[PATCH] spi: meson-spicc: add spicc loopback mode

[Neil Armstrong]

On 12/06/2024 11:44, Xianwei Zhao via B4 Relay wrote:
> From: Xianwei Zhao <xianwei.zhao at amlogic.com>
> 
> Add spicc loopback mode for debugging convenience.
> 
> Signed-off-by: Sunny Luo <sunny.luo at amlogic.com>
> Signed-off-by: Xianwei Zhao <xianwei.zhao at amlogic.com>
> ---
>   drivers/spi/spi-meson-spicc.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
> index 8a4a8ba9dfed..8838a98b04c2 100644
> --- a/drivers/spi/spi-meson-spicc.c
> +++ b/drivers/spi/spi-meson-spicc.c
> @@ -514,7 +514,9 @@ static int meson_spicc_prepare_message(struct spi_controller *host,
>   	/* Setup no wait cycles by default */
>   	writel_relaxed(0, spicc->base + SPICC_PERIODREG);
>   
> -	writel_bits_relaxed(SPICC_LBC_W1, 0, spicc->base + SPICC_TESTREG);
> +	writel_bits_relaxed(SPICC_LBC_W1,
> +			    spi->mode & SPI_LOOP ? SPICC_LBC_W1 : 0,
> +			    spicc->base + SPICC_TESTREG);
>   
>   	return 0;
>   }
> @@ -850,7 +852,7 @@ static int meson_spicc_probe(struct platform_device *pdev)
>   
>   	host->num_chipselect = 4;
>   	host->dev.of_node = pdev->dev.of_node;
> -	host->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH;
> +	host->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LOOP;
>   	host->bits_per_word_mask = SPI_BPW_MASK(32) |
>   				   SPI_BPW_MASK(24) |
>   				   SPI_BPW_MASK(16) |
> 
> ---
> base-commit: ec0d19f2b59699e2e148091debaa0d9d6af5800a
> change-id: 20240611-spi_lbc-0859cebc580e
> 
> Best regards,

Reviewed-by: Neil Armstrong <neil.armstrong at linaro.org>