[PATCH] spi: add SPI_MOSI_IDLE_LOW support from device tree

[PATCH] spi: add SPI_MOSI_IDLE_LOW support from device tree

[charles-antoine.couret]

From: Charles-Antoine Couret <charles-antoine.couret@mind.be>

This flag was introduced but was not added as device tree property which is
limiting the possibility to use this flag on real devices.

This flag can be configured as done for other flags.

Signed-off-by: Charles-Antoine Couret <charles-antoine.couret@mind.be>
---
 Documentation/devicetree/bindings/spi/spi-controller.yaml | 5 +++++
 drivers/spi/spi.c                                         | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml
index 82d051f7bd6e..47025ebb5875 100644
--- a/Documentation/devicetree/bindings/spi/spi-controller.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml
@@ -132,6 +132,11 @@ patternProperties:
         description:
           The device requires inverse clock polarity (CPOL) mode.
 
+      spi-mosi-idle-low:
+        $ref: /schemas/types.yaml#/definitions/flag
+        description:
+          The device requires the MOSI line to be low when it's in idle state.
+
     required:
       - compatible
       - reg
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index a388f372b27a..8fd2169befe3 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2372,6 +2372,8 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 		spi->mode |= SPI_LSB_FIRST;
 	if (of_property_read_bool(nc, "spi-cs-high"))
 		spi->mode |= SPI_CS_HIGH;
+	if (of_property_read_bool(nc, "spi-mosi-idle-low"))
+		spi->mode |= SPI_MOSI_IDLE_LOW;
 
 	/* Device DUAL/QUAD mode */
 	if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
-- 
2.51.0

Re: [PATCH] spi: add SPI_MOSI_IDLE_LOW support from device tree

[Krzysztof Kozlowski]

On 26/08/2025 09:38, charles-antoine.couret@mind.be wrote:
> From: Charles-Antoine Couret <charles-antoine.couret@mind.be>
> 
> This flag was introduced but was not added as device tree property which is
> limiting the possibility to use this flag on real devices.
> 
> This flag can be configured as done for other flags.
> 
> Signed-off-by: Charles-Antoine Couret <charles-antoine.couret@mind.be>
> ---
>  Documentation/devicetree/bindings/spi/spi-controller.yaml | 5 +++++

Please run scripts/checkpatch.pl on the patches and fix reported
warnings. After that, run also 'scripts/checkpatch.pl --strict' on the
patches and (probably) fix more warnings. Some warnings can be ignored,
especially from --strict run, but the code here looks like it needs a
fix. Feel free to get in touch if the warning is not clear.


Please use scripts/get_maintainers.pl to get a list of necessary people
and lists to CC. It might happen, that command when run on an older
kernel, gives you outdated entries. Therefore please be sure you base
your patches on recent Linux kernel.

Tools like b4 or scripts/get_maintainer.pl provide you proper list of
people, so fix your workflow. Tools might also fail if you work on some
ancient tree (don't, instead use mainline) or work on fork of kernel
(don't, instead use mainline). Just use b4 and everything should be
fine, although remember about `b4 prep --auto-to-cc` if you added new
patches to the patchset.

You missed at least devicetree list (maybe more), so this won't be
tested by automated tooling. Performing review on untested code might be
a waste of time.

Please kindly resend and include all necessary To/Cc entries.


Best regards,
Krzysztof