diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-xilinx.c | 62 |
1 files changed, 38 insertions, 24 deletions
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index 6656b2c82693..523da738805f 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -89,6 +89,7 @@ struct xilinx_spi { int remaining_bytes; /* the number of bytes left to transfer */ u8 bits_per_word; int buffer_size; /* buffer size in words */ + u32 cs_inactive; /* Level of the CS pins when inactive*/ unsigned int (*read_fn)(void __iomem *); void (*write_fn)(u32, void __iomem *); void (*tx_fn)(struct xilinx_spi *); @@ -194,33 +195,37 @@ static void xspi_init_hw(struct xilinx_spi *xspi) static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) { struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); + u16 cr; + u32 cs; if (is_on == BITBANG_CS_INACTIVE) { /* Deselect the slave on the SPI bus */ - xspi->write_fn(0xffff, xspi->regs + XSPI_SSR_OFFSET); - } else if (is_on == BITBANG_CS_ACTIVE) { - /* Set the SPI clock phase and polarity */ - u16 cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) - & ~XSPI_CR_MODE_MASK; - if (spi->mode & SPI_CPHA) - cr |= XSPI_CR_CPHA; - if (spi->mode & SPI_CPOL) - cr |= XSPI_CR_CPOL; - if (spi->mode & SPI_LSB_FIRST) - cr |= XSPI_CR_LSB_FIRST; - if (spi->mode & SPI_LOOP) - cr |= XSPI_CR_LOOP; - xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); - - /* We do not check spi->max_speed_hz here as the SPI clock - * frequency is not software programmable (the IP block design - * parameter) - */ - - /* Activate the chip select */ - xspi->write_fn(~(0x0001 << spi->chip_select), - xspi->regs + XSPI_SSR_OFFSET); + xspi->write_fn(xspi->cs_inactive, xspi->regs + XSPI_SSR_OFFSET); + return; } + + /* Set the SPI clock phase and polarity */ + cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_MODE_MASK; + if (spi->mode & SPI_CPHA) + cr |= XSPI_CR_CPHA; + if (spi->mode & SPI_CPOL) + cr |= XSPI_CR_CPOL; + if (spi->mode & SPI_LSB_FIRST) + cr |= XSPI_CR_LSB_FIRST; + if (spi->mode & SPI_LOOP) + cr |= XSPI_CR_LOOP; + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET); + + /* We do not check spi->max_speed_hz here as the SPI clock + * frequency is not software programmable (the IP block design + * parameter) + */ + + cs = xspi->cs_inactive; + cs ^= BIT(spi->chip_select); + + /* Activate the chip select */ + xspi->write_fn(cs, xspi->regs + XSPI_SSR_OFFSET); } /* spi_bitbang requires custom setup_transfer() to be defined if there is a @@ -229,6 +234,13 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on) static int xilinx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { + struct xilinx_spi *xspi = spi_master_get_devdata(spi->master); + + if (spi->mode & SPI_CS_HIGH) + xspi->cs_inactive &= ~BIT(spi->chip_select); + else + xspi->cs_inactive |= BIT(spi->chip_select); + return 0; } @@ -376,9 +388,11 @@ static int xilinx_spi_probe(struct platform_device *pdev) return -ENODEV; /* the spi->mode bits understood by this driver: */ - master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_LOOP; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_LOOP | + SPI_CS_HIGH; xspi = spi_master_get_devdata(master); + xspi->cs_inactive = 0xffffffff; xspi->bitbang.master = master; xspi->bitbang.chipselect = xilinx_spi_chipselect; xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer; |
