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path: root/drivers/clk/clk.c
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-rw-r--r--drivers/clk/clk.c349
1 files changed, 209 insertions, 140 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ddb4b5410..0ebcf4497 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -9,6 +9,7 @@
* Standard functionality for the common clock API. See Documentation/clk.txt
*/
+#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clk/clk-conf.h>
#include <linux/module.h>
@@ -56,8 +57,11 @@ struct clk_core {
struct clk_core *new_parent;
struct clk_core *new_child;
unsigned long flags;
+ bool orphan;
unsigned int enable_count;
unsigned int prepare_count;
+ unsigned long min_rate;
+ unsigned long max_rate;
unsigned long accuracy;
int phase;
struct hlist_head children;
@@ -111,12 +115,14 @@ static void clk_prepare_unlock(void)
}
static unsigned long clk_enable_lock(void)
+ __acquires(enable_lock)
{
unsigned long flags;
if (!spin_trylock_irqsave(&enable_lock, flags)) {
if (enable_owner == current) {
enable_refcnt++;
+ __acquire(enable_lock);
return flags;
}
spin_lock_irqsave(&enable_lock, flags);
@@ -129,12 +135,15 @@ static unsigned long clk_enable_lock(void)
}
static void clk_enable_unlock(unsigned long flags)
+ __releases(enable_lock)
{
WARN_ON_ONCE(enable_owner != current);
WARN_ON_ONCE(enable_refcnt == 0);
- if (--enable_refcnt)
+ if (--enable_refcnt) {
+ __release(enable_lock);
return;
+ }
enable_owner = NULL;
spin_unlock_irqrestore(&enable_lock, flags);
}
@@ -269,27 +278,29 @@ const char *__clk_get_name(struct clk *clk)
}
EXPORT_SYMBOL_GPL(__clk_get_name);
+const char *clk_hw_get_name(const struct clk_hw *hw)
+{
+ return hw->core->name;
+}
+EXPORT_SYMBOL_GPL(clk_hw_get_name);
+
struct clk_hw *__clk_get_hw(struct clk *clk)
{
return !clk ? NULL : clk->core->hw;
}
EXPORT_SYMBOL_GPL(__clk_get_hw);
-u8 __clk_get_num_parents(struct clk *clk)
+unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
{
- return !clk ? 0 : clk->core->num_parents;
+ return hw->core->num_parents;
}
-EXPORT_SYMBOL_GPL(__clk_get_num_parents);
+EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
-struct clk *__clk_get_parent(struct clk *clk)
+struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
{
- if (!clk)
- return NULL;
-
- /* TODO: Create a per-user clk and change callers to call clk_put */
- return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
+ return hw->core->parent ? hw->core->parent->hw : NULL;
}
-EXPORT_SYMBOL_GPL(__clk_get_parent);
+EXPORT_SYMBOL_GPL(clk_hw_get_parent);
static struct clk_core *__clk_lookup_subtree(const char *name,
struct clk_core *core)
@@ -348,18 +359,16 @@ static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
return core->parents[index];
}
-struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
+struct clk_hw *
+clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
{
struct clk_core *parent;
- if (!clk)
- return NULL;
-
- parent = clk_core_get_parent_by_index(clk->core, index);
+ parent = clk_core_get_parent_by_index(hw->core, index);
- return !parent ? NULL : parent->hw->clk;
+ return !parent ? NULL : parent->hw;
}
-EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
+EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
unsigned int __clk_get_enable_count(struct clk *clk)
{
@@ -387,14 +396,11 @@ out:
return ret;
}
-unsigned long __clk_get_rate(struct clk *clk)
+unsigned long clk_hw_get_rate(const struct clk_hw *hw)
{
- if (!clk)
- return 0;
-
- return clk_core_get_rate_nolock(clk->core);
+ return clk_core_get_rate_nolock(hw->core);
}
-EXPORT_SYMBOL_GPL(__clk_get_rate);
+EXPORT_SYMBOL_GPL(clk_hw_get_rate);
static unsigned long __clk_get_accuracy(struct clk_core *core)
{
@@ -410,12 +416,15 @@ unsigned long __clk_get_flags(struct clk *clk)
}
EXPORT_SYMBOL_GPL(__clk_get_flags);
-bool __clk_is_prepared(struct clk *clk)
+unsigned long clk_hw_get_flags(const struct clk_hw *hw)
{
- if (!clk)
- return false;
+ return hw->core->flags;
+}
+EXPORT_SYMBOL_GPL(clk_hw_get_flags);
- return clk_core_is_prepared(clk->core);
+bool clk_hw_is_prepared(const struct clk_hw *hw)
+{
+ return clk_core_is_prepared(hw->core);
}
bool __clk_is_enabled(struct clk *clk)
@@ -436,28 +445,31 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now,
return now <= rate && now > best;
}
-static long
-clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long *best_parent_rate,
- struct clk_hw **best_parent_p,
+static int
+clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
unsigned long flags)
{
struct clk_core *core = hw->core, *parent, *best_parent = NULL;
- int i, num_parents;
- unsigned long parent_rate, best = 0;
+ int i, num_parents, ret;
+ unsigned long best = 0;
+ struct clk_rate_request parent_req = *req;
/* if NO_REPARENT flag set, pass through to current parent */
if (core->flags & CLK_SET_RATE_NO_REPARENT) {
parent = core->parent;
- if (core->flags & CLK_SET_RATE_PARENT)
- best = __clk_determine_rate(parent ? parent->hw : NULL,
- rate, min_rate, max_rate);
- else if (parent)
+ if (core->flags & CLK_SET_RATE_PARENT) {
+ ret = __clk_determine_rate(parent ? parent->hw : NULL,
+ &parent_req);
+ if (ret)
+ return ret;
+
+ best = parent_req.rate;
+ } else if (parent) {
best = clk_core_get_rate_nolock(parent);
- else
+ } else {
best = clk_core_get_rate_nolock(core);
+ }
+
goto out;
}
@@ -467,24 +479,33 @@ clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
parent = clk_core_get_parent_by_index(core, i);
if (!parent)
continue;
- if (core->flags & CLK_SET_RATE_PARENT)
- parent_rate = __clk_determine_rate(parent->hw, rate,
- min_rate,
- max_rate);
- else
- parent_rate = clk_core_get_rate_nolock(parent);
- if (mux_is_better_rate(rate, parent_rate, best, flags)) {
+
+ if (core->flags & CLK_SET_RATE_PARENT) {
+ parent_req = *req;
+ ret = __clk_determine_rate(parent->hw, &parent_req);
+ if (ret)
+ continue;
+ } else {
+ parent_req.rate = clk_core_get_rate_nolock(parent);
+ }
+
+ if (mux_is_better_rate(req->rate, parent_req.rate,
+ best, flags)) {
best_parent = parent;
- best = parent_rate;
+ best = parent_req.rate;
}
}
+ if (!best_parent)
+ return -EINVAL;
+
out:
if (best_parent)
- *best_parent_p = best_parent->hw;
- *best_parent_rate = best;
+ req->best_parent_hw = best_parent->hw;
+ req->best_parent_rate = best;
+ req->rate = best;
- return best;
+ return 0;
}
struct clk *__clk_lookup(const char *name)
@@ -500,8 +521,8 @@ static void clk_core_get_boundaries(struct clk_core *core,
{
struct clk *clk_user;
- *min_rate = 0;
- *max_rate = ULONG_MAX;
+ *min_rate = core->min_rate;
+ *max_rate = core->max_rate;
hlist_for_each_entry(clk_user, &core->clks, clks_node)
*min_rate = max(*min_rate, clk_user->min_rate);
@@ -510,33 +531,30 @@ static void clk_core_get_boundaries(struct clk_core *core,
*max_rate = min(*max_rate, clk_user->max_rate);
}
+void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
+ unsigned long max_rate)
+{
+ hw->core->min_rate = min_rate;
+ hw->core->max_rate = max_rate;
+}
+EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
+
/*
* Helper for finding best parent to provide a given frequency. This can be used
* directly as a determine_rate callback (e.g. for a mux), or from a more
* complex clock that may combine a mux with other operations.
*/
-long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long *best_parent_rate,
- struct clk_hw **best_parent_p)
+int __clk_mux_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
{
- return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
- best_parent_rate,
- best_parent_p, 0);
+ return clk_mux_determine_rate_flags(hw, req, 0);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
-long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long *best_parent_rate,
- struct clk_hw **best_parent_p)
+int __clk_mux_determine_rate_closest(struct clk_hw *hw,
+ struct clk_rate_request *req)
{
- return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
- best_parent_rate,
- best_parent_p,
- CLK_MUX_ROUND_CLOSEST);
+ return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
}
EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
@@ -759,14 +777,11 @@ int clk_enable(struct clk *clk)
}
EXPORT_SYMBOL_GPL(clk_enable);
-static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
- unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate)
+static int clk_core_round_rate_nolock(struct clk_core *core,
+ struct clk_rate_request *req)
{
- unsigned long parent_rate = 0;
struct clk_core *parent;
- struct clk_hw *parent_hw;
+ long rate;
lockdep_assert_held(&prepare_lock);
@@ -774,21 +789,30 @@ static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
return 0;
parent = core->parent;
- if (parent)
- parent_rate = parent->rate;
+ if (parent) {
+ req->best_parent_hw = parent->hw;
+ req->best_parent_rate = parent->rate;
+ } else {
+ req->best_parent_hw = NULL;
+ req->best_parent_rate = 0;
+ }
if (core->ops->determine_rate) {
- parent_hw = parent ? parent->hw : NULL;
- return core->ops->determine_rate(core->hw, rate,
- min_rate, max_rate,
- &parent_rate, &parent_hw);
- } else if (core->ops->round_rate)
- return core->ops->round_rate(core->hw, rate, &parent_rate);
- else if (core->flags & CLK_SET_RATE_PARENT)
- return clk_core_round_rate_nolock(core->parent, rate, min_rate,
- max_rate);
- else
- return core->rate;
+ return core->ops->determine_rate(core->hw, req);
+ } else if (core->ops->round_rate) {
+ rate = core->ops->round_rate(core->hw, req->rate,
+ &req->best_parent_rate);
+ if (rate < 0)
+ return rate;
+
+ req->rate = rate;
+ } else if (core->flags & CLK_SET_RATE_PARENT) {
+ return clk_core_round_rate_nolock(parent, req);
+ } else {
+ req->rate = core->rate;
+ }
+
+ return 0;
}
/**
@@ -800,38 +824,32 @@ static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
*
* Useful for clk_ops such as .set_rate and .determine_rate.
*/
-unsigned long __clk_determine_rate(struct clk_hw *hw,
- unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate)
+int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
- if (!hw)
+ if (!hw) {
+ req->rate = 0;
return 0;
+ }
- return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
+ return clk_core_round_rate_nolock(hw->core, req);
}
EXPORT_SYMBOL_GPL(__clk_determine_rate);
-/**
- * __clk_round_rate - round the given rate for a clk
- * @clk: round the rate of this clock
- * @rate: the rate which is to be rounded
- *
- * Useful for clk_ops such as .set_rate
- */
-unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
+unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
{
- unsigned long min_rate;
- unsigned long max_rate;
+ int ret;
+ struct clk_rate_request req;
- if (!clk)
- return 0;
+ clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
+ req.rate = rate;
- clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
+ ret = clk_core_round_rate_nolock(hw->core, &req);
+ if (ret)
+ return 0;
- return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
+ return req.rate;
}
-EXPORT_SYMBOL_GPL(__clk_round_rate);
+EXPORT_SYMBOL_GPL(clk_hw_round_rate);
/**
* clk_round_rate - round the given rate for a clk
@@ -844,16 +862,24 @@ EXPORT_SYMBOL_GPL(__clk_round_rate);
*/
long clk_round_rate(struct clk *clk, unsigned long rate)
{
- unsigned long ret;
+ struct clk_rate_request req;
+ int ret;
if (!clk)
return 0;
clk_prepare_lock();
- ret = __clk_round_rate(clk, rate);
+
+ clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
+ req.rate = rate;
+
+ ret = clk_core_round_rate_nolock(clk->core, &req);
clk_prepare_unlock();
- return ret;
+ if (ret)
+ return ret;
+
+ return req.rate;
}
EXPORT_SYMBOL_GPL(clk_round_rate);
@@ -1064,18 +1090,40 @@ static int clk_fetch_parent_index(struct clk_core *core,
return -EINVAL;
}
+/*
+ * Update the orphan status of @core and all its children.
+ */
+static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
+{
+ struct clk_core *child;
+
+ core->orphan = is_orphan;
+
+ hlist_for_each_entry(child, &core->children, child_node)
+ clk_core_update_orphan_status(child, is_orphan);
+}
+
static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
{
+ bool was_orphan = core->orphan;
+
hlist_del(&core->child_node);
if (new_parent) {
+ bool becomes_orphan = new_parent->orphan;
+
/* avoid duplicate POST_RATE_CHANGE notifications */
if (new_parent->new_child == core)
new_parent->new_child = NULL;
hlist_add_head(&core->child_node, &new_parent->children);
+
+ if (was_orphan != becomes_orphan)
+ clk_core_update_orphan_status(core, becomes_orphan);
} else {
hlist_add_head(&core->child_node, &clk_orphan_list);
+ if (!was_orphan)
+ clk_core_update_orphan_status(core, true);
}
core->parent = new_parent;
@@ -1160,14 +1208,8 @@ static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
flags = clk_enable_lock();
clk_reparent(core, old_parent);
clk_enable_unlock(flags);
+ __clk_set_parent_after(core, old_parent, parent);
- if (core->prepare_count) {
- flags = clk_enable_lock();
- clk_core_disable(core);
- clk_core_disable(parent);
- clk_enable_unlock(flags);
- clk_core_unprepare(parent);
- }
return ret;
}
@@ -1249,7 +1291,6 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core,
{
struct clk_core *top = core;
struct clk_core *old_parent, *parent;
- struct clk_hw *parent_hw;
unsigned long best_parent_rate = 0;
unsigned long new_rate;
unsigned long min_rate;
@@ -1270,20 +1311,29 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *core,
/* find the closest rate and parent clk/rate */
if (core->ops->determine_rate) {
- parent_hw = parent ? parent->hw : NULL;
- ret = core->ops->determine_rate(core->hw, rate,
- min_rate,
- max_rate,
- &best_parent_rate,
- &parent_hw);
+ struct clk_rate_request req;
+
+ req.rate = rate;
+ req.min_rate = min_rate;
+ req.max_rate = max_rate;
+ if (parent) {
+ req.best_parent_hw = parent->hw;
+ req.best_parent_rate = parent->rate;
+ } else {
+ req.best_parent_hw = NULL;
+ req.best_parent_rate = 0;
+ }
+
+ ret = core->ops->determine_rate(core->hw, &req);
if (ret < 0)
return NULL;
- new_rate = ret;
- parent = parent_hw ? parent_hw->core : NULL;
+ best_parent_rate = req.best_parent_rate;
+ new_rate = req.rate;
+ parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
} else if (core->ops->round_rate) {
ret = core->ops->round_rate(core->hw, rate,
- &best_parent_rate);
+ &best_parent_rate);
if (ret < 0)
return NULL;
@@ -1592,8 +1642,12 @@ struct clk *clk_get_parent(struct clk *clk)
{
struct clk *parent;
+ if (!clk)
+ return NULL;
+
clk_prepare_lock();
- parent = __clk_get_parent(clk);
+ /* TODO: Create a per-user clk and change callers to call clk_put */
+ parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
clk_prepare_unlock();
return parent;
@@ -2324,13 +2378,17 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
* clocks and re-parent any that are children of the clock currently
* being clk_init'd.
*/
- if (core->parent)
+ if (core->parent) {
hlist_add_head(&core->child_node,
&core->parent->children);
- else if (core->flags & CLK_IS_ROOT)
+ core->orphan = core->parent->orphan;
+ } else if (core->flags & CLK_IS_ROOT) {
hlist_add_head(&core->child_node, &clk_root_list);
- else
+ core->orphan = false;
+ } else {
hlist_add_head(&core->child_node, &clk_orphan_list);
+ core->orphan = true;
+ }
/*
* Set clk's accuracy. The preferred method is to use
@@ -2379,7 +2437,8 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
if (orphan->num_parents && orphan->ops->get_parent) {
i = orphan->ops->get_parent(orphan->hw);
- if (!strcmp(core->name, orphan->parent_names[i]))
+ if (i >= 0 && i < orphan->num_parents &&
+ !strcmp(core->name, orphan->parent_names[i]))
clk_core_reparent(orphan, core);
continue;
}
@@ -2479,6 +2538,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
core->hw = hw;
core->flags = hw->init->flags;
core->num_parents = hw->init->num_parents;
+ core->min_rate = 0;
+ core->max_rate = ULONG_MAX;
hw->core = core;
/* allocate local copy in case parent_names is __initdata */
@@ -3054,8 +3115,6 @@ struct clock_provider {
struct list_head node;
};
-static LIST_HEAD(clk_provider_list);
-
/*
* This function looks for a parent clock. If there is one, then it
* checks that the provider for this parent clock was initialized, in
@@ -3106,14 +3165,24 @@ void __init of_clk_init(const struct of_device_id *matches)
struct clock_provider *clk_provider, *next;
bool is_init_done;
bool force = false;
+ LIST_HEAD(clk_provider_list);
if (!matches)
matches = &__clk_of_table;
/* First prepare the list of the clocks providers */
for_each_matching_node_and_match(np, matches, &match) {
- struct clock_provider *parent =
- kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
+ struct clock_provider *parent;
+
+ parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+ if (!parent) {
+ list_for_each_entry_safe(clk_provider, next,
+ &clk_provider_list, node) {
+ list_del(&clk_provider->node);
+ kfree(clk_provider);
+ }
+ return;
+ }
parent->clk_init_cb = match->data;
parent->np = np;