diff options
| author | Talel Shenhar <talel@amazon.com> | 2018-10-11 14:20:07 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-10-11 15:11:04 +0100 |
| commit | f2d704794864a4bb486f2a0eaed40f25dd87303f (patch) | |
| tree | 9b0b39d17cd6cec53a7e3196b025a2668cf1abe7 /drivers/spi | |
| parent | d49a30366793210cd64759edcdf7099a2e32efd6 (diff) | |
dw: spi: add support for Amazon's Alpine spi controller
Add support for a new devicetree compatible string called
'amazon,alpine-apb-ssi', which is necessary for the Amazon Alpine spi
controller. 'amazon,alpine-dw-apb-ssi' is used in the dw spi driver if
specified in the devicetree. Otherwise, fall back to driver default
behavior, i.e. original dw IP hw driver behavior.
Signed-off-by: Talel Shenhar <talel@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-dw-mmio.c | 9 | ||||
| -rw-r--r-- | drivers/spi/spi-dw.c | 6 | ||||
| -rw-r--r-- | drivers/spi/spi-dw.h | 2 |
3 files changed, 17 insertions, 0 deletions
diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index a768461614a0..3ffb6a40fe0c 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -126,6 +126,14 @@ static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev, JAGUAR2_IF_SI_OWNER_OFFSET); } +static int dw_spi_alpine_init(struct platform_device *pdev, + struct dw_spi_mmio *dwsmmio) +{ + dwsmmio->dws.cs_override = 1; + + return 0; +} + static int dw_spi_mmio_probe(struct platform_device *pdev) { int (*init_func)(struct platform_device *pdev, @@ -230,6 +238,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = { { .compatible = "snps,dw-apb-ssi", }, { .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init}, { .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init}, + { .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init}, { /* end of table */} }; MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index 3e205ab60cd4..b705f2bdb8b9 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -144,6 +144,8 @@ void dw_spi_set_cs(struct spi_device *spi, bool enable) if (!enable) dw_writel(dws, DW_SPI_SER, BIT(spi->chip_select)); + else if (dws->cs_override) + dw_writel(dws, DW_SPI_SER, 0); } EXPORT_SYMBOL_GPL(dw_spi_set_cs); @@ -463,6 +465,10 @@ static void spi_hw_init(struct device *dev, struct dw_spi *dws) dws->fifo_len = (fifo == 1) ? 0 : fifo; dev_dbg(dev, "Detected FIFO size: %u bytes\n", dws->fifo_len); } + + /* enable HW fixup for explicit CS deselect for Amazon's alpine chip */ + if (dws->cs_override) + dw_writel(dws, DW_SPI_CS_OVERRIDE, 0xF); } int dw_spi_add_host(struct device *dev, struct dw_spi *dws) diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h index 0168b08364d5..c9c15881e982 100644 --- a/drivers/spi/spi-dw.h +++ b/drivers/spi/spi-dw.h @@ -32,6 +32,7 @@ #define DW_SPI_IDR 0x58 #define DW_SPI_VERSION 0x5c #define DW_SPI_DR 0x60 +#define DW_SPI_CS_OVERRIDE 0xf4 /* Bit fields in CTRLR0 */ #define SPI_DFS_OFFSET 0 @@ -109,6 +110,7 @@ struct dw_spi { u32 fifo_len; /* depth of the FIFO buffer */ u32 max_freq; /* max bus freq supported */ + int cs_override; u32 reg_io_width; /* DR I/O width in bytes */ u16 bus_num; u16 num_cs; /* supported slave numbers */ |