cregit-Linux how code gets into the kernel

Release 4.7 drivers/clk/tegra/clk-super.c

/*
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/clk-provider.h>

#include "clk.h"


#define SUPER_STATE_IDLE 0

#define SUPER_STATE_RUN 1

#define SUPER_STATE_IRQ 2

#define SUPER_STATE_FIQ 3


#define SUPER_STATE_SHIFT 28

#define SUPER_STATE_MASK ((BIT(SUPER_STATE_IDLE) | BIT(SUPER_STATE_RUN) | \
                           BIT(SUPER_STATE_IRQ) | BIT(SUPER_STATE_FIQ)) \
                          << SUPER_STATE_SHIFT)


#define SUPER_LP_DIV2_BYPASS (1 << 16)


#define super_state(s) (BIT(s) << SUPER_STATE_SHIFT)

#define super_state_to_src_shift(m, s) ((m->width * s))

#define super_state_to_src_mask(m) (((1 << m->width) - 1))


static u8 clk_super_get_parent(struct clk_hw *hw) { struct tegra_clk_super_mux *mux = to_clk_super_mux(hw); u32 val, state; u8 source, shift; val = readl_relaxed(mux->reg); state = val & SUPER_STATE_MASK; BUG_ON((state != super_state(SUPER_STATE_RUN)) && (state != super_state(SUPER_STATE_IDLE))); shift = (state == super_state(SUPER_STATE_IDLE)) ? super_state_to_src_shift(mux, SUPER_STATE_IDLE) : super_state_to_src_shift(mux, SUPER_STATE_RUN); source = (val >> shift) & super_state_to_src_mask(mux); /* * If LP_DIV2_BYPASS is not set and PLLX is current parent then * PLLX/2 is the input source to CCLKLP. */ if ((mux->flags & TEGRA_DIVIDER_2) && !(val & SUPER_LP_DIV2_BYPASS) && (source == mux->pllx_index)) source = mux->div2_index; return source; }

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static int clk_super_set_parent(struct clk_hw *hw, u8 index) { struct tegra_clk_super_mux *mux = to_clk_super_mux(hw); u32 val, state; int err = 0; u8 parent_index, shift; unsigned long flags = 0; if (mux->lock) spin_lock_irqsave(mux->lock, flags); val = readl_relaxed(mux->reg); state = val & SUPER_STATE_MASK; BUG_ON((state != super_state(SUPER_STATE_RUN)) && (state != super_state(SUPER_STATE_IDLE))); shift = (state == super_state(SUPER_STATE_IDLE)) ? super_state_to_src_shift(mux, SUPER_STATE_IDLE) : super_state_to_src_shift(mux, SUPER_STATE_RUN); /* * For LP mode super-clock switch between PLLX direct * and divided-by-2 outputs is allowed only when other * than PLLX clock source is current parent. */ if ((mux->flags & TEGRA_DIVIDER_2) && ((index == mux->div2_index) || (index == mux->pllx_index))) { parent_index = clk_super_get_parent(hw); if ((parent_index == mux->div2_index) || (parent_index == mux->pllx_index)) { err = -EINVAL; goto out; } val ^= SUPER_LP_DIV2_BYPASS; writel_relaxed(val, mux->reg); udelay(2); if (index == mux->div2_index) index = mux->pllx_index; } val &= ~((super_state_to_src_mask(mux)) << shift); val |= (index & (super_state_to_src_mask(mux))) << shift; writel_relaxed(val, mux->reg); udelay(2); out: if (mux->lock) spin_unlock_irqrestore(mux->lock, flags); return err; }

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const struct clk_ops tegra_clk_super_ops = { .get_parent = clk_super_get_parent, .set_parent = clk_super_set_parent, };
struct clk *tegra_clk_register_super_mux(const char *name, const char **parent_names, u8 num_parents, unsigned long flags, void __iomem *reg, u8 clk_super_flags, u8 width, u8 pllx_index, u8 div2_index, spinlock_t *lock) { struct tegra_clk_super_mux *super; struct clk *clk; struct clk_init_data init; super = kzalloc(sizeof(*super), GFP_KERNEL); if (!super) { pr_err("%s: could not allocate super clk\n", __func__); return ERR_PTR(-ENOMEM); } init.name = name; init.ops = &tegra_clk_super_ops; init.flags = flags; init.parent_names = parent_names; init.num_parents = num_parents; super->reg = reg; super->pllx_index = pllx_index; super->div2_index = div2_index; super->lock = lock; super->width = width; super->flags = clk_super_flags; /* Data in .init is copied by clk_register(), so stack variable OK */ super->hw.init = &init; clk = clk_register(NULL, &super->hw); if (IS_ERR(clk)) kfree(super); return clk; }

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Total710100.00%2100.00%
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