arch/arm/mach-msm/clock.c

/* arch/arm/mach-msm/clock.c
 *
 * Copyright (C) 2007 Google, Inc.
 * Copyright (c) 2007-2010, 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/version.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/ctype.h>
#include <linux/pm_qos_params.h>
#include <mach/clk.h>

#include "clock.h"
#include "proc_comm.h"

static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clocks_lock);
static LIST_HEAD(clocks);
struct clk *msm_clocks;
unsigned msm_num_clocks;

/*
 * Bitmap of enabled clocks, excluding ACPU which is always
 * enabled
 */
static DECLARE_BITMAP(clock_map_enabled, NR_CLKS);
static DEFINE_SPINLOCK(clock_map_lock);

/*
 * Standard clock functions defined in include/linux/clk.h
 */
struct clk *clk_get(struct device *dev, const char *id)
{
	struct clk *clk;

	mutex_lock(&clocks_mutex);

	list_for_each_entry(clk, &clocks, list)
		if (!strcmp(id, clk->name) && clk->dev == dev)
			goto found_it;

	list_for_each_entry(clk, &clocks, list)
		if (!strcmp(id, clk->name) && clk->dev == NULL)
			goto found_it;

	clk = ERR_PTR(-ENOENT);
found_it:
	mutex_unlock(&clocks_mutex);
	return clk;
}
EXPORT_SYMBOL(clk_get);

void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);

int clk_enable(struct clk *clk)
{
	unsigned long flags;
	spin_lock_irqsave(&clocks_lock, flags);
	clk->count++;
	if (clk->count == 1) {
		clk->ops->enable(clk->id);
		spin_lock(&clock_map_lock);
		clock_map_enabled[BIT_WORD(clk->id)] |= BIT_MASK(clk->id);
		spin_unlock(&clock_map_lock);
	}
	spin_unlock_irqrestore(&clocks_lock, flags);
	return 0;
}
EXPORT_SYMBOL(clk_enable);

void clk_disable(struct clk *clk)
{
	unsigned long flags;
	spin_lock_irqsave(&clocks_lock, flags);
	BUG_ON(clk->count == 0);
	clk->count--;
	if (clk->count == 0) {
		clk->ops->disable(clk->id);
		spin_lock(&clock_map_lock);
		clock_map_enabled[BIT_WORD(clk->id)] &= ~BIT_MASK(clk->id);
		spin_unlock(&clock_map_lock);
	}
	spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

int clk_reset(struct clk *clk, enum clk_reset_action action)
{
	if (!clk->ops->reset)
		clk->ops->reset = &pc_clk_reset;
	return clk->ops->reset(clk->remote_id, action);
}
EXPORT_SYMBOL(clk_reset);

unsigned long clk_get_rate(struct clk *clk)
{
	return clk->ops->get_rate(clk->id);
}
EXPORT_SYMBOL(clk_get_rate);

int clk_set_rate(struct clk *clk, unsigned long rate)
{
	return clk->ops->set_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_set_rate);

long clk_round_rate(struct clk *clk, unsigned long rate)
{
	return clk->ops->round_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_round_rate);

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

int clk_set_max_rate(struct clk *clk, unsigned long rate)
{
	return clk->ops->set_max_rate(clk->id, rate);
}
EXPORT_SYMBOL(clk_set_max_rate);

int clk_set_parent(struct clk *clk, struct clk *parent)
{
	return -ENOSYS;
}
EXPORT_SYMBOL(clk_set_parent);

struct clk *clk_get_parent(struct clk *clk)
{
	return ERR_PTR(-ENOSYS);
}
EXPORT_SYMBOL(clk_get_parent);

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

/* EBI1 is the only shared clock that several clients want to vote on as of
 * this commit. If this changes in the future, then it might be better to
 * make clk_min_rate handle the voting or make ebi1_clk_set_min_rate more
 * generic to support different clocks.
 */
static struct clk *ebi1_clk;

static void __init set_clock_ops(struct clk *clk)
{
	if (!clk->ops) {
		clk->ops = &clk_ops_pcom;
		clk->id = clk->remote_id;
	}
}

void __init msm_clock_init(struct clk *clock_tbl, unsigned num_clocks)
{
	unsigned n;

	spin_lock_init(&clocks_lock);
	mutex_lock(&clocks_mutex);
	msm_clocks = clock_tbl;
	msm_num_clocks = num_clocks;
	for (n = 0; n < msm_num_clocks; n++) {
		set_clock_ops(&msm_clocks[n]);
		list_add_tail(&msm_clocks[n].list, &clocks);
	}
	mutex_unlock(&clocks_mutex);

	ebi1_clk = clk_get(NULL, "ebi1_clk");
	BUG_ON(ebi1_clk == NULL);

}

#if defined(CONFIG_DEBUG_FS)
static struct clk *msm_clock_get_nth(unsigned index)
{
	if (index < msm_num_clocks)
		return msm_clocks + index;
	else
		return 0;
}

static int clock_debug_rate_set(void *data, u64 val)
{
	struct clk *clock = data;
	int ret;

	/* Only increases to max rate will succeed, but that's actually good
	 * for debugging purposes. So we don't check for error. */
	if (clock->flags & CLK_MAX)
		clk_set_max_rate(clock, val);
	if (clock->flags & CLK_MIN)
		ret = clk_set_min_rate(clock, val);
	else
		ret = clk_set_rate(clock, val);
	if (ret != 0)
		printk(KERN_ERR "clk_set%s_rate failed (%d)\n",
			(clock->flags & CLK_MIN) ? "_min" : "", ret);
	return ret;
}

static int clock_debug_rate_get(void *data, u64 *val)
{
	struct clk *clock = data;
	*val = clk_get_rate(clock);
	return 0;
}

static int clock_debug_enable_set(void *data, u64 val)
{
	struct clk *clock = data;
	int rc = 0;

	if (val)
		rc = clock->ops->enable(clock->id);
	else
		clock->ops->disable(clock->id);

	return rc;
}

static int clock_debug_enable_get(void *data, u64 *val)
{
	struct clk *clock = data;

	*val = clock->ops->is_enabled(clock->id);

	return 0;
}

static int clock_debug_local_get(void *data, u64 *val)
{
	struct clk *clock = data;

	*val = clock->ops != &clk_ops_pcom;

	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(clock_rate_fops, clock_debug_rate_get,
			clock_debug_rate_set, "%llu\n");
DEFINE_SIMPLE_ATTRIBUTE(clock_enable_fops, clock_debug_enable_get,
			clock_debug_enable_set, "%llu\n");
DEFINE_SIMPLE_ATTRIBUTE(clock_local_fops, clock_debug_local_get,
			NULL, "%llu\n");

static int __init clock_debug_init(void)
{
	struct dentry *dent_rate, *dent_enable, *dent_local;
	struct clk *clock;
	unsigned n = 0;
	char temp[50], *ptr;

	dent_rate = debugfs_create_dir("clk_rate", 0);
	if (IS_ERR(dent_rate))
		return PTR_ERR(dent_rate);

	dent_enable = debugfs_create_dir("clk_enable", 0);
	if (IS_ERR(dent_enable))
		return PTR_ERR(dent_enable);

	dent_local = debugfs_create_dir("clk_local", NULL);
	if (IS_ERR(dent_local))
		return PTR_ERR(dent_local);

	while ((clock = msm_clock_get_nth(n++)) != 0) {
		strncpy(temp, clock->dbg_name, ARRAY_SIZE(temp)-1);
		for (ptr = temp; *ptr; ptr++)
			*ptr = tolower(*ptr);
		debugfs_create_file(temp, 0644, dent_rate,
				    clock, &clock_rate_fops);
		debugfs_create_file(temp, 0644, dent_enable,
				    clock, &clock_enable_fops);
		debugfs_create_file(temp, S_IRUGO, dent_local,
				    clock, &clock_local_fops);
	}
	return 0;
}

device_initcall(clock_debug_init);
#endif

/* The bootloader and/or AMSS may have left various clocks enabled.
 * Disable any clocks that belong to us (CLKFLAG_AUTO_OFF) but have
 * not been explicitly enabled by a clk_enable() call.
 */
static int __init clock_late_init(void)
{
	unsigned long flags;
	struct clk *clk;
	unsigned count = 0;

	mutex_lock(&clocks_mutex);
	list_for_each_entry(clk, &clocks, list) {
		if (clk->flags & CLKFLAG_AUTO_OFF) {
			spin_lock_irqsave(&clocks_lock, flags);
			if (!clk->count) {
				count++;
				clk->ops->auto_off(clk->id);
			}
			spin_unlock_irqrestore(&clocks_lock, flags);
		}
	}
	mutex_unlock(&clocks_mutex);
	pr_info("clock_late_init() disabled %d unused clocks\n", count);
	return 0;
}

late_initcall(clock_late_init);