Message ID | 1335184992-2381-1-git-send-email-fabio.estevam@freescale.com |
---|---|
State | Changes Requested |
Headers | show |
Dear Fabio Estevam, > MXS SSP controller may have up to three chip selects per port: SS0, SS1 and > SS2. > > Currently only SS0 is supported in the mxs_spi driver. > > Allow all the three chip select to work by selecting the desired one > in bits 20 and 21 of the HW_SSP_CTRL0 register. > > Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> > --- > drivers/spi/mxs_spi.c | 17 +++++++++++++++++ > 1 files changed, 17 insertions(+), 0 deletions(-) > > diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c > index 4e6f14e..c0bfd25 100644 > --- a/drivers/spi/mxs_spi.c > +++ b/drivers/spi/mxs_spi.c > @@ -34,6 +34,8 @@ > > #define MXS_SPI_MAX_TIMEOUT 1000000 > #define MXS_SPI_PORT_OFFSET 0x2000 > +#define MXS_SSP_CHIPSELECT_MASK 0x00300000 > +#define MXS_SSP_CHIPSELECT_SHIFT 20 > > struct mxs_spi_slave { > struct spi_slave slave; > @@ -56,12 +58,19 @@ struct spi_slave *spi_setup_slave(unsigned int bus, > unsigned int cs, { > struct mxs_spi_slave *mxs_slave; > uint32_t addr; > + struct mx28_ssp_regs *ssp_regs; > + int reg; > > if (bus > 3) { > printf("MXS SPI: Max bus number is 3\n"); > return NULL; > } > > + if (cs > 2) { > + printf("MXS SPI: Invalid chip select number: %d\n", cs); > + return NULL; > + } > + > mxs_slave = malloc(sizeof(struct mxs_spi_slave)); > if (!mxs_slave) > return NULL; > @@ -74,6 +83,14 @@ struct spi_slave *spi_setup_slave(unsigned int bus, > unsigned int cs, mxs_slave->mode = mode; > mxs_slave->regs = (struct mx28_ssp_regs *)addr; > > + ssp_regs = mxs_slave->regs; > + > + reg = readl(&ssp_regs->hw_ssp_ctrl0); > + reg &= ~(MXS_SSP_CHIPSELECT_MASK); > + reg |= cs << MXS_SSP_CHIPSELECT_SHIFT; > + > + writel(reg, &ssp_regs->hw_ssp_ctrl0); > + > return &mxs_slave->slave; > } Acked-by: Marek Vasut <marex@denx.de> Best regards, Marek Vasut
On Monday 23 April 2012 08:43:12 Fabio Estevam wrote: > --- a/drivers/spi/mxs_spi.c > +++ b/drivers/spi/mxs_spi.c > @@ -56,12 +58,19 @@ struct spi_slave *spi_setup_slave(unsigned int bus, > > if (bus > 3) { > printf("MXS SPI: Max bus number is 3\n"); > return NULL; > } > > + if (cs > 2) { > + printf("MXS SPI: Invalid chip select number: %d\n", cs); > + return NULL; > + } this stuff really belongs in spi_cs_is_valid(), sans the printf's. -mike
diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c index 4e6f14e..c0bfd25 100644 --- a/drivers/spi/mxs_spi.c +++ b/drivers/spi/mxs_spi.c @@ -34,6 +34,8 @@ #define MXS_SPI_MAX_TIMEOUT 1000000 #define MXS_SPI_PORT_OFFSET 0x2000 +#define MXS_SSP_CHIPSELECT_MASK 0x00300000 +#define MXS_SSP_CHIPSELECT_SHIFT 20 struct mxs_spi_slave { struct spi_slave slave; @@ -56,12 +58,19 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, { struct mxs_spi_slave *mxs_slave; uint32_t addr; + struct mx28_ssp_regs *ssp_regs; + int reg; if (bus > 3) { printf("MXS SPI: Max bus number is 3\n"); return NULL; } + if (cs > 2) { + printf("MXS SPI: Invalid chip select number: %d\n", cs); + return NULL; + } + mxs_slave = malloc(sizeof(struct mxs_spi_slave)); if (!mxs_slave) return NULL; @@ -74,6 +83,14 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, mxs_slave->mode = mode; mxs_slave->regs = (struct mx28_ssp_regs *)addr; + ssp_regs = mxs_slave->regs; + + reg = readl(&ssp_regs->hw_ssp_ctrl0); + reg &= ~(MXS_SSP_CHIPSELECT_MASK); + reg |= cs << MXS_SSP_CHIPSELECT_SHIFT; + + writel(reg, &ssp_regs->hw_ssp_ctrl0); + return &mxs_slave->slave; }
MXS SSP controller may have up to three chip selects per port: SS0, SS1 and SS2. Currently only SS0 is supported in the mxs_spi driver. Allow all the three chip select to work by selecting the desired one in bits 20 and 21 of the HW_SSP_CTRL0 register. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> --- drivers/spi/mxs_spi.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-)