Unverified Commit f2d70479 authored by Talel Shenhar's avatar Talel Shenhar Committed by Mark Brown
Browse files

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: default avatarTalel Shenhar <talel@amazon.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent d49a3036

drivers/spi/spi-dw-mmio.c

+9 −0
Original line number Diff line number Diff line
@@ -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);

drivers/spi/spi-dw.c

+6 −0
Original line number Diff line number Diff line
@@ -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)

drivers/spi/spi-dw.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

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