[PATCH v10 5/6] spi: rockchip: Support cs-gpio

Mark Brown broonie at kernel.org
Fri Feb 11 03:48:26 PST 2022


On Fri, Feb 11, 2022 at 11:43:41AM +0800, Jon Lin wrote:
> 1.Add standard cs-gpio support
> 2.Refer to spi-controller.yaml for details
> 
> Signed-off-by: Jon Lin <jon.lin at rock-chips.com>
> ---
> 
> Changes in v10: None
> Changes in v9: None
> Changes in v8: None
> Changes in v7: None
> Changes in v6: None
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None

Why is this the one patch in the series with any versioning information?

> -		ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
> -				      BIT(spi->chip_select));
> +		if (spi->cs_gpiod)
> +			ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
> +		else
> +			ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));

This appears to be making the device control chip select 0 if a GPIO
chip select is used - that's going to work poorly if there's a device
using that chip select.  It should be fine to prohibit that
configuration if the hardware requires that a GPIO be controlled,
especially if the native chip select can be pinmuxed to a GPIO, but it
ought to be at least documented that this won't work and ideally
detected.
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