spi: dw: Add support for the Canaan K210 SoC SPI (b0dfd948) · Commits · 戴 / test

The Canaan Kendryte K210 RISC-V SoC includes a DW apb_ssi v4 controller which is documented to have a 32 words deep TX and RX FIFO. The FIFO length detection in spi_hw_init() correctly detects this value. However, when the controller RX FIFO is filled up to 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. This likely due to a hardware bug which can be avoided by force setting the fifo_len field of struct dw_spi to 31. Define the dw_spi_canaan_k210_init() function to force set fifo_len to 31 when the device node compatible string is "canaan,k210-spi". Signed-off-by:

Damien Le Moal <damien.lemoal@wdc.com> Acked-by:

Serge Semin <fancer.lancer@gmail.com> Link: https://lore.kernel.org/r/20201206011817.11700-4-damien.lemoal@wdc.com Signed-off-by:

Mark Brown <broonie@kernel.org>

drivers/spi/spi-dw-mmio.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -222,6 +222,21 @@ static int dw_spi_keembay_init(struct platform_device *pdev,
		return 0;
		}

		static int dw_spi_canaan_k210_init(struct platform_device *pdev,
		struct dw_spi_mmio *dwsmmio)
		{
		/*
		* The Canaan Kendryte K210 SoC DW apb_ssi v4 spi controller is
		* documented to have a 32 word deep TX and RX FIFO, which
		* spi_hw_init() detects. However, when the RX FIFO is filled up to
		* 32 entries (RXFLR = 32), an RX FIFO overrun error occurs. Avoid this
		* problem by force setting fifo_len to 31.
		*/
		dwsmmio->dws.fifo_len = 31;

		return 0;
		}

		static int dw_spi_mmio_probe(struct platform_device *pdev)
		{
		int (init_func)(struct platform_device pdev,
		@@ -335,6 +350,7 @@ 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,k210-spi", dw_spi_canaan_k210_init},
		{ /* end of table */}
		};
		MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);

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