spi: rspi: Fix loopback mode for Dual/Quad SPI Transfers

While normal Dual and Quad SPI Transfers are unidirectional, we must do
a bidirectional transfer if loopback mode is enabled, else rx_buf is not
filled.

With spidev it seemed to work, as spidev uses the same buffer for
tranmission and reception.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Geert Uytterhoeven 2014-02-21 17:29:18 +01:00 committed by Mark Brown
parent ab98fcba96
commit ba824d4971

View File

@ -859,7 +859,9 @@ static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,
{
struct rspi_data *rspi = spi_master_get_devdata(master);
if (xfer->tx_buf && xfer->tx_nbits > SPI_NBITS_SINGLE) {
if (spi->mode & SPI_LOOP) {
return qspi_transfer_out_in(rspi, xfer);
} else if (xfer->tx_buf && xfer->tx_nbits > SPI_NBITS_SINGLE) {
/* Quad or Dual SPI Write */
return qspi_transfer_out(rspi, xfer);
} else if (xfer->rx_buf && xfer->rx_nbits > SPI_NBITS_SINGLE) {