clk: mvebu: add clock gating control provider for DT
This driver allows to provide DT clocks for clock gates found on
Marvell Dove and Kirkwood SoCs. The clock gates are referenced by
the phandle index of the corresponding bit in the clock gating control
register to ease lookup in the datasheet.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
diff --git a/Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt b/Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt
new file mode 100644
index 0000000..4ad8ccd
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/mvebu-gated-clock.txt
@@ -0,0 +1,76 @@
+* Gated Clock bindings for Marvell Orion SoCs
+
+Marvell Dove and Kirkwood allow some peripheral clocks to be gated to save
+some power. The clock consumer should specify the desired clock by having
+the clock ID in its "clocks" phandle cell. The clock ID is directly mapped to
+the corresponding clock gating control bit in HW to ease manual clock lookup
+in datasheet.
+
+The following is a list of provided IDs for Dove:
+ID Clock Peripheral
+-----------------------------------
+0 usb0 USB Host 0
+1 usb1 USB Host 1
+2 ge Gigabit Ethernet
+3 sata SATA Host
+4 pex0 PCIe Cntrl 0
+5 pex1 PCIe Cntrl 1
+8 sdio0 SDHCI Host 0
+9 sdio1 SDHCI Host 1
+10 nand NAND Cntrl
+11 camera Camera Cntrl
+12 i2s0 I2S Cntrl 0
+13 i2s1 I2S Cntrl 1
+15 crypto CESA engine
+21 ac97 AC97 Cntrl
+22 pdma Peripheral DMA
+23 xor0 XOR DMA 0
+24 xor1 XOR DMA 1
+30 gephy Gigabit Ethernel PHY
+Note: gephy(30) is implemented as a parent clock of ge(2)
+
+The following is a list of provided IDs for Kirkwood:
+ID Clock Peripheral
+-----------------------------------
+0 ge0 Gigabit Ethernet 0
+2 pex0 PCIe Cntrl 0
+3 usb0 USB Host 0
+4 sdio SDIO Cntrl
+5 tsu Transp. Stream Unit
+6 dunit SDRAM Cntrl
+7 runit Runit
+8 xor0 XOR DMA 0
+9 audio I2S Cntrl 0
+14 sata0 SATA Host 0
+15 sata1 SATA Host 1
+16 xor1 XOR DMA 1
+17 crypto CESA engine
+18 pex1 PCIe Cntrl 1
+19 ge1 Gigabit Ethernet 0
+20 tdm Time Division Mplx
+
+Required properties:
+- compatible : shall be one of the following:
+ "marvell,dove-gating-clock" - for Dove SoC clock gating
+ "marvell,kirkwood-gating-clock" - for Kirkwood SoC clock gating
+- reg : shall be the register address of the Clock Gating Control register
+- #clock-cells : from common clock binding; shall be set to 1
+
+Optional properties:
+- clocks : default parent clock phandle (e.g. tclk)
+
+Example:
+
+gate_clk: clock-gating-control@d0038 {
+ compatible = "marvell,dove-gating-clock";
+ reg = <0xd0038 0x4>;
+ /* default parent clock is tclk */
+ clocks = <&core_clk 0>;
+ #clock-cells = <1>;
+};
+
+sdio0: sdio@92000 {
+ compatible = "marvell,dove-sdhci";
+ /* get clk gate bit 8 (sdio0) */
+ clocks = <&gate_clk 8>;
+};