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Release 4.14 drivers/reset/core.c

Directory: drivers/reset
/*
 * Reset Controller framework
 *
 * Copyright 2013 Philipp Zabel, Pengutronix
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/atomic.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/reset.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>

static DEFINE_MUTEX(reset_list_mutex);
static LIST_HEAD(reset_controller_list);

/**
 * struct reset_control - a reset control
 * @rcdev: a pointer to the reset controller device
 *         this reset control belongs to
 * @list: list entry for the rcdev's reset controller list
 * @id: ID of the reset controller in the reset
 *      controller device
 * @refcnt: Number of gets of this reset_control
 * @shared: Is this a shared (1), or an exclusive (0) reset_control?
 * @deassert_cnt: Number of times this reset line has been deasserted
 * @triggered_count: Number of times this reset line has been reset. Currently
 *                   only used for shared resets, which means that the value
 *                   will be either 0 or 1.
 */

struct reset_control {
	
struct reset_controller_dev *rcdev;
	
struct list_head list;
	
unsigned int id;
	
struct kref refcnt;
	
bool shared;
	
bool array;
	
atomic_t deassert_count;
	
atomic_t triggered_count;
};

/**
 * struct reset_control_array - an array of reset controls
 * @base: reset control for compatibility with reset control API functions
 * @num_rstcs: number of reset controls
 * @rstc: array of reset controls
 */

struct reset_control_array {
	
struct reset_control base;
	
unsigned int num_rstcs;
	
struct reset_control *rstc[];
};

/**
 * of_reset_simple_xlate - translate reset_spec to the reset line number
 * @rcdev: a pointer to the reset controller device
 * @reset_spec: reset line specifier as found in the device tree
 * @flags: a flags pointer to fill in (optional)
 *
 * This simple translation function should be used for reset controllers
 * with 1:1 mapping, where reset lines can be indexed by number without gaps.
 */

static int of_reset_simple_xlate(struct reset_controller_dev *rcdev, const struct of_phandle_args *reset_spec) { if (reset_spec->args[0] >= rcdev->nr_resets) return -EINVAL; return reset_spec->args[0]; }

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Philipp Zabel4197.62%150.00%
Rashika Kheria12.38%150.00%
Total42100.00%2100.00%

/** * reset_controller_register - register a reset controller device * @rcdev: a pointer to the initialized reset controller device */
int reset_controller_register(struct reset_controller_dev *rcdev) { if (!rcdev->of_xlate) { rcdev->of_reset_n_cells = 1; rcdev->of_xlate = of_reset_simple_xlate; } INIT_LIST_HEAD(&rcdev->reset_control_head); mutex_lock(&reset_list_mutex); list_add(&rcdev->list, &reset_controller_list); mutex_unlock(&reset_list_mutex); return 0; }

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Philipp Zabel5584.62%150.00%
Hans de Goede1015.38%150.00%
Total65100.00%2100.00%

EXPORT_SYMBOL_GPL(reset_controller_register); /** * reset_controller_unregister - unregister a reset controller device * @rcdev: a pointer to the reset controller device */
void reset_controller_unregister(struct reset_controller_dev *rcdev) { mutex_lock(&reset_list_mutex); list_del(&rcdev->list); mutex_unlock(&reset_list_mutex); }

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Philipp Zabel2893.33%150.00%
Hans de Goede26.67%150.00%
Total30100.00%2100.00%

EXPORT_SYMBOL_GPL(reset_controller_unregister);
static void devm_reset_controller_release(struct device *dev, void *res) { reset_controller_unregister(*(struct reset_controller_dev **)res); }

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Masahiro Yamada27100.00%1100.00%
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/** * devm_reset_controller_register - resource managed reset_controller_register() * @dev: device that is registering this reset controller * @rcdev: a pointer to the initialized reset controller device * * Managed reset_controller_register(). For reset controllers registered by * this function, reset_controller_unregister() is automatically called on * driver detach. See reset_controller_register() for more information. */
int devm_reset_controller_register(struct device *dev, struct reset_controller_dev *rcdev) { struct reset_controller_dev **rcdevp; int ret; rcdevp = devres_alloc(devm_reset_controller_release, sizeof(*rcdevp), GFP_KERNEL); if (!rcdevp) return -ENOMEM; ret = reset_controller_register(rcdev); if (!ret) { *rcdevp = rcdev; devres_add(dev, rcdevp); } else { devres_free(rcdevp); } return ret; }

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Masahiro Yamada85100.00%1100.00%
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EXPORT_SYMBOL_GPL(devm_reset_controller_register);
static inline struct reset_control_array * rstc_to_array(struct reset_control *rstc) { return container_of(rstc, struct reset_control_array, base); }

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Vivek Gautam25100.00%1100.00%
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static int reset_control_array_reset(struct reset_control_array *resets) { int ret, i; for (i = 0; i < resets->num_rstcs; i++) { ret = reset_control_reset(resets->rstc[i]); if (ret) return ret; } return 0; }

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Vivek Gautam55100.00%1100.00%
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static int reset_control_array_assert(struct reset_control_array *resets) { int ret, i; for (i = 0; i < resets->num_rstcs; i++) { ret = reset_control_assert(resets->rstc[i]); if (ret) goto err; } return 0; err: while (i--) reset_control_deassert(resets->rstc[i]); return ret; }

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Vivek Gautam75100.00%1100.00%
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static int reset_control_array_deassert(struct reset_control_array *resets) { int ret, i; for (i = 0; i < resets->num_rstcs; i++) { ret = reset_control_deassert(resets->rstc[i]); if (ret) goto err; } return 0; err: while (i--) reset_control_assert(resets->rstc[i]); return ret; }

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Vivek Gautam75100.00%1100.00%
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static inline bool reset_control_is_array(struct reset_control *rstc) { return rstc->array; }

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Vivek Gautam17100.00%1100.00%
Total17100.00%1100.00%

/** * reset_control_reset - reset the controlled device * @rstc: reset controller * * On a shared reset line the actual reset pulse is only triggered once for the * lifetime of the reset_control instance: for all but the first caller this is * a no-op. * Consumers must not use reset_control_(de)assert on shared reset lines when * reset_control_reset has been used. * * If rstc is NULL it is an optional reset and the function will just * return 0. */
int reset_control_reset(struct reset_control *rstc) { int ret; if (!rstc) return 0; if (WARN_ON(IS_ERR(rstc))) return -EINVAL; if (reset_control_is_array(rstc)) return reset_control_array_reset(rstc_to_array(rstc)); if (!rstc->rcdev->ops->reset) return -ENOTSUPP; if (rstc->shared) { if (WARN_ON(atomic_read(&rstc->deassert_count) != 0)) return -EINVAL; if (atomic_inc_return(&rstc->triggered_count) != 1) return 0; } ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id); if (rstc->shared && ret) atomic_dec(&rstc->triggered_count); return ret; }

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Martin Blumenstingl6947.26%116.67%
Philipp Zabel4329.45%233.33%
Vivek Gautam1610.96%116.67%
Ramiro Oliveira96.16%116.67%
Hans de Goede96.16%116.67%
Total146100.00%6100.00%

EXPORT_SYMBOL_GPL(reset_control_reset); /** * reset_control_assert - asserts the reset line * @rstc: reset controller * * Calling this on an exclusive reset controller guarantees that the reset * will be asserted. When called on a shared reset controller the line may * still be deasserted, as long as other users keep it so. * * For shared reset controls a driver cannot expect the hw's registers and * internal state to be reset, but must be prepared for this to happen. * Consumers must not use reset_control_reset on shared reset lines when * reset_control_(de)assert has been used. * return 0. * * If rstc is NULL it is an optional reset and the function will just * return 0. */
int reset_control_assert(struct reset_control *rstc) { if (!rstc) return 0; if (WARN_ON(IS_ERR(rstc))) return -EINVAL; if (reset_control_is_array(rstc)) return reset_control_array_assert(rstc_to_array(rstc)); if (rstc->shared) { if (WARN_ON(atomic_read(&rstc->triggered_count) != 0)) return -EINVAL; if (WARN_ON(atomic_read(&rstc->deassert_count) == 0)) return -EINVAL; if (atomic_dec_return(&rstc->deassert_count) != 0) return 0; /* * Shared reset controls allow the reset line to be in any state * after this call, so doing nothing is a valid option. */ if (!rstc->rcdev->ops->assert) return 0; } else { /* * If the reset controller does not implement .assert(), there * is no way to guarantee that the reset line is asserted after * this call. */ if (!rstc->rcdev->ops->assert) return -ENOTSUPP; } return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id); }

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Philipp Zabel7647.20%342.86%
Hans de Goede4125.47%114.29%
Martin Blumenstingl1911.80%114.29%
Vivek Gautam169.94%114.29%
Ramiro Oliveira95.59%114.29%
Total161100.00%7100.00%

EXPORT_SYMBOL_GPL(reset_control_assert); /** * reset_control_deassert - deasserts the reset line * @rstc: reset controller * * After calling this function, the reset is guaranteed to be deasserted. * Consumers must not use reset_control_reset on shared reset lines when * reset_control_(de)assert has been used. * return 0. * * If rstc is NULL it is an optional reset and the function will just * return 0. */
int reset_control_deassert(struct reset_control *rstc) { if (!rstc) return 0; if (WARN_ON(IS_ERR(rstc))) return -EINVAL; if (reset_control_is_array(rstc)) return reset_control_array_deassert(rstc_to_array(rstc)); if (rstc->shared) { if (WARN_ON(atomic_read(&rstc->triggered_count) != 0)) return -EINVAL; if (atomic_inc_return(&rstc->deassert_count) != 1) return 0; } /* * If the reset controller does not implement .deassert(), we assume * that it handles self-deasserting reset lines via .reset(). In that * case, the reset lines are deasserted by default. If that is not the * case, the reset controller driver should implement .deassert() and * return -ENOTSUPP. */ if (!rstc->rcdev->ops->deassert) return 0; return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id); }

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Philipp Zabel5746.34%342.86%
Hans de Goede2217.89%114.29%
Martin Blumenstingl1915.45%114.29%
Vivek Gautam1613.01%114.29%
Ramiro Oliveira97.32%114.29%
Total123100.00%7100.00%

EXPORT_SYMBOL_GPL(reset_control_deassert); /** * reset_control_status - returns a negative errno if not supported, a * positive value if the reset line is asserted, or zero if the reset * line is not asserted or if the desc is NULL (optional reset). * @rstc: reset controller */
int reset_control_status(struct reset_control *rstc) { if (!rstc) return 0; if (WARN_ON(IS_ERR(rstc)) || reset_control_is_array(rstc)) return -EINVAL; if (rstc->rcdev->ops->status) return rstc->rcdev->ops->status(rstc->rcdev, rstc->id); return -ENOTSUPP; }

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Dinh Nguyen4159.42%120.00%
Philipp Zabel1420.29%240.00%
Ramiro Oliveira913.04%120.00%
Vivek Gautam57.25%120.00%
Total69100.00%5100.00%

EXPORT_SYMBOL_GPL(reset_control_status);
static struct reset_control *__reset_control_get_internal( struct reset_controller_dev *rcdev, unsigned int index, bool shared) { struct reset_control *rstc; lockdep_assert_held(&reset_list_mutex); list_for_each_entry(rstc, &rcdev->reset_control_head, list) { if (rstc->id == index) { if (WARN_ON(!rstc->shared || !shared)) return ERR_PTR(-EBUSY); kref_get(&rstc->refcnt); return rstc; } } rstc = kzalloc(sizeof(*rstc), GFP_KERNEL); if (!rstc) return ERR_PTR(-ENOMEM); try_module_get(rcdev->owner); rstc->rcdev = rcdev; list_add(&rstc->list, &rcdev->reset_control_head); rstc->id = index; kref_init(&rstc->refcnt); rstc->shared = shared; return rstc; }

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Hans de Goede14693.59%240.00%
Philipp Zabel95.77%240.00%
Ramiro Oliveira10.64%120.00%
Total156100.00%5100.00%


static void __reset_control_release(struct kref *kref) { struct reset_control *rstc = container_of(kref, struct reset_control, refcnt); lockdep_assert_held(&reset_list_mutex); module_put(rstc->rcdev->owner); list_del(&rstc->list); kfree(rstc); }

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Hans de Goede3666.67%150.00%
Philipp Zabel1833.33%150.00%
Total54100.00%2100.00%


static void __reset_control_put_internal(struct reset_control *rstc) { lockdep_assert_held(&reset_list_mutex); kref_put(&rstc->refcnt, __reset_control_release); }

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Philipp Zabel27100.00%1100.00%
Total27100.00%1100.00%


struct reset_control *__of_reset_control_get(struct device_node *node, const char *id, int index, bool shared, bool optional) { struct reset_control *rstc; struct reset_controller_dev *r, *rcdev; struct of_phandle_args args; int rstc_id; int ret; if (!node) return ERR_PTR(-EINVAL); if (id) { index = of_property_match_string(node, "reset-names", id); if (index == -EILSEQ) return ERR_PTR(index); if (index < 0) return optional ? NULL : ERR_PTR(-ENOENT); } ret = of_parse_phandle_with_args(node, "resets", "#reset-cells", index, &args); if (ret == -EINVAL) return ERR_PTR(ret); if (ret) return optional ? NULL : ERR_PTR(ret); mutex_lock(&reset_list_mutex); rcdev = NULL; list_for_each_entry(r, &reset_controller_list, list) { if (args.np == r->of_node) { rcdev = r; break; } } of_node_put(args.np); if (!rcdev) { mutex_unlock(&reset_list_mutex); return ERR_PTR(-EPROBE_DEFER); } if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) { mutex_unlock(&reset_list_mutex); return ERR_PTR(-EINVAL); } rstc_id = rcdev->of_xlate(rcdev, &args); if (rstc_id < 0) { mutex_unlock(&reset_list_mutex); return ERR_PTR(rstc_id); } /* reset_list_mutex also protects the rcdev's reset_control list */ rstc = __reset_control_get_internal(rcdev, rstc_id, shared); mutex_unlock(&reset_list_mutex); return rstc; }

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Philipp Zabel16054.05%327.27%
Hans de Goede6220.95%327.27%
Ramiro Oliveira3812.84%218.18%
Maxime Ripard3411.49%218.18%
Vince Hsu20.68%19.09%
Total296100.00%11100.00%

EXPORT_SYMBOL_GPL(__of_reset_control_get);
struct reset_control *__reset_control_get(struct device *dev, const char *id, int index, bool shared, bool optional) { if (dev->of_node) return __of_reset_control_get(dev->of_node, id, index, shared, optional); return optional ? NULL : ERR_PTR(-EINVAL); }

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Philipp Zabel59100.00%1100.00%
Total59100.00%1100.00%

EXPORT_SYMBOL_GPL(__reset_control_get);
static void reset_control_array_put(struct reset_control_array *resets) { int i; mutex_lock(&reset_list_mutex); for (i = 0; i < resets->num_rstcs; i++) __reset_control_put_internal(resets->rstc[i]); mutex_unlock(&reset_list_mutex); }

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Vivek Gautam5098.04%150.00%
Philipp Zabel11.96%150.00%
Total51100.00%2100.00%

/** * reset_control_put - free the reset controller * @rstc: reset controller */
void reset_control_put(struct reset_control *rstc) { if (IS_ERR_OR_NULL(rstc)) return; if (reset_control_is_array(rstc)) { reset_control_array_put(rstc_to_array(rstc)); return; } mutex_lock(&reset_list_mutex); __reset_control_put_internal(rstc); mutex_unlock(&reset_list_mutex); }

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Philipp Zabel2343.40%240.00%
Vivek Gautam2037.74%120.00%
Hans de Goede916.98%120.00%
Heiner Kallweit11.89%120.00%
Total53100.00%5100.00%

EXPORT_SYMBOL_GPL(reset_control_put);
static void devm_reset_control_release(struct device *dev, void *res) { reset_control_put(*(struct reset_control **)res); }

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Philipp Zabel27100.00%1100.00%
Total27100.00%1100.00%


struct reset_control *__devm_reset_control_get(struct device *dev, const char *id, int index, bool shared, bool optional) { struct reset_control **ptr, *rstc; ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr), GFP_KERNEL); if (!ptr) return ERR_PTR(-ENOMEM); rstc = __reset_control_get(dev, id, index, shared, optional); if (!IS_ERR(rstc)) { *ptr = rstc; devres_add(dev, ptr); } else { devres_free(ptr); } return rstc; }

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Philipp Zabel9485.45%233.33%
Hans de Goede109.09%233.33%
Ramiro Oliveira65.45%233.33%
Total110100.00%6100.00%

EXPORT_SYMBOL_GPL(__devm_reset_control_get); /** * device_reset - find reset controller associated with the device * and perform reset * @dev: device to be reset by the controller * * Convenience wrapper for reset_control_get() and reset_control_reset(). * This is useful for the common case of devices with single, dedicated reset * lines. */
int device_reset(struct device *dev) { struct reset_control *rstc; int ret; rstc = reset_control_get(dev, NULL); if (IS_ERR(rstc)) return PTR_ERR(rstc); ret = reset_control_reset(rstc); reset_control_put(rstc); return ret; }

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Philipp Zabel55100.00%1100.00%
Total55100.00%1100.00%

EXPORT_SYMBOL_GPL(device_reset); /** * APIs to manage an array of reset controls. */ /** * of_reset_control_get_count - Count number of resets available with a device * * @node: device node that contains 'resets'. * * Returns positive reset count on success, or error number on failure and * on count being zero. */
static int of_reset_control_get_count(struct device_node *node) { int count; if (!node) return -EINVAL; count = of_count_phandle_with_args(node, "resets", "#reset-cells"); if (count == 0) count = -ENOENT; return count; }

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Vivek Gautam48100.00%1100.00%
Total48100.00%1100.00%

/** * of_reset_control_array_get - Get a list of reset controls using * device node. * * @np: device node for the device that requests the reset controls array * @shared: whether reset controls are shared or not * @optional: whether it is optional to get the reset controls * * Returns pointer to allocated reset_control_array on success or * error on failure */
struct reset_control * of_reset_control_array_get(struct device_node *np, bool shared, bool optional) { struct reset_control_array *resets; struct reset_control *rstc; int num, i; num = of_reset_control_get_count(np); if (num < 0) return optional ? NULL : ERR_PTR(num); resets = kzalloc(sizeof(*resets) + sizeof(resets->rstc[0]) * num, GFP_KERNEL); if (!resets) return ERR_PTR(-ENOMEM); for (i = 0; i < num; i++) { rstc = __of_reset_control_get(np, NULL, i, shared, optional); if (IS_ERR(rstc)) goto err_rst; resets->rstc[i] = rstc; } resets->num_rstcs = num; resets->base.array = true; return &resets->base; err_rst: mutex_lock(&reset_list_mutex); while (--i >= 0) __reset_control_put_internal(resets->rstc[i]); mutex_unlock(&reset_list_mutex); kfree(resets); return rstc; }

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Vivek Gautam201100.00%1100.00%
Total201100.00%1100.00%

EXPORT_SYMBOL_GPL(of_reset_control_array_get); /** * devm_reset_control_array_get - Resource managed reset control array get * * @dev: device that requests the list of reset controls * @shared: whether reset controls are shared or not * @optional: whether it is optional to get the reset controls * * The reset control array APIs are intended for a list of resets * that just have to be asserted or deasserted, without any * requirements on the order. * * Returns pointer to allocated reset_control_array on success or * error on failure */
struct reset_control * devm_reset_control_array_get(struct device *dev, bool shared, bool optional) { struct reset_control **devres; struct reset_control *rstc; devres = devres_alloc(devm_reset_control_release, sizeof(*devres), GFP_KERNEL); if (!devres) return ERR_PTR(-ENOMEM); rstc = of_reset_control_array_get(dev->of_node, shared, optional); if (IS_ERR(rstc)) { devres_free(devres); return rstc; } *devres = rstc; devres_add(dev, devres); return rstc; }

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Vivek Gautam101100.00%1100.00%
Total101100.00%1100.00%

EXPORT_SYMBOL_GPL(devm_reset_control_array_get);

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Philipp Zabel89537.01%733.33%
Vivek Gautam75831.35%14.76%
Hans de Goede36415.05%314.29%
Masahiro Yamada1184.88%14.76%
Martin Blumenstingl1114.59%14.76%
Ramiro Oliveira863.56%29.52%
Dinh Nguyen461.90%14.76%
Maxime Ripard361.49%29.52%
Vince Hsu20.08%14.76%
Rashika Kheria10.04%14.76%
Heiner Kallweit10.04%14.76%
Total2418100.00%21100.00%
Directory: drivers/reset
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