[PATCH u-boot] clk: Add get/enable/disable/release for a bulk of clocks

[Neil Armstrong]

This patch adds a "bulk" API to the clock API in order to get/enable/disable
/release a group of clocks associated with a device.

This bulk API will avoid adding a copy of the same code to manage
a group of clocks in drivers.

Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
---
This serie and the "reset bulk" serie is necessary and suggested by Marek Vasut
for the "Add USB Support for Amlogic Meson GXL SoCs" to avoid adding the same
code to manage a bulk of clocks and resets in another driver.
I will push a RFC code to update the other drivers having a similar
code pattern when these patches are merged.

 drivers/clk/clk-uclass.c | 59 +++++++++++++++++++++++++++++++++++++++
 include/clk.h            | 72 +++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 130 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index ad76379..6e99b3b 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -104,6 +104,39 @@ int clk_get_by_index(struct udevice *dev, int index, struct clk *clk)
 	return clk_get_by_indexed_prop(dev, "clocks", index, clk);
 }
 
+int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
+{
+	int i, ret, err, count;
+	
+	bulk->count = 0;
+
+	count = dev_count_phandle_with_args(dev, "clocks", "#clock-cells");
+	if (!count)
+		return 0;
+
+	bulk->clks = devm_kcalloc(dev, count, sizeof(struct clk), GFP_KERNEL);
+	if (!bulk->clks)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		ret = clk_get_by_index(dev, i, &bulk->clks[i]);
+		if (ret < 0)
+			goto bulk_get_err;
+
+		++bulk->count;
+	}
+
+	return 0;
+
+bulk_get_err:
+	err = clk_release_all(bulk->clks, bulk->count);
+	if (err)
+		debug("%s: could release all clocks for %p\n",
+		      __func__, dev);
+
+	return ret;
+}
+
 static int clk_set_default_parents(struct udevice *dev)
 {
 	struct clk clk, parent_clk;
@@ -336,6 +369,19 @@ int clk_enable(struct clk *clk)
 	return ops->enable(clk);
 }
 
+int clk_enable_bulk(struct clk_bulk *bulk)
+{
+	int i, ret;
+
+	for (i = 0; i < bulk->count; i++) {
+		ret = clk_enable(&bulk->clks[i]);
+		if (ret < 0 && ret != -ENOSYS)
+			return ret;
+	}
+
+	return 0;
+}
+
 int clk_disable(struct clk *clk)
 {
 	const struct clk_ops *ops = clk_dev_ops(clk->dev);
@@ -348,6 +394,19 @@ int clk_disable(struct clk *clk)
 	return ops->disable(clk);
 }
 
+int clk_disable_bulk(struct clk_bulk *bulk)
+{
+	int i, ret;
+
+	for (i = 0; i < bulk->count; i++) {
+		ret = clk_disable(&bulk->clks[i]);
+		if (ret < 0 && ret != -ENOSYS)
+			return ret;
+	}
+
+	return 0;
+}
+
 UCLASS_DRIVER(clk) = {
 	.id		= UCLASS_CLK,
 	.name		= "clk",
diff --git a/include/clk.h b/include/clk.h
index a7d95d3..b3a9fce 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -60,6 +60,23 @@ struct clk {
 	unsigned long id;
 };
 
+/**
+ * struct clk_bulk - A handle to (allowing control of) a bulk of clocks.
+ *
+ * Clients provide storage for the clock bulk. The content of the structure is
+ * managed solely by the clock API. A clock bulk struct is
+ * initialized by "get"ing the clock bulk struct.
+ * The clock bulk struct is passed to all other bulk clock APIs to apply
+ * the API to all the clock in the bulk struct.
+ *
+ * @clks: An array of clock handles.
+ * @count: The number of clock handles in the clks array.
+ */
+struct clk_bulk {
+	struct clk *clks;
+	unsigned int count;
+};
+
 #if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(CLK)
 struct phandle_1_arg;
 int clk_get_by_index_platdata(struct udevice *dev, int index,
@@ -83,6 +100,21 @@ int clk_get_by_index_platdata(struct udevice *dev, int index,
 int clk_get_by_index(struct udevice *dev, int index, struct clk *clk);
 
 /**
+ * clock_get_bulk - Get/request all clocks of a device.
+ *
+ * This looks up and requests all clocks of the client device; each device is
+ * assumed to have n clocks associated with it somehow, and this function finds
+ * and requests all of them in a separate structure. The mapping of client
+ * device clock indices to provider clocks may be via device-tree properties,
+ * board-provided mapping tables, or some other mechanism.
+ *
+ * @dev:	The client device.
+ * @bulk	A pointer to a clock bulk struct to initialize.
+ * @return 0 if OK, or a negative error code.
+ */
+int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
+
+/**
  * clock_get_by_name - Get/request a clock by name.
  *
  * This looks up and requests a clock. The name is relative to the client
@@ -120,6 +152,11 @@ static inline int clk_get_by_index(struct udevice *dev, int index,
 	return -ENOSYS;
 }
 
+static inline int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
+{
+	return -ENOSYS;
+}
+
 static inline int clk_get_by_name(struct udevice *dev, const char *name,
 			   struct clk *clk)
 {
@@ -130,7 +167,6 @@ static inline int clk_release_all(struct clk *clk, int count)
 {
 	return -ENOSYS;
 }
-
 #endif
 
 #if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \
@@ -151,6 +187,22 @@ static inline int clk_set_defaults(struct udevice *dev)
 #endif
 
 /**
+ * clk_release_bulk() - Disable (turn off)/Free an array of previously
+ * requested clocks in a clock bulk struct.
+ *
+ * For each clock contained in the clock bulk struct, this function will check
+ * if clock has been previously requested and then will disable and free it.
+ *
+ * @clk:	A clock bulk struct that was previously successfully
+ *		requested by clk_get_bulk().
+ * @return zero on success, or -ve error code.
+ */
+static inline int clk_release_bulk(struct clk_bulk *bulk)
+{
+	return clk_release_all(bulk->clks, bulk->count);
+}
+
+/**
  * clk_request - Request a clock by provider-specific ID.
  *
  * This requests a clock using a provider-specific ID. Generally, this function
@@ -215,6 +267,15 @@ int clk_set_parent(struct clk *clk, struct clk *parent);
 int clk_enable(struct clk *clk);
 
 /**
+ * clk_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct.
+ *
+ * @bulk:	A clock bulk struct that was previously successfully requested
+ *		by clk_get_bulk().
+ * @return zero on success, or -ve error code.
+ */
+int clk_enable_bulk(struct clk_bulk *bulk);
+
+/**
  * clk_disable() - Disable (turn off) a clock.
  *
  * @clk:	A clock struct that was previously successfully requested by
@@ -223,6 +284,15 @@ int clk_enable(struct clk *clk);
  */
 int clk_disable(struct clk *clk);
 
+/**
+ * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct.
+ *
+ * @bulk:	A clock bulk struct that was previously successfully requested
+ *		by clk_get_bulk().
+ * @return zero on success, or -ve error code.
+ */
+int clk_disable_bulk(struct clk_bulk *bulk);
+
 int soc_clk_dump(void);
 
 #endif
-- 
2.7.4