clk: Introduce optional is_prepared callback
To reflect whether a clk_hw is prepared the clk_hw may implement
the optional is_prepared callback. If not implemented we fall back
to use the software prepare counter.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ed87b24..7571b50 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -451,6 +451,27 @@
return !clk ? 0 : clk->flags;
}
+bool __clk_is_prepared(struct clk *clk)
+{
+ int ret;
+
+ if (!clk)
+ return false;
+
+ /*
+ * .is_prepared is optional for clocks that can prepare
+ * fall back to software usage counter if it is missing
+ */
+ if (!clk->ops->is_prepared) {
+ ret = clk->prepare_count ? 1 : 0;
+ goto out;
+ }
+
+ ret = clk->ops->is_prepared(clk->hw);
+out:
+ return !!ret;
+}
+
bool __clk_is_enabled(struct clk *clk)
{
int ret;
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 7f197d7..ee946862 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -45,6 +45,10 @@
* undo any work done in the @prepare callback. Called with
* prepare_lock held.
*
+ * @is_prepared: Queries the hardware to determine if the clock is prepared.
+ * This function is allowed to sleep. Optional, if this op is not
+ * set then the prepare count will be used.
+ *
* @enable: Enable the clock atomically. This must not return until the
* clock is generating a valid clock signal, usable by consumer
* devices. Called with enable_lock held. This function must not
@@ -108,6 +112,7 @@
struct clk_ops {
int (*prepare)(struct clk_hw *hw);
void (*unprepare)(struct clk_hw *hw);
+ int (*is_prepared)(struct clk_hw *hw);
int (*enable)(struct clk_hw *hw);
void (*disable)(struct clk_hw *hw);
int (*is_enabled)(struct clk_hw *hw);
@@ -351,6 +356,7 @@
unsigned int __clk_get_prepare_count(struct clk *clk);
unsigned long __clk_get_rate(struct clk *clk);
unsigned long __clk_get_flags(struct clk *clk);
+bool __clk_is_prepared(struct clk *clk);
bool __clk_is_enabled(struct clk *clk);
struct clk *__clk_lookup(const char *name);