[1/5] gpio: Cygnus: define Broadcom Cygnus GPIO binding

Commit Message

Ray Jui Dec. 6, 2014, 12:40 a.m. UTC

Document the GPIO device tree binding for Broadcom Cygnus SoC

Signed-off-by: Ray Jui <[e-mail]>
Reviewed-by: Scott Branden <[e-mail]>
---
 .../devicetree/bindings/gpio/brcm,cygnus-gpio.txt  |   85 ++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/brcm,cygnus-gpio.txt

Comments

Linus Walleij Jan. 13, 2015, 7:57 a.m. UTC | #1

On Sat, Dec 6, 2014 at 1:40 AM, Ray Jui <[e-mail]> wrote:

> Document the GPIO device tree binding for Broadcom Cygnus SoC
>
> Signed-off-by: Ray Jui <[e-mail]>
> Reviewed-by: Scott Branden <[e-mail]>
(...)
> +- #gpio-cells:
> +    Must be two. The first cell is the GPIO pin number (within the
> +controller's domain) and the second cell is used for the following:
> +    bit[0]: polarity (0 for normal and 1 for inverted)
> +    bit[18:16]: internal pull up/down: 0 - pull up/down disabled
> +                                       1 - pull up enabled
> +                                       2 - pull down enabled
> +    bit[22:20]: drive strength: 0 - 2 mA
> +                                1 - 4 mA
> +                                2 - 6 mA
> +                                3 - 8 mA
> +                                4 - 10 mA
> +                                5 - 12 mA
> +                                6 - 14 mA
> +                                7 - 16 mA

No. This pull up/down and drive strength is pin controller
business, use a pin control backend behind the GPIO driver
see Documentation/pinctrl.txt.

Initial states for these configurations can be set up using
pin control hogs since pin control and GPIO is orthogonal.

Yours,
Linus Walleij

Ray Jui Jan. 13, 2015, 5:07 p.m. UTC | #2

On 1/12/2015 11:57 PM, Linus Walleij wrote:
> On Sat, Dec 6, 2014 at 1:40 AM, Ray Jui <[e-mail]> wrote:
> 
>> Document the GPIO device tree binding for Broadcom Cygnus SoC
>>
>> Signed-off-by: Ray Jui <[e-mail]>
>> Reviewed-by: Scott Branden <[e-mail]>
> (...)
>> +- #gpio-cells:
>> +    Must be two. The first cell is the GPIO pin number (within the
>> +controller's domain) and the second cell is used for the following:
>> +    bit[0]: polarity (0 for normal and 1 for inverted)
>> +    bit[18:16]: internal pull up/down: 0 - pull up/down disabled
>> +                                       1 - pull up enabled
>> +                                       2 - pull down enabled
>> +    bit[22:20]: drive strength: 0 - 2 mA
>> +                                1 - 4 mA
>> +                                2 - 6 mA
>> +                                3 - 8 mA
>> +                                4 - 10 mA
>> +                                5 - 12 mA
>> +                                6 - 14 mA
>> +                                7 - 16 mA
> 
> No. This pull up/down and drive strength is pin controller
> business, use a pin control backend behind the GPIO driver
> see Documentation/pinctrl.txt.
> 
> Initial states for these configurations can be set up using
> pin control hogs since pin control and GPIO is orthogonal.
> 
Yes, I got it! See my reply in the GPIO driver review. Thanks.

> Yours,
> Linus Walleij
>

Patch

diff --git a/Documentation/devicetree/bindings/gpio/brcm,cygnus-gpio.txt b/Documentation/devicetree/bindings/gpio/brcm,cygnus-gpio.txt
new file mode 100644
index 0000000..24a1513
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/brcm,cygnus-gpio.txt
@@ -0,0 +1,85 @@ 
+Broadcom Cygnus GPIO Controller
+
+Required properties:
+
+- compatible:
+    Currently supported Cygnus GPIO controllers include:
+    "brcm,cygnus-ccm-gpio": ChipcommonG GPIO controller
+    "brcm,cygnus-asiu-gpio": ASIU GPIO controller
+    "brcm,cygnus-crmu-gpio": CRMU GPIO controller
+
+- reg:
+    Define the base and range of the I/O address space that contain the Cygnus
+GPIO controller registers
+
+- ngpios:
+    Total number of GPIOs the controller provides
+
+- #gpio-cells:
+    Must be two. The first cell is the GPIO pin number (within the
+controller's domain) and the second cell is used for the following:
+    bit[0]: polarity (0 for normal and 1 for inverted)
+    bit[18:16]: internal pull up/down: 0 - pull up/down disabled
+                                       1 - pull up enabled
+                                       2 - pull down enabled
+    bit[22:20]: drive strength: 0 - 2 mA
+                                1 - 4 mA
+                                2 - 6 mA
+                                3 - 8 mA
+                                4 - 10 mA
+                                5 - 12 mA
+                                6 - 14 mA
+                                7 - 16 mA
+
+- gpio-controller:
+    Specifies that the node is a GPIO controller
+
+Optional properties:
+
+- interrupt-controller:
+    Specifies that the node is an interrupt controller. Not all Cygnus GPIO
+interfaces support interrupt, e.g., the CRMU GPIO controller does not have its
+interrupt routed to the main processor's GIC
+
+- interrupts:
+    The interrupt outputs from the GPIO controller.
+
+- no-interrupt:
+    Specifies that the GPIO interface does not support interrupt
+
+Example:
+	gpio_asiu: gpio@180a5000 {
+		compatible = "brcm,cygnus-asiu-gpio";
+		reg = <0x180a5000 0x668>;
+		ngpios = <122>;
+		#gpio-cells = <2>;
+		gpio-controller;
+		interrupt-controller;
+		interrupts = <GIC_SPI 174 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
+	gpio_crmu: gpio@03024800 {
+		compatible = "brcm,cygnus-crmu-gpio";
+		reg = <0x03024800 0x50>;
+		ngpios = <6>;
+		#gpio-cells = <2>;
+		gpio-controller;
+		no-interrupt;
+	};
+
+	/*
+	 * Touchscreen that uses the ASIU GPIO 100, with internal pull-up
+	 * enabled
+	 */
+	tsc {
+		...
+		...
+		gpio-event = <&gpio_asiu 100 0x10000>;
+	};
+
+	/* Bluetooth that uses the CRMU GPIO 2, with polarity inverted */
+	bluetooth {
+		...
+		...
+		bcm,rfkill-bank-sel = <&gpio_crmu 2 1>
+	}