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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-26 12:42:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-26 12:42:29 -0700
commit27953437059c64d14086196eb96f43c78caa9db3 (patch)
tree0cfd5fb21262a6db3de0c64462847b4c0c43e9df /drivers/clk/clk.c
parentMerge tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc (diff)
parentMerge branch 'clk-next' of git://git.linaro.org/people/mturquette/linux into next/clock (diff)
downloadlinux-dev-27953437059c64d14086196eb96f43c78caa9db3.tar.xz
linux-dev-27953437059c64d14086196eb96f43c78caa9db3.zip
Merge tag 'clock' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull arm-soc clock driver changes from Olof Johansson: "The new clock subsystem was merged in linux-3.4 without any users, this now moves the first three platforms over to it: imx, mxs and spear. The series also contains the changes for the clock subsystem itself, since Mike preferred to have it together with the platforms that require these changes, in order to avoid interdependencies and conflicts." Fix up trivial conflicts in arch/arm/mach-kirkwood/common.c (code removed in one branch, added OF support in another) and drivers/dma/imx-sdma.c (independent changes next to each other). * tag 'clock' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (97 commits) clk: Fix CLK_SET_RATE_GATE flag validation in clk_set_rate(). clk: Provide dummy clk_unregister() SPEAr: Update defconfigs SPEAr: Add SMI NOR partition info in dts files SPEAr: Switch to common clock framework SPEAr: Call clk_prepare() before calling clk_enable SPEAr: clk: Add General Purpose Timer Synthesizer clock SPEAr: clk: Add Fractional Synthesizer clock SPEAr: clk: Add Auxiliary Synthesizer clock SPEAr: clk: Add VCO-PLL Synthesizer clock SPEAr: Add DT bindings for SPEAr's timer ARM i.MX: remove now unused clock files ARM: i.MX6: implement clocks using common clock framework ARM i.MX35: implement clocks using common clock framework ARM i.MX5: implement clocks using common clock framework ARM: Kirkwood: Replace clock gating ARM: Orion: Audio: Add clk/clkdev support ARM: Orion: PCIE: Add support for clk ARM: Orion: XOR: Add support for clk ARM: Orion: CESA: Add support for clk ...
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c279
1 files changed, 182 insertions, 97 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 9cf6f59e3e19..687b00d67c8a 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -194,9 +194,8 @@ static int __init clk_debug_init(void)
late_initcall(clk_debug_init);
#else
static inline int clk_debug_register(struct clk *clk) { return 0; }
-#endif /* CONFIG_COMMON_CLK_DEBUG */
+#endif
-#ifdef CONFIG_COMMON_CLK_DISABLE_UNUSED
/* caller must hold prepare_lock */
static void clk_disable_unused_subtree(struct clk *clk)
{
@@ -246,9 +245,6 @@ static int clk_disable_unused(void)
return 0;
}
late_initcall(clk_disable_unused);
-#else
-static inline int clk_disable_unused(struct clk *clk) { return 0; }
-#endif /* CONFIG_COMMON_CLK_DISABLE_UNUSED */
/*** helper functions ***/
@@ -287,7 +283,7 @@ unsigned long __clk_get_rate(struct clk *clk)
unsigned long ret;
if (!clk) {
- ret = -EINVAL;
+ ret = 0;
goto out;
}
@@ -297,7 +293,7 @@ unsigned long __clk_get_rate(struct clk *clk)
goto out;
if (!clk->parent)
- ret = -ENODEV;
+ ret = 0;
out:
return ret;
@@ -562,7 +558,7 @@ EXPORT_SYMBOL_GPL(clk_enable);
* @clk: the clk whose rate is being returned
*
* Simply returns the cached rate of the clk. Does not query the hardware. If
- * clk is NULL then returns -EINVAL.
+ * clk is NULL then returns 0.
*/
unsigned long clk_get_rate(struct clk *clk)
{
@@ -584,18 +580,22 @@ EXPORT_SYMBOL_GPL(clk_get_rate);
*/
unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
{
- unsigned long unused;
+ unsigned long parent_rate = 0;
if (!clk)
return -EINVAL;
- if (!clk->ops->round_rate)
- return clk->rate;
+ if (!clk->ops->round_rate) {
+ if (clk->flags & CLK_SET_RATE_PARENT)
+ return __clk_round_rate(clk->parent, rate);
+ else
+ return clk->rate;
+ }
- if (clk->flags & CLK_SET_RATE_PARENT)
- return clk->ops->round_rate(clk->hw, rate, &unused);
- else
- return clk->ops->round_rate(clk->hw, rate, NULL);
+ if (clk->parent)
+ parent_rate = clk->parent->rate;
+
+ return clk->ops->round_rate(clk->hw, rate, &parent_rate);
}
/**
@@ -765,25 +765,41 @@ static void clk_calc_subtree(struct clk *clk, unsigned long new_rate)
static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
{
struct clk *top = clk;
- unsigned long best_parent_rate = clk->parent->rate;
+ unsigned long best_parent_rate = 0;
unsigned long new_rate;
- if (!clk->ops->round_rate && !(clk->flags & CLK_SET_RATE_PARENT)) {
- clk->new_rate = clk->rate;
+ /* sanity */
+ if (IS_ERR_OR_NULL(clk))
+ return NULL;
+
+ /* save parent rate, if it exists */
+ if (clk->parent)
+ best_parent_rate = clk->parent->rate;
+
+ /* never propagate up to the parent */
+ if (!(clk->flags & CLK_SET_RATE_PARENT)) {
+ if (!clk->ops->round_rate) {
+ clk->new_rate = clk->rate;
+ return NULL;
+ }
+ new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
+ goto out;
+ }
+
+ /* need clk->parent from here on out */
+ if (!clk->parent) {
+ pr_debug("%s: %s has NULL parent\n", __func__, clk->name);
return NULL;
}
- if (!clk->ops->round_rate && (clk->flags & CLK_SET_RATE_PARENT)) {
+ if (!clk->ops->round_rate) {
top = clk_calc_new_rates(clk->parent, rate);
- new_rate = clk->new_rate = clk->parent->new_rate;
+ new_rate = clk->parent->new_rate;
goto out;
}
- if (clk->flags & CLK_SET_RATE_PARENT)
- new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
- else
- new_rate = clk->ops->round_rate(clk->hw, rate, NULL);
+ new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
if (best_parent_rate != clk->parent->rate) {
top = clk_calc_new_rates(clk->parent, best_parent_rate);
@@ -839,7 +855,7 @@ static void clk_change_rate(struct clk *clk)
old_rate = clk->rate;
if (clk->ops->set_rate)
- clk->ops->set_rate(clk->hw, clk->new_rate);
+ clk->ops->set_rate(clk->hw, clk->new_rate, clk->parent->rate);
if (clk->ops->recalc_rate)
clk->rate = clk->ops->recalc_rate(clk->hw,
@@ -859,38 +875,19 @@ static void clk_change_rate(struct clk *clk)
* @clk: the clk whose rate is being changed
* @rate: the new rate for clk
*
- * In the simplest case clk_set_rate will only change the rate of clk.
- *
- * If clk has the CLK_SET_RATE_GATE flag set and it is enabled this call
- * will fail; only when the clk is disabled will it be able to change
- * its rate.
+ * In the simplest case clk_set_rate will only adjust the rate of clk.
*
- * Setting the CLK_SET_RATE_PARENT flag allows clk_set_rate to
- * recursively propagate up to clk's parent; whether or not this happens
- * depends on the outcome of clk's .round_rate implementation. If
- * *parent_rate is 0 after calling .round_rate then upstream parent
- * propagation is ignored. If *parent_rate comes back with a new rate
- * for clk's parent then we propagate up to clk's parent and set it's
- * rate. Upward propagation will continue until either a clk does not
- * support the CLK_SET_RATE_PARENT flag or .round_rate stops requesting
- * changes to clk's parent_rate. If there is a failure during upstream
- * propagation then clk_set_rate will unwind and restore each clk's rate
- * that had been successfully changed. Afterwards a rate change abort
- * notification will be propagated downstream, starting from the clk
- * that failed.
+ * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
+ * propagate up to clk's parent; whether or not this happens depends on the
+ * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
+ * after calling .round_rate then upstream parent propagation is ignored. If
+ * *parent_rate comes back with a new rate for clk's parent then we propagate
+ * up to clk's parent and set it's rate. Upward propagation will continue
+ * until either a clk does not support the CLK_SET_RATE_PARENT flag or
+ * .round_rate stops requesting changes to clk's parent_rate.
*
- * At the end of all of the rate setting, clk_set_rate internally calls
- * __clk_recalc_rates and propagates the rate changes downstream,
- * starting from the highest clk whose rate was changed. This has the
- * added benefit of propagating post-rate change notifiers.
- *
- * Note that while post-rate change and rate change abort notifications
- * are guaranteed to be sent to a clk only once per call to
- * clk_set_rate, pre-change notifications will be sent for every clk
- * whose rate is changed. Stacking pre-change notifications is noisy
- * for the drivers subscribed to them, but this allows drivers to react
- * to intermediate clk rate changes up until the point where the final
- * rate is achieved at the end of upstream propagation.
+ * Rate changes are accomplished via tree traversal that also recalculates the
+ * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
*
* Returns 0 on success, -EERROR otherwise.
*/
@@ -906,6 +903,11 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
if (rate == clk->rate)
goto out;
+ if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) {
+ ret = -EBUSY;
+ goto out;
+ }
+
/* calculate new rates and get the topmost changed clock */
top = clk_calc_new_rates(clk, rate);
if (!top) {
@@ -1175,40 +1177,41 @@ EXPORT_SYMBOL_GPL(clk_set_parent);
*
* Initializes the lists in struct clk, queries the hardware for the
* parent and rate and sets them both.
- *
- * Any struct clk passed into __clk_init must have the following members
- * populated:
- * .name
- * .ops
- * .hw
- * .parent_names
- * .num_parents
- * .flags
- *
- * Essentially, everything that would normally be passed into clk_register is
- * assumed to be initialized already in __clk_init. The other members may be
- * populated, but are optional.
- *
- * __clk_init is only exposed via clk-private.h and is intended for use with
- * very large numbers of clocks that need to be statically initialized. It is
- * a layering violation to include clk-private.h from any code which implements
- * a clock's .ops; as such any statically initialized clock data MUST be in a
- * separate C file from the logic that implements it's operations.
*/
-void __clk_init(struct device *dev, struct clk *clk)
+int __clk_init(struct device *dev, struct clk *clk)
{
- int i;
+ int i, ret = 0;
struct clk *orphan;
struct hlist_node *tmp, *tmp2;
if (!clk)
- return;
+ return -EINVAL;
mutex_lock(&prepare_lock);
/* check to see if a clock with this name is already registered */
- if (__clk_lookup(clk->name))
+ if (__clk_lookup(clk->name)) {
+ pr_debug("%s: clk %s already initialized\n",
+ __func__, clk->name);
+ ret = -EEXIST;
+ goto out;
+ }
+
+ /* check that clk_ops are sane. See Documentation/clk.txt */
+ if (clk->ops->set_rate &&
+ !(clk->ops->round_rate && clk->ops->recalc_rate)) {
+ pr_warning("%s: %s must implement .round_rate & .recalc_rate\n",
+ __func__, clk->name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (clk->ops->set_parent && !clk->ops->get_parent) {
+ pr_warning("%s: %s must implement .get_parent & .set_parent\n",
+ __func__, clk->name);
+ ret = -EINVAL;
goto out;
+ }
/* throw a WARN if any entries in parent_names are NULL */
for (i = 0; i < clk->num_parents; i++)
@@ -1302,48 +1305,130 @@ void __clk_init(struct device *dev, struct clk *clk)
out:
mutex_unlock(&prepare_lock);
- return;
+ return ret;
}
/**
+ * __clk_register - register a clock and return a cookie.
+ *
+ * Same as clk_register, except that the .clk field inside hw shall point to a
+ * preallocated (generally statically allocated) struct clk. None of the fields
+ * of the struct clk need to be initialized.
+ *
+ * The data pointed to by .init and .clk field shall NOT be marked as init
+ * data.
+ *
+ * __clk_register is only exposed via clk-private.h and is intended for use with
+ * very large numbers of clocks that need to be statically initialized. It is
+ * a layering violation to include clk-private.h from any code which implements
+ * a clock's .ops; as such any statically initialized clock data MUST be in a
+ * separate C file from the logic that implements it's operations. Returns 0
+ * on success, otherwise an error code.
+ */
+struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
+{
+ int ret;
+ struct clk *clk;
+
+ clk = hw->clk;
+ clk->name = hw->init->name;
+ clk->ops = hw->init->ops;
+ clk->hw = hw;
+ clk->flags = hw->init->flags;
+ clk->parent_names = hw->init->parent_names;
+ clk->num_parents = hw->init->num_parents;
+
+ ret = __clk_init(dev, clk);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return clk;
+}
+EXPORT_SYMBOL_GPL(__clk_register);
+
+/**
* clk_register - allocate a new clock, register it and return an opaque cookie
* @dev: device that is registering this clock
- * @name: clock name
- * @ops: operations this clock supports
* @hw: link to hardware-specific clock data
- * @parent_names: array of string names for all possible parents
- * @num_parents: number of possible parents
- * @flags: framework-level hints and quirks
*
* clk_register is the primary interface for populating the clock tree with new
* clock nodes. It returns a pointer to the newly allocated struct clk which
* cannot be dereferenced by driver code but may be used in conjuction with the
- * rest of the clock API.
+ * rest of the clock API. In the event of an error clk_register will return an
+ * error code; drivers must test for an error code after calling clk_register.
*/
-struct clk *clk_register(struct device *dev, const char *name,
- const struct clk_ops *ops, struct clk_hw *hw,
- char **parent_names, u8 num_parents, unsigned long flags)
+struct clk *clk_register(struct device *dev, struct clk_hw *hw)
{
+ int i, ret;
struct clk *clk;
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
- if (!clk)
- return NULL;
+ if (!clk) {
+ pr_err("%s: could not allocate clk\n", __func__);
+ ret = -ENOMEM;
+ goto fail_out;
+ }
- clk->name = name;
- clk->ops = ops;
+ clk->name = kstrdup(hw->init->name, GFP_KERNEL);
+ if (!clk->name) {
+ pr_err("%s: could not allocate clk->name\n", __func__);
+ ret = -ENOMEM;
+ goto fail_name;
+ }
+ clk->ops = hw->init->ops;
clk->hw = hw;
- clk->flags = flags;
- clk->parent_names = parent_names;
- clk->num_parents = num_parents;
+ clk->flags = hw->init->flags;
+ clk->num_parents = hw->init->num_parents;
hw->clk = clk;
- __clk_init(dev, clk);
+ /* allocate local copy in case parent_names is __initdata */
+ clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents),
+ GFP_KERNEL);
- return clk;
+ if (!clk->parent_names) {
+ pr_err("%s: could not allocate clk->parent_names\n", __func__);
+ ret = -ENOMEM;
+ goto fail_parent_names;
+ }
+
+
+ /* copy each string name in case parent_names is __initdata */
+ for (i = 0; i < clk->num_parents; i++) {
+ clk->parent_names[i] = kstrdup(hw->init->parent_names[i],
+ GFP_KERNEL);
+ if (!clk->parent_names[i]) {
+ pr_err("%s: could not copy parent_names\n", __func__);
+ ret = -ENOMEM;
+ goto fail_parent_names_copy;
+ }
+ }
+
+ ret = __clk_init(dev, clk);
+ if (!ret)
+ return clk;
+
+fail_parent_names_copy:
+ while (--i >= 0)
+ kfree(clk->parent_names[i]);
+ kfree(clk->parent_names);
+fail_parent_names:
+ kfree(clk->name);
+fail_name:
+ kfree(clk);
+fail_out:
+ return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(clk_register);
+/**
+ * clk_unregister - unregister a currently registered clock
+ * @clk: clock to unregister
+ *
+ * Currently unimplemented.
+ */
+void clk_unregister(struct clk *clk) {}
+EXPORT_SYMBOL_GPL(clk_unregister);
+
/*** clk rate change notifiers ***/
/**