path: root/scripts
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authorSimon Glass <>2015-06-23 15:39:15 -0600
committerSimon Glass <>2015-07-21 17:39:29 -0600
commitf26c8a8e77629cf9de36a697ea5513f9184a2319 (patch)
treea6466bcd31947349287b062fb92d30683b8b4f5a /scripts
parent30db918768396caaae43f644f7ca9e41f461ab75 (diff)
dm: Add a clock uclass
Clocks are an important feature of platforms and have become increasing complex with time. Most modern SoCs have multiple PLLs and dozens of clock dividers which distribute clocks to on-chip peripherals. Some SoC implementations have a clock API which is private to that SoC family, e.g. Tegra and Exynos. This is useful but it would be better to have a common API that can be understood and used throughout U-Boot. Add a simple clock API as a starting point. It supports querying and setting the rate of a clock. Each clock is a device. To reduce memory and processing overhead the concept of peripheral clocks is provided. These do not need to be explicit devices - it is possible to write a driver that can adjust the I2C clock (for example) without an explicit I2C clock device. This can dramatically reduce the number of devices (and associated overhead) in a complex SoC. Clocks are referenced by a number, and it is expected that SoCs will define that numbering themselves via an enum. Signed-off-by: Simon Glass <>
Diffstat (limited to 'scripts')
1 files changed, 1 insertions, 0 deletions
diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
index 277958ad8e..525f9a238c 100644
--- a/scripts/Makefile.spl
+++ b/scripts/Makefile.spl
@@ -54,6 +54,7 @@ libs-$(HAVE_VENDOR_COMMON_LIB) += board/$(VENDOR)/common/
libs-$(CONFIG_SPL_FRAMEWORK) += common/spl/
+libs-$(CONFIG_SPL_CLK_SUPPORT) += drivers/clk/
libs-$(CONFIG_SPL_DM) += drivers/core/
libs-$(CONFIG_SPL_I2C_SUPPORT) += drivers/i2c/
libs-$(CONFIG_SPL_GPIO_SUPPORT) += drivers/gpio/
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