linux/Documentation/devicetree/bindings/mmc/mmc.txt
Abhilash Kesavan e5d0e9c567 mmc: dt: Add optional pm properties to core binding
Add documentation for pm capabilties such as MMC_PM_KEEP_POWER
and MMC_PM_WAKE_SDIO_IRQ.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-12-06 13:54:52 -05:00

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These properties are common to multiple MMC host controllers. Any host
that requires the respective functionality should implement them using
these definitions.
Interpreted by the OF core:
- reg: Registers location and length.
- interrupts: Interrupts used by the MMC controller.
Required properties:
- bus-width: Number of data lines, can be <1>, <4>, or <8>
Card detection:
If no property below is supplied, standard SDHCI card detect is used.
Only one of the properties in this section should be supplied:
- broken-cd: There is no card detection available; polling must be used.
- cd-gpios: Specify GPIOs for card detection, see gpio binding
- non-removable: non-removable slot (like eMMC); assume always present.
Optional properties:
- wp-gpios: Specify GPIOs for write protection, see gpio binding
- cd-inverted: when present, polarity on the cd gpio line is inverted
- wp-inverted: when present, polarity on the wp gpio line is inverted
- max-frequency: maximum operating clock frequency
Optional SDIO properties:
- keep-power-in-suspend: Preserves card power during a suspend/resume cycle
- enable-sdio-wakeup: Enables wake up of host system on SDIO IRQ assertion
Example:
sdhci@ab000000 {
compatible = "sdhci";
reg = <0xab000000 0x200>;
interrupts = <23>;
bus-width = <4>;
cd-gpios = <&gpio 69 0>;
cd-inverted;
wp-gpios = <&gpio 70 0>;
max-frequency = <50000000>;
keep-power-in-suspend;
enable-sdio-wakeup;
}