[v6,8/8] ARM: sunxi: Add documentation for driver for SD/MMC hosts found on Allwinner sunxi SoCs

Commit Message

David Lanzendörfer Feb. 16, 2014, 5:12 a.m. UTC

Signed-off-by: David Lanzendörfer <[e-mail]>
---
 .../devicetree/bindings/mmc/sunxi-mmc.txt          |   32 ++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/sunxi-mmc.txt

Patch

diff --git a/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt b/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
new file mode 100644
index 0000000..5ce8c5e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
@@ -0,0 +1,32 @@ 
+* Allwinner sunxi MMC controller
+
+The highspeed MMC host controller on Allwinner SoCs provides an interface
+for MMC, SD and SDIO types of memory cards.
+
+Supported maximum speeds are the ones of the eMMC standard 4.5 as well
+as the speed of SD standard 3.0.
+Absolute maximum transfer rate is 200MB/s
+
+Required properties:
+- compatible: Should be "allwinner,<revision>-<chip>-mmc".
+  The supported chips include a10, a10s, 13, a20 and a31.
+- base registers are 0x1000 appart, so the base of mmc1
+  would be 0x01c0f000+0x1000=0x01c10000(see example)
+  and so on.
+- clocks requires the reference at the ahb clock gate
+  with the correct index (mmc0 -> 8, mmc1 -> 9, and so on)
+  as well as the reference to the correct mod0 clock.
+- interrupts requires the correct IRQ line
+  (mmc0 -> 32, mmc1 -> 33, and so on)
+
+Examples:
+
+mmc0: mmc@01c0f000 {
+	compatible = "allwinner,sun5i-a13-mmc";
+	reg = <0x01c0f000 0x1000>;
+	clocks = <&ahb_gates 8>, <&mmc0_clk>;
+	clock-names = "ahb", "mod";
+	interrupts = <0 32 4>;
+	bus-width = <4>;
+	status = "disabled";
+};