u-boot-brain/doc/device-tree-bindings/gpio/altera_pio.txt
Thomas Chou 88d5ecf4b9 nios2 : convert altera_pio to driver model
Convert altera_pio to driver model.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Chin Liang See <clsee@altera.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2015-10-23 07:37:03 +08:00

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Altera GPIO controller bindings
Required properties:
- compatible:
- "altr,pio-1.0"
- reg: Physical base address and length of the controller's registers.
Optional properties:
- altr,gpio-bank-width: Width of the GPIO bank. This defines how many pins the
GPIO device has. Ranges between 1-32. Optional and defaults to 32 if not
specified.
- gpio-bank-name: bank name attached to this device.
Example:
user_led_pio_8out: gpio@0x4cc0 {
compatible = "altr,pio-1.0";
reg = <0x00004cc0 0x00000010>;
resetvalue = <255>;
altr,gpio-bank-width = <8>;
#gpio-cells = <2>;
gpio-controller;
gpio-bank-name = "led";
};
In this example, the gpio can be accessed as led[0..7] using gpio command of
u-boot.
==> gpio clear led0