diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index 403403deae66..18772c0c9220 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -45,6 +45,9 @@ struct dw_spi_mmio { #define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE BIT(13) #define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x) (x << 5) +#define SPARX5_FORCE_ENA 0xa4 +#define SPARX5_FORCE_VAL 0xa8 + /* * For Keem Bay, CTRLR0[31] is used to select controller mode. * 0: SSI is slave @@ -54,7 +57,7 @@ struct dw_spi_mmio { struct dw_spi_mscc { struct regmap *syscon; - void __iomem *spi_mst; + void __iomem *spi_mst; /* Not sparx5 */ }; /* @@ -134,6 +137,70 @@ static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev, JAGUAR2_IF_SI_OWNER_OFFSET); } +/* + * The Designware SPI controller (referred to as master in the + * documentation) automatically deasserts chip select when the tx fifo + * is empty. The chip selects then needs to be driven by a CS override + * register. enable is an active low signal. + */ +static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable) +{ + struct dw_spi *dws = spi_master_get_devdata(spi->master); + struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws); + struct dw_spi_mscc *dwsmscc = dwsmmio->priv; + u8 cs = spi->chip_select; + + if (!enable) { + /* CS override drive enable */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1); + /* Now set CSx enabled */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs)); + /* Allow settle */ + usleep_range(1, 5); + } else { + /* CS value */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0); + /* Allow settle */ + usleep_range(1, 5); + /* CS override drive disable */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0); + } + + dw_spi_set_cs(spi, enable); +} + +static int dw_spi_mscc_sparx5_init(struct platform_device *pdev, + struct dw_spi_mmio *dwsmmio) +{ + const char *syscon_name = "microchip,sparx5-cpu-syscon"; + struct device *dev = &pdev->dev; + struct dw_spi_mscc *dwsmscc; + + if (!IS_ENABLED(CONFIG_SPI_MUX)) { + dev_err(dev, "This driver needs CONFIG_SPI_MUX\n"); + return -EOPNOTSUPP; + } + + dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL); + if (!dwsmscc) + return -ENOMEM; + + dwsmscc->syscon = + syscon_regmap_lookup_by_compatible(syscon_name); + if (IS_ERR(dwsmscc->syscon)) { + dev_err(dev, "No syscon map %s\n", syscon_name); + return PTR_ERR(dwsmscc->syscon); + } + + dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs; + dwsmmio->priv = dwsmscc; + + /* Register hook to configure CTRLR0 */ + dwsmmio->dws.update_cr0 = dw_spi_update_cr0; + + return 0; +} + static int dw_spi_alpine_init(struct platform_device *pdev, struct dw_spi_mmio *dwsmmio) { @@ -297,6 +364,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = { { .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init}, { .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}, { /* end of table */} }; MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);