diff options
| author | Abe Kohandel <abe.kohandel@intel.com> | 2023-06-06 07:54:01 -0700 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2023-06-06 15:59:16 +0100 |
| commit | 0760d5d0e9f0c0e2200a0323a61d1995bb745dee (patch) | |
| tree | b2c71746db527e0b977da8519bdd7c4e38cefa03 /drivers | |
| parent | 8098a931c080d32687aee72a1dfac98507a6034b (diff) | |
spi: dw: Add compatible for Intel Mount Evans SoC
The Intel Mount Evans SoC's Integrated Management Complex uses the SPI
controller for access to a NOR SPI FLASH. However, the SoC doesn't
provide a mechanism to override the native chip select signal.
This driver doesn't use DMA for memory operations when a chip select
override is not provided due to the native chip select timing behavior.
As a result no DMA configuration is done for the controller and this
configuration is not tested.
The controller also has an errata where a full TX FIFO can result in
data corruption. The suggested workaround is to never completely fill
the FIFO. The TX FIFO has a size of 32 so the fifo_len is set to 31.
Signed-off-by: Abe Kohandel <abe.kohandel@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230606145402.474866-2-abe.kohandel@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/spi/spi-dw-mmio.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index 5f2aee69c1c1..c1d16157de61 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -236,6 +236,31 @@ static int dw_spi_intel_init(struct platform_device *pdev, return 0; } +/* + * The Intel Mount Evans SoC's Integrated Management Complex uses the + * SPI controller for access to a NOR SPI FLASH. However, the SoC doesn't + * provide a mechanism to override the native chip select signal. + * + * This driver doesn't use DMA for memory operations when a chip select + * override is not provided due to the native chip select timing behavior. + * As a result no DMA configuration is done for the controller and this + * configuration is not tested. + */ +static int dw_spi_mountevans_imc_init(struct platform_device *pdev, + struct dw_spi_mmio *dwsmmio) +{ + /* + * The Intel Mount Evans SoC's Integrated Management Complex DW + * apb_ssi_v4.02a controller has an errata where a full TX FIFO can + * result in data corruption. The suggested workaround is to never + * completely fill the FIFO. The TX FIFO has a size of 32 so the + * fifo_len is set to 31. + */ + dwsmmio->dws.fifo_len = 31; + + return 0; +} + static int dw_spi_canaan_k210_init(struct platform_device *pdev, struct dw_spi_mmio *dwsmmio) { @@ -405,6 +430,10 @@ static const struct of_device_id dw_spi_mmio_of_match[] = { { .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_hssi_init}, { .compatible = "intel,keembay-ssi", .data = dw_spi_intel_init}, { .compatible = "intel,thunderbay-ssi", .data = dw_spi_intel_init}, + { + .compatible = "intel,mountevans-imc-ssi", + .data = dw_spi_mountevans_imc_init, + }, { .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init}, { .compatible = "canaan,k210-spi", dw_spi_canaan_k210_init}, { .compatible = "amd,pensando-elba-spi", .data = dw_spi_elba_init}, |