gpio-tz1090: add TZ1090 gpio driver

Add a GPIO driver for the main GPIOs found in the TZ1090 (Comet) SoC.
This doesn't include low-power GPIOs as they're controlled separately
via the Powerdown Controller (PDC) registers.

The driver is instantiated by device tree and supports interrupts for
all GPIOs.

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)
 - gpio-tz1090: use of_property_read_u32 instead of of_get_property

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/.
 - some s/unsigned int/bool/ and use of BIT().
 - 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.
 - gpio-tz1090: add REG_ prefix to some constants for consistency.
 - gpio-tz1090: add comment to explain tz1090_gpio_irq_next_edge
   cunningness.

Changes in v2:
 - gpio-tz1090: remove references to Linux flags in dt bindings
 - gpio-tz1090: make use of BIT() from linux/bitops.h
 - gpio-tz1090: make register accessors inline to match pinctrl
 - gpio-tz1090: 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, 88 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gpio/gpio-tz1090.txt b/Documentation/devicetree/bindings/gpio/gpio-tz1090.txt
new file mode 100644
index 000000000000..174cdf309170
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-tz1090.txt
@@ -0,0 +1,88 @@
+ImgTec TZ1090 GPIO Controller
+
+Required properties:
+- compatible: Compatible property value should be "img,tz1090-gpio".
+
+- reg: Physical base address of the controller and length of memory mapped
+  region.
+
+- #address-cells: Should be 1 (for bank subnodes)
+
+- #size-cells: Should be 0 (for bank subnodes)
+
+- Each bank of GPIOs should have a subnode to represent it.
+
+  Bank subnode required properties:
+  - reg: Index of bank in the range 0 to 2.
+
+  - 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]
+        [gpio number within the gpio bank]
+        [gpio flags]>
+
+    Values for gpio specifier:
+    - GPIO number: a value in the range 0 to 29.
+    - 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
+
+  Bank subnode optional properties:
+  - gpio-ranges: Mapping to pin controller pins (as described in
+    Documentation/devicetree/bindings/gpio/gpio.txt)
+
+  - interrupts: Interrupt for the entire bank
+
+  - interrupt-controller: Specifies that the node is an interrupt controller
+
+  - #interrupt-cells: Should be 2. The syntax of the interrupt specifier used by
+    client nodes should have the following values.
+       <[phandle of the interurupt controller]
+        [gpio number within the gpio bank]
+        [irq flags]>
+
+    Values for irq specifier:
+    - GPIO number: a value in the range 0 to 29
+    - IRQ flags: value to describe edge and level triggering, as defined in
+      <dt-bindings/interrupt-controller/irq.h>. Only the following flags are
+      supported:
+        IRQ_TYPE_EDGE_RISING
+        IRQ_TYPE_EDGE_FALLING
+        IRQ_TYPE_EDGE_BOTH
+        IRQ_TYPE_LEVEL_HIGH
+        IRQ_TYPE_LEVEL_LOW
+
+
+
+Example:
+
+        gpios: gpio-controller@02005800 {
+                #address-cells = <1>;
+                #size-cells = <0>;
+                compatible = "img,tz1090-gpio";
+                reg = <0x02005800 0x90>;
+
+                /* bank 0 with an interrupt */
+                gpios0: bank@0 {
+                        #gpio-cells = <2>;
+                        #interrupt-cells = <2>;
+                        reg = <0>;
+                        interrupts = <13 IRQ_TYPE_LEVEL_HIGH>;
+                        gpio-controller;
+                        gpio-ranges = <&pinctrl 0 0 30>;
+                        interrupt-controller;
+                };
+
+                /* bank 2 without interrupt */
+                gpios2: bank@2 {
+                        #gpio-cells = <2>;
+                        reg = <2>;
+                        gpio-controller;
+                        gpio-ranges = <&pinctrl 0 60 30>;
+                };
+        };
+
+