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authorMarek Vasut <marex@denx.de>2012-07-09 00:48:32 +0000
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2012-08-14 00:36:28 +0200
commitaca21732bdebe33542099c773fe62ee59c8ef37a (patch)
treef329ac906e7eed740b178ead90821bad0881a6b7
parent9fe7c73f5886e09734bcd9c287986b8a94c03e60 (diff)
downloadu-boot-linaro-stable-aca21732bdebe33542099c773fe62ee59c8ef37a.tar.gz
MX28: SPI: Pull out the PIO transfer function
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>
-rw-r--r--drivers/spi/mxs_spi.c74
1 files changed, 41 insertions, 33 deletions
diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index a21b02b7f..17332031d 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);
}