Pull out all the PIO transfer logic into separate function, so DMA can be added.
Signed-off-by: Marek Vasut marex@denx.de Cc: Fabio Estevam festevam@gmail.com Cc: Otavio Salvador otavio@ossystems.com.br Cc: Stefano Babic sbabic@denx.de Cc: Wolfgang Denk wd@denx.de --- drivers/spi/mxs_spi.c | 74 +++++++++++++++++++++++++++---------------------- 1 file changed, 41 insertions(+), 33 deletions(-)
diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c index a21b02b..1733203 100644 --- a/drivers/spi/mxs_spi.c +++ b/drivers/spi/mxs_spi.c @@ -140,47 +140,19 @@ static void mxs_spi_end_xfer(struct mx28_ssp_regs *ssp_regs) writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_set); }
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen, - const void *dout, void *din, unsigned long flags) +static int mxs_spi_xfer_pio(struct mxs_spi_slave *slave, + char *data, int length, int write, unsigned long flags) { - struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave); - struct mx28_ssp_regs *ssp_regs = mxs_slave->regs; - int len = bitlen / 8; - char dummy; - int write = 0; - char *data = NULL; - - if (bitlen == 0) { - if (flags & SPI_XFER_END) { - din = (void *)&dummy; - len = 1; - } else - return 0; - } - - /* Half-duplex only */ - if (din && dout) - return -EINVAL; - /* No data */ - if (!din && !dout) - return 0; - - if (dout) { - data = (char *)dout; - write = 1; - } else if (din) { - data = (char *)din; - write = 0; - } + struct mx28_ssp_regs *ssp_regs = slave->regs;
if (flags & SPI_XFER_BEGIN) mxs_spi_start_xfer(ssp_regs);
- while (len--) { + while (length--) { /* We transfer 1 byte */ writel(1, &ssp_regs->hw_ssp_xfer_size);
- if ((flags & SPI_XFER_END) && !len) + if ((flags & SPI_XFER_END) && !length) mxs_spi_end_xfer(ssp_regs);
if (write) @@ -220,4 +192,40 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, }
return 0; + +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *dout, void *din, unsigned long flags) +{ + struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave); + int len = bitlen / 8; + char dummy; + int write = 0; + char *data = NULL; + + if (bitlen == 0) { + if (flags & SPI_XFER_END) { + din = (void *)&dummy; + len = 1; + } else + return 0; + } + + /* Half-duplex only */ + if (din && dout) + return -EINVAL; + /* No data */ + if (!din && !dout) + return 0; + + if (dout) { + data = (char *)dout; + write = 1; + } else if (din) { + data = (char *)din; + write = 0; + } + + return mxs_spi_xfer_pio(mxs_slave, data, len, write, flags); }