Unverified Commit cc760f31 authored by Serge Semin's avatar Serge Semin Committed by Mark Brown
Browse files

spi: dw: Convert CS-override to DW SPI capabilities 



There are several vendor-specific versions of the DW SPI controllers,
each of which may have some peculiarities with respect to the original
IP-core. Seeing it has already caused adding flags and a callback into the
DW SPI private data, let's introduce a generic capabilities interface to
tune the generic DW SPI controller driver up in accordance with the
particular controller specifics. It's done by converting a simple
Alpine-specific CS-override capability into the DW SPI controller
capability activated by setting the DW_SPI_CAP_CS_OVERRIDE flag.

Signed-off-by: default avatarSerge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-10-Sergey.Semin@baikalelectronics.ru


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 675e7c9d

drivers/spi/spi-dw-core.c

+2 −2
Original line number Diff line number Diff line
@@ -104,7 +104,7 @@ void dw_spi_set_cs(struct spi_device *spi, bool enable) 
	 */

	if (cs_high == enable)

		dw_writel(dws, DW_SPI_SER, BIT(spi->chip_select));

	else if (dws->cs_override)

	else if (dws->caps & DW_SPI_CAP_CS_OVERRIDE)

		dw_writel(dws, DW_SPI_SER, 0);

}

EXPORT_SYMBOL_GPL(dw_spi_set_cs);
@@ -444,7 +444,7 @@ static void spi_hw_init(struct device *dev, struct dw_spi *dws) 
	}



	/* enable HW fixup for explicit CS deselect for Amazon's alpine chip */

	if (dws->cs_override)

	if (dws->caps & DW_SPI_CAP_CS_OVERRIDE)

		dw_writel(dws, DW_SPI_CS_OVERRIDE, 0xF);

}

drivers/spi/spi-dw-mmio.c

+1 −1
Original line number Diff line number Diff line
@@ -204,7 +204,7 @@ static int dw_spi_mscc_sparx5_init(struct platform_device *pdev, 
static int dw_spi_alpine_init(struct platform_device *pdev,

			      struct dw_spi_mmio *dwsmmio)

{

	dwsmmio->dws.cs_override = 1;

	dwsmmio->dws.caps = DW_SPI_CAP_CS_OVERRIDE;



	/* Register hook to configure CTRLR0 */

	dwsmmio->dws.update_cr0 = dw_spi_update_cr0;

drivers/spi/spi-dw.h

+6 −1
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#ifndef DW_SPI_HEADER_H

#define DW_SPI_HEADER_H



#include <linux/bits.h>

#include <linux/completion.h>

#include <linux/debugfs.h>

#include <linux/irqreturn.h>
@@ -98,6 +99,9 @@ enum dw_ssi_type { 
	SSI_NS_MICROWIRE,

};



/* DW SPI capabilities */

#define DW_SPI_CAP_CS_OVERRIDE		BIT(0)



struct dw_spi;

struct dw_spi_dma_ops {

	int (*dma_init)(struct device *dev, struct dw_spi *dws);
@@ -118,7 +122,8 @@ struct dw_spi { 
	u32			fifo_len;	/* depth of the FIFO buffer */

	u32			max_freq;	/* max bus freq supported */



	int			cs_override;

	u32			caps;		/* DW SPI capabilities */



	u32			reg_io_width;	/* DR I/O width in bytes */

	u16			bus_num;

	u16			num_cs;		/* supported slave numbers */