| From 2946a19f78d3d4eb45a3c2a3e2af126f013a6d9e Mon Sep 17 00:00:00 2001 |
| From: "H. Nikolaus Schaller" <hns@goldelico.com> |
| Date: Fri, 20 Sep 2019 18:11:15 +0200 |
| Subject: [PATCH] DTS: ARM: gta04: introduce legacy spi-cs-high to make display |
| work again |
| |
| commit f1f028ff89cb0d37db299d48e7b2ce19be040d52 upstream. |
| |
| 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> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| 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"; |
| -- |
| 2.7.4 |
| |
