diff options
Diffstat (limited to 'drivers/spi/spi-imx.c')
| -rw-r--r-- | drivers/spi/spi-imx.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 474d5a7fa95e..67f31183c118 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -239,6 +239,18 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, return true; } +/* + * Note the number of natively supported chip selects for MX51 is 4. Some + * devices may have less actual SS pins but the register map supports 4. When + * using gpio chip selects the cs values passed into the macros below can go + * outside the range 0 - 3. We therefore need to limit the cs value to avoid + * corrupting bits outside the allocated locations. + * + * The simplest way to do this is to just mask the cs bits to 2 bits. This + * still allows all 4 native chip selects to work as well as gpio chip selects + * (which can use any of the 4 chip select configurations). + */ + #define MX51_ECSPI_CTRL 0x08 #define MX51_ECSPI_CTRL_ENABLE (1 << 0) #define MX51_ECSPI_CTRL_XCH (1 << 2) @@ -247,16 +259,16 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, #define MX51_ECSPI_CTRL_DRCTL(drctl) ((drctl) << 16) #define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8 #define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 -#define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18) +#define MX51_ECSPI_CTRL_CS(cs) ((cs & 3) << 18) #define MX51_ECSPI_CTRL_BL_OFFSET 20 #define MX51_ECSPI_CTRL_BL_MASK (0xfff << 20) #define MX51_ECSPI_CONFIG 0x0c -#define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs) + 0)) -#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs) + 4)) -#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs) + 8)) -#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs) + 12)) -#define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs) + 20)) +#define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs & 3) + 0)) +#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs & 3) + 4)) +#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs & 3) + 8)) +#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs & 3) + 12)) +#define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs & 3) + 20)) #define MX51_ECSPI_INT 0x10 #define MX51_ECSPI_INT_TEEN (1 << 0) @@ -431,8 +443,7 @@ static unsigned int mx51_ecspi_clkdiv(struct spi_imx_data *spi_imx, unsigned int pre, post; unsigned int fin = spi_imx->spi_clk; - if (unlikely(fspi > fin)) - return 0; + fspi = min(fspi, fin); post = fls(fin) - fls(fspi); if (fin > fspi << post) |