| Message ID | 20201119120253.390883-3-damien.lemoal@wdc.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/3] spi: dw: Add support for 32-bits max xfer size | expand |
On Thu, Nov 19, 2020 at 09:02:52PM +0900, Damien Le Moal wrote: > 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". Looking good. Thanks. Acked-by: Serge Semin <fancer.lancer@gmail.com> > > Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> > --- > drivers/spi/spi-dw-mmio.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c > index d0cc5bf4fa4e..17c06039a74d 100644 > --- a/drivers/spi/spi-dw-mmio.c > +++ b/drivers/spi/spi-dw-mmio.c > @@ -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); > -- > 2.28.0 >
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index d0cc5bf4fa4e..17c06039a74d 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -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);
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> --- drivers/spi/spi-dw-mmio.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)