* Atmel SDHCI controller

This file documents the differences between the core properties in
Documentation/devicetree/bindings/mmc/mmc.txt and the properties used by the
sdhci-of-at91 driver.

Required properties:
- compatible:		Must be "atmel,sama5d2-sdhci" or "microchip,sam9x60-sdhci".
- clocks:		Phandlers to the clocks.
- clock-names:		Must be "hclock", "multclk", "baseclk" for
			"atmel,sama5d2-sdhci".
			Must be "hclock", "multclk" for "microchip,sam9x60-sdhci".

Optional properties:
- assigned-clocks:	The same with "multclk".
- assigned-clock-rates	The rate of "multclk" in order to not rely on the
			gck configuration set by previous components.
- microchip,sdcal-inverted: when present, polarity on the SDCAL SoC pin is
  inverted. The default polarity for this signal is described in the datasheet.
  For instance on SAMA5D2, the pin is usually tied to the GND with a resistor
  and a capacitor (see "SDMMC I/O Calibration" chapter).

Example:

mmc0: sdio-host@a0000000 {
	compatible = "atmel,sama5d2-sdhci";
	reg = <0xa0000000 0x300>;
	interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>;
	clocks = <&sdmmc0_hclk>, <&sdmmc0_gclk>, <&main>;
	clock-names = "hclock", "multclk", "baseclk";
	assigned-clocks = <&sdmmc0_gclk>;
	assigned-clock-rates = <480000000>;
};