sh: move sh clock.c contents to drivers/sh/clk.

This patch is V2 of the SH clock framework move from
arch/sh/kernel/cpu/clock.c to drivers/sh/clk.c. All
code except the following functions are moved:
clk_init(), clk_get() and clk_put().

The init function is still kept in clock.c since it
depends on the SH-specific machvec implementation.

The symbols clk_get() and clk_put() already exist in
the common ARM clkdev code, those symbols are left in
the SH tree to avoid duplicating them for SH-Mobile ARM.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 549 insertions, 0 deletions

diff --git a/drivers/sh/Makefile b/drivers/sh/Makefile
index 4956bf1f2134..033a949c496a 100644
--- a/drivers/sh/Makefile
+++ b/drivers/sh/Makefile
@@ -4,4 +4,5 @@
 obj-$(CONFIG_SUPERHYWAY)	+= superhyway/
 obj-$(CONFIG_MAPLE)		+= maple/
 obj-$(CONFIG_GENERIC_GPIO)	+= pfc.o
+obj-$(CONFIG_SUPERH)		+= clk.o
 obj-y				+= intc.o
diff --git a/drivers/sh/clk.c b/drivers/sh/clk.c
new file mode 100644
index 000000000000..c90a3e1e1085
--- /dev/null
+++ b/drivers/sh/clk.c
@@ -0,0 +1,548 @@
+/*
+ * drivers/sh/clk.c - SuperH clock framework
+ *
+ *  Copyright (C) 2005 - 2009  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.
+ */
+#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/platform_device.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;
+
+	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;
+}
+
+long clk_rate_table_round(struct clk *clk,
+			  struct cpufreq_frequency_table *freq_table,
+			  unsigned long rate)
+{
+	unsigned long rate_error, rate_error_prev = ~0UL;
+	unsigned long rate_best_fit = rate;
+	unsigned long highest, lowest;
+	int i;
+
+	highest = lowest = 0;
+
+	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 > highest)
+			highest = freq;
+		if (freq < lowest)
+			lowest = freq;
+
+		rate_error = abs(freq - rate);
+		if (rate_error < rate_error_prev) {
+			rate_best_fit = freq;
+			rate_error_prev = rate_error;
+		}
+
+		if (rate_error == 0)
+			break;
+	}
+
+	if (rate >= highest)
+		rate_best_fit = highest;
+	if (rate <= lowest)
+		rate_best_fit = lowest;
+
+	return rate_best_fit;
+}
+
+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 (clk->usecount == 0) {
+		printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
+		       clk->name);
+		WARN_ON(1);
+		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);
+	}
+}
+
+int clk_register(struct clk *clk)
+{
+	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;
+
+	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);
+	mutex_unlock(&clock_list_sem);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(clk_register);
+
+void clk_unregister(struct clk *clk)
+{
+	mutex_lock(&clock_list_sem);
+	list_del(&clk->sibling);
+	list_del(&clk->node);
+	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) {
+			pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
+				 clk->name, clk->parent->name, clk->rate);
+			if (clk->ops->recalc)
+				clk->rate = clk->ops->recalc(clk);
+			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, "%s", c->name);
+	if (c->id >= 0)
+		sprintf(p, ":%d", c->id);
+	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 && c->name) {
+		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);