From 97fa4cf442ff2872000d9110686371775795a32b Mon Sep 17 00:00:00 2001 From: Sebastian Hesselbarth Date: Sat, 17 Nov 2012 15:22:22 +0100 Subject: clk: mvebu: add mvebu core clocks. This driver allows to provide DT clocks for core clocks found on Marvell Kirkwood, Dove & 370/XP SoCs. The core clock frequencies and ratios are determined by decoding the Sample-At-Reset registers. Although technically correct, using a divider of 0 will lead to div_by_zero panic. Let's use a ratio of 0/1 instead to fail later with a zero clock. Signed-off-by: Gregory CLEMENT Signed-off-by: Sebastian Hesselbarth Signed-off-by: Andrew Lunn Tested-by Gregory CLEMENT --- .../devicetree/bindings/clock/mvebu-core-clock.txt | 47 ++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/mvebu-core-clock.txt (limited to 'Documentation/devicetree/bindings/clock/mvebu-core-clock.txt') diff --git a/Documentation/devicetree/bindings/clock/mvebu-core-clock.txt b/Documentation/devicetree/bindings/clock/mvebu-core-clock.txt new file mode 100644 index 00000000000..1e662948661 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/mvebu-core-clock.txt @@ -0,0 +1,47 @@ +* Core Clock bindings for Marvell MVEBU SoCs + +Marvell MVEBU SoCs usually allow to determine core clock frequencies by +reading the Sample-At-Reset (SAR) register. The core clock consumer should +specify the desired clock by having the clock ID in its "clocks" phandle cell. + +The following is a list of provided IDs and clock names on Armada 370/XP: + 0 = tclk (Internal Bus clock) + 1 = cpuclk (CPU clock) + 2 = nbclk (L2 Cache clock) + 3 = hclk (DRAM control clock) + 4 = dramclk (DDR clock) + +The following is a list of provided IDs and clock names on Kirkwood and Dove: + 0 = tclk (Internal Bus clock) + 1 = cpuclk (CPU0 clock) + 2 = l2clk (L2 Cache clock derived from CPU0 clock) + 3 = ddrclk (DDR controller clock derived from CPU0 clock) + +Required properties: +- compatible : shall be one of the following: + "marvell,armada-370-core-clock" - For Armada 370 SoC core clocks + "marvell,armada-xp-core-clock" - For Armada XP SoC core clocks + "marvell,dove-core-clock" - for Dove SoC core clocks + "marvell,kirkwood-core-clock" - for Kirkwood SoC (except mv88f6180) + "marvell,mv88f6180-core-clock" - for Kirkwood MV88f6180 SoC +- reg : shall be the register address of the Sample-At-Reset (SAR) register +- #clock-cells : from common clock binding; shall be set to 1 + +Optional properties: +- clock-output-names : from common clock binding; allows overwrite default clock + output names ("tclk", "cpuclk", "l2clk", "ddrclk") + +Example: + +core_clk: core-clocks@d0214 { + compatible = "marvell,dove-core-clock"; + reg = <0xd0214 0x4>; + #clock-cells = <1>; +}; + +spi0: spi@10600 { + compatible = "marvell,orion-spi"; + /* ... */ + /* get tclk from core clock provider */ + clocks = <&core_clk 0>; +}; -- cgit v1.2.3