Hi Laurent, Linus, On Tue, Jun 30, 2015 at 11:49 AM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > On Tuesday 30 June 2015 09:45:21 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 led1-high (chip r8a73a4_pfc, offset 28) 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 ranges are 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@xxxxxxxxx> > > 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@xxxxxxxxxxxxxxxx> Thank you! Any wise words from Linus? Thanks again! > >> --- >> arch/arm/boot/dts/r8a73a4.dtsi | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/arch/arm/boot/dts/r8a73a4.dtsi b/arch/arm/boot/dts/r8a73a4.dtsi >> index 5090d1a8f652e8be..cb4f7b2798fe23be 100644 >> --- a/arch/arm/boot/dts/r8a73a4.dtsi >> +++ b/arch/arm/boot/dts/r8a73a4.dtsi >> @@ -207,6 +207,13 @@ >> reg = <0 0xe6050000 0 0x9000>; >> gpio-controller; >> #gpio-cells = <2>; >> + gpio-ranges = >> + <&pfc 0 0 31>, <&pfc 32 32 9>, >> + <&pfc 64 64 22>, <&pfc 96 96 31>, >> + <&pfc 128 128 7>, <&pfc 160 160 19>, >> + <&pfc 192 192 31>, <&pfc 224 224 27>, >> + <&pfc 256 256 28>, <&pfc 288 288 21>, >> + <&pfc 320 320 10>; >> interrupts-extended = >> <&irqc0 0 0>, <&irqc0 1 0>, <&irqc0 2 0>, <&irqc0 3 0>, >> <&irqc0 4 0>, <&irqc0 5 0>, <&irqc0 6 0>, <&irqc0 7 0>, Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html