ralink: Add support for GPIO as interrupt-controller

The gpio-ralink driver has everything it needs to be used as an
interrupt controller except for device tree support.  This simple patch
adds that support by configuring the irq domain to use two cells and
adding the appropriate documentation to the devicetree bindings.

Signed-off-by: Daniel Santos <[email protected]>
(backported from 89eb1a6d7250c33ff5b43f4af3c0c78ffd3d8eb9)
(rebased patches)
Signed-off-by: Jo-Philipp Wich <[email protected]>

diff --git a/target/linux/ramips/patches-4.14/0029-gpio-ralink-Add-support-for-GPIO-as-interrupt-contro.patch b/target/linux/ramips/patches-4.14/0029-gpio-ralink-Add-support-for-GPIO-as-interrupt-contro.patch
new file mode 100644 (file)
index 0000000..8520ce3
--- /dev/null
+++ b/target/linux/ramips/patches-4.14/0029-gpio-ralink-Add-support-for-GPIO-as-interrupt-contro.patch
@@ -0,0 +1,44 @@
+From 57fa7f2f4ef6f78ce1d30509c0d111aa3791b524 Mon Sep 17 00:00:00 2001
+From: Daniel Santos <[email protected]>
+Date: Sun, 4 Nov 2018 20:24:32 -0600
+Subject: gpio-ralink: Add support for GPIO as interrupt-controller
+
+Signed-off-by: Daniel Santos <[email protected]>
+---
+ Documentation/devicetree/bindings/gpio/gpio-ralink.txt | 6 ++++++
+ drivers/gpio/gpio-ralink.c                             | 2 +-
+ 2 files changed, 7 insertions(+), 1 deletion(-)
+
+--- a/Documentation/devicetree/bindings/gpio/gpio-ralink.txt
++++ b/Documentation/devicetree/bindings/gpio/gpio-ralink.txt
+@@ -17,6 +17,9 @@ Required properties:
+ 
+ Optional properties:
+ - ralink,gpio-base : Specify the GPIO chips base number
++- interrupt-controller : marks this as an interrupt controller
++- #interrupt-cells : a standard two-cell interrupt flag, see
++  interrupt-controller/interrupts.txt
+ 
+ Example:
+ 
+@@ -28,6 +31,9 @@ Example:
+ 
+               reg = <0x600 0x34>;
+ 
++              interrupt-controller;
++              #interrupt-cells = <2>;
++
+               interrupt-parent = <&intc>;
+               interrupts = <6>;
+ 
+--- a/drivers/gpio/gpio-ralink.c
++++ b/drivers/gpio/gpio-ralink.c
+@@ -220,7 +220,7 @@ static int gpio_map(struct irq_domain *d
+ }
+ 
+ static const struct irq_domain_ops irq_domain_ops = {
+-      .xlate = irq_domain_xlate_onecell,
++      .xlate = irq_domain_xlate_twocell,
+       .map = gpio_map,
+ };
+