[PATCH v5 2/3] Documentation: gpio: Update description for X-Gene standby GPIO controller DTS binding

Quan Nguyen
2016-01-29T04:28:54Z

Update description for X-Gene standby GPIO controller DTS binding to
support GPIO line configuration as input, output or external IRQ pin.

Signed-off-by: Y Vo <yvo@apm.com>
Signed-off-by: Quan Nguyen <qnguyen@apm.com>
---
.../devicetree/bindings/gpio/gpio-xgene-sb.txt | 47 ++++++++++++++++++----
1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt b/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt
index dae1300..7b8b4cb 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-xgene-sb.txt
@@ -1,10 +1,20 @@
APM X-Gene Standby GPIO controller bindings

-This is a gpio controller in the standby domain.
-
-There are 20 GPIO pins from 0..21. There is no GPIO_DS14 or GPIO_DS15,
-only GPIO_DS8..GPIO_DS13 support interrupts. The IRQ mapping
-is currently 1-to-1 on interrupts 0x28 thru 0x2d.
+This is a gpio controller in the standby domain. It also supports interrupt in
+some particular pins which are sourced to its parent interrupt controller
+as diagram below:
+ +-----------------+
+ | X-Gene standby |
+ | GPIO controller +--------- GPIO_0
++------------+ | | ...
+| Parent IRQ | | +--------- GPIO_8/EXT_INT_0
+| controller | EXT_INT_0 | | ...
+| (GICv2) +-------------+ +--------- GPIO_[N+8]/EXT_INT_N
+| | ... | |
+| | EXT_INT_N | +--------- GPIO_[N+9]
+| +-------------+ | ...
+| | | +--------- GPIO_MAX
++------------+ +-----------------+

Required properties:
- compatible: "apm,xgene-gpio-sb" for the X-Gene Standby GPIO controller
@@ -15,10 +25,18 @@ Required properties:
0 = active high
1 = active low
- gpio-controller: Marks the device node as a GPIO controller.
-- interrupts: Shall contain exactly 6 interrupts.
+- interrupts: The EXT_INT_0 parent interrupt resource must be listed first.
+- interrupt-parent: Phandle of the parent interrupt controller.
+- interrupt-cells: Should be two.
+ - first cell is 0-N coresponding for EXT_INT_0 to EXT_INT_N.
+ - second cell is used to specify flags.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- apm,nr-gpios: Optional, specify number of gpios pin.
+- apm,nr-irqs: Optional, specify number of interrupt pins.
+- apm,irq-start: Optional, specify lowest gpio pin support interrupt.

Example:
- sbgpio: sbgpio@17001000 {
+ sbgpio: gpio@17001000{
compatible = "apm,xgene-gpio-sb";
reg = <0x0 0x17001000 0x0 0x400>;
#gpio-cells = <2>;
@@ -29,4 +47,19 @@ Example:
<0x0 0x2b 0x1>,
<0x0 0x2c 0x1>,
<0x0 0x2d 0x1>;
+ interrupt-parent = <&gic>;
+ #interrupt-cells = <2>;
+ interrupt-controller;
+ apm,nr-gpios = <22>;
+ apm,nr-irqs = <6>;
+ apm,irq-start = <8>;
+ };
+
+ testuser {
+ compatible = "example,testuser";
+ /* Use the GPIO_13/EXT_INT_5 line as an active high triggered
+ * level interrupt
+ */
+ interrupts = <5 4>;
+ interrupt-parent = <&sbgpio>;
};
--
1.7.12.4