Re: [PATCH 06/32] spi: dw: Add support for the Kendryte K210 SoC

From: Sean Anderson <seanga2@gmail.com>
To: Damien Le Moal <damien.lemoal@wdc.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	linux-riscv@lists.infradead.org, Rob Herring <robh+dt@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>,
	devicetree@vger.kernel.org, Serge Semin <fancer.lancer@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	linux-spi@vger.kernel.org, Stephen Boyd <sboyd@kernel.org>,
	linux-clk@vger.kernel.org,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-gpio@vger.kernel.org,
	Philipp Zabel <p.zabel@pengutronix.de>
Subject: Re: [PATCH 06/32] spi: dw: Add support for the Kendryte K210 SoC
Date: Sat, 7 Nov 2020 08:31:22 -0500	[thread overview]
Message-ID: <53859725-ca0b-5f57-9147-10346707b3cb@gmail.com> (raw)
In-Reply-To: <20201107081420.60325-7-damien.lemoal@wdc.com>

On 11/7/20 3:13 AM, Damien Le Moal wrote:
> The DW SPI master of the Kendryte K210 RISC-V SoC uses the 32-bits
> ctrlr0 register format. This SoC is also quite slow and gets significant
> SD card performance improvements from using no-delay polled transfers.
> Add the dw_spi_k210_init() function tied to the
> "canaan,kendryte-k210-spi" compatible string to set the
> DW_SPI_CAP_DFS_32 and DW_SPI_CAP_POLL_NODELAY DW SPI capability fields
> for this SoC.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> ---
>  drivers/spi/spi-dw-mmio.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
> index 3f1bc384cb45..a00def6c5b39 100644
> --- a/drivers/spi/spi-dw-mmio.c
> +++ b/drivers/spi/spi-dw-mmio.c
> @@ -223,6 +223,14 @@ static int dw_spi_keembay_init(struct platform_device *pdev,
>  	return 0;
>  }
>  
> +static int dw_spi_k210_init(struct platform_device *pdev,
> +			    struct dw_spi_mmio *dwsmmio)
> +{
> +	dwsmmio->dws.caps = DW_SPI_CAP_DFS_32 | DW_SPI_CAP_POLL_NODELAY;

Can't you do runtime detection of DFS_32 in probe?

--Sean

> +
> +	return 0;
> +}
> +
>  static int dw_spi_mmio_probe(struct platform_device *pdev)
>  {
>  	int (*init_func)(struct platform_device *pdev,
> @@ -340,6 +348,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = {
>  	{ .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init},
>  	{ .compatible = "intel,keembay-ssi", .data = dw_spi_keembay_init},
>  	{ .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init},
> +	{ .compatible = "canaan,kendryte-k210-spi", .data = dw_spi_k210_init},
>  	{ /* end of table */}
>  };
>  MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
> 