If a GPIO driver uses gpiochip_add_pin_range() (which is usually the
case for GPIO/PFC combos), the GPIO hogging mechanism configured from DT
doesn't work:
requesting hog GPIO lcd0 (chip r8a7740_pfc, offset 176) failed
The actual error code is -517 == -EPROBE_DEFER.
The problem is that PFC+GPIO registration is handled in multiple steps:
1. pinctrl_register(),
2. gpiochip_add(),
3. gpiochip_add_pin_range().
Configuration of the hogs is handled in gpiochip_add():
gpiochip_add
of_gpiochip_add
of_gpiochip_scan_hogs
gpiod_hog
gpiochip_request_own_desc
__gpiod_request
chip->request
pinctrl_request_gpio
pinctrl_get_device_gpio_range
However, at this point the GPIO controller hasn't been added to
pinctrldev_list yet, so the range can't be found, and the operation fails
with -EPROBE_DEFER.
To fix this, add a "gpio-ranges" property to the gpio device node, so
the range is added by of_gpiochip_add_pin_range(), which is called by
of_gpiochip_add() before the call to of_gpiochip_scan_hogs().
Signed-off-by: Geert Uytterhoeven <[email protected]>
Acked-by: Laurent Pinchart <[email protected]>
Acked-by: Linus Walleij <[email protected]>
---
v2:
- Add Acked-by.
---
arch/arm/boot/dts/r8a7740.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/boot/dts/r8a7740.dtsi b/arch/arm/boot/dts/r8a7740.dtsi
index d84714468cce18df..e14cb1438216e8df 100644
--- a/arch/arm/boot/dts/r8a7740.dtsi
+++ b/arch/arm/boot/dts/r8a7740.dtsi
@@ -291,6 +291,7 @@
<0xe605800c 0x20>;
gpio-controller;
#gpio-cells = <2>;
+ gpio-ranges = <&pfc 0 0 212>;
interrupts-extended =
<&irqpin0 0 0>, <&irqpin0 1 0>, <&irqpin0 2 0>,
<&irqpin0 3 0>,
<&irqpin0 4 0>, <&irqpin0 5 0>, <&irqpin0 6 0>,
<&irqpin0 7 0>,
--
1.9.1
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