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| author | H. Nikolaus Schaller <hns@goldelico.com> | 2019-09-20 18:11:15 +0200 |
|---|---|---|
| committer | Tony Lindgren <tony@atomide.com> | 2019-09-23 10:33:49 -0700 |
| commit | f1f028ff89cb0d37db299d48e7b2ce19be040d52 (patch) | |
| tree | c62f762ad8c26277ea8fbda8f4e85309257344ec | |
| parent | 2d3c8ba3cffa00f76bedb713c8c2126c82d8cd13 (diff) | |
| download | linux-f1f028ff89cb0d37db299d48e7b2ce19be040d52.tar.bz2 | |
DTS: ARM: gta04: introduce legacy spi-cs-high to make display work again
commit 6953c57ab172 "gpio: of: Handle SPI chipselect legacy bindings"
did introduce logic to centrally handle the legacy spi-cs-high property
in combination with cs-gpios. This assumes that the polarity
of the CS has to be inverted if spi-cs-high is missing, even
and especially if non-legacy GPIO_ACTIVE_HIGH is specified.
The DTS for the GTA04 was orginally introduced under the assumption
that there is no need for spi-cs-high if the gpio is defined with
proper polarity GPIO_ACTIVE_HIGH.
This was not a problem until gpiolib changed the interpretation of
GPIO_ACTIVE_HIGH and missing spi-cs-high.
The effect is that the missing spi-cs-high is now interpreted as CS being
low (despite GPIO_ACTIVE_HIGH) which turns off the SPI interface when the
panel is to be programmed by the panel driver.
Therefore, we have to add the redundant and legacy spi-cs-high property
to properly activate CS.
Cc: stable@vger.kernel.org
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
| -rw-r--r-- | arch/arm/boot/dts/omap3-gta04.dtsi | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm/boot/dts/omap3-gta04.dtsi b/arch/arm/boot/dts/omap3-gta04.dtsi index b295f6fad2a5..954c216140ad 100644 --- a/arch/arm/boot/dts/omap3-gta04.dtsi +++ b/arch/arm/boot/dts/omap3-gta04.dtsi @@ -120,6 +120,7 @@ spi-max-frequency = <100000>; spi-cpol; spi-cpha; + spi-cs-high; backlight= <&backlight>; label = "lcd"; |