[PATCH 1/2] spi: spi-fsl-lpspi: support multiple cs for lpspi

[PATCH 1/2] spi: spi-fsl-lpspi: support multiple cs for lpspi

[Han Xu]

support to get chip select number from DT file.

Signed-off-by: Han Xu <han.xu@nxp.com>
---
 drivers/spi/spi-fsl-lpspi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 6454b88c31fe..7f0562ed4d09 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -98,6 +98,7 @@ struct fsl_lpspi_data {
 	struct clk *clk_ipg;
 	struct clk *clk_per;
 	bool is_slave;
+	u32 num_cs;
 	bool is_only_cs1;
 	bool is_first_byte;
 
@@ -850,6 +851,9 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 	fsl_lpspi->is_slave = is_slave;
 	fsl_lpspi->is_only_cs1 = of_property_read_bool((&pdev->dev)->of_node,
 						"fsl,spi-only-use-cs1-sel");
+	if (of_property_read_u32((&pdev->dev)->of_node, "num-cs",
+				 &fsl_lpspi->num_cs))
+		fsl_lpspi->num_cs = 1;
 
 	controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
 	controller->transfer_one = fsl_lpspi_transfer_one;
@@ -859,6 +863,7 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 	controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
 	controller->dev.of_node = pdev->dev.of_node;
 	controller->bus_num = pdev->id;
+	controller->num_chipselect = fsl_lpspi->num_cs;
 	controller->slave_abort = fsl_lpspi_slave_abort;
 	if (!fsl_lpspi->is_slave)
 		controller->use_gpio_descriptors = true;
-- 
2.25.1

[PATCH 2/2] dt-bindings: spi: spi-fsl-lpspi: add num-cs for lpspi

[Han Xu]

Add num-cs property to support multiple cs for lpspi. This property is
optional.

Signed-off-by: Han Xu <han.xu@nxp.com>
---
 Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml b/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
index 8b44284d30c6..94caa2b7e241 100644
--- a/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
@@ -56,6 +56,13 @@ properties:
       this property to re-config the chipselect value in the LPSPI driver.
     type: boolean
 
+  num-cs:
+    description:
+      number of chip selects.
+    minimum: 1
+    maximum: 2
+    default: 1
+
 required:
   - compatible
   - reg
@@ -80,4 +87,5 @@ examples:
         clock-names = "per", "ipg";
         spi-slave;
         fsl,spi-only-use-cs1-sel;
+        num-cs = <2>;
     };
-- 
2.25.1

Re: [PATCH 1/2] spi: spi-fsl-lpspi: support multiple cs for lpspi

[Dhruva Gole]

Hi,

On 07/12/22 04:24, Han Xu wrote:
> support to get chip select number from DT file.

In my humble opinion, a  more elaborate commit message would help.
You can add perhaps which DT node is to be set, like you might want
to say,

support to get chip select number by Setting the value of num-cs in DT

or something on those lines.
> 
> Signed-off-by: Han Xu <han.xu@nxp.com>
> ---
>   drivers/spi/spi-fsl-lpspi.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
> index 6454b88c31fe..7f0562ed4d09 100644
> --- a/drivers/spi/spi-fsl-lpspi.c
> +++ b/drivers/spi/spi-fsl-lpspi.c
> @@ -98,6 +98,7 @@ struct fsl_lpspi_data {
>   	struct clk *clk_ipg;
>   	struct clk *clk_per;
>   	bool is_slave;
> +	u32 num_cs;
>   	bool is_only_cs1;
>   	bool is_first_byte;
>   
> @@ -850,6 +851,9 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
>   	fsl_lpspi->is_slave = is_slave;
>   	fsl_lpspi->is_only_cs1 = of_property_read_bool((&pdev->dev)->of_node,
>   						"fsl,spi-only-use-cs1-sel");
> +	if (of_property_read_u32((&pdev->dev)->of_node, "num-cs",
Running a checkpatch on this patch gave me the following,

CHECK: Unnecessary parentheses around '&pdev->dev'
#36: FILE: drivers/spi/spi-fsl-lpspi.c:854:
+       if (of_property_read_u32((&pdev->dev)->of_node, "num-cs",
+                                &fsl_lpspi->num_cs))

You might want to just do &pdev->dev->of_node instead

> +				 &fsl_lpspi->num_cs))
> +		fsl_lpspi->num_cs = 1;
I am not sure I understand why you are setting this to 1 here?
I am assuming it is because you want num_cs to default to 1 if
it is not specified in DT.

Please can you also add a dev_err and be sure to warn about this?

Also adding a comment or even a message inside dev err that you are
setting this to 1 if it fails to get from DT would be helpful.

>   
>   	controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
>   	controller->transfer_one = fsl_lpspi_transfer_one;
> @@ -859,6 +863,7 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
>   	controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
>   	controller->dev.of_node = pdev->dev.of_node;
>   	controller->bus_num = pdev->id;
> +	controller->num_chipselect = fsl_lpspi->num_cs;
>   	controller->slave_abort = fsl_lpspi_slave_abort;
>   	if (!fsl_lpspi->is_slave)
>   		controller->use_gpio_descriptors = true;

-- 
Thanks and Regards,
Dhruva Gole

Re: [PATCH 2/2] dt-bindings: spi: spi-fsl-lpspi: add num-cs for lpspi

[Krzysztof Kozlowski]

On 06/12/2022 23:54, Han Xu wrote:
> Add num-cs property to support multiple cs for lpspi. This property is
> optional.
> 
> Signed-off-by: Han Xu <han.xu@nxp.com>
> ---
>  Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml b/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
> index 8b44284d30c6..94caa2b7e241 100644
> --- a/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
> +++ b/Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml
> @@ -56,6 +56,13 @@ properties:
>        this property to re-config the chipselect value in the LPSPI driver.
>      type: boolean
>  
> +  num-cs:
> +    description:
> +      number of chip selects.

You do not need description, it's already in spi-controller.yaml.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH 1/2] spi: spi-fsl-lpspi: support multiple cs for lpspi

[Mark Brown]

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On Wed, Dec 07, 2022 at 12:08:43PM +0530, Dhruva Gole wrote:
> On 07/12/22 04:24, Han Xu wrote:
> > support to get chip select number from DT file.

> > +		fsl_lpspi->num_cs = 1;
> I am not sure I understand why you are setting this to 1 here?
> I am assuming it is because you want num_cs to default to 1 if
> it is not specified in DT.

> Please can you also add a dev_err and be sure to warn about this?

The binding says that this property is optional with a default of 1 so
it should be totally fine for a system to not specify anything.

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Re: [PATCH 1/2] spi: spi-fsl-lpspi: support multiple cs for lpspi

[Mark Brown]

On Tue, 06 Dec 2022 16:54:09 -0600, Han Xu wrote:
> support to get chip select number from DT file.
> 
> 

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/2] spi: spi-fsl-lpspi: support multiple cs for lpspi
      commit: 5f947746f0089529c85654704643f158b420ff92
[2/2] dt-bindings: spi: spi-fsl-lpspi: add num-cs for lpspi
      commit: bc9ab1b7a6c687370b5d4edf34064bf04af8d369

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