Merge branch 'v6v7' into devel

[linux/fpc-iii.git] / arch / arm / mach-tegra / clock.c

/*
 *
 * Copyright (C) 2010 Google, Inc.
 *
 * Author:
 *      Colin Cross <ccross@google.com>
 *
 * 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/clk.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/regulator/consumer.h>
#include <linux/clkdev.h>

#include "clock.h"
#include "board.h"
#include "fuse.h"

static LIST_HEAD(clocks);

static DEFINE_SPINLOCK(clock_lock);
static DEFINE_MUTEX(dvfs_lock);

static int clk_is_dvfs(struct clk *c)
{
        return (c->dvfs != NULL);
};

static int dvfs_set_rate(struct dvfs *d, unsigned long rate)
{
        struct dvfs_table *t;

        if (d->table == NULL)
                return -ENODEV;

        for (t = d->table; t->rate != 0; t++) {
                if (rate <= t->rate) {
                        if (!d->reg)
                                return 0;

                        return regulator_set_voltage(d->reg,
                                t->millivolts * 1000,
                                d->max_millivolts * 1000);
                }
        }

        return -EINVAL;
}

static void dvfs_init(struct clk *c)
{
        int process_id;
        int i;
        struct dvfs_table *table;

        process_id = c->dvfs->cpu ? tegra_core_process_id() :
                tegra_cpu_process_id();

        for (i = 0; i < c->dvfs->process_id_table_length; i++)
                if (process_id == c->dvfs->process_id_table[i].process_id)
                        c->dvfs->table = c->dvfs->process_id_table[i].table;

        if (c->dvfs->table == NULL) {
                pr_err("Failed to find dvfs table for clock %s process %d\n",
                        c->name, process_id);
                return;
        }

        c->dvfs->max_millivolts = 0;
        for (table = c->dvfs->table; table->rate != 0; table++)
                if (c->dvfs->max_millivolts < table->millivolts)
                        c->dvfs->max_millivolts = table->millivolts;

        c->dvfs->reg = regulator_get(NULL, c->dvfs->reg_id);

        if (IS_ERR(c->dvfs->reg)) {
                pr_err("Failed to get regulator %s for clock %s\n",
                        c->dvfs->reg_id, c->name);
                c->dvfs->reg = NULL;
                return;
        }

        if (c->refcnt > 0)
                dvfs_set_rate(c->dvfs, c->rate);
}

struct clk *tegra_get_clock_by_name(const char *name)
{
        struct clk *c;
        struct clk *ret = NULL;
        unsigned long flags;
        spin_lock_irqsave(&clock_lock, flags);
        list_for_each_entry(c, &clocks, node) {
                if (strcmp(c->name, name) == 0) {
                        ret = c;
                        break;
                }
        }
        spin_unlock_irqrestore(&clock_lock, flags);
        return ret;
}

static void clk_recalculate_rate(struct clk *c)
{
        u64 rate;

        if (!c->parent)
                return;

        rate = c->parent->rate;

        if (c->mul != 0 && c->div != 0) {
                rate = rate * c->mul;
                do_div(rate, c->div);
        }

        if (rate > c->max_rate)
                pr_warn("clocks: Set clock %s to rate %llu, max is %lu\n",
                        c->name, rate, c->max_rate);

        c->rate = rate;
}

int clk_reparent(struct clk *c, struct clk *parent)
{
        pr_debug("%s: %s\n", __func__, c->name);
        c->parent = parent;
        list_del(&c->sibling);
        list_add_tail(&c->sibling, &parent->children);
        return 0;
}

static void propagate_rate(struct clk *c)
{
        struct clk *clkp;
        pr_debug("%s: %s\n", __func__, c->name);
        list_for_each_entry(clkp, &c->children, sibling) {
                pr_debug("   %s\n", clkp->name);
                clk_recalculate_rate(clkp);
                propagate_rate(clkp);
        }
}

void clk_init(struct clk *c)
{
        unsigned long flags;

        pr_debug("%s: %s\n", __func__, c->name);

        spin_lock_irqsave(&clock_lock, flags);

        INIT_LIST_HEAD(&c->children);
        INIT_LIST_HEAD(&c->sibling);

        if (c->ops && c->ops->init)
                c->ops->init(c);

        clk_recalculate_rate(c);

        list_add(&c->node, &clocks);

        if (c->parent)
                list_add_tail(&c->sibling, &c->parent->children);

        spin_unlock_irqrestore(&clock_lock, flags);
}

int clk_enable_locked(struct clk *c)
{
        int ret;
        pr_debug("%s: %s\n", __func__, c->name);
        if (c->refcnt == 0) {
                if (c->parent) {
                        ret = clk_enable_locked(c->parent);
                        if (ret)
                                return ret;
                }

                if (c->ops && c->ops->enable) {
                        ret = c->ops->enable(c);
                        if (ret) {
                                if (c->parent)
                                        clk_disable_locked(c->parent);
                                return ret;
                        }
                        c->state = ON;
#ifdef CONFIG_DEBUG_FS
                        c->set = 1;
#endif
                }
        }
        c->refcnt++;

        return 0;
}

int clk_enable_cansleep(struct clk *c)
{
        int ret;
        unsigned long flags;

        mutex_lock(&dvfs_lock);

        if (clk_is_dvfs(c) && c->refcnt > 0)
                dvfs_set_rate(c->dvfs, c->rate);

        spin_lock_irqsave(&clock_lock, flags);
        ret = clk_enable_locked(c);
        spin_unlock_irqrestore(&clock_lock, flags);

        mutex_unlock(&dvfs_lock);

        return ret;
}
EXPORT_SYMBOL(clk_enable_cansleep);

int clk_enable(struct clk *c)
{
        int ret;
        unsigned long flags;

        if (clk_is_dvfs(c))
                BUG();

        spin_lock_irqsave(&clock_lock, flags);
        ret = clk_enable_locked(c);
        spin_unlock_irqrestore(&clock_lock, flags);

        return ret;
}
EXPORT_SYMBOL(clk_enable);

void clk_disable_locked(struct clk *c)
{
        pr_debug("%s: %s\n", __func__, c->name);
        if (c->refcnt == 0) {
                WARN(1, "Attempting to disable clock %s with refcnt 0", c->name);
                return;
        }
        if (c->refcnt == 1) {
                if (c->ops && c->ops->disable)
                        c->ops->disable(c);

                if (c->parent)
                        clk_disable_locked(c->parent);

                c->state = OFF;
        }
        c->refcnt--;
}

void clk_disable_cansleep(struct clk *c)
{
        unsigned long flags;

        mutex_lock(&dvfs_lock);

        spin_lock_irqsave(&clock_lock, flags);
        clk_disable_locked(c);
        spin_unlock_irqrestore(&clock_lock, flags);

        if (clk_is_dvfs(c) && c->refcnt == 0)
                dvfs_set_rate(c->dvfs, c->rate);

        mutex_unlock(&dvfs_lock);
}
EXPORT_SYMBOL(clk_disable_cansleep);

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

        if (clk_is_dvfs(c))
                BUG();

        spin_lock_irqsave(&clock_lock, flags);
        clk_disable_locked(c);
        spin_unlock_irqrestore(&clock_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

int clk_set_parent_locked(struct clk *c, struct clk *parent)
{
        int ret;

        pr_debug("%s: %s\n", __func__, c->name);

        if (!c->ops || !c->ops->set_parent)
                return -ENOSYS;

        ret = c->ops->set_parent(c, parent);

        if (ret)
                return ret;

        clk_recalculate_rate(c);

        propagate_rate(c);

        return 0;
}

int clk_set_parent(struct clk *c, struct clk *parent)
{
        int ret;
        unsigned long flags;
        spin_lock_irqsave(&clock_lock, flags);
        ret = clk_set_parent_locked(c, parent);
        spin_unlock_irqrestore(&clock_lock, flags);
        return ret;
}
EXPORT_SYMBOL(clk_set_parent);

struct clk *clk_get_parent(struct clk *c)
{
        return c->parent;
}
EXPORT_SYMBOL(clk_get_parent);

int clk_set_rate_locked(struct clk *c, unsigned long rate)
{
        int ret;

        if (rate > c->max_rate)
                rate = c->max_rate;

        if (!c->ops || !c->ops->set_rate)
                return -ENOSYS;

        ret = c->ops->set_rate(c, rate);

        if (ret)
                return ret;

        clk_recalculate_rate(c);

        propagate_rate(c);

        return 0;
}

int clk_set_rate_cansleep(struct clk *c, unsigned long rate)
{
        int ret = 0;
        unsigned long flags;

        pr_debug("%s: %s\n", __func__, c->name);

        mutex_lock(&dvfs_lock);

        if (rate > c->rate)
                ret = dvfs_set_rate(c->dvfs, rate);
        if (ret)
                goto out;

        spin_lock_irqsave(&clock_lock, flags);
        ret = clk_set_rate_locked(c, rate);
        spin_unlock_irqrestore(&clock_lock, flags);

        if (ret)
                goto out;

        ret = dvfs_set_rate(c->dvfs, rate);

out:
        mutex_unlock(&dvfs_lock);
        return ret;
}
EXPORT_SYMBOL(clk_set_rate_cansleep);

int clk_set_rate(struct clk *c, unsigned long rate)
{
        int ret = 0;
        unsigned long flags;

        pr_debug("%s: %s\n", __func__, c->name);

        if (clk_is_dvfs(c))
                BUG();

        spin_lock_irqsave(&clock_lock, flags);
        ret = clk_set_rate_locked(c, rate);
        spin_unlock_irqrestore(&clock_lock, flags);

        return ret;
}
EXPORT_SYMBOL(clk_set_rate);

unsigned long clk_get_rate(struct clk *c)
{
        unsigned long flags;
        unsigned long ret;

        spin_lock_irqsave(&clock_lock, flags);

        pr_debug("%s: %s\n", __func__, c->name);

        ret = c->rate;

        spin_unlock_irqrestore(&clock_lock, flags);
        return ret;
}
EXPORT_SYMBOL(clk_get_rate);

long clk_round_rate(struct clk *c, unsigned long rate)
{
        pr_debug("%s: %s\n", __func__, c->name);

        if (!c->ops || !c->ops->round_rate)
                return -ENOSYS;

        if (rate > c->max_rate)
                rate = c->max_rate;

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

static int tegra_clk_init_one_from_table(struct tegra_clk_init_table *table)
{
        struct clk *c;
        struct clk *p;

        int ret = 0;

        c = tegra_get_clock_by_name(table->name);

        if (!c) {
                pr_warning("Unable to initialize clock %s\n",
                        table->name);
                return -ENODEV;
        }

        if (table->parent) {
                p = tegra_get_clock_by_name(table->parent);
                if (!p) {
                        pr_warning("Unable to find parent %s of clock %s\n",
                                table->parent, table->name);
                        return -ENODEV;
                }

                if (c->parent != p) {
                        ret = clk_set_parent(c, p);
                        if (ret) {
                                pr_warning("Unable to set parent %s of clock %s: %d\n",
                                        table->parent, table->name, ret);
                                return -EINVAL;
                        }
                }
        }

        if (table->rate && table->rate != clk_get_rate(c)) {
                ret = clk_set_rate(c, table->rate);
                if (ret) {
                        pr_warning("Unable to set clock %s to rate %lu: %d\n",
                                table->name, table->rate, ret);
                        return -EINVAL;
                }
        }

        if (table->enabled) {
                ret = clk_enable(c);
                if (ret) {
                        pr_warning("Unable to enable clock %s: %d\n",
                                table->name, ret);
                        return -EINVAL;
                }
        }

        return 0;
}

void tegra_clk_init_from_table(struct tegra_clk_init_table *table)
{
        for (; table->name; table++)
                tegra_clk_init_one_from_table(table);
}
EXPORT_SYMBOL(tegra_clk_init_from_table);

void tegra_periph_reset_deassert(struct clk *c)
{
        tegra2_periph_reset_deassert(c);
}
EXPORT_SYMBOL(tegra_periph_reset_deassert);

void tegra_periph_reset_assert(struct clk *c)
{
        tegra2_periph_reset_assert(c);
}
EXPORT_SYMBOL(tegra_periph_reset_assert);

void __init tegra_init_clock(void)
{
        tegra2_init_clocks();
}

int __init tegra_init_dvfs(void)
{
        struct clk *c, *safe;

        mutex_lock(&dvfs_lock);

        list_for_each_entry_safe(c, safe, &clocks, node)
                if (c->dvfs)
                        dvfs_init(c);

        mutex_unlock(&dvfs_lock);

        return 0;
}

late_initcall(tegra_init_dvfs);

#ifdef CONFIG_DEBUG_FS
static struct dentry *clk_debugfs_root;


static void clock_tree_show_one(struct seq_file *s, struct clk *c, int level)
{
        struct clk *child;
        struct clk *safe;
        const char *state = "uninit";
        char div[8] = {0};

        if (c->state == ON)
                state = "on";
        else if (c->state == OFF)
                state = "off";

        if (c->mul != 0 && c->div != 0) {
                if (c->mul > c->div) {
                        int mul = c->mul / c->div;
                        int mul2 = (c->mul * 10 / c->div) % 10;
                        int mul3 = (c->mul * 10) % c->div;
                        if (mul2 == 0 && mul3 == 0)
                                snprintf(div, sizeof(div), "x%d", mul);
                        else if (mul3 == 0)
                                snprintf(div, sizeof(div), "x%d.%d", mul, mul2);
                        else
                                snprintf(div, sizeof(div), "x%d.%d..", mul, mul2);
                } else {
                        snprintf(div, sizeof(div), "%d%s", c->div / c->mul,
                                (c->div % c->mul) ? ".5" : "");
                }
        }

        seq_printf(s, "%*s%c%c%-*s %-6s %-3d %-8s %-10lu\n",
                level * 3 + 1, "",
                c->rate > c->max_rate ? '!' : ' ',
                !c->set ? '*' : ' ',
                30 - level * 3, c->name,
                state, c->refcnt, div, c->rate);
        list_for_each_entry_safe(child, safe, &c->children, sibling) {
                clock_tree_show_one(s, child, level + 1);
        }
}

static int clock_tree_show(struct seq_file *s, void *data)
{
        struct clk *c;
        unsigned long flags;
        seq_printf(s, "   clock                          state  ref div      rate\n");
        seq_printf(s, "--------------------------------------------------------------\n");
        spin_lock_irqsave(&clock_lock, flags);
        list_for_each_entry(c, &clocks, node)
                if (c->parent == NULL)
                        clock_tree_show_one(s, c, 0);
        spin_unlock_irqrestore(&clock_lock, flags);
        return 0;
}

static int clock_tree_open(struct inode *inode, struct file *file)
{
        return single_open(file, clock_tree_show, inode->i_private);
}

static const struct file_operations clock_tree_fops = {
        .open           = clock_tree_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int possible_parents_show(struct seq_file *s, void *data)
{
        struct clk *c = s->private;
        int i;

        for (i = 0; c->inputs[i].input; i++) {
                char *first = (i == 0) ? "" : " ";
                seq_printf(s, "%s%s", first, c->inputs[i].input->name);
        }
        seq_printf(s, "\n");
        return 0;
}

static int possible_parents_open(struct inode *inode, struct file *file)
{
        return single_open(file, possible_parents_show, inode->i_private);
}

static const struct file_operations possible_parents_fops = {
        .open           = possible_parents_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int clk_debugfs_register_one(struct clk *c)
{
        struct dentry *d, *child, *child_tmp;

        d = debugfs_create_dir(c->name, clk_debugfs_root);
        if (!d)
                return -ENOMEM;
        c->dent = d;

        d = debugfs_create_u8("refcnt", S_IRUGO, c->dent, (u8 *)&c->refcnt);
        if (!d)
                goto err_out;

        d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
        if (!d)
                goto err_out;

        d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
        if (!d)
                goto err_out;

        if (c->inputs) {
                d = debugfs_create_file("possible_parents", S_IRUGO, c->dent,
                        c, &possible_parents_fops);
                if (!d)
                        goto err_out;
        }

        return 0;

err_out:
        d = c->dent;
        list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child)
                debugfs_remove(child);
        debugfs_remove(c->dent);
        return -ENOMEM;
}

static int clk_debugfs_register(struct clk *c)
{
        int err;
        struct clk *pa = c->parent;

        if (pa && !pa->dent) {
                err = clk_debugfs_register(pa);
                if (err)
                        return err;
        }

        if (!c->dent) {
                err = clk_debugfs_register_one(c);
                if (err)
                        return err;
        }
        return 0;
}

static int __init clk_debugfs_init(void)
{
        struct clk *c;
        struct dentry *d;
        int err = -ENOMEM;

        d = debugfs_create_dir("clock", NULL);
        if (!d)
                return -ENOMEM;
        clk_debugfs_root = d;

        d = debugfs_create_file("clock_tree", S_IRUGO, clk_debugfs_root, NULL,
                &clock_tree_fops);
        if (!d)
                goto err_out;

        list_for_each_entry(c, &clocks, node) {
                err = clk_debugfs_register(c);
                if (err)
                        goto err_out;
        }
        return 0;
err_out:
        debugfs_remove_recursive(clk_debugfs_root);
        return err;
}

late_initcall(clk_debugfs_init);
#endif