Add a method which can locate a clock for a device, given its index. This
uses the normal device tree bindings to return the clock device and the
first argument which is normally used as a peripheral ID in U-Boot.
Signed-off-by: Simon Glass <s...@chromium.org>
---
Changes in v2:
- Make the peripheral ID a return value
- Add an assert for clk_devp
- Make the function dependent on OF_CONTROL
drivers/clk/clk-uclass.c | 28 ++++++++++++++++++++++++++++
include/clk.h | 14 ++++++++++++++
2 files changed, 42 insertions(+)
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index 8078b0f..f80beaf 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -12,6 +12,8 @@
#include <dm/lists.h>
#include <dm/root.h>
+DECLARE_GLOBAL_DATA_PTR;
+
ulong clk_get_rate(struct udevice *dev)
{
struct clk_ops *ops = clk_get_ops(dev);
@@ -62,6 +64,32 @@ int clk_get_id(struct udevice *dev, int args_count, uint32_t
*args)
return ops->get_id(dev, args_count, args);
}
+#ifdef CONFIG_OF_CONTROL
+int clk_get_by_index(struct udevice *dev, int index, struct udevice **clk_devp)
+{
+ struct fdtdec_phandle_args args;
+ int ret;
+
+ assert(*clk_devp);
+ ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
+ "clocks", "#clock-cells", 0, index,
+ &args);
+ if (ret) {
+ debug("%s: fdtdec_parse_phandle_with_args failed: err=%d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = uclass_get_device_by_of_offset(UCLASS_CLK, args.node, clk_devp);
+ if (ret) {
+ debug("%s: uclass_get_device_by_of_offset failed: err=%d\n",
+ __func__, ret);
+ return ret;
+ }
+ return args.args_count > 0 ? args.args[0] : 0;
+}
+#endif
+
UCLASS_DRIVER(clk) = {
.id = UCLASS_CLK,
.name = "clk",
diff --git a/include/clk.h b/include/clk.h
index ce2db41..0af2824 100644
--- a/include/clk.h
+++ b/include/clk.h
@@ -150,4 +150,18 @@ static inline int fdt_clk_get(const void *fdt, int
nodeoffset, int index,
}
#endif
+/**
+ * clk_get_by_index() - look up a clock referenced by a device
+ *
+ * Parse a device's 'clocks' list, returning information on the indexed clock,
+ * ensuring that it is activated.
+ *
+ * @dev: Device containing the clock reference
+ * @index: Clock index to return (0 = first)
+ * @clk_devp: Returns clock device
+ * @return: Peripheral ID for the device to control. This is the first
+ * argument after the clock node phandle. If there is no arguemnt,
+ * returns 0. Return -ve error code on any error
+ */
+int clk_get_by_index(struct udevice *dev, int index, struct udevice
**clk_devp);
#endif /* _CLK_H_ */
--
2.6.0.rc2.230.g3dd15c0
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