#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
-#include <linux/debugfs.h>
-#include <linux/delay.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
/*
* Locking:
*
- * Each struct clk has a spinlock.
- *
- * To avoid AB-BA locking problems, locks must always be traversed from child
- * clock to parent clock. For example, when enabling a clock, the clock's lock
- * is taken, and then clk_enable is called on the parent, which take's the
- * parent clock's lock. There is one exceptions to this ordering: When dumping
- * the clock tree through debugfs. In this case, clk_lock_all is called,
- * which attemps to iterate through the entire list of clocks and take every
- * clock lock. If any call to spin_trylock fails, all locked clocks are
- * unlocked, and the process is retried. When all the locks are held,
- * the only clock operation that can be called is clk_get_rate_all_locked.
- *
- * Within a single clock, no clock operation can call another clock operation
- * on itself, except for clk_get_rate_locked and clk_set_rate_locked. Any
- * clock operation can call any other clock operation on any of it's possible
- * parents.
- *
* An additional mutex, clock_list_lock, is used to protect the list of all
* clocks.
*
- * The clock operations must lock internally to protect against
- * read-modify-write on registers that are shared by multiple clocks
*/
static DEFINE_MUTEX(clock_list_lock);
static LIST_HEAD(clocks);
-#ifndef CONFIG_COMMON_CLK
-struct clk *tegra_get_clock_by_name(const char *name)
-{
- struct clk *c;
- struct clk *ret = NULL;
- mutex_lock(&clock_list_lock);
- list_for_each_entry(c, &clocks, node) {
- if (strcmp(c->name, name) == 0) {
- ret = c;
- break;
- }
- }
- mutex_unlock(&clock_list_lock);
- return ret;
-}
-
-/* Must be called with c->spinlock held */
-static unsigned long clk_predict_rate_from_parent(struct clk *c, struct clk *p)
-{
- u64 rate;
-
- rate = clk_get_rate(p);
-
- if (c->mul != 0 && c->div != 0) {
- rate *= c->mul;
- rate += c->div - 1; /* round up */
- do_div(rate, c->div);
- }
-
- return rate;
-}
-
-/* Must be called with c->spinlock held */
-unsigned long clk_get_rate_locked(struct clk *c)
-{
- unsigned long rate;
-
- if (c->parent)
- rate = clk_predict_rate_from_parent(c, c->parent);
- else
- rate = c->rate;
-
- return rate;
-}
-
-unsigned long clk_get_rate(struct clk *c)
-{
- unsigned long flags;
- unsigned long rate;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- rate = clk_get_rate_locked(c);
-
- spin_unlock_irqrestore(&c->spinlock, flags);
-
- return rate;
-}
-EXPORT_SYMBOL(clk_get_rate);
-
-int clk_reparent(struct clk *c, struct clk *parent)
-{
- c->parent = parent;
- return 0;
-}
-
-void clk_init(struct clk *c)
-{
- spin_lock_init(&c->spinlock);
-
- if (c->ops && c->ops->init)
- c->ops->init(c);
-
- if (!c->ops || !c->ops->enable) {
- c->refcnt++;
- c->set = true;
- if (c->parent)
- c->state = c->parent->state;
- else
- c->state = ON;
- }
-
- mutex_lock(&clock_list_lock);
- list_add(&c->node, &clocks);
- mutex_unlock(&clock_list_lock);
-}
-
-int clk_enable(struct clk *c)
-{
- int ret = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- if (c->refcnt == 0) {
- if (c->parent) {
- ret = clk_enable(c->parent);
- if (ret)
- goto out;
- }
-
- if (c->ops && c->ops->enable) {
- ret = c->ops->enable(c);
- if (ret) {
- if (c->parent)
- clk_disable(c->parent);
- goto out;
- }
- c->state = ON;
- c->set = true;
- }
- }
- c->refcnt++;
-out:
- spin_unlock_irqrestore(&c->spinlock, flags);
- return ret;
-}
-EXPORT_SYMBOL(clk_enable);
-
-void clk_disable(struct clk *c)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- if (c->refcnt == 0) {
- WARN(1, "Attempting to disable clock %s with refcnt 0", c->name);
- spin_unlock_irqrestore(&c->spinlock, flags);
- return;
- }
- if (c->refcnt == 1) {
- if (c->ops && c->ops->disable)
- c->ops->disable(c);
-
- if (c->parent)
- clk_disable(c->parent);
-
- c->state = OFF;
- }
- c->refcnt--;
-
- spin_unlock_irqrestore(&c->spinlock, flags);
-}
-EXPORT_SYMBOL(clk_disable);
-
-int clk_set_parent(struct clk *c, struct clk *parent)
-{
- int ret;
- unsigned long flags;
- unsigned long new_rate;
- unsigned long old_rate;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- if (!c->ops || !c->ops->set_parent) {
- ret = -ENOSYS;
- goto out;
- }
-
- new_rate = clk_predict_rate_from_parent(c, parent);
- old_rate = clk_get_rate_locked(c);
-
- ret = c->ops->set_parent(c, parent);
- if (ret)
- goto out;
-
-out:
- spin_unlock_irqrestore(&c->spinlock, 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)
-{
- long new_rate;
-
- if (!c->ops || !c->ops->set_rate)
- return -ENOSYS;
-
- if (rate > c->max_rate)
- rate = c->max_rate;
-
- if (c->ops && c->ops->round_rate) {
- new_rate = c->ops->round_rate(c, rate);
-
- if (new_rate < 0)
- return new_rate;
-
- rate = new_rate;
- }
-
- return c->ops->set_rate(c, rate);
-}
-
-int clk_set_rate(struct clk *c, unsigned long rate)
-{
- int ret;
- unsigned long flags;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- ret = clk_set_rate_locked(c, rate);
-
- spin_unlock_irqrestore(&c->spinlock, flags);
-
- return ret;
-}
-EXPORT_SYMBOL(clk_set_rate);
-
-
-/* Must be called with clocks lock and all indvidual clock locks held */
-unsigned long clk_get_rate_all_locked(struct clk *c)
-{
- u64 rate;
- int mul = 1;
- int div = 1;
- struct clk *p = c;
-
- while (p) {
- c = p;
- if (c->mul != 0 && c->div != 0) {
- mul *= c->mul;
- div *= c->div;
- }
- p = c->parent;
- }
-
- rate = c->rate;
- rate *= mul;
- do_div(rate, div);
-
- return rate;
-}
-
-long clk_round_rate(struct clk *c, unsigned long rate)
-{
- unsigned long flags;
- long ret;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- if (!c->ops || !c->ops->round_rate) {
- ret = -ENOSYS;
- goto out;
- }
-
- if (rate > c->max_rate)
- rate = c->max_rate;
-
- ret = c->ops->round_rate(c, rate);
-
-out:
- spin_unlock_irqrestore(&c->spinlock, flags);
- return ret;
-}
-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)
-{
- BUG_ON(!c->ops->reset);
- c->ops->reset(c, false);
-}
-EXPORT_SYMBOL(tegra_periph_reset_deassert);
-
-void tegra_periph_reset_assert(struct clk *c)
-{
- BUG_ON(!c->ops->reset);
- c->ops->reset(c, true);
-}
-EXPORT_SYMBOL(tegra_periph_reset_assert);
-
-/* Several extended clock configuration bits (e.g., clock routing, clock
- * phase control) are included in PLL and peripheral clock source
- * registers. */
-int tegra_clk_cfg_ex(struct clk *c, enum tegra_clk_ex_param p, u32 setting)
-{
- int ret = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&c->spinlock, flags);
-
- if (!c->ops || !c->ops->clk_cfg_ex) {
- ret = -ENOSYS;
- goto out;
- }
- ret = c->ops->clk_cfg_ex(c, p, setting);
-
-out:
- spin_unlock_irqrestore(&c->spinlock, flags);
-
- return ret;
-}
-
-#ifdef CONFIG_DEBUG_FS
-
-static int __clk_lock_all_spinlocks(void)
-{
- struct clk *c;
-
- list_for_each_entry(c, &clocks, node)
- if (!spin_trylock(&c->spinlock))
- goto unlock_spinlocks;
-
- return 0;
-
-unlock_spinlocks:
- list_for_each_entry_continue_reverse(c, &clocks, node)
- spin_unlock(&c->spinlock);
-
- return -EAGAIN;
-}
-
-static void __clk_unlock_all_spinlocks(void)
-{
- struct clk *c;
-
- list_for_each_entry_reverse(c, &clocks, node)
- spin_unlock(&c->spinlock);
-}
-
-/*
- * This function retries until it can take all locks, and may take
- * an arbitrarily long time to complete.
- * Must be called with irqs enabled, returns with irqs disabled
- * Must be called with clock_list_lock held
- */
-static void clk_lock_all(void)
-{
- int ret;
-retry:
- local_irq_disable();
-
- ret = __clk_lock_all_spinlocks();
- if (ret)
- goto failed_spinlocks;
-
- /* All locks taken successfully, return */
- return;
-
-failed_spinlocks:
- local_irq_enable();
- yield();
- goto retry;
-}
-
-/*
- * Unlocks all clocks after a clk_lock_all
- * Must be called with irqs disabled, returns with irqs enabled
- * Must be called with clock_list_lock held
- */
-static void clk_unlock_all(void)
-{
- __clk_unlock_all_spinlocks();
-
- local_irq_enable();
-}
-
-static struct dentry *clk_debugfs_root;
-
-
-static void clock_tree_show_one(struct seq_file *s, struct clk *c, int level)
-{
- struct clk *child;
- 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, clk_get_rate_all_locked(c));
-
- list_for_each_entry(child, &clocks, node) {
- if (child->parent != c)
- continue;
-
- clock_tree_show_one(s, child, level + 1);
- }
-}
-
-static int clock_tree_show(struct seq_file *s, void *data)
-{
- struct clk *c;
- seq_printf(s, " clock state ref div rate\n");
- seq_printf(s, "--------------------------------------------------------------\n");
-
- mutex_lock(&clock_list_lock);
-
- clk_lock_all();
-
- list_for_each_entry(c, &clocks, node)
- if (c->parent == NULL)
- clock_tree_show_one(s, c, 0);
-
- clk_unlock_all();
-
- mutex_unlock(&clock_list_lock);
- 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;
-
- 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:
- debugfs_remove_recursive(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;
-}
-
-int __init tegra_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;
-}
-#endif
-#else
-
void tegra_clk_add(struct clk *clk)
{
struct clk_tegra *c = to_clk_tegra(__clk_get_hw(clk));
out:
return ret;
}
-#endif /* !CONFIG_COMMON_CLK */
projects / platform / upstream / kernel-adaptation-pc.git / commitdiff