@@ -21,6 +21,7 @@
#include <linux/of.h>
#include <linux/device.h>
#include <linux/init.h>
+#include <linux/pm_runtime.h>
#include <linux/sched.h>
#include <linux/clkdev.h>
@@ -46,6 +47,7 @@ struct clk_core {
const struct clk_ops *ops;
struct clk_hw *hw;
struct module *owner;
+ struct device *dev;
struct clk_core *parent;
const char **parent_names;
struct clk_core **parents;
@@ -87,6 +89,26 @@ struct clk {
struct hlist_node clks_node;
};
+/*** runtime pm ***/
+static int clk_pm_runtime_get(struct clk_core *core)
+{
+ int ret = 0;
+
+ if (!core->dev)
+ return 0;
+
+ ret = pm_runtime_get_sync(core->dev);
+ return ret < 0 ? ret : 0;
+}
+
+static void clk_pm_runtime_put(struct clk_core *core)
+{
+ if (!core->dev)
+ return;
+
+ pm_runtime_put_sync(core->dev);
+}
+
/*** locking ***/
static void clk_prepare_lock(void)
{
@@ -150,6 +172,8 @@ static void clk_enable_unlock(unsigned long flags)
static bool clk_core_is_prepared(struct clk_core *core)
{
+ bool ret = false;
+
/*
* .is_prepared is optional for clocks that can prepare
* fall back to software usage counter if it is missing
@@ -157,11 +181,18 @@ static bool clk_core_is_prepared(struct clk_core *core)
if (!core->ops->is_prepared)
return core->prepare_count;
- return core->ops->is_prepared(core->hw);
+ if (!clk_pm_runtime_get(core)) {
+ ret = core->ops->is_prepared(core->hw);
+ clk_pm_runtime_put(core);
+ }
+
+ return ret;
}
static bool clk_core_is_enabled(struct clk_core *core)
{
+ bool ret = false;
+
/*
* .is_enabled is only mandatory for clocks that gate
* fall back to software usage counter if .is_enabled is missing
@@ -169,7 +200,29 @@ static bool clk_core_is_enabled(struct clk_core *core)
if (!core->ops->is_enabled)
return core->enable_count;
- return core->ops->is_enabled(core->hw);
+ /*
+ * Check if clock controller's device is runtime active before
+ * calling .is_enabled callback. If not, assume that clock is
+ * disabled, because we might be called from atomic context, from
+ * which pm_runtime_get() is not allowed.
+ * This function is called mainly from clk_disable_unused_subtree,
+ * which ensures proper runtime pm activation of controller before
+ * taking enable spinlock, but the below check is needed if one tries
+ * to call it from other places.
+ */
+ if (core->dev) {
+ pm_runtime_get_noresume(core->dev);
+ if (!pm_runtime_active(core->dev)) {
+ ret = false;
+ goto done;
+ }
+ }
+
+ ret = core->ops->is_enabled(core->hw);
+done:
+ clk_pm_runtime_put(core);
+
+ return ret;
}
/*** helper functions ***/
@@ -489,6 +542,8 @@ static void clk_core_unprepare(struct clk_core *core)
if (core->ops->unprepare)
core->ops->unprepare(core->hw);
+ clk_pm_runtime_put(core);
+
trace_clk_unprepare_complete(core);
clk_core_unprepare(core->parent);
}
@@ -530,10 +585,14 @@ static int clk_core_prepare(struct clk_core *core)
return 0;
if (core->prepare_count == 0) {
- ret = clk_core_prepare(core->parent);
+ ret = clk_pm_runtime_get(core);
if (ret)
return ret;
+ ret = clk_core_prepare(core->parent);
+ if (ret)
+ goto runtime_put;
+
trace_clk_prepare(core);
if (core->ops->prepare)
@@ -541,15 +600,18 @@ static int clk_core_prepare(struct clk_core *core)
trace_clk_prepare_complete(core);
- if (ret) {
- clk_core_unprepare(core->parent);
- return ret;
- }
+ if (ret)
+ goto unprepare;
}
core->prepare_count++;
return 0;
+unprepare:
+ clk_core_unprepare(core->parent);
+runtime_put:
+ clk_pm_runtime_put(core);
+ return ret;
}
static int clk_core_prepare_lock(struct clk_core *core)
@@ -745,6 +807,9 @@ static void clk_unprepare_unused_subtree(struct clk_core *core)
if (core->flags & CLK_IGNORE_UNUSED)
return;
+ if (clk_pm_runtime_get(core))
+ return;
+
if (clk_core_is_prepared(core)) {
trace_clk_unprepare(core);
if (core->ops->unprepare_unused)
@@ -753,6 +818,8 @@ static void clk_unprepare_unused_subtree(struct clk_core *core)
core->ops->unprepare(core->hw);
trace_clk_unprepare_complete(core);
}
+
+ clk_pm_runtime_put(core);
}
static void clk_disable_unused_subtree(struct clk_core *core)
@@ -768,6 +835,9 @@ static void clk_disable_unused_subtree(struct clk_core *core)
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_prepare_enable(core->parent);
+ if (clk_pm_runtime_get(core))
+ goto unprepare_out;
+
flags = clk_enable_lock();
if (core->enable_count)
@@ -792,6 +862,8 @@ static void clk_disable_unused_subtree(struct clk_core *core)
unlock_out:
clk_enable_unlock(flags);
+ clk_pm_runtime_put(core);
+unprepare_out:
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_disable_unprepare(core->parent);
}
@@ -1038,9 +1110,13 @@ long clk_get_accuracy(struct clk *clk)
static unsigned long clk_recalc(struct clk_core *core,
unsigned long parent_rate)
{
- if (core->ops->recalc_rate)
- return core->ops->recalc_rate(core->hw, parent_rate);
- return parent_rate;
+ unsigned long rate = parent_rate;
+
+ if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
+ rate = core->ops->recalc_rate(core->hw, parent_rate);
+ clk_pm_runtime_put(core);
+ }
+ return rate;
}
/**
@@ -1565,6 +1641,7 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
{
struct clk_core *top, *fail_clk;
unsigned long rate = req_rate;
+ int ret = 0;
if (!core)
return 0;
@@ -1581,21 +1658,28 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
if (!top)
return -EINVAL;
+ ret = clk_pm_runtime_get(core);
+ if (ret)
+ return ret;
+
/* notify that we are about to change rates */
fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
if (fail_clk) {
pr_debug("%s: failed to set %s rate\n", __func__,
fail_clk->name);
clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
- return -EBUSY;
+ ret = -EBUSY;
+ goto err;
}
/* change the rates */
clk_change_rate(top);
core->req_rate = req_rate;
+err:
+ clk_pm_runtime_put(core);
- return 0;
+ return ret;
}
/**
@@ -1826,12 +1910,16 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
p_rate = parent->rate;
}
+ ret = clk_pm_runtime_get(core);
+ if (ret)
+ goto out;
+
/* propagate PRE_RATE_CHANGE notifications */
ret = __clk_speculate_rates(core, p_rate);
/* abort if a driver objects */
if (ret & NOTIFY_STOP_MASK)
- goto out;
+ goto runtime_put;
/* do the re-parent */
ret = __clk_set_parent(core, parent, p_index);
@@ -1844,6 +1932,8 @@ static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
__clk_recalc_accuracies(core);
}
+runtime_put:
+ clk_pm_runtime_put(core);
out:
clk_prepare_unlock();
@@ -2583,6 +2673,12 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
goto fail_name;
}
core->ops = hw->init->ops;
+ if (dev && pm_runtime_enabled(dev)) {
+ core->dev = dev;
+ ret = clk_pm_runtime_get(core);
+ if (ret)
+ goto fail_pm;
+ }
if (dev && dev->driver)
core->owner = dev->driver->owner;
core->hw = hw;
@@ -2629,12 +2725,13 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
}
ret = __clk_core_init(core);
- if (!ret)
+ if (!ret) {
+ clk_pm_runtime_put(core);
return hw->clk;
+ }
__clk_free_clk(hw->clk);
hw->clk = NULL;
-
fail_parents:
kfree(core->parents);
fail_parent_names_copy:
@@ -2642,6 +2739,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
kfree_const(core->parent_names[i]);
kfree(core->parent_names);
fail_parent_names:
+ clk_pm_runtime_put(core);
+fail_pm:
kfree_const(core->name);
fail_name:
kfree(core);