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

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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: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112914.26501-10-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Serge Semin
2020-09-20 14:28:53 +03:00
committed by Mark Brown
parent 675e7c9d71
commit cc760f3143
3 changed files with 9 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/spi/spi-dw-core.c
View File

@@ -104,7 +104,7 @@ void dw_spi_set_cs(struct spi_device *spi, bool enable)
*/ */
if (cs_high == enable) if (cs_high == enable)
dw_writel(dws, DW_SPI_SER, BIT(spi->chip_select)); 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); dw_writel(dws, DW_SPI_SER, 0);
} }
EXPORT_SYMBOL_GPL(dw_spi_set_cs); 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 */ /* 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); dw_writel(dws, DW_SPI_CS_OVERRIDE, 0xF);
} }

2
drivers/spi/spi-dw-mmio.c
View File

@@ -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, static int dw_spi_alpine_init(struct platform_device *pdev,
struct dw_spi_mmio *dwsmmio) struct dw_spi_mmio *dwsmmio)
{ {
dwsmmio->dws.cs_override = 1; dwsmmio->dws.caps = DW_SPI_CAP_CS_OVERRIDE;
/* Register hook to configure CTRLR0 */ /* Register hook to configure CTRLR0 */
dwsmmio->dws.update_cr0 = dw_spi_update_cr0; dwsmmio->dws.update_cr0 = dw_spi_update_cr0;

7
drivers/spi/spi-dw.h
View File

@@ -2,6 +2,7 @@
#ifndef DW_SPI_HEADER_H #ifndef DW_SPI_HEADER_H
#define DW_SPI_HEADER_H #define DW_SPI_HEADER_H
#include <linux/bits.h>
#include <linux/completion.h> #include <linux/completion.h>
#include <linux/debugfs.h> #include <linux/debugfs.h>
#include <linux/irqreturn.h> #include <linux/irqreturn.h>
@@ -98,6 +99,9 @@ enum dw_ssi_type {
SSI_NS_MICROWIRE, SSI_NS_MICROWIRE,
}; };
/* DW SPI capabilities */
#define DW_SPI_CAP_CS_OVERRIDE BIT(0)
struct dw_spi; struct dw_spi;
struct dw_spi_dma_ops { struct dw_spi_dma_ops {
int (*dma_init)(struct device *dev, struct dw_spi *dws); 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 fifo_len; /* depth of the FIFO buffer */
u32 max_freq; /* max bus freq supported */ 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 */ u32 reg_io_width; /* DR I/O width in bytes */
u16 bus_num; u16 bus_num;
u16 num_cs; /* supported slave numbers */ u16 num_cs; /* supported slave numbers */