequency. This can be used * directly as a determine_rate callback (e.g. for a mux), or from a more * complex clock that may combine a mux with other operations. * * Returns: 0 on success, -EERROR value on error */ int __clk_mux_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { return clk_mux_determine_rate_flags(hw, req, 0); } EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); int __clk_mux_determine_rate_closest(struct clk_hw *hw, struct clk_rate_request *req) { return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST); } EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest); /*** clk api ***/ static void clk_core_rate_unprotect(struct clk_core *core) { lockdep_assert_held(&prepare_lock); if (!core) return; if (WARN(core->protect_count == 0, "%s already unprotected\n", core->name)) return; if (--core->protect_count > 0) return; clk_core_rate_unprotect(core->parent); } static int clk_core_rate_nuke_protect(struct clk_core *core) { int ret; lockdep_assert_held(&prepare_lock); if (!core) return -EINVAL; if (core->protect_count == 0) return 0; ret = core->protect_count; core->protect_count = 1; clk_core_rate_unprotect(core); return ret; } /** * clk_rate_exclusive_put - release exclusivity over clock rate control * @clk: the clk over which the exclusivity is released * * clk_rate_exclusive_put() completes a critical section during which a clock * consumer cannot tolerate any other consumer making any operation on the * clock which could result in a rate change or rate glitch. Exclusive clocks * cannot have their rate changed, either directly or indirectly due to changes * further up the parent chain of clocks. As a result, clocks up parent chain * also get under exclusive control of the calling consumer. * * If exlusivity is claimed more than once on clock, even by the same consumer, * the rate effectively gets locked as exclusivity can't be preempted. * * Calls to clk_rate_exclusive_put() must be balanced with calls to * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return * error status. */ void clk_rate_exclusive_put(struct clk *clk) { if (!clk) return; clk_prepare_lock(); /* * if there is something wrong with this consumer protect count, stop * here before messing with the provider */ if (WARN_ON(clk->exclusive_count <= 0)) goto out; clk_core_rate_unprotect(clk->core); clk->exclusive_count--; out: clk_prepare_unlock(); } EXPORT_SYMBOL_GPL(clk_rate_exclusive_put); static void clk_core_rate_protect(struct clk_core *core) { lockdep_assert_held(&prepare_lock); if (!core) return; if (core->protect_count == 0) clk_core_rate_protect(core->parent); core->protect_count++; } static void clk_core_rate_restore_protect(struct clk_core *core, int count) { lockdep_assert_held(&prepare_lock); if (!core) return; if (count == 0) return; clk_core_rate_protect(core); core->protect_count = count; } /** * clk_rate_exclusive_get - get exclusivity over the clk rate control * @clk: the clk over which the exclusity of rate control is requested * * clk_rate_exclusive_get() begins a critical section during which a clock * consumer cannot tolerate any other consumer making any operation on the * clock which could result in a rate change or rate glitch. Exclusive clocks * cannot have their rate changed, either directly or indirectly due to changes * further up the parent chain of clocks. As a result, clocks up parent chain * also get under exclusive control of the calling consumer. * * If exlusivity is claimed more than once on clock, even by the same consumer, * the rate effectively gets locked as exclusivity can't be preempted. * * Calls to clk_rate_exclusive_get() should be balanced with calls to * clk_rate_exclusive_put(). Calls to this function may sleep. * Returns 0 on success, -EERROR otherwise */ int clk_rate_exclusive_get(struct clk *clk) { if (!clk) return 0; clk_prepare_lock(); clk_core_rate_protect(clk->core); clk->exclusive_count++; clk_prepare_unlock(); return 0; } EXPORT_SYMBOL_GPL(clk_rate_exclusive_get); static void clk_core_unprepare(struct clk_core *core) { lockdep_assert_held(&prepare_lock); if (!core) return; if (WARN(core->prepare_count == 0, "%s already unprepared\n", core->name)) return; if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL, "Unpreparing critical %s\n", core->name)) return; if (core->flags & CLK_SET_RATE_GATE) clk_core_rate_unprotect(core); if (--core->prepare_count > 0) return; WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name); trace_clk_unprepare(core); if (core->ops->unprepare) core->ops->unprepare(core->hw); trace_clk_unprepare_complete(core); clk_core_unprepare(core->parent); clk_pm_runtime_put(core); } static void clk_core_unprepare_lock(struct clk_core *core) { clk_prepare_lock(); clk_core_unprepare(core); clk_prepare_unlock(); } /** * clk_unprepare - undo preparation of a clock source * @clk: the clk being unprepared * * clk_unprepare may sleep, which differentiates it from clk_disable. In a * simple case, clk_unprepare can be used instead of clk_disable to gate a clk * if the operation may sleep. One example is a clk which is accessed over * I2c. In the complex case a clk gate operation may require a fast and a slow * part. It is this reason that clk_unprepare and clk_disable are not mutually * exclusive. In fact clk_disable must be called before clk_unprepare. */ void clk_unprepare(struct clk *clk) { if (IS_ERR_OR_NULL(clk)) return; clk_core_unprepare_lock(clk->core); } EXPORT_SYMBOL_GPL(clk_unprepare); static int clk_core_prepare(struct clk_core *core) { int ret = 0; lockdep_assert_held(&prepare_lock); if (!core) return 0; if (core->prepare_count == 0) { ret = clk_pm_runtime_get(core); if (ret) return ret; ret = clk_core_prepare(core->parent); if (ret) goto runtime_put; trace_clk_prepare(core); if (core->ops->prepare) ret = core->ops->prepare(core->hw); trace_clk_prepare_complete(core); if (ret) goto unprepare; } core->prepare_count++; /* * CLK_SET_RATE_GATE is a special case of clock protection * Instead of a consumer claiming exclusive rate control, it is * actually the provider which prevents any consumer from making any * operation which could result in a rate change or rate glitch while * the clock is prepared. */ if (core->flags & CLK_SET_RATE_GATE) clk_core_rate_protect(core); return 0; unprepare: clk_core_unprepare(core->parent); runtime_put: clk_pm_runtime_put(core); return ret; } static int clk_core_prepare_lock(struct clk_core *core) { int ret; clk_prepare_lock(); ret = clk_core_prepare(core); clk_prepare_unlock(); return ret; } /** * clk_prepare - prepare a clock source * @clk: the clk being prepared * * clk_prepare may sleep, which differentiates it from clk_enable. In a simple * case, clk_prepare can be used instead of clk_enable to ungate a clk if the * operation may sleep. One example is a clk which is accessed over I2c. In * the complex case a clk ungate operation may require a fast and a slow part. * It is this reason that clk_prepare and clk_enable are not mutually * exclusive. In fact clk_prepare must be called before clk_enable. * Returns 0 on success, -EERROR otherwise. */ int clk_prepare(struct clk *clk) { if (!clk) return 0; return clk_core_prepare_lock(clk->core); } EXPORT_SYMBOL_GPL(clk_prepare); static void clk_core_disable(struct clk_core *core) { lockdep_assert_held(&enable_lock); if (!core) return; if (WARN(core->enable_count == 0, "%s already disabled\n", core->name)) return; if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL, "Disabling critical %s\n", core->name)) return; if (--core->enable_count > 0) return; trace_clk_disable_rcuidle(core); if (core->ops->disable) core->ops->disable(core->hw); trace_clk_disable_complete_rcuidle(core); clk_core_disable(core->parent); } static void clk_core_disable_lock(struct clk_core *core) { unsigned long flags; flags = clk_enable_lock(); clk_core_disable(core); clk_enable_unlock(flags); } /** * clk_disable - gate a clock * @clk: the clk being gated * * clk_disable must not sleep, which differentiates it from clk_unprepare. In * a simple case, clk_disable can be used instead of clk_unprepare to gate a * clk if the operation is fast and will never sleep. One example is a * SoC-internal clk which is controlled via simple register writes. In the * complex case a clk gate operation may require a fast and a slow part. It is * this reason that clk_unprepare and clk_disable are not mutually exclusive. * In fact clk_disable must be called before clk_unprepare. */ void clk_disable(struct clk *clk) { if (IS_ERR_OR_NULL(clk)) return; clk_core_disable_lock(clk->core); } EXPORT_SYMBOL_GPL(clk_disable); static int clk_core_enable(struct clk_core *core) { int ret = 0; lockdep_assert_held(&enable_lock); if (!core) return 0; if (WARN(core->prepare_count == 0, "Enabling unprepared %s\n", core->name)) return -ESHUTDOWN; if (core->enable_count == 0) { ret = clk_core_enable(core->parent); if (ret) return ret; trace_clk_enable_rcuidle(core); if (core->ops->enable) ret = core->ops->enable(core->hw); trace_clk_enable_complete_rcuidle(core); if (ret) { clk_core_disable(core->parent); return ret; } } core->enable_count++; return 0; } static int clk_core_enable_lock(struct clk_core *core) { unsigned long flags; int ret; flags = clk_enable_lock(); ret = clk_core_enable(core); clk_enable_unlock(flags); return ret; } /** * clk_gate_restore_context - restore context for poweroff * @hw: the clk_hw pointer of clock whose state is to be restored * * The clock gate restore context function enables or disables * the gate clocks based on the enable_count. This is done in cases * where the clock context is lost and based on the enable_count * the clock either needs to be enabled/disabled. This * helps restore the state of gate clocks. */ void clk_gate_restore_context(struct clk_hw *hw) { struct clk_core *core = hw->core; if (core->enable_count) core->ops->enable(hw); else core->ops->disable(hw); } EXPORT_SYMBOL_GPL(clk_gate_restore_context); static int clk_core_save_context(struct clk_core *core) { struct clk_core *child; int ret = 0; hlist_for_each_entry(child, &core->children, child_node) { ret = clk_core_save_context(child); if (ret < 0) return ret; } if (core->ops && core->ops->save_context) ret = core->ops->save_context(core->hw); return ret; } static void clk_core_restore_context(struct clk_core *core) { struct clk_core *child; if (core->ops && core->ops->restore_context) core->ops->restore_context(core->hw); hlist_for_each_entry(child, &core->children, child_node) clk_core_restore_context(child); } /** * clk_save_context - save clock context for poweroff * * Saves the context of the clock register for powerstates in which the * contents of the registers will be lost. Occurs deep within the suspend * code. Returns 0 on success. */ int clk_save_context(void) { struct clk_core *clk; int ret; hlist_for_each_entry(clk, &clk_root_list, child_node) { ret = clk_core_save_context(clk); if (ret < 0) return ret; } hlist_for_each_entry(clk, &clk_orphan_list, child_node) { ret = clk_core_save_context(clk); if (ret < 0) return ret; } return 0; } EXPORT_SYMBOL_GPL(clk_save_context); /** * clk_restore_context - restore clock context after poweroff * * Restore the saved clock context upon resume. * */ void clk_restore_context(void) { struct clk_core *core; hlist_for_each_entry(core, &clk_root_list, child_node) clk_core_restore_context(core); hlist_for_each_entry(core, &clk_orphan_list, child_node) clk_core_restore_context(core); } EXPORT_SYMBOL_GPL(clk_restore_context); /** * clk_enable - ungate a clock * @clk: the clk being ungated * * clk_enable must not sleep, which differentiates it from clk_prepare. In a * simple case, clk_enable can be used instead of clk_prepare to ungate a clk * if the operation will never sleep. One example is a SoC-internal clk which * is controlled via simple register writes. In the complex case a clk ungate * operation may require a fast and a slow part. It is this reason that * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare * must be called before clk_enable. Returns 0 on success, -EERROR * otherwise. */ int clk_enable(struct clk *clk) { if (!clk) return 0; return clk_core_enable_lock(clk->core); } EXPORT_SYMBOL_GPL(clk_enable); /** * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it. * @clk: clock source * * Returns true if clk_prepare() implicitly enables the clock, effectively * making clk_enable()/clk_disable() no-ops, false otherwise. * * This is of interest mainly to power management code where actually * disabling the clock also requires unpreparing it to have any material * effect. * * Regardless of the value returned here, the caller must always invoke * clk_enable() or clk_prepare_enable() and counterparts for usage counts * to be right. */ bool clk_is_enabled_when_prepared(struct clk *clk) { return clk && !(clk->core->ops->enable && clk->core->ops->disable); } EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared); static int clk_core_prepare_enable(struct clk_core *core) { int ret; ret = clk_core_prepare_lock(core); if (ret) return ret; ret = clk_core_enable_lock(core); if (ret) clk_core_unprepare_lock(core); return ret; } static void clk_core_disable_unprepare(struct clk_core *core) { clk_core_disable_lock(core); clk_core_unprepare_lock(core); } static void __init clk_unprepare_unused_subtree(struct clk_core *core) { struct clk_core *child; lockdep_assert_held(&prepare_lock); hlist_for_each_entry(child, &core->children, child_node) clk_unprepare_unused_subtree(child); if (core->prepare_count) return; if (core->flags & CLK_IGNORE_UNUSED) return; if (clk_pm_runtime_get(core)) return; if (clk_core_is_prepared(core)) { trace_clk_unprepare(core); if (core->ops->unprepare_unused) core->ops->unprepare_unused(core->hw); else if (core->ops->unprepare) core->ops->unprepare(core->hw); trace_clk_unprepare_complete(core); } clk_pm_runtime_put(core); } static void __init clk_disable_unused_subtree(struct clk_core *core) { struct clk_core *child; unsigned long flags; lockdep_assert_held(&prepare_lock); hlist_for_each_entry(child, &core->children, child_node) clk_disable_unused_subtree(child); if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_prepare_enable(core->parent); if (clk_pm_runtime_get(core)) goto unprepare_out; flags = clk_enable_lock(); if (core->enable_count) goto unlock_out; if (core->flags & CLK_IGNORE_UNUSED) goto unlock_out; /* * some gate clocks have special needs during the disable-unused * sequence. call .disable_unused if available, otherwise fall * back to .disable */ if (clk_core_is_enabled(core)) { trace_clk_disable(core); if (core->ops->disable_unused) core->ops->disable_unused(core->hw); else if (core->ops->disable) core->ops->disable(core->hw); trace_clk_disable_complete(core); } unlock_out: clk_enable_unlock(flags); clk_pm_runtime_put(core); unprepare_out: if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_disable_unprepare(core->parent); } static bool clk_ignore_unused __initdata; static int __init clk_ignore_unused_setup(char *__unused) { clk_ignore_unused = true; return 1; } __setup("clk_ignore_unused", clk_ignore_unused_setup); static int __init clk_disable_unused(void) { struct clk_core *core; if (clk_ignore_unused) { pr_warn("clk: Not disabling unused clocks\n"); return 0; } clk_prepare_lock(); hlist_for_each_entry(core, &clk_root_list, child_node) clk_disable_unused_subtree(core); hlist_for_each_entry(core, &clk_orphan_list, child_node) clk_disable_unused_subtree(core); hlist_for_each_entry(core, &clk_root_list, child_node) clk_unprepare_unused_subtree(core); hlist_for_each_entry(core, &clk_orphan_list, child_node) clk_unprepare_unused_subtree(core); clk_prepare_unlock(); return 0; } late_initcall_sync(clk_disable_unused); static int clk_core_determine_round_nolock(struct clk_core *core, struct clk_rate_request *req) { long rate; lockdep_assert_held(&prepare_lock); if (!core) return 0; req->rate = clamp(req->rate, req->min_rate, req->max_rate); /* * At this point, core protection will be disabled * - if the provider is not protected at all * - if the calling consumer is the only one which has exclusivity * over the provider */ if (clk_core_rate_is_protected(core)) { req->rate = core->rate; } else if (core->ops->determine_rate) { return core->ops->determine_rate(core->hw, req); } else if (core->ops->round_rate) { rate = core->ops->round_rate(core->hw, req->rate, &req->best_parent_rate); if (rate < 0) return rate; req->rate = rate; } else { return -EINVAL; } return 0; } static void clk_core_init_rate_req(struct clk_core * const core, struct clk_rate_request *req) { struct clk_core *parent; if (WARN_ON(!core || !req)) return; parent = core->parent; if (parent) { req->best_parent_hw = parent->hw; req->best_parent_rate = parent->rate; } else { req->best_parent_hw = NULL; req->best_parent_rate = 0; } } static bool clk_core_can_round(struct clk_core * const core) { return core->ops->determine_rate || core->ops->round_rate; } static int clk_core_round_rate_nolock(struct clk_core *core, struct clk_rate_request *req) { lockdep_assert_held(&prepare_lock); if (!core) { req->rate = 0; return 0; } clk_core_init_rate_req(core, req); if (clk_core_can_round(core)) return clk_core_determine_round_nolock(core, req); else if (core->flags & CLK_SET_RATE_PARENT) return clk_core_round_rate_nolock(core->parent, req); req->rate = core->rate; return 0; } /** * __clk_determine_rate - get the closest rate actually supported by a clock * @hw: determine the rate of this clock * @req: target rate request * * Useful for clk_ops such as .set_rate and .determine_rate. */ int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { if (!hw) { req->rate = 0; return 0; } return clk_core_round_rate_nolock(hw->core, req); } EXPORT_SYMBOL_GPL(__clk_determine_rate); /** * clk_hw_round_rate() - round the given rate for a hw clk * @hw: the hw clk for which we are rounding a rate * @rate: the rate which is to be rounded * * Takes in a rate as input and rounds it to a rate that the clk can actually * use. * * Context: prepare_lock must be held. * For clk providers to call from within clk_ops such as .round_rate, * .determine_rate. * * Return: returns rounded rate of hw clk if clk supports round_rate operation * else returns the parent rate. */ unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate) { int ret; struct clk_rate_request req; clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate); req.rate = rate; ret = clk_core_round_rate_nolock(hw->core, &req); if (ret) return 0; return req.rate; } EXPORT_SYMBOL_GPL(clk_hw_round_rate); /** * clk_round_rate - round the given rate for a clk * @clk: the clk for which we are rounding a rate * @rate: the rate which is to be rounded * * Takes in a rate as input and rounds it to a rate that the clk can actually * use which is then returned. If clk doesn't support round_rate operation * then the parent rate is returned. */ long clk_round_rate(struct clk *clk, unsigned long rate) { struct clk_rate_request req; int ret; if (!clk) return 0; clk_prepare_lock(); if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate); req.rate = rate; ret = clk_core_round_rate_nolock(clk->core, &req); if (clk->exclusive_count) clk_core_rate_protect(clk->core); clk_prepare_unlock(); if (ret) return ret; return req.rate; } EXPORT_SYMBOL_GPL(clk_round_rate); /** * __clk_notify - call clk notifier chain * @core: clk that is changing rate * @msg: clk notifier type (see include/linux/clk.h) * @old_rate: old clk rate * @new_rate: new clk rate * * Triggers a notifier call chain on the clk rate-change notification * for 'clk'. Passes a pointer to the struct clk and the previous * and current rates to the notifier callback. Intended to be called by * internal clock code only. Returns NOTIFY_DONE from the last driver * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if * a driver returns that. */ static int __clk_notify(struct clk_core *core, unsigned long msg, unsigned long old_rate, unsigned long new_rate) { struct clk_notifier *cn; struct clk_notifier_data cnd; int ret = NOTIFY_DONE; cnd.old_rate = old_rate; cnd.new_rate = new_rate; list_for_each_entry(cn, &clk_notifier_list, node) { if (cn->clk->core == core) { cnd.clk = cn->clk; ret = srcu_notifier_call_chain(&cn->notifier_head, msg, &cnd); if (ret & NOTIFY_STOP_MASK) return ret; } } return ret; } /** * __clk_recalc_accuracies * @core: first clk in the subtree * * Walks the subtree of clks starting with clk and recalculates accuracies as * it goes. Note that if a clk does not implement the .recalc_accuracy * callback then it is assumed that the clock will take on the accuracy of its * parent. */ static void __clk_recalc_accuracies(struct clk_core *core) { unsigned long parent_accuracy = 0; struct clk_core *child; lockdep_assert_held(&prepare_lock); if (core->parent) parent_accuracy = core->parent->accuracy; if (core->ops->recalc_accuracy) core->accuracy = core->ops->recalc_accuracy(core->hw, parent_accuracy); else core->accuracy = parent_accuracy; hlist_for_each_entry(child, &core->children, child_node) __clk_recalc_accuracies(child); } static long clk_core_get_accuracy_recalc(struct clk_core *core) { if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE)) __clk_recalc_accuracies(core); return clk_core_get_accuracy_no_lock(core); } /** * clk_get_accuracy - return the accuracy of clk * @clk: the clk whose accuracy is being returned * * Simply returns the cached accuracy of the clk, unless * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be * issued. * If clk is NULL then returns 0. */ long clk_get_accuracy(struct clk *clk) { long accuracy; if (!clk) return 0; clk_prepare_lock(); accuracy = clk_core_get_accuracy_recalc(clk->core); clk_prepare_unlock(); return accuracy; } EXPORT_SYMBOL_GPL(clk_get_accuracy); static unsigned long clk_recalc(struct clk_core *core, unsigned long parent_rate) { unsigned long rate = parent_rate; if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) { rate = core->ops->recalc_rate(core->hw, parent_rate); clk_pm_runtime_put(core); } return rate; } /** * __clk_recalc_rates * @core: first clk in the subtree * @msg: notification type (see include/linux/clk.h) * * Walks the subtree of clks starting with clk and recalculates rates as it * goes. Note that if a clk does not implement the .recalc_rate callback then * it is assumed that the clock will take on the rate of its parent. * * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, * if necessary. */ static void __clk_recalc_rates(struct clk_core *core, unsigned long msg) { unsigned long old_rate; unsigned long parent_rate = 0; struct clk_core *child; lockdep_assert_held(&prepare_lock); old_rate = core->rate; if (core->parent) parent_rate = core->parent->rate; core->rate = clk_recalc(core, parent_rate); /* * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE * & ABORT_RATE_CHANGE notifiers */ if (core->notifier_count && msg) __clk_notify(core, msg, old_rate, core->rate); hlist_for_each_entry(child, &core->children, child_node) __clk_recalc_rates(child, msg); } static unsigned long clk_core_get_rate_recalc(struct clk_core *core) { if (core && (core->flags & CLK_GET_RATE_NOCACHE)) __clk_recalc_rates(core, 0); return clk_core_get_rate_nolock(core); } /** * clk_get_rate - return the rate of clk * @clk: the clk whose rate is being returned * * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag * is set, which means a recalc_rate will be issued. * If clk is NULL then returns 0. */ unsigned long clk_get_rate(struct clk *clk) { unsigned long rate; if (!clk) return 0; clk_prepare_lock(); rate = clk_core_get_rate_recalc(clk->core); clk_prepare_unlock(); return rate; } EXPORT_SYMBOL_GPL(clk_get_rate); static int clk_fetch_parent_index(struct clk_core *core, struct clk_core *parent) { int i; if (!parent) return -EINVAL; for (i = 0; i < core->num_parents; i++) { /* Found it first try! */ if (core->parents[i].core == parent) return i; /* Something else is here, so keep looking */ if (core->parents[i].core) continue; /* Maybe core hasn't been cached but the hw is all we know? */ if (core->parents[i].hw) { if (core->parents[i].hw == parent->hw) break; /* Didn't match, but we're expecting a clk_hw */ continue; } /* Maybe it hasn't been cached (clk_set_parent() path) */ if (parent == clk_core_get(core, i)) break; /* Fallback to comparing globally unique names */ if (core->parents[i].name && !strcmp(parent->name, core->parents[i].name)) break; } if (i == core->num_parents) return -EINVAL; core->parents[i].core = parent; return i; } /** * clk_hw_get_parent_index - return the index of the parent clock * @hw: clk_hw associated with the clk being consumed * * Fetches and returns the index of parent clock. Returns -EINVAL if the given * clock does not have a current parent. */ int clk_hw_get_parent_index(struct clk_hw *hw) { struct clk_hw *parent = clk_hw_get_parent(hw); if (WARN_ON(parent == NULL)) return -EINVAL; return clk_fetch_parent_index(hw->core, parent->core); } EXPORT_SYMBOL_GPL(clk_hw_get_parent_index); /* * Update the orphan status of @core and all its children. */ static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan) { struct clk_core *child; core->orphan = is_orphan; hlist_for_each_entry(child, &core->children, child_node) clk_core_update_orphan_status(child, is_orphan); } static void clk_reparent(struct clk_core *core, struct clk_core *new_parent) { bool was_orphan = core->orphan; hlist_del(&core->child_node); if (new_parent) { bool becomes_orphan = new_parent->orphan; /* avoid duplicate POST_RATE_CHANGE notifications */ if (new_parent->new_child == core) new_parent->new_child = NULL; hlist_add_head(&core->child_node, &new_parent->children); if (was_orphan != becomes_orphan) clk_core_update_orphan_status(core, becomes_orphan); } else { hlist_add_head(&core->child_node, &clk_orphan_list); if (!was_orphan) clk_core_update_orphan_status(core, true); } core->parent = new_parent; } static struct clk_core *__clk_set_parent_before(struct clk_core *core, struct clk_core *parent) { unsigned long flags; struct clk_core *old_parent = core->parent; /* * 1. enable parents for CLK_OPS_PARENT_ENABLE clock * * 2. Migrate prepare state between parents and prevent race with * clk_enable(). * * If the clock is not prepared, then a race with * clk_enable/disable() is impossible since we already have the * prepare lock (future calls to clk_enable() need to be preceded by * a clk_prepare()). * * If the clock is prepared, migrate the prepared state to the new * parent and also protect against a race with clk_enable() by * forcing the clock and the new parent on. This ensures that all * future calls to clk_enable() are practically NOPs with respect to * hardware and software states. * * See also: Comment for clk_set_parent() below. */ /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */ if (core->flags & CLK_OPS_PARENT_ENABLE) { clk_core_prepare_enable(old_parent); clk_core_prepare_enable(parent); } /* migrate prepare count if > 0 */ if (core->prepare_count) { clk_core_prepare_enable(parent); clk_core_enable_lock(core); } /* update the clk tree topology */ flags = clk_enable_lock(); clk_reparent(core, parent); clk_enable_unlock(flags); return old_parent; } static void __clk_set_parent_after(struct clk_core *core, struct clk_core *parent, struct clk_core *old_parent) { /* * Finish the migration of prepare state and undo the changes done * for preventing a race with clk_enable(). */ if (core->prepare_count) { clk_core_disable_lock(core); clk_core_disable_unprepare(old_parent); } /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */ if (core->flags & CLK_OPS_PARENT_ENABLE) { clk_core_disable_unprepare(parent); clk_core_disable_unprepare(old_parent); } } static int __clk_set_parent(struct clk_core *core, struct clk_core *parent, u8 p_index) { unsigned long flags; int ret = 0; struct clk_core *old_parent; old_parent = __clk_set_parent_before(core, parent); trace_clk_set_parent(core, parent); /* change clock input source */ if (parent && core->ops->set_parent) ret = core->ops->set_parent(core->hw, p_index); trace_clk_set_parent_complete(core, parent); if (ret) { flags = clk_enable_lock(); clk_reparent(core, old_parent); clk_enable_unlock(flags); __clk_set_parent_after(core, old_parent, parent); return ret; } __clk_set_parent_after(core, parent, old_parent); return 0; } /** * __clk_speculate_rates * @core: first clk in the subtree * @parent_rate: the "future" rate of clk's parent * * Walks the subtree of clks starting with clk, speculating rates as it * goes and firing off PRE_RATE_CHANGE notifications as necessary. * * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending * pre-rate change notifications and returns early if no clks in the * subtree have subscribed to the notifications. Note that if a clk does not * implement the .recalc_rate callback then it is assumed that the clock will * take on the rate of its parent. */ static int __clk_speculate_rates(struct clk_core *core, unsigned long parent_rate) { struct clk_core *child; unsigned long new_rate; int ret = NOTIFY_DONE; lockdep_assert_held(&prepare_lock); new_rate = clk_recalc(core, parent_rate); /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ if (core->notifier_count) ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate); if (ret & NOTIFY_STOP_MASK) { pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", __func__, core->name, ret); goto out; } hlist_for_each_entry(child, &core->children, child_node) { ret = __clk_speculate_rates(child, new_rate); if (ret & NOTIFY_STOP_MASK) break; } out: return ret; } static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate, struct clk_core *new_parent, u8 p_index) { struct clk_core *child; core->new_rate = new_rate; core->new_parent = new_parent; core->new_parent_index = p_index; /* include clk in new parent's PRE_RATE_CHANGE notifications */ core->new_child = NULL; if (new_parent && new_parent != core->parent) new_parent->new_child = core; hlist_for_each_entry(child, &core->children, child_node) { child->new_rate = clk_recalc(child, new_rate); clk_calc_subtree(child, child->new_rate, NULL, 0); } } /* * calculate the new rates returning the topmost clock that has to be * changed. */ static struct clk_core *clk_calc_new_rates(struct clk_core *core, unsigned long rate) { struct clk_core *top = core; struct clk_core *old_parent, *parent; unsigned long best_parent_rate = 0; unsigned long new_rate; unsigned long min_rate; unsigned long max_rate; int p_index = 0; long ret; /* sanity */ if (IS_ERR_OR_NULL(core)) return NULL; /* save parent rate, if it exists */ parent = old_parent = core->parent; if (parent) best_parent_rate = parent->rate; clk_core_get_boundaries(core, &min_rate, &max_rate); /* find the closest rate and parent clk/rate */ if (clk_core_can_round(core)) { struct clk_rate_request req; req.rate = rate; req.min_rate = min_rate; req.max_rate = max_rate; clk_core_init_rate_req(core, &req); ret = clk_core_determine_round_nolock(core, &req); if (ret < 0) return NULL; best_parent_rate = req.best_parent_rate; new_rate = req.rate; parent = req.best_parent_hw ? req.best_parent_hw->core : NULL; if (new_rate < min_rate || new_rate > max_rate) return NULL; } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) { /* pass-through clock without adjustable parent */ core->new_rate = core->rate; return NULL; } else { /* pass-through clock with adjustable parent */ top = clk_calc_new_rates(parent, rate); new_rate = parent->new_rate; goto out; } /* some clocks must be gated to change parent */ if (parent != old_parent && (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) { pr_debug("%s: %s not gated but wants to reparent\n", __func__, core->name); return NULL; } /* try finding the new parent index */ if (parent && core->num_parents > 1) { p_index = clk_fetch_parent_index(core, parent); if (p_index < 0) { pr_debug("%s: clk %s can not be parent of clk %s\n", __func__, parent->name, core->name); return NULL; } } if ((core->flags & CLK_SET_RATE_PARENT) && parent && best_parent_rate != parent->rate) top = clk_calc_new_rates(parent, best_parent_rate); out: clk_calc_subtree(core, new_rate, parent, p_index); return top; } /* * Notify about rate changes in a subtree. Always walk down the whole tree * so that in case of an error we can walk down the whole tree again and * abort the change. */ static struct clk_core *clk_propagate_rate_change(struct clk_core *core, unsigned long event) { struct clk_core *child, *tmp_clk, *fail_clk = NULL; int ret = NOTIFY_DONE; if (core->rate == core->new_rate) return NULL; if (core->notifier_count) { ret = __clk_notify(core, event, core->rate, core->new_rate); if (ret & NOTIFY_STOP_MASK) fail_clk = core; } hlist_for_each_entry(child, &core->children, child_node) { /* Skip children who will be reparented to another clock */ if (child->new_parent && child->new_parent != core) continue; tmp_clk = clk_propagate_rate_change(child, event); if (tmp_clk) fail_clk = tmp_clk; } /* handle the new child who might not be in core->children yet */ if (core->new_child) { tmp_clk = clk_propagate_rate_change(core->new_child, event); if (tmp_clk) fail_clk = tmp_clk; } return fail_clk; } /* * walk down a subtree and set the new rates notifying the rate * change on the way */ static void clk_change_rate(struct clk_core *core) { struct clk_core *child; struct hlist_node *tmp; unsigned long old_rate; unsigned long best_parent_rate = 0; bool skip_set_rate = false; struct clk_core *old_parent; struct clk_core *parent = NULL; old_rate = core->rate; if (core->new_parent) { parent = core->new_parent; best_parent_rate = core->new_parent->rate; } else if (core->parent) { parent = core->parent; best_parent_rate = core->parent->rate; } if (clk_pm_runtime_get(core)) return; if (core->flags & CLK_SET_RATE_UNGATE) { clk_core_prepare(core); clk_core_enable_lock(core); } if (core->new_parent && core->new_parent != core->parent) { old_parent = __clk_set_parent_before(core, core->new_parent); trace_clk_set_parent(core, core->new_parent); if (core->ops->set_rate_and_parent) { skip_set_rate = true; core->ops->set_rate_and_parent(core->hw, core->new_rate, best_parent_rate, core->new_parent_index); } else if (core->ops->set_parent) { core->ops->set_parent(core->hw, core->new_parent_index); } trace_clk_set_parent_complete(core, core->new_parent); __clk_set_parent_after(core, core->new_parent, old_parent); } if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_prepare_enable(parent); trace_clk_set_rate(core, core->new_rate); if (!skip_set_rate && core->ops->set_rate) core->ops->set_rate(core->hw, core->new_rate, best_parent_rate); trace_clk_set_rate_complete(core, core->new_rate); core->rate = clk_recalc(core, best_parent_rate); if (core->flags & CLK_SET_RATE_UNGATE) { clk_core_disable_lock(core); clk_core_unprepare(core); } if (core->flags & CLK_OPS_PARENT_ENABLE) clk_core_disable_unprepare(parent); if (core->notifier_count && old_rate != core->rate) __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate); if (core->flags & CLK_RECALC_NEW_RATES) (void)clk_calc_new_rates(core, core->new_rate); /* * Use safe iteration, as change_rate can actually swap parents * for certain clock types. */ hlist_for_each_entry_safe(child, tmp, &core->children, child_node) { /* Skip children who will be reparented to another clock */ if (child->new_parent && child->new_parent != core) continue; clk_change_rate(child); } /* handle the new child who might not be in core->children yet */ if (core->new_child) clk_change_rate(core->new_child); clk_pm_runtime_put(core); } static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core, unsigned long req_rate) { int ret, cnt; struct clk_rate_request req; lockdep_assert_held(&prepare_lock); if (!core) return 0; /* simulate what the rate would be if it could be freely set */ cnt = clk_core_rate_nuke_protect(core); if (cnt < 0) return cnt; clk_core_get_boundaries(core, &req.min_rate, &req.max_rate); req.rate = req_rate; ret = clk_core_round_rate_nolock(core, &req); /* restore the protection */ clk_core_rate_restore_protect(core, cnt); return ret ? 0 : req.rate; } static int clk_core_set_rate_nolock(struct clk_core *core, unsigned long req_rate) { struct clk_core *top, *fail_clk; unsigned long rate; int ret = 0; if (!core) return 0; rate = clk_core_req_round_rate_nolock(core, req_rate); /* bail early if nothing to do */ if (rate == clk_core_get_rate_nolock(core)) return 0; /* fail on a direct rate set of a protected provider */ if (clk_core_rate_is_protected(core)) return -EBUSY; /* calculate new rates and get the topmost changed clock */ top = clk_calc_new_rates(core, req_rate); if (!top) return -EINVAL; ret = clk_pm_runtime_get(core); if (ret) return ret; /* notify that we are about to change rates */ fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); if (fail_clk) { pr_debug("%s: failed to set %s rate\n", __func__, fail_clk->name); clk_propagate_rate_change(top, ABORT_RATE_CHANGE); ret = -EBUSY; goto err; } /* change the rates */ clk_change_rate(top); core->req_rate = req_rate; err: clk_pm_runtime_put(core); return ret; } /** * clk_set_rate - specify a new rate for clk * @clk: the clk whose rate is being changed * @rate: the new rate for clk * * In the simplest case clk_set_rate will only adjust the rate of clk. * * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to * propagate up to clk's parent; whether or not this happens depends on the * outcome of clk's .round_rate implementation. If *parent_rate is unchanged * after calling .round_rate then upstream parent propagation is ignored. If * *parent_rate comes back with a new rate for clk's parent then we propagate * up to clk's parent and set its rate. Upward propagation will continue * until either a clk does not support the CLK_SET_RATE_PARENT flag or * .round_rate stops requesting changes to clk's parent_rate. * * Rate changes are accomplished via tree traversal that also recalculates the * rates for the clocks and fires off POST_RATE_CHANGE notifiers. * * Returns 0 on success, -EERROR otherwise. */ int clk_set_rate(struct clk *clk, unsigned long rate) { int ret; if (!clk) return 0; /* prevent racing with updates to the clock topology */ clk_prepare_lock(); if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); ret = clk_core_set_rate_nolock(clk->core, rate); if (clk->exclusive_count) clk_core_rate_protect(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_set_rate); /** * clk_set_rate_exclusive - specify a new rate and get exclusive control * @clk: the clk whose rate is being changed * @rate: the new rate for clk * * This is a combination of clk_set_rate() and clk_rate_exclusive_get() * within a critical section * * This can be used initially to ensure that at least 1 consumer is * satisfied when several consumers are competing for exclusivity over the * same clock provider. * * The exclusivity is not applied if setting the rate failed. * * Calls to clk_rate_exclusive_get() should be balanced with calls to * clk_rate_exclusive_put(). * * Returns 0 on success, -EERROR otherwise. */ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) { int ret; if (!clk) return 0; /* prevent racing with updates to the clock topology */ clk_prepare_lock(); /* * The temporary protection removal is not here, on purpose * This function is meant to be used instead of clk_rate_protect, * so before the consumer code path protect the clock provider */ ret = clk_core_set_rate_nolock(clk->core, rate); if (!ret) { clk_core_rate_protect(clk->core); clk->exclusive_count++; } clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_set_rate_exclusive); /** * clk_set_rate_range - set a rate range for a clock source * @clk: clock source * @min: desired minimum clock rate in Hz, inclusive * @max: desired maximum clock rate in Hz, inclusive * * Returns success (0) or negative errno. */ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) { int ret = 0; unsigned long old_min, old_max, rate; if (!clk) return 0; trace_clk_set_rate_range(clk->core, min, max); if (min > max) { pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n", __func__, clk->core->name, clk->dev_id, clk->con_id, min, max); return -EINVAL; } clk_prepare_lock(); if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); /* Save the current values in case we need to rollback the change */ old_min = clk->min_rate; old_max = clk->max_rate; clk->min_rate = min; clk->max_rate = max; if (!clk_core_check_boundaries(clk->core, min, max)) { ret = -EINVAL; goto out; } /* * Since the boundaries have been changed, let's give the * opportunity to the provider to adjust the clock rate based on * the new boundaries. * * We also need to handle the case where the clock is currently * outside of the boundaries. Clamping the last requested rate * to the current minimum and maximum will also handle this. * * FIXME: * There is a catch. It may fail for the usual reason (clock * broken, clock protected, etc) but also because: * - round_rate() was not favorable and fell on the wrong * side of the boundary * - the determine_rate() callback does not really check for * this corner case when determining the rate */ rate = clamp(clk->core->req_rate, min, max); ret = clk_core_set_rate_nolock(clk->core, rate); if (ret) { /* rollback the changes */ clk->min_rate = old_min; clk->max_rate = old_max; } out: if (clk->exclusive_count) clk_core_rate_protect(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_set_rate_range); /** * clk_set_min_rate - set a minimum clock rate for a clock source * @clk: clock source * @rate: desired minimum clock rate in Hz, inclusive * * Returns success (0) or negative errno. */ int clk_set_min_rate(struct clk *clk, unsigned long rate) { if (!clk) return 0; trace_clk_set_min_rate(clk->core, rate); return clk_set_rate_range(clk, rate, clk->max_rate); } EXPORT_SYMBOL_GPL(clk_set_min_rate); /** * clk_set_max_rate - set a maximum clock rate for a clock source * @clk: clock source * @rate: desired maximum clock rate in Hz, inclusive * * Returns success (0) or negative errno. */ int clk_set_max_rate(struct clk *clk, unsigned long rate) { if (!clk) return 0; trace_clk_set_max_rate(clk->core, rate); return clk_set_rate_range(clk, clk->min_rate, rate); } EXPORT_SYMBOL_GPL(clk_set_max_rate); /** * clk_get_parent - return the parent of a clk * @clk: the clk whose parent gets returned * * Simply returns clk->parent. Returns NULL if clk is NULL. */ struct clk *clk_get_parent(struct clk *clk) { struct clk *parent; if (!clk) return NULL; clk_prepare_lock(); /* TODO: Create a per-user clk and change callers to call clk_put */ parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk; clk_prepare_unlock(); return parent; } EXPORT_SYMBOL_GPL(clk_get_parent); static struct clk_core *__clk_init_parent(struct clk_core *core) { u8 index = 0; if (core->num_parents > 1 && core->ops->get_parent) index = core->ops->get_parent(core->hw); return clk_core_get_parent_by_index(core, index); } static void clk_core_reparent(struct clk_core *core, struct clk_core *new_parent) { clk_reparent(core, new_parent); __clk_recalc_accuracies(core); __clk_recalc_rates(core, POST_RATE_CHANGE); } void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) { if (!hw) return; clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core); } /** * clk_has_parent - check if a clock is a possible parent for another * @clk: clock source * @parent: parent clock source * * This function can be used in drivers that need to check that a clock can be * the parent of another without actually changing the parent. * * Returns true if @parent is a possible parent for @clk, false otherwise. */ bool clk_has_parent(struct clk *clk, struct clk *parent) { struct clk_core *core, *parent_core; int i; /* NULL clocks should be nops, so return success if either is NULL. */ if (!clk || !parent) return true; core = clk->core; parent_core = parent->core; /* Optimize for the case where the parent is already the parent. */ if (core->parent == parent_core) return true; for (i = 0; i < core->num_parents; i++) if (!strcmp(core->parents[i].name, parent_core->name)) return true; return false; } EXPORT_SYMBOL_GPL(clk_has_parent); static int clk_core_set_parent_nolock(struct clk_core *core, struct clk_core *parent) { int ret = 0; int p_index = 0; unsigned long p_rate = 0; lockdep_assert_held(&prepare_lock); if (!core) return 0; if (core->parent == parent) return 0; /* verify ops for multi-parent clks */ if (core->num_parents > 1 && !core->ops->set_parent) return -EPERM; /* check that we are allowed to re-parent if the clock is in use */ if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) return -EBUSY; if (clk_core_rate_is_protected(core)) return -EBUSY; /* try finding the new parent index */ if (parent) { p_index = clk_fetch_parent_index(core, parent); if (p_index < 0) { pr_debug("%s: clk %s can not be parent of clk %s\n", __func__, parent->name, core->name); return p_index; } p_rate = parent->rate; } ret = clk_pm_runtime_get(core); if (ret) return ret; /* propagate PRE_RATE_CHANGE notifications */ ret = __clk_speculate_rates(core, p_rate); /* abort if a driver objects */ if (ret & NOTIFY_STOP_MASK) goto runtime_put; /* do the re-parent */ ret = __clk_set_parent(core, parent, p_index); /* propagate rate an accuracy recalculation accordingly */ if (ret) { __clk_recalc_rates(core, ABORT_RATE_CHANGE); } else { __clk_recalc_rates(core, POST_RATE_CHANGE); __clk_recalc_accuracies(core); } runtime_put: clk_pm_runtime_put(core); return ret; } int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent) { return clk_core_set_parent_nolock(hw->core, parent->core); } EXPORT_SYMBOL_GPL(clk_hw_set_parent); /** * clk_set_parent - switch the parent of a mux clk * @clk: the mux clk whose input we are switching * @parent: the new input to clk * * Re-parent clk to use parent as its new input source. If clk is in * prepared state, the clk will get enabled for the duration of this call. If * that's not acceptable for a specific clk (Eg: the consumer can't handle * that, the reparenting is glitchy in hardware, etc), use the * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. * * After successfully changing clk's parent clk_set_parent will update the * clk topology, sysfs topology and propagate rate recalculation via * __clk_recalc_rates. * * Returns 0 on success, -EERROR otherwise. */ int clk_set_parent(struct clk *clk, struct clk *parent) { int ret; if (!clk) return 0; clk_prepare_lock(); if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); ret = clk_core_set_parent_nolock(clk->core, parent ? parent->core : NULL); if (clk->exclusive_count) clk_core_rate_protect(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_set_parent); static int clk_core_set_phase_nolock(struct clk_core *core, int degrees) { int ret = -EINVAL; lockdep_assert_held(&prepare_lock); if (!core) return 0; if (clk_core_rate_is_protected(core)) return -EBUSY; trace_clk_set_phase(core, degrees); if (core->ops->set_phase) { ret = core->ops->set_phase(core->hw, degrees); if (!ret) core->phase = degrees; } trace_clk_set_phase_complete(core, degrees); return ret; } /** * clk_set_phase - adjust the phase shift of a clock signal * @clk: clock signal source * @degrees: number of degrees the signal is shifted * * Shifts the phase of a clock signal by the specified * degrees. Returns 0 on success, -EERROR otherwise. * * This function makes no distinction about the input or reference * signal that we adjust the clock signal phase against. For example * phase locked-loop clock signal generators we may shift phase with * respect to feedback clock signal input, but for other cases the * clock phase may be shifted with respect to some other, unspecified * signal. * * Additionally the concept of phase shift does not propagate through * the clock tree hierarchy, which sets it apart from clock rates and * clock accuracy. A parent clock phase attribute does not have an * impact on the phase attribute of a child clock. */ int clk_set_phase(struct clk *clk, int degrees) { int ret; if (!clk) return 0; /* sanity check degrees */ degrees %= 360; if (degrees < 0) degrees += 360; clk_prepare_lock(); if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); ret = clk_core_set_phase_nolock(clk->core, degrees); if (clk->exclusive_count) clk_core_rate_protect(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_set_phase); static int clk_core_get_phase(struct clk_core *core) { int ret; lockdep_assert_held(&prepare_lock); if (!core->ops->get_phase) return 0; /* Always try to update cached phase if possible */ ret = core->ops->get_phase(core->hw); if (ret >= 0) core->phase = ret; return ret; } /** * clk_get_phase - return the phase shift of a clock signal * @clk: clock signal source * * Returns the phase shift of a clock node in degrees, otherwise returns * -EERROR. */ int clk_get_phase(struct clk *clk) { int ret; if (!clk) return 0; clk_prepare_lock(); ret = clk_core_get_phase(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_get_phase); static void clk_core_reset_duty_cycle_nolock(struct clk_core *core) { /* Assume a default value of 50% */ core->duty.num = 1; core->duty.den = 2; } static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core); static int clk_core_update_duty_cycle_nolock(struct clk_core *core) { struct clk_duty *duty = &core->duty; int ret = 0; if (!core->ops->get_duty_cycle) return clk_core_update_duty_cycle_parent_nolock(core); ret = core->ops->get_duty_cycle(core->hw, duty); if (ret) goto reset; /* Don't trust the clock provider too much */ if (duty->den == 0 || duty->num > duty->den) { ret = -EINVAL; goto reset; } return 0; reset: clk_core_reset_duty_cycle_nolock(core); return ret; } static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core) { int ret = 0; if (core->parent && core->flags & CLK_DUTY_CYCLE_PARENT) { ret = clk_core_update_duty_cycle_nolock(core->parent); memcpy(&core->duty, &core->parent->duty, sizeof(core->duty)); } else { clk_core_reset_duty_cycle_nolock(core); } return ret; } static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core, struct clk_duty *duty); static int clk_core_set_duty_cycle_nolock(struct clk_core *core, struct clk_duty *duty) { int ret; lockdep_assert_held(&prepare_lock); if (clk_core_rate_is_protected(core)) return -EBUSY; trace_clk_set_duty_cycle(core, duty); if (!core->ops->set_duty_cycle) return clk_core_set_duty_cycle_parent_nolock(core, duty); ret = core->ops->set_duty_cycle(core->hw, duty); if (!ret) memcpy(&core->duty, duty, sizeof(*duty)); trace_clk_set_duty_cycle_complete(core, duty); return ret; } static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core, struct clk_duty *duty) { int ret = 0; if (core->parent && core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) { ret = clk_core_set_duty_cycle_nolock(core->parent, duty); memcpy(&core->duty, &core->parent->duty, sizeof(core->duty)); } return ret; } /** * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal * @clk: clock signal source * @num: numerator of the duty cycle ratio to be applied * @den: denominator of the duty cycle ratio to be applied * * Apply the duty cycle ratio if the ratio is valid and the clock can * perform this operation * * Returns (0) on success, a negative errno otherwise. */ int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den) { int ret; struct clk_duty duty; if (!clk) return 0; /* sanity check the ratio */ if (den == 0 || num > den) return -EINVAL; duty.num = num; duty.den = den; clk_prepare_lock(); if (clk->exclusive_count) clk_core_rate_unprotect(clk->core); ret = clk_core_set_duty_cycle_nolock(clk->core, &duty); if (clk->exclusive_count) clk_core_rate_protect(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_set_duty_cycle); static int clk_core_get_scaled_duty_cycle(struct clk_core *core, unsigned int scale) { struct clk_duty *duty = &core->duty; int ret; clk_prepare_lock(); ret = clk_core_update_duty_cycle_nolock(core); if (!ret) ret = mult_frac(scale, duty->num, duty->den); clk_prepare_unlock(); return ret; } /** * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal * @clk: clock signal source * @scale: scaling factor to be applied to represent the ratio as an integer * * Returns the duty cycle ratio of a clock node multiplied by the provided * scaling factor, or negative errno on error. */ int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale) { if (!clk) return 0; return clk_core_get_scaled_duty_cycle(clk->core, scale); } EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle); /** * clk_is_match - check if two clk's point to the same hardware clock * @p: clk compared against q * @q: clk compared against p * * Returns true if the two struct clk pointers both point to the same hardware * clock node. Put differently, returns true if struct clk *p and struct clk *q * share the same struct clk_core object. * * Returns false otherwise. Note that two NULL clks are treated as matching. */ bool clk_is_match(const struct clk *p, const struct clk *q) { /* trivial case: identical struct clk's or both NULL */ if (p == q) return true; /* true if clk->core pointers match. Avoid dereferencing garbage */ if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q)) if (p->core == q->core) return true; return false; } EXPORT_SYMBOL_GPL(clk_is_match); /*** debugfs support ***/ #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> static struct dentry *rootdir; static int inited = 0; static DEFINE_MUTEX(clk_debug_lock); static HLIST_HEAD(clk_debug_list); static struct hlist_head *orphan_list[] = { &clk_orphan_list, NULL, }; static void clk_summary_show_one(struct seq_file *s, struct clk_core *c, int level) { int phase; seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ", level * 3 + 1, "", 30 - level * 3, c->name, c->enable_count, c->prepare_count, c->protect_count, clk_core_get_rate_recalc(c), clk_core_get_accuracy_recalc(c)); phase = clk_core_get_phase(c); if (phase >= 0) seq_printf(s, "%5d", phase); else seq_puts(s, "-----"); seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000)); if (c->ops->is_enabled) seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N'); else if (!c->ops->enable) seq_printf(s, " %9c\n", 'Y'); else seq_printf(s, " %9c\n", '?'); } static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c, int level) { struct clk_core *child; clk_pm_runtime_get(c); clk_summary_show_one(s, c, level); clk_pm_runtime_put(c); hlist_for_each_entry(child, &c->children, child_node) clk_summary_show_subtree(s, child, level + 1); } static int clk_summary_show(struct seq_file *s, void *data) { struct clk_core *c; struct hlist_head **lists = (struct hlist_head **)s->private; seq_puts(s, " enable prepare protect duty hardware\n"); seq_puts(s, " clock count count count rate accuracy phase cycle enable\n"); seq_puts(s, "-------------------------------------------------------------------------------------------------------\n"); clk_prepare_lock(); for (; *lists; lists++) hlist_for_each_entry(c, *lists, child_node) clk_summary_show_subtree(s, c, 0); clk_prepare_unlock(); return 0; } DEFINE_SHOW_ATTRIBUTE(clk_summary); static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level) { int phase; unsigned long min_rate, max_rate; clk_core_get_boundaries(c, &min_rate, &max_rate); /* This should be JSON format, i.e. elements separated with a comma */ seq_printf(s, "\"%s\": { ", c->name); seq_printf(s, "\"enable_count\": %d,", c->enable_count); seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); seq_printf(s, "\"protect_count\": %d,", c->protect_count); seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c)); seq_printf(s, "\"min_rate\": %lu,", min_rate); seq_printf(s, "\"max_rate\": %lu,", max_rate); seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c)); phase = clk_core_get_phase(c); if (phase >= 0) seq_printf(s, "\"phase\": %d,", phase); seq_printf(s, "\"duty_cycle\": %u", clk_core_get_scaled_duty_cycle(c, 100000)); } static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level) { struct clk_core *child; clk_dump_one(s, c, level); hlist_for_each_entry(child, &c->children, child_node) { seq_putc(s, ','); clk_dump_subtree(s, child, level + 1); } seq_putc(s, '}'); } static int clk_dump_show(struct seq_file *s, void *data) { struct clk_core *c; bool first_node = true; struct hlist_head **lists = (struct hlist_head **)s->private; seq_putc(s, '{'); clk_prepare_lock(); for (; *lists; lists++) { hlist_for_each_entry(c, *lists, child_node) { if (!first_node) seq_putc(s, ','); first_node = false; clk_dump_subtree(s, c, 0); } } clk_prepare_unlock(); seq_puts(s, "}\n"); return 0; } DEFINE_SHOW_ATTRIBUTE(clk_dump); #undef CLOCK_ALLOW_WRITE_DEBUGFS #ifdef CLOCK_ALLOW_WRITE_DEBUGFS /* * This can be dangerous, therefore don't provide any real compile time * configuration option for this feature. * People who want to use this will need to modify the source code directly. */ static int clk_rate_set(void *data, u64 val) { struct clk_core *core = data; int ret; clk_prepare_lock(); ret = clk_core_set_rate_nolock(core, val); clk_prepare_unlock(); return ret; } #define clk_rate_mode 0644 static int clk_prepare_enable_set(void *data, u64 val) { struct clk_core *core = data; int ret = 0; if (val) ret = clk_prepare_enable(core->hw->clk); else clk_disable_unprepare(core->hw->clk); return ret; } static int clk_prepare_enable_get(void *data, u64 *val) { struct clk_core *core = data; *val = core->enable_count && core->prepare_count; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get, clk_prepare_enable_set, "%llu\n"); #else #define clk_rate_set NULL #define clk_rate_mode 0444 #endif static int clk_rate_get(void *data, u64 *val) { struct clk_core *core = data; clk_prepare_lock(); *val = clk_core_get_rate_recalc(core); clk_prepare_unlock(); return 0; } DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n"); static const struct { unsigned long flag; const char *name; } clk_flags[] = { #define ENTRY(f) { f, #f } ENTRY(CLK_SET_RATE_GATE), ENTRY(CLK_SET_PARENT_GATE), ENTRY(CLK_SET_RATE_PARENT), ENTRY(CLK_IGNORE_UNUSED), ENTRY(CLK_GET_RATE_NOCACHE), ENTRY(CLK_SET_RATE_NO_REPARENT), ENTRY(CLK_GET_ACCURACY_NOCACHE), ENTRY(CLK_RECALC_NEW_RATES), ENTRY(CLK_SET_RATE_UNGATE), ENTRY(CLK_IS_CRITICAL), ENTRY(CLK_OPS_PARENT_ENABLE), ENTRY(CLK_DUTY_CYCLE_PARENT), #undef ENTRY }; static int clk_flags_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; unsigned long flags = core->flags; unsigned int i; for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) { if (flags & clk_flags[i].flag) { seq_printf(s, "%s\n", clk_flags[i].name); flags &= ~clk_flags[i].flag; } } if (flags) { /* Unknown flags */ seq_printf(s, "0x%lx\n", flags); } return 0; } DEFINE_SHOW_ATTRIBUTE(clk_flags); static void possible_parent_show(struct seq_file *s, struct clk_core *core, unsigned int i, char terminator) { struct clk_core *parent; /* * Go through the following options to fetch a parent's name. * * 1. Fetch the registered parent clock and use its name * 2. Use the global (fallback) name if specified * 3. Use the local fw_name if provided * 4. Fetch parent clock's clock-output-name if DT index was set * * This may still fail in some cases, such as when the parent is * specified directly via a struct clk_hw pointer, but it isn't * registered (yet). */ parent = clk_core_get_parent_by_index(core, i); if (parent) seq_puts(s, parent->name); else if (core->parents[i].name) seq_puts(s, core->parents[i].name); else if (core->parents[i].fw_name) seq_printf(s, "<%s>(fw)", core->parents[i].fw_name); else if (core->parents[i].index >= 0) seq_puts(s, of_clk_get_parent_name(core->of_node, core->parents[i].index)); else seq_puts(s, "(missing)"); seq_putc(s, terminator); } static int possible_parents_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; int i; for (i = 0; i < core->num_parents - 1; i++) possible_parent_show(s, core, i, ' '); possible_parent_show(s, core, i, '\n'); return 0; } DEFINE_SHOW_ATTRIBUTE(possible_parents); static int current_parent_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; if (core->parent) seq_printf(s, "%s\n", core->parent->name); return 0; } DEFINE_SHOW_ATTRIBUTE(current_parent); #ifdef CLOCK_ALLOW_WRITE_DEBUGFS static ssize_t current_parent_write(struct file *file, const char __user *ubuf, size_t count, loff_t *ppos) { struct seq_file *s = file->private_data; struct clk_core *core = s->private; struct clk_core *parent; u8 idx; int err; err = kstrtou8_from_user(ubuf, count, 0, &idx); if (err < 0) return err; parent = clk_core_get_parent_by_index(core, idx); if (!parent) return -ENOENT; clk_prepare_lock(); err = clk_core_set_parent_nolock(core, parent); clk_prepare_unlock(); if (err) return err; return count; } static const struct file_operations current_parent_rw_fops = { .open = current_parent_open, .write = current_parent_write, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #endif static int clk_duty_cycle_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; struct clk_duty *duty = &core->duty; seq_printf(s, "%u/%u\n", duty->num, duty->den); return 0; } DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle); static int clk_min_rate_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; unsigned long min_rate, max_rate; clk_prepare_lock(); clk_core_get_boundaries(core, &min_rate, &max_rate); clk_prepare_unlock(); seq_printf(s, "%lu\n", min_rate); return 0; } DEFINE_SHOW_ATTRIBUTE(clk_min_rate); static int clk_max_rate_show(struct seq_file *s, void *data) { struct clk_core *core = s->private; unsigned long min_rate, max_rate; clk_prepare_lock(); clk_core_get_boundaries(core, &min_rate, &max_rate); clk_prepare_unlock(); seq_printf(s, "%lu\n", max_rate); return 0; } DEFINE_SHOW_ATTRIBUTE(clk_max_rate); static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) { struct dentry *root; if (!core || !pdentry) return; root = debugfs_create_dir(core->name, pdentry); core->dentry = root; debugfs_create_file("clk_rate", clk_rate_mode, root, core, &clk_rate_fops); debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops); debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops); debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy); debugfs_create_u32("clk_phase", 0444, root, &core->phase); debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops); debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count); debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count); debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count); debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count); debugfs_create_file("clk_duty_cycle", 0444, root, core, &clk_duty_cycle_fops); #ifdef CLOCK_ALLOW_WRITE_DEBUGFS debugfs_create_file("clk_prepare_enable", 0644, root, core, &clk_prepare_enable_fops); if (core->num_parents > 1) debugfs_create_file("clk_parent", 0644, root, core, ¤t_parent_rw_fops); else #endif if (core->num_parents > 0) debugfs_create_file("clk_parent", 0444, root, core, ¤t_parent_fops); if (core->num_parents > 1) debugfs_create_file("clk_possible_parents", 0444, root, core, &possible_parents_fops); if (core->ops->debug_init) core->ops->debug_init(core->hw, core->dentry); } /** * clk_debug_register - add a clk node to the debugfs clk directory * @core: the clk being added to the debugfs clk directory * * Dynamically adds a clk to the debugfs clk directory if debugfs has been * initialized. Otherwise it bails out early since the debugfs clk directory * will be created lazily by clk_debug_init as part of a late_initcall. */ static void clk_debug_register(struct clk_core *core) { mutex_lock(&clk_debug_lock); hlist_add_head(&core->debug_node, &clk_debug_list); if (inited) clk_debug_create_one(core, rootdir); mutex_unlock(&clk_debug_lock); } /** * clk_debug_unregister - remove a clk node from the debugfs clk directory * @core: the clk being removed from the debugfs clk directory * * Dynamically removes a clk and all its child nodes from the * debugfs clk directory if clk->dentry points to debugfs created by * clk_debug_register in __clk_core_init. */ static void clk_debug_unregister(struct clk_core *core) { mutex_lock(&clk_debug_lock); hlist_del_init(&core->debug_node); debugfs_remove_recursive(core->dentry); core->dentry = NULL; mutex_unlock(&clk_debug_lock); } /** * clk_debug_init - lazily populate the debugfs clk directory * * clks are often initialized very early during boot before memory can be * dynamically allocated and well before debugfs is setup. This function * populates the debugfs clk directory once at boot-time when we know that * debugfs is setup. It should only be called once at boot-time, all other clks * added dynamically will be done so with clk_debug_register. */ static int __init clk_debug_init(void) { struct clk_core *core; #ifdef CLOCK_ALLOW_WRITE_DEBUGFS pr_warn("\n"); pr_warn("********************************************************************\n"); pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); pr_warn("** **\n"); pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n"); pr_warn("** **\n"); pr_warn("** This means that this kernel is built to expose clk operations **\n"); pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n"); pr_warn("** to userspace, which may compromise security on your system. **\n"); pr_warn("** **\n"); pr_warn("** If you see this message and you are not debugging the **\n"); pr_warn("** kernel, report this immediately to your vendor! **\n"); pr_warn("** **\n"); pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); pr_warn("********************************************************************\n"); #endif rootdir = debugfs_create_dir("clk", NULL); debugfs_create_file("clk_summary", 0444, rootdir, &all_lists, &clk_summary_fops); debugfs_create_file("clk_dump", 0444, rootdir, &all_lists, &clk_dump_fops); debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list, &clk_summary_fops); debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list, &clk_dump_fops); mutex_lock(&clk_debug_lock); hlist_for_each_entry(core, &clk_debug_list, debug_node) clk_debug_create_one(core, rootdir); inited = 1; mutex_unlock(&clk_debug_lock); return 0; } late_initcall(clk_debug_init); #else static inline void clk_debug_register(struct clk_core *core) { } static inline void clk_debug_unregister(struct clk_core *core) { } #endif static void clk_core_reparent_orphans_nolock(void) { struct clk_core *orphan; struct hlist_node *tmp2; /* * walk the list of orphan clocks and reparent any that newly finds a * parent. */ hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { struct clk_core *parent = __clk_init_parent(orphan); /* * We need to use __clk_set_parent_before() and _after() to * to properly migrate any prepare/enable count of the orphan * clock. This is important for CLK_IS_CRITICAL clocks, which * are enabled during init but might not have a parent yet. */ if (parent) { /* update the clk tree topology */ __clk_set_parent_before(orphan, parent); __clk_set_parent_after(orphan, parent, NULL); __clk_recalc_accuracies(orphan); __clk_recalc_rates(orphan, 0); /* * __clk_init_parent() will set the initial req_rate to * 0 if the clock doesn't have clk_ops::recalc_rate and * is an orphan when it's registered. * * 'req_rate' is used by clk_set_rate_range() and * clk_put() to trigger a clk_set_rate() call whenever * the boundaries are modified. Let's make sure * 'req_rate' is set to something non-zero so that * clk_set_rate_range() doesn't drop the frequency. */ orphan->req_rate = orphan->rate; } } } /** * __clk_core_init - initialize the data structures in a struct clk_core * @core: clk_core being initialized * * Initializes the lists in struct clk_core, queries the hardware for the * parent and rate and sets them both. */ static int __clk_core_init(struct clk_core *core) { int ret; struct clk_core *parent; unsigned long rate; int phase; clk_prepare_lock(); /* * Set hw->core after grabbing the prepare_lock to synchronize with * callers of clk_core_fill_parent_index() where we treat hw->core * being NULL as the clk not being registered yet. This is crucial so * that clks aren't parented until their parent is fully registered. */ core->hw->core = core; ret = clk_pm_runtime_get(core); if (ret) goto unlock; /* check to see if a clock with this name is already registered */ if (clk_core_lookup(core->name)) { pr_debug("%s: clk %s already initialized\n", __func__, core->name); ret = -EEXIST; goto out; } /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */ if (core->ops->set_rate && !((core->ops->round_rate || core->ops->determine_rate) && core->ops->recalc_rate)) { pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", __func__, core->name); ret = -EINVAL; goto out; } if (core->ops->set_parent && !core->ops->get_parent) { pr_err("%s: %s must implement .get_parent & .set_parent\n", __func__, core->name); ret = -EINVAL; goto out; } if (core->num_parents > 1 && !core->ops->get_parent) { pr_err("%s: %s must implement .get_parent as it has multi parents\n", __func__, core->name); ret = -EINVAL; goto out; } if (core->ops->set_rate_and_parent && !(core->ops->set_parent && core->ops->set_rate)) { pr_err("%s: %s must implement .set_parent & .set_rate\n", __func__, core->name); ret = -EINVAL; goto out; } /* * optional platform-specific magic * * The .init callback is not used by any of the basic clock types, but * exists for weird hardware that must perform initialization magic for * CCF to get an accurate view of clock for any other callbacks. It may * also be used needs to perform dynamic allocations. Such allocation * must be freed in the terminate() callback. * This callback shall not be used to initialize the parameters state, * such as rate, parent, etc ... * * If it exist, this callback should called before any other callback of * the clock */ if (core->ops->init) { ret = core->ops->init(core->hw); if (ret) goto out; } parent = core->parent = __clk_init_parent(core); /* * Populate core->parent if parent has already been clk_core_init'd. If * parent has not yet been clk_core_init'd then place clk in the orphan * list. If clk doesn't have any parents then place it in the root * clk list. * * Every time a new clk is clk_init'd then we walk the list of orphan * clocks and re-parent any that are children of the clock currently * being clk_init'd. */ if (parent) { hlist_add_head(&core->child_node, &parent->children); core->orphan = parent->orphan; } else if (!core->num_parents) { hlist_add_head(&core->child_node, &clk_root_list); core->orphan = false; } else { hlist_add_head(&core->child_node, &clk_orphan_list); core->orphan = true; } /* * Set clk's accuracy. The preferred method is to use * .recalc_accuracy. For simple clocks and lazy developers the default * fallback is to use the parent's accuracy. If a clock doesn't have a * parent (or is orphaned) then accuracy is set to zero (perfect * clock). */ if (core->ops->recalc_accuracy) core->accuracy = core->ops->recalc_accuracy(core->hw, clk_core_get_accuracy_no_lock(parent)); else if (parent) core->accuracy = parent->accuracy; else core->accuracy = 0; /* * Set clk's phase by clk_core_get_phase() caching the phase. * Since a phase is by definition relative to its parent, just * query the current clock phase, or just assume it's in phase. */ phase = clk_core_get_phase(core); if (phase < 0) { ret = phase; pr_warn("%s: Failed to get phase for clk '%s'\n", __func__, core->name); goto out; } /* * Set clk's duty cycle. */ clk_core_update_duty_cycle_nolock(core); /* * Set clk's rate. The preferred method is to use .recalc_rate. For * simple clocks and lazy developers the default fallback is to use the * parent's rate. If a clock doesn't have a parent (or is orphaned) * then rate is set to zero. */ if (core->ops->recalc_rate) rate = core->ops->recalc_rate(core->hw, clk_core_get_rate_nolock(parent)); else if (parent) rate = parent->rate; else rate = 0; core->rate = core->req_rate = rate; /* * Enable CLK_IS_CRITICAL clocks so newly added critical clocks * don't get accidentally disabled when walking the orphan tree and * reparenting clocks */ if (core->flags & CLK_IS_CRITICAL) { ret = clk_core_prepare(core); if (ret) { pr_warn("%s: critical clk '%s' failed to prepare\n", __func__, core->name); goto out; } ret = clk_core_enable_lock(core); if (ret) { pr_warn("%s: critical clk '%s' failed to enable\n", __func__, core->name); clk_core_unprepare(core); goto out; } } clk_core_reparent_orphans_nolock(); kref_init(&core->ref); out: clk_pm_runtime_put(core); unlock: if (ret) { hlist_del_init(&core->child_node); core->hw->core = NULL; } clk_prepare_unlock(); if (!ret) clk_debug_register(core); return ret; } /** * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core * @core: clk to add consumer to * @clk: consumer to link to a clk */ static void clk_core_link_consumer(struct clk_core *core, struct clk *clk) { clk_prepare_lock(); hlist_add_head(&clk->clks_node, &core->clks); clk_prepare_unlock(); } /** * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core * @clk: consumer to unlink */ static void clk_core_unlink_consumer(struct clk *clk) { lockdep_assert_held(&prepare_lock); hlist_del(&clk->clks_node); } /** * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core * @core: clk to allocate a consumer for * @dev_id: string describing device name * @con_id: connection ID string on device * * Returns: clk consumer left unlinked from the consumer list */ static struct clk *alloc_clk(struct clk_core *core, const char *dev_id, const char *con_id) { struct clk *clk; clk = kzalloc(sizeof(*clk), GFP_KERNEL); if (!clk) return ERR_PTR(-ENOMEM); clk->core = core; clk->dev_id = dev_id; clk->con_id = kstrdup_const(con_id, GFP_KERNEL); clk->max_rate = ULONG_MAX; return clk; } /** * free_clk - Free a clk consumer * @clk: clk consumer to free * * Note, this assumes the clk has been unlinked from the clk_core consumer * list. */ static void free_clk(struct clk *clk) { kfree_const(clk->con_id); kfree(clk); } /** * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given * a clk_hw * @dev: clk consumer device * @hw: clk_hw associated with the clk being consumed * @dev_id: string describing device name * @con_id: connection ID string on device * * This is the main function used to create a clk pointer for use by clk * consumers. It connects a consumer to the clk_core and clk_hw structures * used by the framework and clk provider respectively. */ struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw, const char *dev_id, const char *con_id) { struct clk *clk; struct clk_core *core; /* This is to allow this function to be chained to others */ if (IS_ERR_OR_NULL(hw)) return ERR_CAST(hw); core = hw->core; clk = alloc_clk(core, dev_id, con_id); if (IS_ERR(clk)) return clk; clk->dev = dev; if (!try_module_get(core->owner)) { free_clk(clk); return ERR_PTR(-ENOENT); } kref_get(&core->ref); clk_core_link_consumer(core, clk); return clk; } /** * clk_hw_get_clk - get clk consumer given an clk_hw * @hw: clk_hw associated with the clk being consumed * @con_id: connection ID string on device * * Returns: new clk consumer * This is the function to be used by providers which need * to get a consumer clk and act on the clock element * Calls to this function must be balanced with calls clk_put() */ struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id) { struct device *dev = hw->core->dev; const char *name = dev ? dev_name(dev) : NULL; return clk_hw_create_clk(dev, hw, name, con_id); } EXPORT_SYMBOL(clk_hw_get_clk); static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist) { const char *dst; if (!src) { if (must_exist) return -EINVAL; return 0; } *dst_p = dst = kstrdup_const(src, GFP_KERNEL); if (!dst) return -ENOMEM; return 0; } static int clk_core_populate_parent_map(struct clk_core *core, const struct clk_init_data *init) { u8 num_parents = init->num_parents; const char * const *parent_names = init->parent_names; const struct clk_hw **parent_hws = init->parent_hws; const struct clk_parent_data *parent_data = init->parent_data; int i, ret = 0; struct clk_parent_map *parents, *parent; if (!num_parents) return 0; /* * Avoid unnecessary string look-ups of clk_core's possible parents by * having a cache of names/clk_hw pointers to clk_core pointers. */ parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL); core->parents = parents; if (!parents) return -ENOMEM; /* Copy everything over because it might be __initdata */ for (i = 0, parent = parents; i < num_parents; i++, parent++) { parent->index = -1; if (parent_names) { /* throw a WARN if any entries are NULL */ WARN(!parent_names[i], "%s: invalid NULL in %s's .parent_names\n", __func__, core->name); ret = clk_cpy_name(&parent->name, parent_names[i], true); } else if (parent_data) { parent->hw = parent_data[i].hw; parent->index = parent_data[i].index; ret = clk_cpy_name(&parent->fw_name, parent_data[i].fw_name, false); if (!ret) ret = clk_cpy_name(&parent->name, parent_data[i].name, false); } else if (parent_hws) { parent->hw = parent_hws[i]; } else { ret = -EINVAL; WARN(1, "Must specify parents if num_parents > 0\n"); } if (ret) { do { kfree_const(parents[i].name); kfree_const(parents[i].fw_name); } while (--i >= 0); kfree(parents); return ret; } } return 0; } static void clk_core_free_parent_map(struct clk_core *core) { int i = core->num_parents; if (!core->num_parents) return; while (--i >= 0) { kfree_const(core->parents[i].name); kfree_const(core->parents[i].fw_name); } kfree(core->parents); } static struct clk * __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) { int ret; struct clk_core *core; const struct clk_init_data *init = hw->init; /* * The init data is not supposed to be used outside of registration path. * Set it to NULL so that provider drivers can't use it either and so that * we catch use of hw->init early on in the core. */ hw->init = NULL; core = kzalloc(sizeof(*core), GFP_KERNEL); if (!core) { ret = -ENOMEM; goto fail_out; } core->name = kstrdup_const(init->name, GFP_KERNEL); if (!core->name) { ret = -ENOMEM; goto fail_name; } if (WARN_ON(!init->ops)) { ret = -EINVAL; goto fail_ops; } core->ops = init->ops; if (dev && pm_runtime_enabled(dev)) core->rpm_enabled = true; core->dev = dev; core->of_node = np; if (dev && dev->driver) core->owner = dev->driver->owner; core->hw = hw; core->flags = init->flags; core->num_parents = init->num_parents; core->min_rate = 0; core->max_rate = ULONG_MAX; ret = clk_core_populate_parent_map(core, init); if (ret) goto fail_parents; INIT_HLIST_HEAD(&core->clks); /* * Don't call clk_hw_create_clk() here because that would pin the * provider module to itself and prevent it from ever being removed. */ hw->clk = alloc_clk(core, NULL, NULL); if (IS_ERR(hw->clk)) { ret = PTR_ERR(hw->clk); goto fail_create_clk; } clk_core_link_consumer(core, hw->clk); ret = __clk_core_init(core); if (!ret) return hw->clk; clk_prepare_lock(); clk_core_unlink_consumer(hw->clk); clk_prepare_unlock(); free_clk(hw->clk); hw->clk = NULL; fail_create_clk: clk_core_free_parent_map(core); fail_parents: fail_ops: kfree_const(core->name); fail_name: kfree(core); fail_out: return ERR_PTR(ret); } /** * dev_or_parent_of_node() - Get device node of @dev or @dev's parent * @dev: Device to get device node of * * Return: device node pointer of @dev, or the device node pointer of * @dev->parent if dev doesn't have a device node, or NULL if neither * @dev or @dev->parent have a device node. */ static struct device_node *dev_or_parent_of_node(struct device *dev) { struct device_node *np; if (!dev) return NULL; np = dev_of_node(dev); if (!np) np = dev_of_node(dev->parent); return np; } /** * clk_register - allocate a new clock, register it and return an opaque cookie * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * clk_register is the *deprecated* interface for populating the clock tree with * new clock nodes. Use clk_hw_register() instead. * * Returns: a pointer to the newly allocated struct clk which * cannot be dereferenced by driver code but may be used in conjunction with the * rest of the clock API. In the event of an error clk_register will return an * error code; drivers must test for an error code after calling clk_register. */ struct clk *clk_register(struct device *dev, struct clk_hw *hw) { return __clk_register(dev, dev_or_parent_of_node(dev), hw); } EXPORT_SYMBOL_GPL(clk_register); /** * clk_hw_register - register a clk_hw and return an error code * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * clk_hw_register is the primary interface for populating the clock tree with * new clock nodes. It returns an integer equal to zero indicating success or * less than zero indicating failure. Drivers must test for an error code after * calling clk_hw_register(). */ int clk_hw_register(struct device *dev, struct clk_hw *hw) { return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev), hw)); } EXPORT_SYMBOL_GPL(clk_hw_register); /* * of_clk_hw_register - register a clk_hw and return an error code * @node: device_node of device that is registering this clock * @hw: link to hardware-specific clock data * * of_clk_hw_register() is the primary interface for populating the clock tree * with new clock nodes when a struct device is not available, but a struct * device_node is. It returns an integer equal to zero indicating success or * less than zero indicating failure. Drivers must test for an error code after * calling of_clk_hw_register(). */ int of_clk_hw_register(struct device_node *node, struct clk_hw *hw) { return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw)); } EXPORT_SYMBOL_GPL(of_clk_hw_register); /* Free memory allocated for a clock. */ static void __clk_release(struct kref *ref) { struct clk_core *core = container_of(ref, struct clk_core, ref); lockdep_assert_held(&prepare_lock); clk_core_free_parent_map(core); kfree_const(core->name); kfree(core); } /* * Empty clk_ops for unregistered clocks. These are used temporarily * after clk_unregister() was called on a clock and until last clock * consumer calls clk_put() and the struct clk object is freed. */ static int clk_nodrv_prepare_enable(struct clk_hw *hw) { return -ENXIO; } static void clk_nodrv_disable_unprepare(struct clk_hw *hw) { WARN_ON_ONCE(1); } static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { return -ENXIO; } static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) { return -ENXIO; } static const struct clk_ops clk_nodrv_ops = { .enable = clk_nodrv_prepare_enable, .disable = clk_nodrv_disable_unprepare, .prepare = clk_nodrv_prepare_enable, .unprepare = clk_nodrv_disable_unprepare, .set_rate = clk_nodrv_set_rate, .set_parent = clk_nodrv_set_parent, }; static void clk_core_evict_parent_cache_subtree(struct clk_core *root, const struct clk_core *target) { int i; struct clk_core *child; for (i = 0; i < root->num_parents; i++) if (root->parents[i].core == target) root->parents[i].core = NULL; hlist_for_each_entry(child, &root->children, child_node) clk_core_evict_parent_cache_subtree(child, target); } /* Remove this clk from all parent caches */ static void clk_core_evict_parent_cache(struct clk_core *core) { const struct hlist_head **lists; struct clk_core *root; lockdep_assert_held(&prepare_lock); for (lists = all_lists; *lists; lists++) hlist_for_each_entry(root, *lists, child_node) clk_core_evict_parent_cache_subtree(root, core); } /** * clk_unregister - unregister a currently registered clock * @clk: clock to unregister */ void clk_unregister(struct clk *clk) { unsigned long flags; const struct clk_ops *ops; if (!clk || WARN_ON_ONCE(IS_ERR(clk))) return; clk_debug_unregister(clk->core); clk_prepare_lock(); ops = clk->core->ops; if (ops == &clk_nodrv_ops) { pr_err("%s: unregistered clock: %s\n", __func__, clk->core->name); goto unlock; } /* * Assign empty clock ops for consumers that might still hold * a reference to this clock. */ flags = clk_enable_lock(); clk->core->ops = &clk_nodrv_ops; clk_enable_unlock(flags); if (ops->terminate) ops->terminate(clk->core->hw); if (!hlist_empty(&clk->core->children)) { struct clk_core *child; struct hlist_node *t; /* Reparent all children to the orphan list. */ hlist_for_each_entry_safe(child, t, &clk->core->children, child_node) clk_core_set_parent_nolock(child, NULL); } clk_core_evict_parent_cache(clk->core); hlist_del_init(&clk->core->child_node); if (clk->core->prepare_count) pr_warn("%s: unregistering prepared clock: %s\n", __func__, clk->core->name); if (clk->core->protect_count) pr_warn("%s: unregistering protected clock: %s\n", __func__, clk->core->name); kref_put(&clk->core->ref, __clk_release); free_clk(clk); unlock: clk_prepare_unlock(); } EXPORT_SYMBOL_GPL(clk_unregister); /** * clk_hw_unregister - unregister a currently registered clk_hw * @hw: hardware-specific clock data to unregister */ void clk_hw_unregister(struct clk_hw *hw) { clk_unregister(hw->clk); } EXPORT_SYMBOL_GPL(clk_hw_unregister); static void devm_clk_unregister_cb(struct device *dev, void *res) { clk_unregister(*(struct clk **)res); } static void devm_clk_hw_unregister_cb(struct device *dev, void *res) { clk_hw_unregister(*(struct clk_hw **)res); } /** * devm_clk_register - resource managed clk_register() * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead. * * Clocks returned from this function are automatically clk_unregister()ed on * driver detach. See clk_register() for more information. */ struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) { struct clk *clk; struct clk **clkp; clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL); if (!clkp) return ERR_PTR(-ENOMEM); clk = clk_register(dev, hw); if (!IS_ERR(clk)) { *clkp = clk; devres_add(dev, clkp); } else { devres_free(clkp); } return clk; } EXPORT_SYMBOL_GPL(devm_clk_register); /** * devm_clk_hw_register - resource managed clk_hw_register() * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * Managed clk_hw_register(). Clocks registered by this function are * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register() * for more information. */ int devm_clk_hw_register(struct device *dev, struct clk_hw *hw) { struct clk_hw **hwp; int ret; hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL); if (!hwp) return -ENOMEM; ret = clk_hw_register(dev, hw); if (!ret) { *hwp = hw; devres_add(dev, hwp); } else { devres_free(hwp); } return ret; } EXPORT_SYMBOL_GPL(devm_clk_hw_register); static void devm_clk_release(struct device *dev, void *res) { clk_put(*(struct clk **)res); } /** * devm_clk_hw_get_clk - resource managed clk_hw_get_clk() * @dev: device that is registering this clock * @hw: clk_hw associated with the clk being consumed * @con_id: connection ID string on device * * Managed clk_hw_get_clk(). Clocks got with this function are * automatically clk_put() on driver detach. See clk_put() * for more information. */ struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw, const char *con_id) { struct clk *clk; struct clk **clkp; /* This should not happen because it would mean we have drivers * passing around clk_hw pointers instead of having the caller use * proper clk_get() style APIs */ WARN_ON_ONCE(dev != hw->core->dev); clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); if (!clkp) return ERR_PTR(-ENOMEM); clk = clk_hw_get_clk(hw, con_id); if (!IS_ERR(clk)) { *clkp = clk; devres_add(dev, clkp); } else { devres_free(clkp); } return clk; } EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk); /* * clkdev helpers */ void __clk_put(struct clk *clk) { struct module *owner; if (!clk || WARN_ON_ONCE(IS_ERR(clk))) return; clk_prepare_lock(); /* * Before calling clk_put, all calls to clk_rate_exclusive_get() from a * given user should be balanced with calls to clk_rate_exclusive_put() * and by that same consumer */ if (WARN_ON(clk->exclusive_count)) { /* We voiced our concern, let's sanitize the situation */ clk->core->protect_count -= (clk->exclusive_count - 1); clk_core_rate_unprotect(clk->core); clk->exclusive_count = 0; } hlist_del(&clk->clks_node); if (clk->min_rate > clk->core->req_rate || clk->max_rate < clk->core->req_rate) clk_core_set_rate_nolock(clk->core, clk->core->req_rate); owner = clk->core->owner; kref_put(&clk->core->ref, __clk_release); clk_prepare_unlock(); module_put(owner); free_clk(clk); } /*** clk rate change notifiers ***/ /** * clk_notifier_register - add a clk rate change notifier * @clk: struct clk * to watch * @nb: struct notifier_block * with callback info * * Request notification when clk's rate changes. This uses an SRCU * notifier because we want it to block and notifier unregistrations are * uncommon. The callbacks associated with the notifier must not * re-enter into the clk framework by calling any top-level clk APIs; * this will cause a nested prepare_lock mutex. * * In all notification cases (pre, post and abort rate change) the original * clock rate is passed to the callback via struct clk_notifier_data.old_rate * and the new frequency is passed via struct clk_notifier_data.new_rate. * * clk_notifier_register() must be called from non-atomic context. * Returns -EINVAL if called with null arguments, -ENOMEM upon * allocation failure; otherwise, passes along the return value of * srcu_notifier_chain_register(). */ int clk_notifier_register(struct clk *clk, struct notifier_block *nb) { struct clk_notifier *cn; int ret = -ENOMEM; if (!clk || !nb) return -EINVAL; clk_prepare_lock(); /* search the list of notifiers for this clk */ list_for_each_entry(cn, &clk_notifier_list, node) if (cn->clk == clk) goto found; /* if clk wasn't in the notifier list, allocate new clk_notifier */ cn = kzalloc(sizeof(*cn), GFP_KERNEL); if (!cn) goto out; cn->clk = clk; srcu_init_notifier_head(&cn->notifier_head); list_add(&cn->node, &clk_notifier_list); found: ret = srcu_notifier_chain_register(&cn->notifier_head, nb); clk->core->notifier_count++; out: clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_notifier_register); /** * clk_notifier_unregister - remove a clk rate change notifier * @clk: struct clk * * @nb: struct notifier_block * with callback info * * Request no further notification for changes to 'clk' and frees memory * allocated in clk_notifier_register. * * Returns -EINVAL if called with null arguments; otherwise, passes * along the return value of srcu_notifier_chain_unregister(). */ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) { struct clk_notifier *cn; int ret = -ENOENT; if (!clk || !nb) return -EINVAL; clk_prepare_lock(); list_for_each_entry(cn, &clk_notifier_list, node) { if (cn->clk == clk) { ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); clk->core->notifier_count--; /* XXX the notifier code should handle this better */ if (!cn->notifier_head.head) { srcu_cleanup_notifier_head(&cn->notifier_head); list_del(&cn->node); kfree(cn); } break; } } clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_notifier_unregister); struct clk_notifier_devres { struct clk *clk; struct notifier_block *nb; }; static void devm_clk_notifier_release(struct device *dev, void *res) { struct clk_notifier_devres *devres = res; clk_notifier_unregister(devres->clk, devres->nb); } int devm_clk_notifier_register(struct device *dev, struct clk *clk, struct notifier_block *nb) { struct clk_notifier_devres *devres; int ret; devres = devres_alloc(devm_clk_notifier_release, sizeof(*devres), GFP_KERNEL); if (!devres) return -ENOMEM; ret = clk_notifier_register(clk, nb); if (!ret) { devres->clk = clk; devres->nb = nb; } else { devres_free(devres); } return ret; } EXPORT_SYMBOL_GPL(devm_clk_notifier_register); #ifdef CONFIG_OF static void clk_core_reparent_orphans(void) { clk_prepare_lock(); clk_core_reparent_orphans_nolock(); clk_prepare_unlock(); } /** * struct of_clk_provider - Clock provider registration structure * @link: Entry in global list of clock providers * @node: Pointer to device tree node of clock provider * @get: Get clock callback. Returns NULL or a struct clk for the * given clock specifier * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a * struct clk_hw for the given clock specifier * @data: context pointer to be passed into @get callback */ struct of_clk_provider { struct list_head link; struct device_node *node; struct clk *(*get)(struct of_phandle_args *clkspec, void *data); struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data); void *data; }; extern struct of_device_id __clk_of_table; static const struct of_device_id __clk_of_table_sentinel __used __section("__clk_of_table_end"); static LIST_HEAD(of_clk_providers); static DEFINE_MUTEX(of_clk_mutex); struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, void *data) { return data; } EXPORT_SYMBOL_GPL(of_clk_src_simple_get); struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data) { return data; } EXPORT_SYMBOL_GPL(of_clk_hw_simple_get); struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) { struct clk_onecell_data *clk_data = data; unsigned int idx = clkspec->args[0]; if (idx >= clk_data->clk_num) { pr_err("%s: invalid clock index %u\n", __func__, idx); return ERR_PTR(-EINVAL); } return clk_data->clks[idx]; } EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); struct clk_hw * of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data) { struct clk_hw_onecell_data *hw_data = data; unsigned int idx = clkspec->args[0]; if (idx >= hw_data->num) { pr_err("%s: invalid index %u\n", __func__, idx); return ERR_PTR(-EINVAL); } return hw_data->hws[idx]; } EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get); /** * of_clk_add_provider() - Register a clock provider for a node * @np: Device node pointer associated with clock provider * @clk_src_get: callback for decoding clock * @data: context pointer for @clk_src_get callback. * * This function is *deprecated*. Use of_clk_add_hw_provider() instead. */ int of_clk_add_provider(struct device_node *np, struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, void *data), void *data) { struct of_clk_provider *cp; int ret; if (!np) return 0; cp = kzalloc(sizeof(*cp), GFP_KERNEL); if (!cp) return -ENOMEM; cp->node = of_node_get(np); cp->data = data; cp->get = clk_src_get; mutex_lock(&of_clk_mutex); list_add(&cp->link, &of_clk_providers); mutex_unlock(&of_clk_mutex); pr_debug("Added clock from %pOF\n", np); clk_core_reparent_orphans(); ret = of_clk_set_defaults(np, true); if (ret < 0) of_clk_del_provider(np); fwnode_dev_initialized(&np->fwnode, true); return ret; } EXPORT_SYMBOL_GPL(of_clk_add_provider); /** * of_clk_add_hw_provider() - Register a clock provider for a node * @np: Device node pointer associated with clock provider * @get: callback for decoding clk_hw * @data: context pointer for @get callback. */ int of_clk_add_hw_provider(struct device_node *np, struct clk_hw *(*get)(struct of_phandle_args *clkspec, void *data), void *data) { struct of_clk_provider *cp; int ret; if (!np) return 0; cp = kzalloc(sizeof(*cp), GFP_KERNEL); if (!cp) return -ENOMEM; cp->node = of_node_get(np); cp->data = data; cp->get_hw = get; mutex_lock(&of_clk_mutex); list_add(&cp->link, &of_clk_providers); mutex_unlock(&of_clk_mutex); pr_debug("Added clk_hw provider from %pOF\n", np); clk_core_reparent_orphans(); ret = of_clk_set_defaults(np, true); if (ret < 0) of_clk_del_provider(np); fwnode_dev_initialized(&np->fwnode, true); return ret; } EXPORT_SYMBOL_GPL(of_clk_add_hw_provider); static void devm_of_clk_release_provider(struct device *dev, void *res) { of_clk_del_provider(*(struct device_node **)res); } /* * We allow a child device to use its parent device as the clock provider node * for cases like MFD sub-devices where the child device driver wants to use * devm_*() APIs but not list the device in DT as a sub-node. */ static struct device_node *get_clk_provider_node(struct device *dev) { struct device_node *np, *parent_np; np = dev->of_node; parent_np = dev->parent ? dev->parent->of_node : NULL; if (!of_find_property(np, "#clock-cells", NULL)) if (of_find_property(parent_np, "#clock-cells", NULL)) np = parent_np; return np; } /** * devm_of_clk_add_hw_provider() - Managed clk provider node registration * @dev: Device acting as the clock provider (used for DT node and lifetime) * @get: callback for decoding clk_hw * @data: context pointer for @get callback * * Registers clock provider for given device's node. If the device has no DT * node or if the device node lacks of clock provider information (#clock-cells) * then the parent device's node is scanned for this information. If parent node * has the #clock-cells then it is used in registration. Provider is * automatically released at device exit. * * Return: 0 on success or an errno on failure. */ int devm_of_clk_add_hw_provider(struct device *dev, struct clk_hw *(*get)(struct of_phandle_args *clkspec, void *data), void *data) { struct device_node **ptr, *np; int ret; ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr), GFP_KERNEL); if (!ptr) return -ENOMEM; np = get_clk_provider_node(dev); ret = of_clk_add_hw_provider(np, get, data); if (!ret) { *ptr = np; devres_add(dev, ptr); } else { devres_free(ptr); } return ret; } EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider); /** * of_clk_del_provider() - Remove a previously registered clock provider * @np: Device node pointer associated with clock provider */ void of_clk_del_provider(struct device_node *np) { struct of_clk_provider *cp; if (!np) return; mutex_lock(&of_clk_mutex); list_for_each_entry(cp, &of_clk_providers, link) { if (cp->node == np) { list_del(&cp->link); fwnode_dev_initialized(&np->fwnode, false); of_node_put(cp->node); kfree(cp); break; } } mutex_unlock(&of_clk_mutex); } EXPORT_SYMBOL_GPL(of_clk_del_provider); static int devm_clk_provider_match(struct device *dev, void *res, void *data) { struct device_node **np = res; if (WARN_ON(!np || !*np)) return 0; return *np == data; } /** * devm_of_clk_del_provider() - Remove clock provider registered using devm * @dev: Device to whose lifetime the clock provider was bound */ void devm_of_clk_del_provider(struct device *dev) { int ret; struct device_node *np = get_clk_provider_node(dev); ret = devres_release(dev, devm_of_clk_release_provider, devm_clk_provider_match, np); WARN_ON(ret); } EXPORT_SYMBOL(devm_of_clk_del_provider); /** * of_parse_clkspec() - Parse a DT clock specifier for a given device node * @np: device node to parse clock specifier from * @index: index of phandle to parse clock out of. If index < 0, @name is used * @name: clock name to find and parse. If name is NULL, the index is used * @out_args: Result of parsing the clock specifier * * Parses a device node's "clocks" and "clock-names" properties to find the * phandle and cells for the index or name that is desired. The resulting clock * specifier is placed into @out_args, or an errno is returned when there's a * parsing error. The @index argument is ignored if @name is non-NULL. * * Example: * * phandle1: clock-controller@1 { * #clock-cells = <2>; * } * * phandle2: clock-controller@2 { * #clock-cells = <1>; * } * * clock-consumer@3 { * clocks = <&phandle1 1 2 &phandle2 3>; * clock-names = "name1", "name2"; * } * * To get a device_node for `clock-controller@2' node you may call this * function a few different ways: * * of_parse_clkspec(clock-consumer@3, -1, "name2", &args); * of_parse_clkspec(clock-consumer@3, 1, NULL, &args); * of_parse_clkspec(clock-consumer@3, 1, "name2", &args); * * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in * the "clock-names" property of @np. */ static int of_parse_clkspec(const struct device_node *np, int index, const char *name, struct of_phandle_args *out_args) { int ret = -ENOENT; /* Walk up the tree of devices looking for a clock property that matches */ while (np) { /* * For named clocks, first look up the name in the * "clock-names" property. If it cannot be found, then index * will be an error code and of_parse_phandle_with_args() will * return -EINVAL. */ if (name) index = of_property_match_string(np, "clock-names", name); ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, out_args); if (!ret) break; if (name && index >= 0) break; /* * No matching clock found on this node. If the parent node * has a "clock-ranges" property, then we can try one of its * clocks. */ np = np->parent; if (np && !of_get_property(np, "clock-ranges", NULL)) break; index = 0; } return ret; } static struct clk_hw * __of_clk_get_hw_from_provider(struct of_clk_provider *provider, struct of_phandle_args *clkspec) { struct clk *clk; if (provider->get_hw) return provider->get_hw(clkspec, provider->data); clk = provider->get(clkspec, provider->data); if (IS_ERR(clk)) return ERR_CAST(clk); return __clk_get_hw(clk); } static struct clk_hw * of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) { struct of_clk_provider *provider; struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER); if (!clkspec) return ERR_PTR(-EINVAL); mutex_lock(&of_clk_mutex); list_for_each_entry(provider, &of_clk_providers, link) { if (provider->node == clkspec->np) { hw = __of_clk_get_hw_from_provider(provider, clkspec); if (!IS_ERR(hw)) break; } } mutex_unlock(&of_clk_mutex); return hw; } /** * of_clk_get_from_provider() - Lookup a clock from a clock provider * @clkspec: pointer to a clock specifier data structure * * This function looks up a struct clk from the registered list of clock * providers, an input is a clock specifier data structure as returned * from the of_parse_phandle_with_args() function call. */ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) { struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec); return clk_hw_create_clk(NULL, hw, NULL, __func__); } EXPORT_SYMBOL_GPL(of_clk_get_from_provider); struct clk_hw *of_clk_get_hw(struct device_node *np, int index, const char *con_id) { int ret; struct clk_hw *hw; struct of_phandle_args clkspec; ret = of_parse_clkspec(np, index, con_id, &clkspec); if (ret) return ERR_PTR(ret); hw = of_clk_get_hw_from_clkspec(&clkspec); of_node_put(clkspec.np); return hw; } static struct clk *__of_clk_get(struct device_node *np, int index, const char *dev_id, const char *con_id) { struct clk_hw *hw = of_clk_get_hw(np, index, con_id); return clk_hw_create_clk(NULL, hw, dev_id, con_id); } struct clk *of_clk_get(struct device_node *np, int index) { return __of_clk_get(np, index, np->full_name, NULL); } EXPORT_SYMBOL(of_clk_get); /** * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node * @np: pointer to clock consumer node * @name: name of consumer's clock input, or NULL for the first clock reference * * This function parses the clocks and clock-names properties, * and uses them to look up the struct clk from the registered list of clock * providers. */ struct clk *of_clk_get_by_name(struct device_node *np, const char *name) { if (!np) return ERR_PTR(-ENOENT); return __of_clk_get(np, 0, np->full_name, name); } EXPORT_SYMBOL(of_clk_get_by_name); /** * of_clk_get_parent_count() - Count the number of clocks a device node has * @np: device node to count * * Returns: The number of clocks that are possible parents of this node */ unsigned int of_clk_get_parent_count(const struct device_node *np) { int count; count = of_count_phandle_with_args(np, "clocks", "#clock-cells"); if (count < 0) return 0; return count; } EXPORT_SYMBOL_GPL(of_clk_get_parent_count); const char *of_clk_get_parent_name(const struct device_node *np, int index) { struct of_phandle_args clkspec; struct property *prop; const char *clk_name; const __be32 *vp; u32 pv; int rc; int count; struct clk *clk; rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, &clkspec); if (rc) return NULL; index = clkspec.args_count ? clkspec.args[0] : 0; count = 0; /* if there is an indices property, use it to transfer the index * specified into an array offset for the clock-output-names property. */ of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { if (index == pv) { index = count; break; } count++; } /* We went off the end of 'clock-indices' without finding it */ if (prop && !vp) return NULL; if (of_property_read_string_index(clkspec.np, "clock-output-names", index, &clk_name) < 0) { /* * Best effort to get the name if the clock has been * registered with the framework. If the clock isn't * registered, we return the node name as the name of * the clock as long as #clock-cells = 0. */ clk = of_clk_get_from_provider(&clkspec); if (IS_ERR(clk)) { if (clkspec.args_count == 0) clk_name = clkspec.np->name; else clk_name = NULL; } else { clk_name = __clk_get_name(clk); clk_put(clk); } } of_node_put(clkspec.np); return clk_name; } EXPORT_SYMBOL_GPL(of_clk_get_parent_name); /** * of_clk_parent_fill() - Fill @parents with names of @np's parents and return * number of parents * @np: Device node pointer associated with clock provider * @parents: pointer to char array that hold the parents' names * @size: size of the @parents array * * Return: number of parents for the clock node. */ int of_clk_parent_fill(struct device_node *np, const char **parents, unsigned int size) { unsigned int i = 0; while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL) i++; return i; } EXPORT_SYMBOL_GPL(of_clk_parent_fill); struct clock_provider { void (*clk_init_cb)(struct device_node *); struct device_node *np; struct list_head node; }; /* * This function looks for a parent clock. If there is one, then it * checks that the provider for this parent clock was initialized, in * this case the parent clock will be ready. */ static int parent_ready(struct device_node *np) { int i = 0; while (true) { struct clk *clk = of_clk_get(np, i); /* this parent is ready we can check the next one */ if (!IS_ERR(clk)) { clk_put(clk); i++; continue; } /* at least one parent is not ready, we exit now */ if (PTR_ERR(clk) == -EPROBE_DEFER) return 0; /* * Here we make assumption that the device tree is * written correctly. So an error means that there is * no more parent. As we didn't exit yet, then the * previous parent are ready. If there is no clock * parent, no need to wait for them, then we can * consider their absence as being ready */ return 1; } } /** * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree * @np: Device node pointer associated with clock provider * @index: clock index * @flags: pointer to top-level framework flags * * Detects if the clock-critical property exists and, if so, sets the * corresponding CLK_IS_CRITICAL flag. * * Do not use this function. It exists only for legacy Device Tree * bindings, such as the one-clock-per-node style that are outdated. * Those bindings typically put all clock data into .dts and the Linux * driver has no clock data, thus making it impossible to set this flag * correctly from the driver. Only those drivers may call * of_clk_detect_critical from their setup functions. * * Return: error code or zero on success */ int of_clk_detect_critical(struct device_node *np, int index, unsigned long *flags) { struct property *prop; const __be32 *cur; uint32_t idx; if (!np || !flags) return -EINVAL; of_property_for_each_u32(np, "clock-critical", prop, cur, idx) if (index == idx) *flags |= CLK_IS_CRITICAL; return 0; } /** * of_clk_init() - Scan and init clock providers from the DT * @matches: array of compatible values and init functions for providers. * * This function scans the device tree for matching clock providers * and calls their initialization functions. It also does it by trying * to follow the dependencies. */ void __init of_clk_init(const struct of_device_id *matches) { const struct of_device_id *match; struct device_node *np; struct clock_provider *clk_provider, *next; bool is_init_done; bool force = false; LIST_HEAD(clk_provider_list); if (!matches) matches = &__clk_of_table; /* First prepare the list of the clocks providers */ for_each_matching_node_and_match(np, matches, &match) { struct clock_provider *parent; if (!of_device_is_available(np)) continue; parent = kzalloc(sizeof(*parent), GFP_KERNEL); if (!parent) { list_for_each_entry_safe(clk_provider, next, &clk_provider_list, node) { list_del(&clk_provider->node); of_node_put(clk_provider->np); kfree(clk_provider); } of_node_put(np); return; } parent->clk_init_cb = match->data; parent->np = of_node_get(np); list_add_tail(&parent->node, &clk_provider_list); } while (!list_empty(&clk_provider_list)) { is_init_done = false; list_for_each_entry_safe(clk_provider, next, &clk_provider_list, node) { if (force || parent_ready(clk_provider->np)) { /* Don't populate platform devices */ of_node_set_flag(clk_provider->np, OF_POPULATED); clk_provider->clk_init_cb(clk_provider->np); of_clk_set_defaults(clk_provider->np, true); list_del(&clk_provider->node); of_node_put(clk_provider->np); kfree(clk_provider); is_init_done = true; } } /* * We didn't manage to initialize any of the * remaining providers during the last loop, so now we * initialize all the remaining ones unconditionally * in case the clock parent was not mandatory */ if (!is_init_done) force = true; } } #endif
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