[U-Boot] [PATCH v2 07/22] clock-uclass: allow disabling a peripheral clock

[Benjamin Tietz]

From: Benjamin Tietz <benjamin at micronet24.de>

Currently, clocks can be enabled, only. To be feature-complete - and allow
a bit of power-saving in applications - disabling a clock should be
possible, too.

This extend the API of the DM clock driver to allow a clock to be disabled.

The corresponding operation is optional for not breaking existing drivers.
---
 drivers/clk/clk-uclass.c |   10 ++++++++++
 include/clk.h            |   18 ++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index b483c1e..462f5f8 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -44,6 +44,16 @@ int clk_enable(struct udevice *dev, int periph)
 	return ops->enable(dev, periph);
 }
 
+int clk_disable(struct udevice *dev, int periph)
+{
+	struct clk_ops *ops = clk_get_ops(dev);
+
+	if (!ops->disable)
+		return -ENOSYS;
+
+	return ops->disable(dev, periph);
+}
+
 ulong clk_get_periph_rate(struct udevice *dev, int periph)
 {
 	struct clk_ops *ops = clk_get_ops(dev);
diff --git a/include/clk.h b/include/clk.h
index ca20c3d..395f813 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -43,6 +43,15 @@ struct clk_ops {
 	int (*enable)(struct udevice *dev, int periph);
 
 	/**
+	 * disable() - Disable the clock for a peripheral
+	 *
+	 * @dev:	clock provider
+	 * @periph:	Peripheral ID to enable
+	 * @return zero on success, or -ve error code
+	 */
+	int (*disable)(struct udevice *dev, int periph);
+
+	/**
 	 * get_periph_rate() - Get clock rate for a peripheral
 	 *
 	 * @dev:	Device to check (UCLASS_CLK)
@@ -90,6 +99,15 @@ ulong clk_set_rate(struct udevice *dev, ulong rate);
 int clk_enable(struct udevice *dev, int periph);
 
 /**
+ * clk_disable() - Disable the clock for a peripheral
+ *
+ * @dev:	clock provider
+ * @periph:	Peripheral ID to enable
+ * @return zero on success, or -ve error code
+ */
+int clk_disable(struct udevice *dev, int periph);
+
+/**
  * clk_get_periph_rate() - Get current clock rate for a peripheral
  *
  * @dev:	Device to check (UCLASS_CLK)