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>

1 files changed, 28 insertions, 0 deletions

diff --git a/doc/device-tree-bindings/gpio/altera_pio.txt b/doc/device-tree-bindings/gpio/altera_pio.txt
new file mode 100644
index 0000000000..cf71eb2824
--- /dev/null
+++ b/doc/device-tree-bindings/gpio/altera_pio.txt
@@ -0,0 +1,28 @@
+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