[v5,5/8] pinctrl: Cygnus: define Broadcom Cygnus GPIO/PINCONF binding

Commit Message

Ray Jui March 5, 2015, 12:35 a.m. UTC

Document the GPIO/PINCONF device tree binding for Broadcom Cygnus SoC

Signed-off-by: Ray Jui <[e-mail]>
Reviewed-by: Scott Branden <[e-mail]>
---
 .../bindings/pinctrl/brcm,cygnus-gpio.txt          |  102 ++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt

Comments

Linus Walleij March 9, 2015, 4:30 p.m. UTC | #1

On Thu, Mar 5, 2015 at 1:35 AM, Ray Jui <[e-mail]> wrote:

> Document the GPIO/PINCONF device tree binding for Broadcom Cygnus SoC
>
> Signed-off-by: Ray Jui <[e-mail]>
> Reviewed-by: Scott Branden <[e-mail]>
(...)

> +- ngpios:
> +    Total number of GPIOs the controller provides

Remind me again. Why don't we know this from the compatible string?

(I paused applying the patches here waiting for the answer.)

Yours,
Linus Walleij

Ray Jui March 9, 2015, 4:41 p.m. UTC | #2

Hi Linus,

On 3/9/2015 9:30 AM, Linus Walleij wrote:
> On Thu, Mar 5, 2015 at 1:35 AM, Ray Jui <[e-mail]> wrote:
> 
>> Document the GPIO/PINCONF device tree binding for Broadcom Cygnus SoC
>>
>> Signed-off-by: Ray Jui <[e-mail]>
>> Reviewed-by: Scott Branden <[e-mail]>
> (...)
> 
>> +- ngpios:
>> +    Total number of GPIOs the controller provides
> 
> Remind me again. Why don't we know this from the compatible string?

Is hard coding the number of GPIO pins in the driver based on compatible
string the preferred approach? If so, I can make the change. Note the
current driver only has one compatible string "brcm,cygnus-gpio." To do
this, I need to introduce 3 compatible strings "brcm,cygnus-asiu-gpio",
"brcm,cygnus-ccm-gpio", "brcm,cygnus-aon-gpio", and assign hard coded
ngpios to each of them during probe.

> 
> (I paused applying the patches here waiting for the answer.)
> 
> Yours,
> Linus Walleij
>

Patch

diff --git a/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt
new file mode 100644
index 0000000..9b9196c
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt
@@ -0,0 +1,102 @@ 
+Broadcom Cygnus GPIO/PINCONF Controller
+
+Required properties:
+
+- compatible:
+    Must be "brcm,cygnus-gpio"
+
+- reg:
+    Define the base and range of the I/O address space that contains the Cygnus
+GPIO/PINCONF 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 pin space) and the second cell is used for the following:
+    bit[0]: polarity (0 for active high and 1 for active low)
+
+- gpio-controller:
+    Specifies that the node is a GPIO controller
+
+Optional properties:
+
+- interrupts:
+    Interrupt ID
+
+- interrupt-controller:
+    Specifies that the node is an interrupt controller
+
+- pinmux:
+    Specifies the phandle to the IOMUX device, where pins can be individually
+muxed to GPIO
+
+Supported generic PINCONF properties in child nodes:
+
+- pins:
+    The list of pins (within the controller's own pin space) that properties
+in the node apply to. Pin names are "gpio-<pin>"
+
+- bias-disable:
+    Disable pin bias
+
+- bias-pull-up:
+    Enable internal pull up resistor
+
+- bias-pull-down:
+    Enable internal pull down resistor
+
+- drive-strength:
+    Valid drive strength values include 2, 4, 6, 8, 10, 12, 14, 16 (mA)
+
+Example:
+	gpio_ccm: gpio@1800a000 {
+		compatible = "brcm,cygnus-gpio";
+		reg = <0x1800a000 0x50>,
+		      <0x0301d164 0x20>;
+		ngpios = <24>;
+		#gpio-cells = <2>;
+		gpio-controller;
+		interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-controller;
+
+		touch_pins: touch_pins {
+			pwr: pwr {
+				pins = "gpio-0";
+				drive-strength = <16>;
+			};
+
+			event: event {
+				pins = "gpio-1";
+				bias-pull-up;
+			};
+		};
+	};
+
+	gpio_asiu: gpio@180a5000 {
+		compatible = "brcm,cygnus-gpio";
+		reg = <0x180a5000 0x668>;
+		ngpios = <146>;
+		#gpio-cells = <2>;
+		gpio-controller;
+		interrupts = <GIC_SPI 174 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-controller;
+	};
+
+	/*
+	 * Touchscreen that uses the CCM GPIO 0 and 1
+	 */
+	tsc {
+		...
+		...
+		gpio-pwr = <&gpio_ccm 0 0>;
+		gpio-event = <&gpio_ccm 1 0>;
+	};
+
+	/* Bluetooth that uses the ASIU GPIO 5, with polarity inverted */
+	bluetooth {
+		...
+		...
+		bcm,rfkill-bank-sel = <&gpio_asiu 5 1>
+	}