| Message ID | 20241216095739.27320-1-ikerpedrosam@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] spi: dt-bindings: Document CS active-high | expand |
On Mon, 16 Dec 2024 10:57:33 +0100, Iker Pedrosa wrote: > The current documentation does not clearly explain how to invert the SPI > CS signal to make it active-high. This makes it very difficult to > understand. > > This patch adds a simple explanation on how to set the CS line in > active-high and adds an example to make it easier for users who need > that setup for their SPI peripherals. > > Link: https://forums.raspberrypi.com/viewtopic.php?t=378222 > Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com> > --- > > Changes in v3: > - Use subject line reflecting the style of the subsystem (Mark Brown) > - Change compatible display to an existing one and adapt SPI MAX frequency (Rob > Herring) > > Changes in v2: > - Include header for GPIO_ACTIVE_HIGH (Rob Herring) > > .../bindings/spi/spi-controller.yaml | 25 +++++++++++++++++++ > 1 file changed, 25 insertions(+) > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
On Mon, 16 Dec 2024 10:57:33 +0100, Iker Pedrosa wrote: > The current documentation does not clearly explain how to invert the SPI > CS signal to make it active-high. This makes it very difficult to > understand. > > This patch adds a simple explanation on how to set the CS line in > active-high and adds an example to make it easier for users who need > that setup for their SPI peripherals. > > [...] Applied to https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next Thanks! [1/1] spi: dt-bindings: Document CS active-high commit: 7b4035ebf2af2c2f1450e8c38bf4f41acd3f01bf All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml index 093150c0cb87..82d051f7bd6e 100644 --- a/Documentation/devicetree/bindings/spi/spi-controller.yaml +++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml @@ -69,6 +69,11 @@ properties: Should be generally avoided and be replaced by spi-cs-high + ACTIVE_HIGH. + The simplest way to obtain an active-high CS signal is to configure the + controller's cs-gpio property with the ACTIVE_HIGH flag and set the + peripheral's spi-cs-high property. See example below for a better + understanding. + fifo-depth: $ref: /schemas/types.yaml#/definitions/uint32 description: @@ -189,3 +194,23 @@ examples: stacked-memories = /bits/ 64 <0x10000000 0x10000000>; }; }; + + - | + #include <dt-bindings/gpio/gpio.h> + + spi@20204000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "brcm,bcm2835-spi"; + reg = <0x7e204000 0x1000>; + interrupts = <2 22>; + clocks = <&clk_spi>; + cs-gpios = <&gpio 8 GPIO_ACTIVE_HIGH>; + + display@0 { + compatible = "lg,lg4573"; + spi-max-frequency = <1000000>; + reg = <0>; + spi-cs-high; + }; + };
The current documentation does not clearly explain how to invert the SPI CS signal to make it active-high. This makes it very difficult to understand. This patch adds a simple explanation on how to set the CS line in active-high and adds an example to make it easier for users who need that setup for their SPI peripherals. Link: https://forums.raspberrypi.com/viewtopic.php?t=378222 Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com> --- Changes in v3: - Use subject line reflecting the style of the subsystem (Mark Brown) - Change compatible display to an existing one and adapt SPI MAX frequency (Rob Herring) Changes in v2: - Include header for GPIO_ACTIVE_HIGH (Rob Herring) .../bindings/spi/spi-controller.yaml | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+)