| Message ID | 20190318153122.10257-1-linus.walleij@linaro.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | fa9463564e77067df81b0b8dec91adbbbc47bfb4 |
| Headers | show |
| Series | ARM: dts: nomadik: Fix polarity of SPI CS | expand |
On Mon, Mar 18, 2019 at 4:31 PM Linus Walleij <linus.walleij@linaro.org> wrote: > > The SPI DT bindings are for historical reasons a pitfall, > the ability to flag a GPIO line as active high/low with > the second cell flags was introduced later so the SPI > subsystem will only accept the bool flag spi-cs-high > to indicate that the line is active high. > > It worked by mistake, but the mistake was corrected > in another commit. > > The comment in the DTS file was also misleading: this > CS is indeed active high. > > Fixes: cffbb02dafa3 ("ARM: dts: nomadik: Augment NHK15 panel setting") > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Applied to fixes, thanks! Arnd
Dear ARM SoC maintainers, can you please revert this patch. It was the wrong solution to the wrong problem, and I must have acted in stress. Andrey fixed the real bug in a proper way in these commits: commit e5545c94e43b8f6599ffc01df8d1aedf18ee912a "gpio: of: Check propname before applying "cs-gpios" quirks" commit 7ce40277bf848391705011ba37eac2e377cbd9e6 "gpio: of: Check for "spi-cs-high" in child instead of parent node" On Mon, Mar 18, 2019 at 4:31 PM Linus Walleij <linus.walleij@linaro.org> wrote: > The SPI DT bindings are for historical reasons a pitfall, > the ability to flag a GPIO line as active high/low with > the second cell flags was introduced later so the SPI > subsystem will only accept the bool flag spi-cs-high > to indicate that the line is active high. > > It worked by mistake, but the mistake was corrected > in another commit. > > The comment in the DTS file was also misleading: this > CS is indeed active high. > > Fixes: cffbb02dafa3 ("ARM: dts: nomadik: Augment NHK15 panel setting") > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Thanks, Linus Walleij
On Sun, Apr 07, 2019 at 12:16:25PM +0200, Linus Walleij wrote: > Dear ARM SoC maintainers, > > can you please revert this patch. It was the wrong solution to the > wrong problem, and I must have acted in stress. Andrey fixed the > real bug in a proper way in these commits: > > commit e5545c94e43b8f6599ffc01df8d1aedf18ee912a > "gpio: of: Check propname before applying "cs-gpios" quirks" > commit 7ce40277bf848391705011ba37eac2e377cbd9e6 > "gpio: of: Check for "spi-cs-high" in child instead of parent node" Done, thanks! -Olof
diff --git a/arch/arm/boot/dts/ste-nomadik-nhk15.dts b/arch/arm/boot/dts/ste-nomadik-nhk15.dts index 04066f9cb8a3..f2f6558a00f1 100644 --- a/arch/arm/boot/dts/ste-nomadik-nhk15.dts +++ b/arch/arm/boot/dts/ste-nomadik-nhk15.dts @@ -213,12 +213,13 @@ gpio-sck = <&gpio0 5 GPIO_ACTIVE_HIGH>; gpio-mosi = <&gpio0 4 GPIO_ACTIVE_HIGH>; /* - * It's not actually active high, but the frameworks assume - * the polarity of the passed-in GPIO is "normal" (active - * high) then actively drives the line low to select the - * chip. + * This chipselect is active high. Just setting the flags + * to GPIO_ACTIVE_HIGH is not enough for the SPI DT bindings, + * it will be ignored, only the special "spi-cs-high" flag + * really counts. */ cs-gpios = <&gpio0 6 GPIO_ACTIVE_HIGH>; + spi-cs-high; num-chipselects = <1>; /*
The SPI DT bindings are for historical reasons a pitfall, the ability to flag a GPIO line as active high/low with the second cell flags was introduced later so the SPI subsystem will only accept the bool flag spi-cs-high to indicate that the line is active high. It worked by mistake, but the mistake was corrected in another commit. The comment in the DTS file was also misleading: this CS is indeed active high. Fixes: cffbb02dafa3 ("ARM: dts: nomadik: Augment NHK15 panel setting") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ARM SoC people: please apply this directly for fixes if you're OK with it. --- arch/arm/boot/dts/ste-nomadik-nhk15.dts | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)