/* 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/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"
#include "clock-7x30.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)
{
        int ret;
        if (clk->flags & CLKFLAG_MAX) {
                ret = clk->ops->set_max_rate(clk->id, rate);
                if (ret)
                        return ret;
        }
        if (clk->flags & CLKFLAG_MIN) {
                ret = clk->ops->set_min_rate(clk->id, rate);
                if (ret)
                        return ret;
        }

        if (clk->flags & CLKFLAG_MAX || clk->flags & CLKFLAG_MIN)
                return ret;

        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);