Messages in this thread | | | Date | Mon, 23 Sep 2019 10:34:41 -0700 | From | Tony Lindgren <> | Subject | Re: [PATCH v2] DTS: ARM: gta04: introduce legacy spi-cs-high to make display work again |
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* H. Nikolaus Schaller <hns@goldelico.com> [190920 09:12]: > 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.
Thanks applying into fixes.
Tony
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