u-boot/drivers/Kconfig
Simon Glass f26c8a8e77 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 <sjg@chromium.org>
2015-07-21 17:39:29 -06:00

71 lines
1.3 KiB
Text

menu "Device Drivers"
source "drivers/clk/Kconfig"
source "drivers/core/Kconfig"
source "drivers/cpu/Kconfig"
source "drivers/demo/Kconfig"
source "drivers/pci/Kconfig"
source "drivers/pcmcia/Kconfig"
source "drivers/mtd/Kconfig"
source "drivers/block/Kconfig"
source "drivers/misc/Kconfig"
source "drivers/net/Kconfig"
source "drivers/input/Kconfig"
source "drivers/led/Kconfig"
source "drivers/serial/Kconfig"
source "drivers/tpm/Kconfig"
source "drivers/i2c/Kconfig"
source "drivers/spi/Kconfig"
source "drivers/gpio/Kconfig"
source "drivers/power/Kconfig"
source "drivers/ram/Kconfig"
source "drivers/hwmon/Kconfig"
source "drivers/watchdog/Kconfig"
source "drivers/video/Kconfig"
source "drivers/sound/Kconfig"
source "drivers/usb/Kconfig"
source "drivers/dfu/Kconfig"
source "drivers/mmc/Kconfig"
source "drivers/rtc/Kconfig"
source "drivers/dma/Kconfig"
source "drivers/crypto/Kconfig"
source "drivers/thermal/Kconfig"
endmenu
config PHYS_TO_BUS
bool "Custom physical to bus address mapping"
help
Some SoCs use a different address map for CPU physical addresses and
peripheral DMA master accesses. If yours does, select this option in
your platform's Kconfig, and implement the appropriate mapping
functions in your platform's support code.