[PATCH v2 3/3] spi: spi-microchip-core: Add support for GPIO based CS

Conor Dooley conor at kernel.org
Tue May 14 10:57:04 PDT 2024


Prajna, Mark,

On Tue, May 14, 2024 at 11:45:08AM +0100, Prajna Rajendra Kumar wrote:
> The SPI "hard" controller within the PolarFire SoC is capable of
> handling eight CS lines, but only one CS line is wired. Therefore, use
> GPIO descriptors to configure additional CS lines.
> 
> Signed-off-by: Prajna Rajendra Kumar <prajna.rajendrakumar at microchip.com>

I provided an ack on v1, so here it is again:
Acked-by: Conor Dooley <conor.dooley at microchip.com>

In general you can keep tags between versions, if you intentionally drop
tags you should mention why you dropped them.

> ---
>  drivers/spi/spi-microchip-core.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/spi/spi-microchip-core.c b/drivers/spi/spi-microchip-core.c
> index c10de45aa472..6246254e1dff 100644
> --- a/drivers/spi/spi-microchip-core.c
> +++ b/drivers/spi/spi-microchip-core.c
> @@ -258,6 +258,9 @@ static int mchp_corespi_setup(struct spi_device *spi)
>  	struct mchp_corespi *corespi = spi_controller_get_devdata(spi->controller);
>  	u32 reg;
>  
> +	if (spi_is_csgpiod(spi))
> +		return 0;

Mark,

This has no users outside of core code, but is < 6 months old. Is using
it in a driver like this okay?

Cheers,
Conor.

> +
>  	/*
>  	 * Active high targets need to be specifically set to their inactive
>  	 * states during probe by adding them to the "control group" & thus
> @@ -516,6 +519,7 @@ static int mchp_corespi_probe(struct platform_device *pdev)
>  
>  	host->num_chipselect = num_cs;
>  	host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
> +	host->use_gpio_descriptors = true;
>  	host->setup = mchp_corespi_setup;
>  	host->bits_per_word_mask = SPI_BPW_MASK(8);
>  	host->transfer_one = mchp_corespi_transfer_one;
> -- 
> 2.25.1
> 
> 
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