diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2020-03-18 03:15:53 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-03-19 01:44:54 +0300 |
| commit | 671ffde1752f594c60ccdfd75378defacfaf7c83 (patch) | |
| tree | 5e34af3778a26c73146855a0737e32a71a80c0af /drivers/spi | |
| parent | 4fcc7c2292def2fcb21a9644969583771c52724e (diff) | |
| download | linux-671ffde1752f594c60ccdfd75378defacfaf7c83.tar.xz | |
spi: spi-fsl-dspi: Fix little endian access to PUSHR CMD and TXDATA
In XSPI mode, the 32-bit PUSHR register can be written to separately:
the higher 16 bits are for commands and the lower 16 bits are for data.
This has nicely been hacked around, by defining a second regmap with a
width of 16 bits, and effectively splitting a 32-bit register into 2
16-bit ones, from the perspective of this regmap_pushr.
The problem is the assumption about the controller's endianness. If the
controller is little endian (such as anything post-LS1046A), then the
first 2 bytes, in the order imposed by memory layout, will actually hold
the TXDATA, and the last 2 bytes will hold the CMD.
So take the controller's endianness into account when performing split
writes to PUSHR. The obvious and simple solution would have been to call
regmap_get_val_endian(), but that is an internal regmap function and we
don't want to change regmap just for this. Therefore, we just re-read
the "big-endian" device tree property.
Fixes: 58ba07ec79e6 ("spi: spi-fsl-dspi: Add support for XSPI mode registers")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-3-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 6ca35881881b..be717776dd98 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -103,10 +103,6 @@ #define SPI_FRAME_BITS(bits) SPI_CTAR_FMSZ((bits) - 1) #define SPI_FRAME_EBITS(bits) SPI_CTARE_FMSZE(((bits) - 1) >> 4) -/* Register offsets for regmap_pushr */ -#define PUSHR_CMD 0x0 -#define PUSHR_TX 0x2 - #define DMA_COMPLETION_TIMEOUT msecs_to_jiffies(3000) struct chip_data { @@ -240,6 +236,13 @@ struct fsl_dspi { int words_in_flight; + /* + * Offsets for CMD and TXDATA within SPI_PUSHR when accessed + * individually (in XSPI mode) + */ + int pushr_cmd; + int pushr_tx; + void (*host_to_dev)(struct fsl_dspi *dspi, u32 *txdata); void (*dev_to_host)(struct fsl_dspi *dspi, u32 rxdata); }; @@ -673,12 +676,12 @@ static void dspi_pushr_cmd_write(struct fsl_dspi *dspi, u16 cmd) */ if (dspi->len > dspi->oper_word_size) cmd |= SPI_PUSHR_CMD_CONT; - regmap_write(dspi->regmap_pushr, PUSHR_CMD, cmd); + regmap_write(dspi->regmap_pushr, dspi->pushr_cmd, cmd); } static void dspi_pushr_txdata_write(struct fsl_dspi *dspi, u16 txdata) { - regmap_write(dspi->regmap_pushr, PUSHR_TX, txdata); + regmap_write(dspi->regmap_pushr, dspi->pushr_tx, txdata); } static void dspi_xspi_write(struct fsl_dspi *dspi, int cnt, bool eoq) @@ -1259,6 +1262,7 @@ static int dspi_probe(struct platform_device *pdev) struct fsl_dspi *dspi; struct resource *res; void __iomem *base; + bool big_endian; ctlr = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi)); if (!ctlr) @@ -1284,6 +1288,7 @@ static int dspi_probe(struct platform_device *pdev) /* Only Coldfire uses platform data */ dspi->devtype_data = &devtype_data[MCF5441X]; + big_endian = true; } else { ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num); @@ -1305,6 +1310,15 @@ static int dspi_probe(struct platform_device *pdev) ret = -EFAULT; goto out_ctlr_put; } + + big_endian = of_device_is_big_endian(np); + } + if (big_endian) { + dspi->pushr_cmd = 0; + dspi->pushr_tx = 2; + } else { + dspi->pushr_cmd = 2; + dspi->pushr_tx = 0; } if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE) |