/*
* arch/sh/kernel/cpu/clock.c - SuperH clock framework
*
- * Copyright (C) 2005, 2006, 2007 Paul Mundt
+ * Copyright (C) 2005 - 2009 Paul Mundt
*
* This clock framework is derived from the OMAP version by:
*
- * Copyright (C) 2004 - 2005 Nokia Corporation
+ * 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>
*
+ * With clkdev bits:
+ *
+ * Copyright (C) 2008 Russell King.
+ *
* 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/module.h>
#include <linux/mutex.h>
#include <linux/list.h>
-#include <linux/kref.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/proc_fs.h>
+#include <linux/debugfs.h>
#include <asm/clock.h>
-#include <asm/timer.h>
+#include <asm/machvec.h>
static LIST_HEAD(clock_list);
static DEFINE_SPINLOCK(clock_lock);
static DEFINE_MUTEX(clock_list_sem);
-/*
- * Each subtype is expected to define the init routines for these clocks,
- * as each subtype (or processor family) will have these clocks at the
- * very least. These are all provided through the CPG, which even some of
- * the more quirky parts (such as ST40, SH4-202, etc.) still have.
- *
- * The processor-specific code is expected to register any additional
- * clock sources that are of interest.
- */
-static struct clk master_clk = {
- .name = "master_clk",
- .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
- .rate = CONFIG_SH_PCLK_FREQ,
-};
+/* 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;
+}
-static struct clk module_clk = {
- .name = "module_clk",
- .parent = &master_clk,
- .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
-};
+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;
-static struct clk bus_clk = {
- .name = "bus_clk",
- .parent = &master_clk,
- .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
-};
+ /* now do the debugfs renaming to reattach the child
+ to the proper parent */
-static struct clk cpu_clk = {
- .name = "cpu_clk",
- .parent = &master_clk,
- .flags = CLK_ALWAYS_ENABLED,
-};
-
-/*
- * The ordering of these clocks matters, do not change it.
- */
-static struct clk *onchip_clocks[] = {
- &master_clk,
- &module_clk,
- &bus_clk,
- &cpu_clk,
-};
+ return 0;
+}
-static void propagate_rate(struct clk *clk)
+/* Propagate rate to children */
+void propagate_rate(struct clk *tclk)
{
struct clk *clkp;
- list_for_each_entry(clkp, &clock_list, node) {
- if (likely(clkp->parent != clk))
- continue;
- if (likely(clkp->ops && clkp->ops->recalc))
- clkp->ops->recalc(clkp);
- if (unlikely(clkp->flags & CLK_RATE_PROPAGATES))
- propagate_rate(clkp);
+ list_for_each_entry(clkp, &tclk->children, sibling) {
+ if (clkp->ops && clkp->ops->recalc)
+ clkp->rate = clkp->ops->recalc(clkp);
+ if (clkp->ops && clkp->ops->build_rate_table)
+ clkp->ops->build_rate_table(clkp);
+
+ propagate_rate(clkp);
}
}
-static int __clk_enable(struct clk *clk)
+static void __clk_disable(struct clk *clk)
{
- /*
- * See if this is the first time we're enabling the clock, some
- * clocks that are always enabled still require "special"
- * initialization. This is especially true if the clock mode
- * changes and the clock needs to hunt for the proper set of
- * divisors to use before it can effectively recalc.
- */
- if (unlikely(atomic_read(&clk->kref.refcount) == 1))
- if (clk->ops && clk->ops->init)
- clk->ops->init(clk);
+ if (clk->usecount == 0) {
+ printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
+ clk->name);
+ WARN_ON(1);
+ return;
+ }
- kref_get(&clk->kref);
+ if (!(--clk->usecount)) {
+ if (likely(clk->ops && clk->ops->disable))
+ clk->ops->disable(clk);
+ if (likely(clk->parent))
+ __clk_disable(clk->parent);
+ }
+}
- if (clk->flags & CLK_ALWAYS_ENABLED)
- return 0;
+void clk_disable(struct clk *clk)
+{
+ unsigned long flags;
- if (likely(clk->ops && clk->ops->enable))
- clk->ops->enable(clk);
+ if (!clk)
+ return;
- return 0;
+ 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)
if (!clk)
return -EINVAL;
- clk_enable(clk->parent);
-
spin_lock_irqsave(&clock_lock, flags);
ret = __clk_enable(clk);
spin_unlock_irqrestore(&clock_lock, flags);
}
EXPORT_SYMBOL_GPL(clk_enable);
-static void clk_kref_release(struct kref *kref)
-{
- /* Nothing to do */
-}
+static LIST_HEAD(root_clks);
-static void __clk_disable(struct clk *clk)
+/**
+ * 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)
{
- int count = kref_put(&clk->kref, clk_kref_release);
-
- if (clk->flags & CLK_ALWAYS_ENABLED)
- return;
+ struct clk *clkp;
- if (!count) { /* count reaches zero, disable the clock */
- if (likely(clk->ops && clk->ops->disable))
- clk->ops->disable(clk);
+ list_for_each_entry(clkp, &root_clks, sibling) {
+ if (clkp->ops && clkp->ops->recalc)
+ clkp->rate = clkp->ops->recalc(clkp);
+ propagate_rate(clkp);
}
}
-void clk_disable(struct clk *clk)
+int clk_register(struct clk *clk)
{
- unsigned long flags;
+ if (clk == NULL || IS_ERR(clk))
+ return -EINVAL;
- if (!clk)
- return;
+ /*
+ * trap out already registered clocks
+ */
+ if (clk->node.next || clk->node.prev)
+ return 0;
- spin_lock_irqsave(&clock_lock, flags);
- __clk_disable(clk);
- spin_unlock_irqrestore(&clock_lock, flags);
+ mutex_lock(&clock_list_sem);
- clk_disable(clk->parent);
-}
-EXPORT_SYMBOL_GPL(clk_disable);
+ INIT_LIST_HEAD(&clk->children);
+ clk->usecount = 0;
-int clk_register(struct clk *clk)
-{
- mutex_lock(&clock_list_sem);
+ if (clk->parent)
+ list_add(&clk->sibling, &clk->parent->children);
+ else
+ list_add(&clk->sibling, &root_clks);
list_add(&clk->node, &clock_list);
- kref_init(&clk->kref);
-
+ if (clk->ops && clk->ops->init)
+ clk->ops->init(clk);
mutex_unlock(&clock_list_sem);
- if (clk->flags & CLK_ALWAYS_ENABLED) {
- pr_debug( "Clock '%s' is ALWAYS_ENABLED\n", clk->name);
- if (clk->ops && clk->ops->init)
- clk->ops->init(clk);
- if (clk->ops && clk->ops->enable)
- clk->ops->enable(clk);
- pr_debug( "Enabled.");
- }
-
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);
+static 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;
int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
{
int ret = -EOPNOTSUPP;
+ unsigned long flags;
- if (likely(clk->ops && clk->ops->set_rate)) {
- unsigned long flags;
+ spin_lock_irqsave(&clock_lock, flags);
- spin_lock_irqsave(&clock_lock, flags);
+ if (likely(clk->ops && clk->ops->set_rate)) {
ret = clk->ops->set_rate(clk, rate, algo_id);
- spin_unlock_irqrestore(&clock_lock, flags);
+ if (ret != 0)
+ goto out_unlock;
+ } else {
+ clk->rate = rate;
+ ret = 0;
}
- if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
- propagate_rate(clk);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(clk_set_rate_ex);
+ if (clk->ops && clk->ops->recalc)
+ clk->rate = clk->ops->recalc(clk);
-void clk_recalc_rate(struct clk *clk)
-{
- if (likely(clk->ops && clk->ops->recalc)) {
- unsigned long flags;
+ propagate_rate(clk);
- spin_lock_irqsave(&clock_lock, flags);
- clk->ops->recalc(clk);
- spin_unlock_irqrestore(&clock_lock, flags);
- }
+out_unlock:
+ spin_unlock_irqrestore(&clock_lock, flags);
- if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
- propagate_rate(clk);
+ return ret;
}
-EXPORT_SYMBOL_GPL(clk_recalc_rate);
+EXPORT_SYMBOL_GPL(clk_set_rate_ex);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
+ unsigned long flags;
int ret = -EINVAL;
- struct clk *old;
if (!parent || !clk)
return ret;
+ if (clk->parent == parent)
+ return 0;
- old = clk->parent;
- if (likely(clk->ops && clk->ops->set_parent)) {
- unsigned long flags;
- spin_lock_irqsave(&clock_lock, flags);
- ret = clk->ops->set_parent(clk, parent);
- spin_unlock_irqrestore(&clock_lock, flags);
- clk->parent = (ret ? old : parent);
- }
+ 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);
- if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
- propagate_rate(clk);
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_parent);
}
EXPORT_SYMBOL_GPL(clk_round_rate);
+/*
+ * Find the correct struct clk for the device and connection ID.
+ * We do slightly fuzzy matching here:
+ * An entry with a NULL ID is assumed to be a wildcard.
+ * If an entry has a device ID, it must match
+ * If an entry has a connection ID, it must match
+ * Then we take the most specific entry - with the following
+ * order of precidence: dev+con > dev only > con only.
+ */
+static struct clk *clk_find(const char *dev_id, const char *con_id)
+{
+ struct clk_lookup *p;
+ struct clk *clk = NULL;
+ int match, best = 0;
+
+ list_for_each_entry(p, &clock_list, node) {
+ match = 0;
+ if (p->dev_id) {
+ if (!dev_id || strcmp(p->dev_id, dev_id))
+ continue;
+ match += 2;
+ }
+ if (p->con_id) {
+ if (!con_id || strcmp(p->con_id, con_id))
+ continue;
+ match += 1;
+ }
+ if (match == 0)
+ continue;
+
+ if (match > best) {
+ clk = p->clk;
+ best = match;
+ }
+ }
+ return clk;
+}
+
+struct clk *clk_get_sys(const char *dev_id, const char *con_id)
+{
+ struct clk *clk;
+
+ mutex_lock(&clock_list_sem);
+ clk = clk_find(dev_id, con_id);
+ mutex_unlock(&clock_list_sem);
+
+ return clk ? clk : ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL_GPL(clk_get_sys);
+
/*
* Returns a clock. Note that we first try to use device id on the bus
* and clock name. If this fails, we try to use clock name only.
*/
struct clk *clk_get(struct device *dev, const char *id)
{
+ const char *dev_id = dev ? dev_name(dev) : NULL;
struct clk *p, *clk = ERR_PTR(-ENOENT);
int idno;
+ clk = clk_get_sys(dev_id, id);
+ if (clk && !IS_ERR(clk))
+ return clk;
+
if (dev == NULL || dev->bus != &platform_bus_type)
idno = -1;
else
}
EXPORT_SYMBOL_GPL(clk_put);
-void __init __attribute__ ((weak))
-arch_init_clk_ops(struct clk_ops **ops, int type)
-{
-}
-
-int __init __attribute__ ((weak))
-arch_clk_init(void)
-{
- return 0;
-}
-
-static int show_clocks(char *buf, char **start, off_t off,
- int len, int *eof, void *data)
-{
- struct clk *clk;
- char *p = buf;
-
- list_for_each_entry_reverse(clk, &clock_list, node) {
- unsigned long rate = clk_get_rate(clk);
-
- p += sprintf(p, "%-12s\t: %ld.%02ldMHz\t%s\n", clk->name,
- rate / 1000000, (rate % 1000000) / 10000,
- ((clk->flags & CLK_ALWAYS_ENABLED) ||
- (atomic_read(&clk->kref.refcount) != 1)) ?
- "enabled" : "disabled");
- }
-
- return p - buf;
-}
-
#ifdef CONFIG_PM
static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state)
{
switch (state.event) {
case PM_EVENT_ON:
/* Resumeing from hibernation */
- if (prev_state.event == PM_EVENT_FREEZE) {
- 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->ops->recalc(clkp);
- }
+ 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:
int __init clk_init(void)
{
- int i, ret = 0;
-
- BUG_ON(!master_clk.rate);
-
- for (i = 0; i < ARRAY_SIZE(onchip_clocks); i++) {
- struct clk *clk = onchip_clocks[i];
+ int ret;
- arch_init_clk_ops(&clk->ops, i);
- ret |= clk_register(clk);
+ ret = arch_clk_init();
+ if (unlikely(ret)) {
+ pr_err("%s: CPU clock registration failed.\n", __func__);
+ return ret;
}
- ret |= arch_clk_init();
+ if (sh_mv.mv_clk_init) {
+ ret = sh_mv.mv_clk_init();
+ if (unlikely(ret)) {
+ pr_err("%s: machvec clock initialization failed.\n",
+ __func__);
+ return ret;
+ }
+ }
/* Kick the child clocks.. */
- propagate_rate(&master_clk);
- propagate_rate(&bus_clk);
+ recalculate_root_clocks();
+
+ /* Enable the necessary init clocks */
+ clk_enable_init_clocks();
return ret;
}
-static int __init clk_proc_init(void)
+/*
+ * debugfs support to trace clock tree hierarchy and attributes
+ */
+static struct dentry *clk_debugfs_root;
+
+static int clk_debugfs_register_one(struct clk *c)
{
- struct proc_dir_entry *p;
- p = create_proc_read_entry("clocks", S_IRUSR, NULL,
- show_clocks, NULL);
- if (unlikely(!p))
- return -EINVAL;
+ int err;
+ struct dentry *d, *child;
+ 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(child, &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(clk_debugfs_root); /* REVISIT: Cleanup correctly */
+ return err;
}
-subsys_initcall(clk_proc_init);
+late_initcall(clk_debugfs_init);
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