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| author | Simon Glass <sjg@chromium.org> | 2016-01-20 19:43:02 -0700 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2016-01-21 19:47:29 -0700 |
| commit | e70cc438311c753edc1f19214ffc090061e60880 (patch) | |
| tree | f7ab2b660954da09ef3cbecd24fb3fa45fb8fe58 | |
| parent | b21e20b255a02393727c93b1927a381ce3008fa4 (diff) | |
| download | u-boot-imx-e70cc438311c753edc1f19214ffc090061e60880.zip u-boot-imx-e70cc438311c753edc1f19214ffc090061e60880.tar.gz u-boot-imx-e70cc438311c753edc1f19214ffc090061e60880.tar.bz2 | |
dm: clk: Add support for decoding clocks from the device tree
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 <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
| -rw-r--r-- | drivers/clk/clk-uclass.c | 28 | ||||
| -rw-r--r-- | include/clk.h | 24 |
2 files changed, 52 insertions, 0 deletions
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index 19f6f07..8a4c568 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 @@ ulong clk_set_periph_rate(struct udevice *dev, int periph, ulong rate) return ops->set_periph_rate(dev, periph, rate); } +#if CONFIG_IS_ENABLED(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 941808a..ca20c3d 100644 --- a/include/clk.h +++ b/include/clk.h @@ -8,6 +8,7 @@ #ifndef _CLK_H_ #define _CLK_H_ +#include <errno.h> #include <linux/types.h> struct udevice; @@ -105,4 +106,27 @@ ulong clk_get_periph_rate(struct udevice *dev, int periph); */ ulong clk_set_periph_rate(struct udevice *dev, int periph, ulong rate); +#if CONFIG_IS_ENABLED(OF_CONTROL) +/** + * 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); +#else +static inline int clk_get_by_index(struct udevice *dev, int index, + struct udevice **clk_devp) +{ + return -ENOSYS; +} +#endif + #endif /* _CLK_H_ */ |