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spi: mxs: Allow other chip selects to work 

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>
Acked-by: Marek Vasut <marex@denx.de>
This commit is contained in:
Fabio Estevam 2012-04-23 08:30:50 +00:00 committed by Albert ARIBAUD
parent 79cb14ab39
commit 148ca64f32
1 changed files with 10 additions and 0 deletions
drivers/spi
mxs_spi.c

10
drivers/spi/mxs_spi.c
View File

@ -34,6 +34,8 @@
#define MXS_SPI_MAX_TIMEOUT 1000000 #define MXS_SPI_MAX_TIMEOUT 1000000
#define MXS_SPI_PORT_OFFSET 0x2000 #define MXS_SPI_PORT_OFFSET 0x2000
#define MXS_SSP_CHIPSELECT_MASK 0x00300000
#define MXS_SSP_CHIPSELECT_SHIFT 20
struct mxs_spi_slave { struct mxs_spi_slave {
struct spi_slave slave; struct spi_slave slave;
@ -65,6 +67,8 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
{ {
struct mxs_spi_slave *mxs_slave; struct mxs_spi_slave *mxs_slave;
uint32_t addr; uint32_t addr;
struct mx28_ssp_regs *ssp_regs;
int reg;
if (!spi_cs_is_valid(bus, cs)) { if (!spi_cs_is_valid(bus, cs)) {
printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs); printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
@ -82,7 +86,13 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
mxs_slave->max_khz = max_hz / 1000; mxs_slave->max_khz = max_hz / 1000;
mxs_slave->mode = mode; mxs_slave->mode = mode;
mxs_slave->regs = (struct mx28_ssp_regs *)addr; 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; return &mxs_slave->slave;
} }