gpio-tz1090-pdc: add TZ1090 PDC gpio driver

Add a GPIO driver for the low-power Powerdown Controller GPIOs in the
TZ1090 SoC.

The driver is instantiated by device tree and supports interrupts for
the SysWake GPIOs only.

Changes in v4:
 - fix typos in DT bindings compatible properties
 - reference Documentation/devicetree/bindings/gpio/gpio.txt in
   gpio-ranges description in DT bindings
 - fix gpio-ranges examples in DT bindings (it must now have 3 cells)

Changes in v3:
 - separated from irq-imgpdc and removed arch/metag changes to allow
   these patches to go upstream separately via the pinctrl[/gpio] trees
   (particularly the pinctrl drivers depend on the new pinconf DT
   bindings).
 - some s/unsigned/unsigned int/.
 - gpio-tz1090*: refer to <dt-bindings/gpio/gpio.h> and
   <dt-bindings/interrupt-controller/irq.h> flags in bindings.
 - gpio-tz1090*: move initcall from postcore to subsys.

Changes in v2:
 - gpio-tz1090-pdc: remove references to Linux flags in dt bindings
 - gpio-tz1090-pdc: make use of BIT() from linux/bitops.h
 - gpio-tz1090-pdc: make register accessors inline to match pinctrl
 - gpio-tz1090-pdc: update gpio-ranges to use 3 cells after recent ABI
   breakage

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-doc@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gpio/gpio-tz1090-pdc.txt b/Documentation/devicetree/bindings/gpio/gpio-tz1090-pdc.txt
new file mode 100644
index 0000000..1fd98ff
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-tz1090-pdc.txt
@@ -0,0 +1,45 @@
+ImgTec TZ1090 PDC GPIO Controller
+
+Required properties:
+- compatible: Compatible property value should be "img,tz1090-pdc-gpio".
+
+- reg: Physical base address of the controller and length of memory mapped
+  region. This starts at and cover the SOC_GPIO_CONTROL registers.
+
+- gpio-controller: Specifies that the node is a gpio controller.
+
+- #gpio-cells: Should be 2. The syntax of the gpio specifier used by client
+  nodes should have the following values.
+     <[phandle of the gpio controller node]
+      [PDC gpio number]
+      [gpio flags]>
+
+  Values for gpio specifier:
+  - GPIO number: a value in the range 0 to 6.
+  - GPIO flags: bit field of flags, as defined in <dt-bindings/gpio/gpio.h>.
+    Only the following flags are supported:
+      GPIO_ACTIVE_HIGH
+      GPIO_ACTIVE_LOW
+
+Optional properties:
+- gpio-ranges: Mapping to pin controller pins (as described in
+  Documentation/devicetree/bindings/gpio/gpio.txt)
+
+- interrupts: Individual syswake interrupts (other GPIOs cannot interrupt)
+
+
+Example:
+
+	pdc_gpios: gpio-controller@02006500 {
+		gpio-controller;
+		#gpio-cells = <2>;
+
+		compatible = "img,tz1090-pdc-gpio";
+		reg = <0x02006500 0x100>;
+
+		interrupt-parent = <&pdc>;
+		interrupts =	<8  IRQ_TYPE_NONE>,	/* Syswake 0 */
+				<9  IRQ_TYPE_NONE>,	/* Syswake 1 */
+				<10 IRQ_TYPE_NONE>;	/* Syswake 2 */
+		gpio-ranges = <&pdc_pinctrl 0 0 7>;
+	};