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path: root/drivers/sh/clk/core.c
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-rw-r--r--drivers/sh/clk/core.c694
1 files changed, 694 insertions, 0 deletions
diff --git a/drivers/sh/clk/core.c b/drivers/sh/clk/core.c
new file mode 100644
index 000000000000..fd0d1b98901c
--- /dev/null
+++ b/drivers/sh/clk/core.c
@@ -0,0 +1,694 @@
+/*
+ * SuperH clock framework
+ *
+ * Copyright (C) 2005 - 2010 Paul Mundt
+ *
+ * This clock framework is derived from the OMAP version by:
+ *
+ * Copyright (C) 2004 - 2008 Nokia Corporation
+ * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
+ *
+ * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) "clock: " fmt
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/kobject.h>
+#include <linux/sysdev.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/debugfs.h>
+#include <linux/cpufreq.h>
+#include <linux/clk.h>
+#include <linux/sh_clk.h>
+
+static LIST_HEAD(clock_list);
+static DEFINE_SPINLOCK(clock_lock);
+static DEFINE_MUTEX(clock_list_sem);
+
+void clk_rate_table_build(struct clk *clk,
+ struct cpufreq_frequency_table *freq_table,
+ int nr_freqs,
+ struct clk_div_mult_table *src_table,
+ unsigned long *bitmap)
+{
+ unsigned long mult, div;
+ unsigned long freq;
+ int i;
+
+ clk->nr_freqs = nr_freqs;
+
+ for (i = 0; i < nr_freqs; i++) {
+ div = 1;
+ mult = 1;
+
+ if (src_table->divisors && i < src_table->nr_divisors)
+ div = src_table->divisors[i];
+
+ if (src_table->multipliers && i < src_table->nr_multipliers)
+ mult = src_table->multipliers[i];
+
+ if (!div || !mult || (bitmap && !test_bit(i, bitmap)))
+ freq = CPUFREQ_ENTRY_INVALID;
+ else
+ freq = clk->parent->rate * mult / div;
+
+ freq_table[i].index = i;
+ freq_table[i].frequency = freq;
+ }
+
+ /* Termination entry */
+ freq_table[i].index = i;
+ freq_table[i].frequency = CPUFREQ_TABLE_END;
+}
+
+struct clk_rate_round_data;
+
+struct clk_rate_round_data {
+ unsigned long rate;
+ unsigned int min, max;
+ long (*func)(unsigned int, struct clk_rate_round_data *);
+ void *arg;
+};
+
+#define for_each_frequency(pos, r, freq) \
+ for (pos = r->min, freq = r->func(pos, r); \
+ pos <= r->max; pos++, freq = r->func(pos, r)) \
+ if (unlikely(freq == 0)) \
+ ; \
+ else
+
+static long clk_rate_round_helper(struct clk_rate_round_data *rounder)
+{
+ unsigned long rate_error, rate_error_prev = ~0UL;
+ unsigned long rate_best_fit = rounder->rate;
+ unsigned long highest, lowest, freq;
+ int i;
+
+ highest = 0;
+ lowest = ~0UL;
+
+ for_each_frequency(i, rounder, freq) {
+ if (freq > highest)
+ highest = freq;
+ if (freq < lowest)
+ lowest = freq;
+
+ rate_error = abs(freq - rounder->rate);
+ if (rate_error < rate_error_prev) {
+ rate_best_fit = freq;
+ rate_error_prev = rate_error;
+ }
+
+ if (rate_error == 0)
+ break;
+ }
+
+ if (rounder->rate >= highest)
+ rate_best_fit = highest;
+ if (rounder->rate <= lowest)
+ rate_best_fit = lowest;
+
+ return rate_best_fit;
+}
+
+static long clk_rate_table_iter(unsigned int pos,
+ struct clk_rate_round_data *rounder)
+{
+ struct cpufreq_frequency_table *freq_table = rounder->arg;
+ unsigned long freq = freq_table[pos].frequency;
+
+ if (freq == CPUFREQ_ENTRY_INVALID)
+ freq = 0;
+
+ return freq;
+}
+
+long clk_rate_table_round(struct clk *clk,
+ struct cpufreq_frequency_table *freq_table,
+ unsigned long rate)
+{
+ struct clk_rate_round_data table_round = {
+ .min = 0,
+ .max = clk->nr_freqs - 1,
+ .func = clk_rate_table_iter,
+ .arg = freq_table,
+ .rate = rate,
+ };
+
+ if (clk->nr_freqs < 1)
+ return 0;
+
+ return clk_rate_round_helper(&table_round);
+}
+
+static long clk_rate_div_range_iter(unsigned int pos,
+ struct clk_rate_round_data *rounder)
+{
+ return clk_get_rate(rounder->arg) / pos;
+}
+
+long clk_rate_div_range_round(struct clk *clk, unsigned int div_min,
+ unsigned int div_max, unsigned long rate)
+{
+ struct clk_rate_round_data div_range_round = {
+ .min = div_min,
+ .max = div_max,
+ .func = clk_rate_div_range_iter,
+ .arg = clk_get_parent(clk),
+ .rate = rate,
+ };
+
+ return clk_rate_round_helper(&div_range_round);
+}
+
+int clk_rate_table_find(struct clk *clk,
+ struct cpufreq_frequency_table *freq_table,
+ unsigned long rate)
+{
+ int i;
+
+ for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
+ unsigned long freq = freq_table[i].frequency;
+
+ if (freq == CPUFREQ_ENTRY_INVALID)
+ continue;
+
+ if (freq == rate)
+ return i;
+ }
+
+ return -ENOENT;
+}
+
+/* Used for clocks that always have same value as the parent clock */
+unsigned long followparent_recalc(struct clk *clk)
+{
+ return clk->parent ? clk->parent->rate : 0;
+}
+
+int clk_reparent(struct clk *child, struct clk *parent)
+{
+ list_del_init(&child->sibling);
+ if (parent)
+ list_add(&child->sibling, &parent->children);
+ child->parent = parent;
+
+ /* now do the debugfs renaming to reattach the child
+ to the proper parent */
+
+ return 0;
+}
+
+/* Propagate rate to children */
+void propagate_rate(struct clk *tclk)
+{
+ struct clk *clkp;
+
+ list_for_each_entry(clkp, &tclk->children, sibling) {
+ if (clkp->ops && clkp->ops->recalc)
+ clkp->rate = clkp->ops->recalc(clkp);
+
+ propagate_rate(clkp);
+ }
+}
+
+static void __clk_disable(struct clk *clk)
+{
+ if (WARN(!clk->usecount, "Trying to disable clock %p with 0 usecount\n",
+ clk))
+ return;
+
+ if (!(--clk->usecount)) {
+ if (likely(clk->ops && clk->ops->disable))
+ clk->ops->disable(clk);
+ if (likely(clk->parent))
+ __clk_disable(clk->parent);
+ }
+}
+
+void clk_disable(struct clk *clk)
+{
+ unsigned long flags;
+
+ if (!clk)
+ return;
+
+ spin_lock_irqsave(&clock_lock, flags);
+ __clk_disable(clk);
+ spin_unlock_irqrestore(&clock_lock, flags);
+}
+EXPORT_SYMBOL_GPL(clk_disable);
+
+static int __clk_enable(struct clk *clk)
+{
+ int ret = 0;
+
+ if (clk->usecount++ == 0) {
+ if (clk->parent) {
+ ret = __clk_enable(clk->parent);
+ if (unlikely(ret))
+ goto err;
+ }
+
+ if (clk->ops && clk->ops->enable) {
+ ret = clk->ops->enable(clk);
+ if (ret) {
+ if (clk->parent)
+ __clk_disable(clk->parent);
+ goto err;
+ }
+ }
+ }
+
+ return ret;
+err:
+ clk->usecount--;
+ return ret;
+}
+
+int clk_enable(struct clk *clk)
+{
+ unsigned long flags;
+ int ret;
+
+ if (!clk)
+ return -EINVAL;
+
+ spin_lock_irqsave(&clock_lock, flags);
+ ret = __clk_enable(clk);
+ spin_unlock_irqrestore(&clock_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_enable);
+
+static LIST_HEAD(root_clks);
+
+/**
+ * recalculate_root_clocks - recalculate and propagate all root clocks
+ *
+ * Recalculates all root clocks (clocks with no parent), which if the
+ * clock's .recalc is set correctly, should also propagate their rates.
+ * Called at init.
+ */
+void recalculate_root_clocks(void)
+{
+ struct clk *clkp;
+
+ list_for_each_entry(clkp, &root_clks, sibling) {
+ if (clkp->ops && clkp->ops->recalc)
+ clkp->rate = clkp->ops->recalc(clkp);
+ propagate_rate(clkp);
+ }
+}
+
+static struct clk_mapping dummy_mapping;
+
+static struct clk *lookup_root_clock(struct clk *clk)
+{
+ while (clk->parent)
+ clk = clk->parent;
+
+ return clk;
+}
+
+static int clk_establish_mapping(struct clk *clk)
+{
+ struct clk_mapping *mapping = clk->mapping;
+
+ /*
+ * Propagate mappings.
+ */
+ if (!mapping) {
+ struct clk *clkp;
+
+ /*
+ * dummy mapping for root clocks with no specified ranges
+ */
+ if (!clk->parent) {
+ clk->mapping = &dummy_mapping;
+ return 0;
+ }
+
+ /*
+ * If we're on a child clock and it provides no mapping of its
+ * own, inherit the mapping from its root clock.
+ */
+ clkp = lookup_root_clock(clk);
+ mapping = clkp->mapping;
+ BUG_ON(!mapping);
+ }
+
+ /*
+ * Establish initial mapping.
+ */
+ if (!mapping->base && mapping->phys) {
+ kref_init(&mapping->ref);
+
+ mapping->base = ioremap_nocache(mapping->phys, mapping->len);
+ if (unlikely(!mapping->base))
+ return -ENXIO;
+ } else if (mapping->base) {
+ /*
+ * Bump the refcount for an existing mapping
+ */
+ kref_get(&mapping->ref);
+ }
+
+ clk->mapping = mapping;
+ return 0;
+}
+
+static void clk_destroy_mapping(struct kref *kref)
+{
+ struct clk_mapping *mapping;
+
+ mapping = container_of(kref, struct clk_mapping, ref);
+
+ iounmap(mapping->base);
+}
+
+static void clk_teardown_mapping(struct clk *clk)
+{
+ struct clk_mapping *mapping = clk->mapping;
+
+ /* Nothing to do */
+ if (mapping == &dummy_mapping)
+ return;
+
+ kref_put(&mapping->ref, clk_destroy_mapping);
+ clk->mapping = NULL;
+}
+
+int clk_register(struct clk *clk)
+{
+ int ret;
+
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
+
+ /*
+ * trap out already registered clocks
+ */
+ if (clk->node.next || clk->node.prev)
+ return 0;
+
+ mutex_lock(&clock_list_sem);
+
+ INIT_LIST_HEAD(&clk->children);
+ clk->usecount = 0;
+
+ ret = clk_establish_mapping(clk);
+ if (unlikely(ret))
+ goto out_unlock;
+
+ if (clk->parent)
+ list_add(&clk->sibling, &clk->parent->children);
+ else
+ list_add(&clk->sibling, &root_clks);
+
+ list_add(&clk->node, &clock_list);
+ if (clk->ops && clk->ops->init)
+ clk->ops->init(clk);
+
+out_unlock:
+ mutex_unlock(&clock_list_sem);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_register);
+
+void clk_unregister(struct clk *clk)
+{
+ mutex_lock(&clock_list_sem);
+ list_del(&clk->sibling);
+ list_del(&clk->node);
+ clk_teardown_mapping(clk);
+ mutex_unlock(&clock_list_sem);
+}
+EXPORT_SYMBOL_GPL(clk_unregister);
+
+void clk_enable_init_clocks(void)
+{
+ struct clk *clkp;
+
+ list_for_each_entry(clkp, &clock_list, node)
+ if (clkp->flags & CLK_ENABLE_ON_INIT)
+ clk_enable(clkp);
+}
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+ return clk->rate;
+}
+EXPORT_SYMBOL_GPL(clk_get_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+ return clk_set_rate_ex(clk, rate, 0);
+}
+EXPORT_SYMBOL_GPL(clk_set_rate);
+
+int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
+{
+ int ret = -EOPNOTSUPP;
+ unsigned long flags;
+
+ spin_lock_irqsave(&clock_lock, flags);
+
+ if (likely(clk->ops && clk->ops->set_rate)) {
+ ret = clk->ops->set_rate(clk, rate, algo_id);
+ if (ret != 0)
+ goto out_unlock;
+ } else {
+ clk->rate = rate;
+ ret = 0;
+ }
+
+ if (clk->ops && clk->ops->recalc)
+ clk->rate = clk->ops->recalc(clk);
+
+ propagate_rate(clk);
+
+out_unlock:
+ spin_unlock_irqrestore(&clock_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_rate_ex);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ unsigned long flags;
+ int ret = -EINVAL;
+
+ if (!parent || !clk)
+ return ret;
+ if (clk->parent == parent)
+ return 0;
+
+ spin_lock_irqsave(&clock_lock, flags);
+ if (clk->usecount == 0) {
+ if (clk->ops->set_parent)
+ ret = clk->ops->set_parent(clk, parent);
+ else
+ ret = clk_reparent(clk, parent);
+
+ if (ret == 0) {
+ if (clk->ops->recalc)
+ clk->rate = clk->ops->recalc(clk);
+ pr_debug("set parent of %p to %p (new rate %ld)\n",
+ clk, clk->parent, clk->rate);
+ propagate_rate(clk);
+ }
+ } else
+ ret = -EBUSY;
+ spin_unlock_irqrestore(&clock_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_parent);
+
+struct clk *clk_get_parent(struct clk *clk)
+{
+ return clk->parent;
+}
+EXPORT_SYMBOL_GPL(clk_get_parent);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+ if (likely(clk->ops && clk->ops->round_rate)) {
+ unsigned long flags, rounded;
+
+ spin_lock_irqsave(&clock_lock, flags);
+ rounded = clk->ops->round_rate(clk, rate);
+ spin_unlock_irqrestore(&clock_lock, flags);
+
+ return rounded;
+ }
+
+ return clk_get_rate(clk);
+}
+EXPORT_SYMBOL_GPL(clk_round_rate);
+
+#ifdef CONFIG_PM
+static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state)
+{
+ static pm_message_t prev_state;
+ struct clk *clkp;
+
+ switch (state.event) {
+ case PM_EVENT_ON:
+ /* Resumeing from hibernation */
+ if (prev_state.event != PM_EVENT_FREEZE)
+ break;
+
+ list_for_each_entry(clkp, &clock_list, node) {
+ if (likely(clkp->ops)) {
+ unsigned long rate = clkp->rate;
+
+ if (likely(clkp->ops->set_parent))
+ clkp->ops->set_parent(clkp,
+ clkp->parent);
+ if (likely(clkp->ops->set_rate))
+ clkp->ops->set_rate(clkp,
+ rate, NO_CHANGE);
+ else if (likely(clkp->ops->recalc))
+ clkp->rate = clkp->ops->recalc(clkp);
+ }
+ }
+ break;
+ case PM_EVENT_FREEZE:
+ break;
+ case PM_EVENT_SUSPEND:
+ break;
+ }
+
+ prev_state = state;
+ return 0;
+}
+
+static int clks_sysdev_resume(struct sys_device *dev)
+{
+ return clks_sysdev_suspend(dev, PMSG_ON);
+}
+
+static struct sysdev_class clks_sysdev_class = {
+ .name = "clks",
+};
+
+static struct sysdev_driver clks_sysdev_driver = {
+ .suspend = clks_sysdev_suspend,
+ .resume = clks_sysdev_resume,
+};
+
+static struct sys_device clks_sysdev_dev = {
+ .cls = &clks_sysdev_class,
+};
+
+static int __init clk_sysdev_init(void)
+{
+ sysdev_class_register(&clks_sysdev_class);
+ sysdev_driver_register(&clks_sysdev_class, &clks_sysdev_driver);
+ sysdev_register(&clks_sysdev_dev);
+
+ return 0;
+}
+subsys_initcall(clk_sysdev_init);
+#endif
+
+/*
+ * debugfs support to trace clock tree hierarchy and attributes
+ */
+static struct dentry *clk_debugfs_root;
+
+static int clk_debugfs_register_one(struct clk *c)
+{
+ int err;
+ struct dentry *d, *child, *child_tmp;
+ struct clk *pa = c->parent;
+ char s[255];
+ char *p = s;
+
+ p += sprintf(p, "%p", c);
+ d = debugfs_create_dir(s, pa ? pa->dentry : clk_debugfs_root);
+ if (!d)
+ return -ENOMEM;
+ c->dentry = d;
+
+ d = debugfs_create_u8("usecount", S_IRUGO, c->dentry, (u8 *)&c->usecount);
+ if (!d) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ d = debugfs_create_u32("rate", S_IRUGO, c->dentry, (u32 *)&c->rate);
+ if (!d) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ d = debugfs_create_x32("flags", S_IRUGO, c->dentry, (u32 *)&c->flags);
+ if (!d) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ return 0;
+
+err_out:
+ d = c->dentry;
+ list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child)
+ debugfs_remove(child);
+ debugfs_remove(c->dentry);
+ return err;
+}
+
+static int clk_debugfs_register(struct clk *c)
+{
+ int err;
+ struct clk *pa = c->parent;
+
+ if (pa && !pa->dentry) {
+ err = clk_debugfs_register(pa);
+ if (err)
+ return err;
+ }
+
+ if (!c->dentry) {
+ 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;
+
+ d = debugfs_create_dir("clock", NULL);
+ if (!d)
+ return -ENOMEM;
+ clk_debugfs_root = d;
+
+ list_for_each_entry(c, &clock_list, 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 01:58:10 +0000