linux/Documentation/devicetree/bindings/mmc/sunxi-mmc.txt
Chen-Yu Tsai ac98caefe1 mmc: sunxi: Add support for A83T eMMC (MMC2)
The third MMC controller (MMC2) on the Allwinner A83T SoC is slightly
different. It supports a wider 8-bit bus, has a dedicated controllable
reset pin for eMMC, and a "new timing mode" which is supposed to deliver
better signals and thus better performance.

Add a compatible for this one to use the new timing mode not found in the
other controllers.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-08-30 14:01:49 +02:00

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* 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 one of:
* "allwinner,sun4i-a10-mmc"
* "allwinner,sun5i-a13-mmc"
* "allwinner,sun7i-a20-mmc"
* "allwinner,sun8i-a83t-emmc"
* "allwinner,sun9i-a80-mmc"
* "allwinner,sun50i-a64-emmc"
* "allwinner,sun50i-a64-mmc"
- reg : mmc controller base registers
- clocks : a list with 4 phandle + clock specifier pairs
- clock-names : must contain "ahb", "mmc", "output" and "sample"
- interrupts : mmc controller interrupt
Optional properties:
- resets : phandle + reset specifier pair
- reset-names : must contain "ahb"
- for cd, bus-width and additional generic mmc parameters
please refer to mmc.txt within this directory
Examples:
- Within .dtsi:
mmc0: mmc@01c0f000 {
compatible = "allwinner,sun5i-a13-mmc";
reg = <0x01c0f000 0x1000>;
clocks = <&ahb_gates 8>, <&mmc0_clk>, <&mmc0_output_clk>, <&mmc0_sample_clk>;
clock-names = "ahb", "mod", "output", "sample";
interrupts = <0 32 4>;
status = "disabled";
};
- Within dts:
mmc0: mmc@01c0f000 {
pinctrl-names = "default", "default";
pinctrl-0 = <&mmc0_pins_a>;
pinctrl-1 = <&mmc0_cd_pin_reference_design>;
bus-width = <4>;
cd-gpios = <&pio 7 1 0>; /* PH1 */
cd-inverted;
status = "okay";
};