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

On 2020/11/07 22:31, Sean Anderson wrote:

On 11/7/20 3:13 AM, Damien Le Moal wrote:

quoted

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 <redacted>
---
 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?

I think it is possible, but it was much easier this way given that it seems that
only the K210 uses the DFS_32.

--Sean

quoted

+
+	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);

-- 
Damien Le Moal
Western Digital Research