The PM clocks framework requires clients to pass either a con-id or a
valid clk pointer in order to add a clock to a device. Add a new
function pm_clk_add_clks_of() to allows device clocks to be retrieved
from device-tree and populated for a given device. Note that there
should be no need to add a stub function for this new function when
CONFIG_OF is not selected because the OF functions used already have
stubs functions.
In order to handle errors encountered when adding clocks from
device-tree, add a function pm_clk_remove_clk() to remove any clocks
(using a pointer to the clk structure) that have been added
successfully before the error occurred.
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/base/power/clock_ops.c | 85 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_clock.h | 9 +++++
2 files changed, 94 insertions(+)
diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
index 272a52ebafc0..5aa7365699c1 100644
--- a/drivers/base/power/clock_ops.c
+++ b/drivers/base/power/clock_ops.c
@@ -138,6 +138,58 @@ int pm_clk_add_clk(struct device *dev, struct clk *clk)
}
/**
+ * pm_clk_add_clks_of - Start using device clock(s) for power management.
+ * @dev: Device whose clock(s) is going to be used for power management.
+ *
+ * Add a series of clocks described in the 'clocks' device-tree node for
+ * a device to the list of clocks used for the power management of @dev.
+ */
+int pm_clk_add_clks_of(struct device *dev)
+{
+ struct clk **clks;
+ unsigned int i, count;
+ int ret;
+
+ if (!dev || !dev->of_node)
+ return -EINVAL;
+
+ count = of_count_phandle_with_args(dev->of_node, "clocks",
+ "#clock-cells");
+ if (count == 0)
+ return -ENODEV;
+
+ clks = kcalloc(count, sizeof(*clks), GFP_KERNEL);
+ if (!clks)
+ return -ENOMEM;
+
+ for (i = 0; i < count; i++) {
+ clks[i] = of_clk_get(dev->of_node, i);
+ if (IS_ERR(clks[i])) {
+ ret = PTR_ERR(clks[i]);
+ goto error;
+ }
+
+ ret = pm_clk_add_clk(dev, clks[i]);
+ if (ret) {
+ clk_put(clks[i]);
+ goto error;
+ }
+ }
+
+ kfree(clks);
+
+ return 0;
+
+error:
+ while (i--)
+ pm_clk_remove_clk(dev, clks[i]);
+
+ kfree(clks);
+
+ return ret;
+}
+
+/**
* __pm_clk_remove - Destroy PM clock entry.
* @ce: PM clock entry to destroy.
*/
@@ -198,6 +250,39 @@ void pm_clk_remove(struct device *dev, const char *con_id)
}
/**
+ * pm_clk_remove_clk - Stop using a device clock for power management.
+ * @dev: Device whose clock should not be used for PM any more.
+ * @clk: Clock pointer
+ *
+ * Remove the clock pointed to by @clk from the list of clocks used for
+ * the power management of @dev.
+ */
+void pm_clk_remove_clk(struct device *dev, struct clk *clk)
+{
+ struct pm_subsys_data *psd = dev_to_psd(dev);
+ struct pm_clock_entry *ce;
+
+ if (!psd || !clk)
+ return;
+
+ spin_lock_irq(&psd->lock);
+
+ list_for_each_entry(ce, &psd->clock_list, node) {
+ if (clk == ce->clk)
+ goto remove;
+ }
+
+ spin_unlock_irq(&psd->lock);
+ return;
+
+ remove:
+ list_del(&ce->node);
+ spin_unlock_irq(&psd->lock);
+
+ __pm_clk_remove(ce);
+}
+
+/**
* pm_clk_init - Initialize a device's list of power management clocks.
* @dev: Device to initialize the list of PM clocks for.
*
diff --git a/include/linux/pm_clock.h b/include/linux/pm_clock.h
index ffefbf2df1aa..6f609226bd85 100644
--- a/include/linux/pm_clock.h
+++ b/include/linux/pm_clock.h
@@ -42,7 +42,9 @@ extern int pm_clk_create(struct device *dev);
extern void pm_clk_destroy(struct device *dev);
extern int pm_clk_add(struct device *dev, const char *con_id);
extern int pm_clk_add_clk(struct device *dev, struct clk *clk);
+extern int pm_clk_add_clks_of(struct device *dev);
extern void pm_clk_remove(struct device *dev, const char *con_id);
+extern void pm_clk_remove_clk(struct device *dev, struct clk *clk);
extern int pm_clk_suspend(struct device *dev);
extern int pm_clk_resume(struct device *dev);
#else
@@ -69,9 +71,16 @@ static inline int pm_clk_add_clk(struct device *dev, struct clk *clk)
{
return -EINVAL;
}
+static inline int pm_clk_add_clks_of(struct device *dev)
+{
+ return -EINVAL;
+}
static inline void pm_clk_remove(struct device *dev, const char *con_id)
{
}
+static inline void pm_clk_remove_clk(struct device *dev, struct clk *clk)
+{
+}
static inline int pm_clk_suspend(struct device *dev)
{
return -EINVAL;
--
2.1.4
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