From f26c8a8e77629cf9de36a697ea5513f9184a2319 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Tue, 23 Jun 2015 15:39:15 -0600 Subject: 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 --- drivers/Kconfig | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/Kconfig') diff --git a/drivers/Kconfig b/drivers/Kconfig index 64c27931aa..092bc02b30 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -1,5 +1,7 @@ menu "Device Drivers" +source "drivers/clk/Kconfig" + source "drivers/core/Kconfig" source "drivers/cpu/Kconfig" -- cgit v1.2.1