arch/arm/mach-msm/clock.c - kernel/msm - Gitiles

 /* arch/arm/mach-msm/clock.c
  *
  * Copyright (C) 2007 Google, Inc.
  * Copyright (c) 2007-2011, Code Aurora Forum. All rights reserved.
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that 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.
  *
  */

 #include <linux/kernel.h>
 #include <linux/err.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/module.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>

 #include "clock.h"

 /* Find the voltage level required for a given rate. */
 static int find_vdd_level(struct clk *clk, unsigned long rate)
 {
 	int level;

 	for (level = 0; level < ARRAY_SIZE(clk->fmax); level++)
 		if (rate <= clk->fmax[level])
 			break;

 	if (level == ARRAY_SIZE(clk->fmax)) {
 		pr_err("Rate %lu for %s is greater than highest Fmax\n", rate,
 			clk->dbg_name);
 		return -EINVAL;
 	}

 	return level;
 }

 /* Update voltage level given the current votes. */
 static int update_vdd(struct clk_vdd_class *vdd_class)
 {
 	int level, rc;

 	for (level = ARRAY_SIZE(vdd_class->level_votes)-1; level > 0; level--)
 		if (vdd_class->level_votes[level])
 			break;

 	if (level == vdd_class->cur_level)
 		return 0;

 	rc = vdd_class->set_vdd(vdd_class, level);
 	if (!rc)
 		vdd_class->cur_level = level;

 	return rc;
 }

 /* Vote for a voltage level. */
 int vote_vdd_level(struct clk_vdd_class *vdd_class, int level)
 {
 	unsigned long flags;
 	int rc;

 	spin_lock_irqsave(&vdd_class->lock, flags);
 	vdd_class->level_votes[level]++;
 	rc = update_vdd(vdd_class);
 	if (rc)
 		vdd_class->level_votes[level]--;
 	spin_unlock_irqrestore(&vdd_class->lock, flags);

 	return rc;
 }

 /* Remove vote for a voltage level. */
 int unvote_vdd_level(struct clk_vdd_class *vdd_class, int level)
 {
 	unsigned long flags;
 	int rc = 0;

 	spin_lock_irqsave(&vdd_class->lock, flags);
 	if (WARN(!vdd_class->level_votes[level],
 			"Reference counts are incorrect for %s level %d\n",
 			vdd_class->class_name, level))
 		goto out;
 	vdd_class->level_votes[level]--;
 	rc = update_vdd(vdd_class);
 	if (rc)
 		vdd_class->level_votes[level]++;
 out:
 	spin_unlock_irqrestore(&vdd_class->lock, flags);
 	return rc;
 }

 /* Vote for a voltage level corresponding to a clock's rate. */
 static int vote_rate_vdd(struct clk *clk, unsigned long rate)
 {
 	int level;

 	if (!clk->vdd_class)
 		return 0;

 	level = find_vdd_level(clk, rate);
 	if (level < 0)
 		return level;

 	return vote_vdd_level(clk->vdd_class, level);
 }

 /* Remove vote for a voltage level corresponding to a clock's rate. */
 static void unvote_rate_vdd(struct clk *clk, unsigned long rate)
 {
 	int level;

 	if (!clk->vdd_class)
 		return;

 	level = find_vdd_level(clk, rate);
 	if (level < 0)
 		return;

 	unvote_vdd_level(clk->vdd_class, level);
 }

 /*
  * Standard clock functions defined in include/linux/clk.h
  */
 int clk_enable(struct clk *clk)
 {
 	int ret = 0;
 	unsigned long flags;
 	struct clk *parent;

 	if (!clk)
 		return 0;

 	spin_lock_irqsave(&clk->lock, flags);
 	if (clk->count == 0) {
 		parent = clk_get_parent(clk);

 		ret = clk_enable(parent);
 		if (ret)
 			goto err_enable_parent;
 		ret = clk_enable(clk->depends);
 		if (ret)
 			goto err_enable_depends;

 		ret = vote_rate_vdd(clk, clk->rate);
 		if (ret)
 			goto err_vote_vdd;
 		if (clk->ops->enable)
 			ret = clk->ops->enable(clk);
 		if (ret)
 			goto err_enable_clock;
 	} else if (clk->flags & CLKFLAG_HANDOFF_RATE) {
 		/*
 		 * The clock was already enabled by handoff code so there is no
 		 * need to enable it again here. Clearing the handoff flag will
 		 * prevent the lateinit handoff code from disabling the clock if
 		 * a client driver still has it enabled.
 		 */
 		clk->flags &= ~CLKFLAG_HANDOFF_RATE;
 		goto out;
 	}
 	clk->count++;
 out:
 	spin_unlock_irqrestore(&clk->lock, flags);

 	return 0;

 err_enable_clock:
 	unvote_rate_vdd(clk, clk->rate);
 err_vote_vdd:
 	clk_disable(clk->depends);
 err_enable_depends:
 	clk_disable(parent);
 err_enable_parent:
 	spin_unlock_irqrestore(&clk->lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(clk_enable);

 void clk_disable(struct clk *clk)
 {
 	unsigned long flags;

 	if (!clk)
 		return;

 	spin_lock_irqsave(&clk->lock, flags);
 	if (WARN(clk->count == 0, "%s is unbalanced", clk->dbg_name))
 		goto out;
 	if (clk->count == 1) {
 		struct clk *parent = clk_get_parent(clk);

 		if (clk->ops->disable)
 			clk->ops->disable(clk);
 		unvote_rate_vdd(clk, clk->rate);
 		clk_disable(clk->depends);
 		clk_disable(parent);
 	}
 	clk->count--;
 out:
 	spin_unlock_irqrestore(&clk->lock, flags);
 }
 EXPORT_SYMBOL(clk_disable);

 int clk_reset(struct clk *clk, enum clk_reset_action action)
 {
 	if (!clk->ops->reset)
 		return -ENOSYS;

 	return clk->ops->reset(clk, action);
 }
 EXPORT_SYMBOL(clk_reset);

 unsigned long clk_get_rate(struct clk *clk)
 {
 	if (!clk->ops->get_rate)
 		return 0;

 	return clk->ops->get_rate(clk);
 }
 EXPORT_SYMBOL(clk_get_rate);

 static int _clk_set_rate(struct clk *clk, unsigned long rate,
 			 int (*set_fn)(struct clk *, unsigned long))
 {
 	unsigned long start_rate, flags;
 	int rc;

 	if (!set_fn)
 		return -ENOSYS;

 	spin_lock_irqsave(&clk->lock, flags);
 	if (clk->count) {
 		start_rate = clk->rate;
 		/* Enforce vdd requirements for target frequency. */
 		rc = vote_rate_vdd(clk, rate);
 		if (rc)
 			goto err_vote_vdd;
 		rc = set_fn(clk, rate);
 		if (rc)
 			goto err_set_rate;
 		/* Release vdd requirements for starting frequency. */
 		unvote_rate_vdd(clk, start_rate);
 	} else {
 		rc = set_fn(clk, rate);
 	}

 	if (!rc)
 		clk->rate = rate;

 	spin_unlock_irqrestore(&clk->lock, flags);
 	return rc;

 err_set_rate:
 	unvote_rate_vdd(clk, rate);
 err_vote_vdd:
 	spin_unlock_irqrestore(&clk->lock, flags);
 	return rc;
 }

 long clk_round_rate(struct clk *clk, unsigned long rate)
 {
 	if (!clk->ops->round_rate)
 		return -ENOSYS;

 	return clk->ops->round_rate(clk, rate);
 }
 EXPORT_SYMBOL(clk_round_rate);

 int clk_set_rate(struct clk *clk, unsigned long rate)
 {
 	if (clk->flags & CLKFLAG_MIN)
 		return _clk_set_rate(clk, rate, clk->ops->set_min_rate);
 	else
 		return _clk_set_rate(clk, rate, clk->ops->set_rate);
 }
 EXPORT_SYMBOL(clk_set_rate);

 int clk_set_min_rate(struct clk *clk, unsigned long rate)
 {
 	return _clk_set_rate(clk, rate, clk->ops->set_min_rate);
 }
 EXPORT_SYMBOL(clk_set_min_rate);

 int clk_set_max_rate(struct clk *clk, unsigned long rate)
 {
 	if (!clk->ops->set_max_rate)
 		return -ENOSYS;

 	return clk->ops->set_max_rate(clk, rate);
 }
 EXPORT_SYMBOL(clk_set_max_rate);

 int clk_set_parent(struct clk *clk, struct clk *parent)
 {
 	if (!clk->ops->set_parent)
 		return 0;

 	return clk->ops->set_parent(clk, parent);
 }
 EXPORT_SYMBOL(clk_set_parent);

 struct clk *clk_get_parent(struct clk *clk)
 {
 	if (!clk->ops->get_parent)
 		return NULL;

 	return clk->ops->get_parent(clk);
 }
 EXPORT_SYMBOL(clk_get_parent);

 int clk_set_flags(struct clk *clk, unsigned long flags)
 {
 	if (clk == NULL || IS_ERR(clk))
 		return -EINVAL;
 	if (!clk->ops->set_flags)
 		return -ENOSYS;

 	return clk->ops->set_flags(clk, flags);
 }
 EXPORT_SYMBOL(clk_set_flags);

 static struct clock_init_data __initdata *clk_init_data;

 void __init msm_clock_init(struct clock_init_data *data)
 {
 	unsigned n;
 	struct clk_lookup *clock_tbl;
 	size_t num_clocks;

 	clk_init_data = data;
 	if (clk_init_data->init)
 		clk_init_data->init();

 	clock_tbl = data->table;
 	num_clocks = data->size;

 	for (n = 0; n < num_clocks; n++) {
 		struct clk *clk = clock_tbl[n].clk;
 		struct clk *parent = clk_get_parent(clk);
 		clk_set_parent(clk, parent);
 		if (clk->ops->handoff && !(clk->flags & CLKFLAG_HANDOFF_RATE)) {
 			if (clk->ops->handoff(clk)) {
 				clk->flags |= CLKFLAG_HANDOFF_RATE;
 				clk_enable(clk);
 			}
 		}
 	}

 	clkdev_add_table(clock_tbl, num_clocks);
 }

 /*
  * The bootloader and/or AMSS may have left various clocks enabled.
  * Disable any clocks that have not been explicitly enabled by a
  * clk_enable() call and don't have the CLKFLAG_SKIP_AUTO_OFF flag.
  */
 static int __init clock_late_init(void)
 {
 	unsigned n, count = 0;
 	unsigned long flags;
 	int ret = 0;

 	clock_debug_init(clk_init_data);
 	for (n = 0; n < clk_init_data->size; n++) {
 		struct clk *clk = clk_init_data->table[n].clk;
 		bool handoff = false;

 		clock_debug_add(clk);
 		if (!(clk->flags & CLKFLAG_SKIP_AUTO_OFF)) {
 			spin_lock_irqsave(&clk->lock, flags);
 			if (!clk->count && clk->ops->auto_off) {
 				count++;
 				clk->ops->auto_off(clk);
 			}
 			if (clk->flags & CLKFLAG_HANDOFF_RATE) {
 				clk->flags &= ~CLKFLAG_HANDOFF_RATE;
 				handoff = true;
 			}
 			spin_unlock_irqrestore(&clk->lock, flags);
 			/*
 			 * Calling clk_disable() outside the lock is safe since
 			 * it doesn't need to be atomic with the flag change.
 			 */
 			if (handoff)
 				clk_disable(clk);
 		}
 	}
 	pr_info("clock_late_init() disabled %d unused clocks\n", count);
 	if (clk_init_data->late_init)
 		ret = clk_init_data->late_init();
 	return ret;
 }
 late_initcall(clock_late_init);
	/* arch/arm/mach-msm/clock.c
	*
	* Copyright (C) 2007 Google, Inc.
	* Copyright (c) 2007-2011, Code Aurora Forum. All rights reserved.
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that 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.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/err.h>
	#include <linux/spinlock.h>
	#include <linux/string.h>
	#include <linux/module.h>
	#include <linux/clk.h>
	#include <linux/clkdev.h>

	#include "clock.h"

	/* Find the voltage level required for a given rate. */
	static int find_vdd_level(struct clk *clk, unsigned long rate)
	{
	int level;

	for (level = 0; level < ARRAY_SIZE(clk->fmax); level++)
	if (rate <= clk->fmax[level])
	break;

	if (level == ARRAY_SIZE(clk->fmax)) {
	pr_err("Rate %lu for %s is greater than highest Fmax\n", rate,
	clk->dbg_name);
	return -EINVAL;
	}

	return level;
	}

	/* Update voltage level given the current votes. */
	static int update_vdd(struct clk_vdd_class *vdd_class)
	{
	int level, rc;

	for (level = ARRAY_SIZE(vdd_class->level_votes)-1; level > 0; level--)
	if (vdd_class->level_votes[level])
	break;

	if (level == vdd_class->cur_level)
	return 0;

	rc = vdd_class->set_vdd(vdd_class, level);
	if (!rc)
	vdd_class->cur_level = level;

	return rc;
	}

	/* Vote for a voltage level. */
	int vote_vdd_level(struct clk_vdd_class *vdd_class, int level)
	{
	unsigned long flags;
	int rc;

	spin_lock_irqsave(&vdd_class->lock, flags);
	vdd_class->level_votes[level]++;
	rc = update_vdd(vdd_class);
	if (rc)
	vdd_class->level_votes[level]--;
	spin_unlock_irqrestore(&vdd_class->lock, flags);

	return rc;
	}

	/* Remove vote for a voltage level. */
	int unvote_vdd_level(struct clk_vdd_class *vdd_class, int level)
	{
	unsigned long flags;
	int rc = 0;

	spin_lock_irqsave(&vdd_class->lock, flags);
	if (WARN(!vdd_class->level_votes[level],
	"Reference counts are incorrect for %s level %d\n",
	vdd_class->class_name, level))
	goto out;
	vdd_class->level_votes[level]--;
	rc = update_vdd(vdd_class);
	if (rc)
	vdd_class->level_votes[level]++;
	out:
	spin_unlock_irqrestore(&vdd_class->lock, flags);
	return rc;
	}

	/* Vote for a voltage level corresponding to a clock's rate. */
	static int vote_rate_vdd(struct clk *clk, unsigned long rate)
	{
	int level;

	if (!clk->vdd_class)
	return 0;

	level = find_vdd_level(clk, rate);
	if (level < 0)
	return level;

	return vote_vdd_level(clk->vdd_class, level);
	}

	/* Remove vote for a voltage level corresponding to a clock's rate. */
	static void unvote_rate_vdd(struct clk *clk, unsigned long rate)
	{
	int level;

	if (!clk->vdd_class)
	return;

	level = find_vdd_level(clk, rate);
	if (level < 0)
	return;

	unvote_vdd_level(clk->vdd_class, level);
	}

	/*
	* Standard clock functions defined in include/linux/clk.h
	*/
	int clk_enable(struct clk *clk)
	{
	int ret = 0;
	unsigned long flags;
	struct clk *parent;

	if (!clk)
	return 0;

	spin_lock_irqsave(&clk->lock, flags);
	if (clk->count == 0) {
	parent = clk_get_parent(clk);

	ret = clk_enable(parent);
	if (ret)
	goto err_enable_parent;
	ret = clk_enable(clk->depends);
	if (ret)
	goto err_enable_depends;

	ret = vote_rate_vdd(clk, clk->rate);
	if (ret)
	goto err_vote_vdd;
	if (clk->ops->enable)
	ret = clk->ops->enable(clk);
	if (ret)
	goto err_enable_clock;
	} else if (clk->flags & CLKFLAG_HANDOFF_RATE) {
	/*
	* The clock was already enabled by handoff code so there is no
	* need to enable it again here. Clearing the handoff flag will
	* prevent the lateinit handoff code from disabling the clock if
	* a client driver still has it enabled.
	*/
	clk->flags &= ~CLKFLAG_HANDOFF_RATE;
	goto out;
	}
	clk->count++;
	out:
	spin_unlock_irqrestore(&clk->lock, flags);

	return 0;

	err_enable_clock:
	unvote_rate_vdd(clk, clk->rate);
	err_vote_vdd:
	clk_disable(clk->depends);
	err_enable_depends:
	clk_disable(parent);
	err_enable_parent:
	spin_unlock_irqrestore(&clk->lock, flags);
	return ret;
	}
	EXPORT_SYMBOL(clk_enable);

	void clk_disable(struct clk *clk)
	{
	unsigned long flags;

	if (!clk)
	return;

	spin_lock_irqsave(&clk->lock, flags);
	if (WARN(clk->count == 0, "%s is unbalanced", clk->dbg_name))
	goto out;
	if (clk->count == 1) {
	struct clk *parent = clk_get_parent(clk);

	if (clk->ops->disable)
	clk->ops->disable(clk);
	unvote_rate_vdd(clk, clk->rate);
	clk_disable(clk->depends);
	clk_disable(parent);
	}
	clk->count--;
	out:
	spin_unlock_irqrestore(&clk->lock, flags);
	}
	EXPORT_SYMBOL(clk_disable);

	int clk_reset(struct clk *clk, enum clk_reset_action action)
	{
	if (!clk->ops->reset)
	return -ENOSYS;

	return clk->ops->reset(clk, action);
	}
	EXPORT_SYMBOL(clk_reset);

	unsigned long clk_get_rate(struct clk *clk)
	{
	if (!clk->ops->get_rate)
	return 0;

	return clk->ops->get_rate(clk);
	}
	EXPORT_SYMBOL(clk_get_rate);

	static int _clk_set_rate(struct clk *clk, unsigned long rate,
	int (set_fn)(struct clk , unsigned long))
	{
	unsigned long start_rate, flags;
	int rc;

	if (!set_fn)
	return -ENOSYS;

	spin_lock_irqsave(&clk->lock, flags);
	if (clk->count) {
	start_rate = clk->rate;
	/* Enforce vdd requirements for target frequency. */
	rc = vote_rate_vdd(clk, rate);
	if (rc)
	goto err_vote_vdd;
	rc = set_fn(clk, rate);
	if (rc)
	goto err_set_rate;
	/* Release vdd requirements for starting frequency. */
	unvote_rate_vdd(clk, start_rate);
	} else {
	rc = set_fn(clk, rate);
	}

	if (!rc)
	clk->rate = rate;

	spin_unlock_irqrestore(&clk->lock, flags);
	return rc;

	err_set_rate:
	unvote_rate_vdd(clk, rate);
	err_vote_vdd:
	spin_unlock_irqrestore(&clk->lock, flags);
	return rc;
	}

	long clk_round_rate(struct clk *clk, unsigned long rate)
	{
	if (!clk->ops->round_rate)
	return -ENOSYS;

	return clk->ops->round_rate(clk, rate);
	}
	EXPORT_SYMBOL(clk_round_rate);

	int clk_set_rate(struct clk *clk, unsigned long rate)
	{
	if (clk->flags & CLKFLAG_MIN)
	return _clk_set_rate(clk, rate, clk->ops->set_min_rate);
	else
	return _clk_set_rate(clk, rate, clk->ops->set_rate);
	}
	EXPORT_SYMBOL(clk_set_rate);

	int clk_set_min_rate(struct clk *clk, unsigned long rate)
	{
	return _clk_set_rate(clk, rate, clk->ops->set_min_rate);
	}
	EXPORT_SYMBOL(clk_set_min_rate);

	int clk_set_max_rate(struct clk *clk, unsigned long rate)
	{
	if (!clk->ops->set_max_rate)
	return -ENOSYS;

	return clk->ops->set_max_rate(clk, rate);
	}
	EXPORT_SYMBOL(clk_set_max_rate);

	int clk_set_parent(struct clk clk, struct clk parent)
	{
	if (!clk->ops->set_parent)
	return 0;

	return clk->ops->set_parent(clk, parent);
	}
	EXPORT_SYMBOL(clk_set_parent);

	struct clk clk_get_parent(struct clk clk)
	{
	if (!clk->ops->get_parent)
	return NULL;

	return clk->ops->get_parent(clk);
	}
	EXPORT_SYMBOL(clk_get_parent);

	int clk_set_flags(struct clk *clk, unsigned long flags)
	{
	if (clk == NULL \|\| IS_ERR(clk))
	return -EINVAL;
	if (!clk->ops->set_flags)
	return -ENOSYS;

	return clk->ops->set_flags(clk, flags);
	}
	EXPORT_SYMBOL(clk_set_flags);

	static struct clock_init_data __initdata *clk_init_data;

	void __init msm_clock_init(struct clock_init_data *data)
	{
	unsigned n;
	struct clk_lookup *clock_tbl;
	size_t num_clocks;

	clk_init_data = data;
	if (clk_init_data->init)
	clk_init_data->init();

	clock_tbl = data->table;
	num_clocks = data->size;

	for (n = 0; n < num_clocks; n++) {
	struct clk *clk = clock_tbl[n].clk;
	struct clk *parent = clk_get_parent(clk);
	clk_set_parent(clk, parent);
	if (clk->ops->handoff && !(clk->flags & CLKFLAG_HANDOFF_RATE)) {
	if (clk->ops->handoff(clk)) {
	clk->flags \|= CLKFLAG_HANDOFF_RATE;
	clk_enable(clk);
	}
	}
	}

	clkdev_add_table(clock_tbl, num_clocks);
	}

	/*
	* The bootloader and/or AMSS may have left various clocks enabled.
	* Disable any clocks that have not been explicitly enabled by a
	* clk_enable() call and don't have the CLKFLAG_SKIP_AUTO_OFF flag.
	*/
	static int __init clock_late_init(void)
	{
	unsigned n, count = 0;
	unsigned long flags;
	int ret = 0;

	clock_debug_init(clk_init_data);
	for (n = 0; n < clk_init_data->size; n++) {
	struct clk *clk = clk_init_data->table[n].clk;
	bool handoff = false;

	clock_debug_add(clk);
	if (!(clk->flags & CLKFLAG_SKIP_AUTO_OFF)) {
	spin_lock_irqsave(&clk->lock, flags);
	if (!clk->count && clk->ops->auto_off) {
	count++;
	clk->ops->auto_off(clk);
	}
	if (clk->flags & CLKFLAG_HANDOFF_RATE) {
	clk->flags &= ~CLKFLAG_HANDOFF_RATE;
	handoff = true;
	}
	spin_unlock_irqrestore(&clk->lock, flags);
	/*
	* Calling clk_disable() outside the lock is safe since
	* it doesn't need to be atomic with the flag change.
	*/
	if (handoff)
	clk_disable(clk);
	}
	}
	pr_info("clock_late_init() disabled %d unused clocks\n", count);
	if (clk_init_data->late_init)
	ret = clk_init_data->late_init();
	return ret;
	}
	late_initcall(clock_late_init);