xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/mmc/mmci.txt

* ARM PrimeCell MultiMedia Card Interface (MMCI) PL180/1

The ARM PrimeCell MMCI PL180 and PL181 provides an interface for
reading and writing to MultiMedia and SD cards alike.

This file documents differences between the core properties described
by mmc.txt and the properties used by the mmci driver. Using "st" as
the prefix for a property, indicates support by the ST Micro variant.

Required properties:
- compatible             : contains "arm,pl18x", "arm,primecell".
- vmmc-supply            : phandle to the regulator device tree node, mentioned
                           as the VCC/VDD supply in the eMMC/SD specs.

Optional properties:
- arm,primecell-periphid : contains the PrimeCell Peripheral ID, it overrides
                           the ID provided by the HW
- resets                 : phandle to internal reset line.
			   Should be defined for sdmmc variant.
- vqmmc-supply           : phandle to the regulator device tree node, mentioned
                           as the VCCQ/VDD_IO supply in the eMMC/SD specs.
specific for ux500 variant:
- st,sig-dir-dat0        : bus signal direction pin used for DAT[0].
- st,sig-dir-dat2        : bus signal direction pin used for DAT[2].
- st,sig-dir-dat31       : bus signal direction pin used for DAT[3] and DAT[1].
- st,sig-dir-dat74       : bus signal direction pin used for DAT[4] to DAT[7].
- st,sig-dir-cmd         : cmd signal direction pin used for CMD.
- st,sig-pin-fbclk       : feedback clock signal pin used.

specific for sdmmc variant:
- reg			 : a second base register may be defined if a delay
                           block is present and used for tuning.
- st,sig-dir             : signal direction polarity used for cmd, dat0 dat123.
- st,neg-edge            : data & command phase relation, generated on
                           sd clock falling edge.
- st,use-ckin            : use ckin pin from an external driver to sample
                           the receive data (example: with voltage
			   switch transceiver).

Deprecated properties:
- mmc-cap-mmc-highspeed  : indicates whether MMC is high speed capable.
- mmc-cap-sd-highspeed   : indicates whether SD is high speed capable.

Example:

sdi0_per1@80126000 {
	compatible = "arm,pl18x", "arm,primecell";
	reg = <0x80126000 0x1000>;
	interrupts = <0 60 IRQ_TYPE_LEVEL_HIGH>;

	dmas = <&dma 29 0 0x2>, /* Logical - DevToMem */
	       <&dma 29 0 0x0>; /* Logical - MemToDev */
	dma-names = "rx", "tx";

	clocks = <&prcc_kclk 1 5>, <&prcc_pclk 1 5>;
	clock-names = "sdi", "apb_pclk";

	max-frequency = <100000000>;
	bus-width = <4>;
	cap-sd-highspeed;
	cap-mmc-highspeed;
	cd-gpios  = <&gpio2 31 0x4>; // 95
	st,sig-dir-dat0;
	st,sig-dir-dat2;
	st,sig-dir-cmd;
	st,sig-pin-fbclk;

	vmmc-supply = <&ab8500_ldo_aux3_reg>;
	vqmmc-supply = <&vmmci>;

	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&sdi0_default_mode>;
	pinctrl-1 = <&sdi0_sleep_mode>;
};