| Message ID | 1435650327-2542-3-git-send-email-geert+renesas@glider.be |
|---|---|
| State | New |
| Headers | show |
Hi Geert, Thank you for the patch. On Tuesday 30 June 2015 09:45:22 Geert Uytterhoeven wrote: > 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 <geert+renesas@glider.be> This looks sane to me, even though referencing the same DT node seems a bit dodgy. I'll let Linus comment on that, but for the implementation itself, Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > 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 3aaab195132bfc2c..15977b5834de9579 100644 > --- a/arch/arm/boot/dts/r8a7740.dtsi > +++ b/arch/arm/boot/dts/r8a7740.dtsi > @@ -316,6 +316,7 @@ > <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>,
diff --git a/arch/arm/boot/dts/r8a7740.dtsi b/arch/arm/boot/dts/r8a7740.dtsi index 3aaab195132bfc2c..15977b5834de9579 100644 --- a/arch/arm/boot/dts/r8a7740.dtsi +++ b/arch/arm/boot/dts/r8a7740.dtsi @@ -316,6 +316,7 @@ <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>,
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 <geert+renesas@glider.be> --- arch/arm/boot/dts/r8a7740.dtsi | 1 + 1 file changed, 1 insertion(+)