Logo Search packages:      
Sourcecode: linux version File versions  Download package

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

Generated by  Doxygen 1.6.0   Back to index