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authorSourav Poddar <sourav.poddar@ti.com>2013-08-22 21:20:48 +0530
committerMark Brown <broonie@linaro.org>2013-08-22 19:05:39 +0100
commitdb90a44177ac39fc22b2da5235b231fccdd4c673 (patch)
tree492a20db7dea81485f18da313a50e1a4136a9575 /drivers
parentf477b7fb13df2b843997559ff34e87d054ba6538 (diff)
spi: conditional checking of mode and transfer bits.
There is a bug in the following patch: http://comments.gmane.org/gmane.linux.kernel.spi.devel/14420 spi: DUAL and QUAD support fix the previous patch some mistake below: 1. DT in slave node, use "spi-tx-nbits = <1/2/4>" in place of using "spi-tx-dual, spi-tx-quad" directly, same to rx. So correct the previous way to get the property in @of_register_spi_devices(). 2. Change the value of transfer bit macro(SPI_NBITS_SINGLE, SPI_NBITS_DUAL SPI_NBITS_QUAD) to 0x01, 0x02 and 0x04 to match the actual wires. 3. Add the following check (1)keep the tx_nbits and rx_nbits in spi_transfer is not beyond the single, dual and quad. (2)keep tx_nbits and rx_nbits are contained by @spi_device->mode example: if @spi_device->mode = DUAL, then tx/rx_nbits can not be set to QUAD(SPI_NBITS_QUAD) (3)if "@spi_device->mode & SPI_3WIRE", then tx/rx_nbits should be in single(SPI_NBITS_SINGLE) Checking of the tx/rx transfer bits and mode bits should be done conditionally based on type of buffer filled else EINVAL condition will always get hit either for rx or tx. Signed-off-by: Sourav Poddar <sourav.poddar@ti.com> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/spi.c56
1 files changed, 30 insertions, 26 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 39d38756e984..50f7fc3ed793 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1473,33 +1473,37 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message)
* 2. keep tx/rx_nbits is contained by mode in spi_device
* 3. if SPI_3WIRE, tx/rx_nbits should be in single
*/
- if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
- xfer->tx_nbits != SPI_NBITS_DUAL &&
- xfer->tx_nbits != SPI_NBITS_QUAD)
- return -EINVAL;
- if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
- !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
- return -EINVAL;
- if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
- !(spi->mode & SPI_TX_QUAD))
- return -EINVAL;
- if ((spi->mode & SPI_3WIRE) &&
- (xfer->tx_nbits != SPI_NBITS_SINGLE))
- return -EINVAL;
+ if (xfer->tx_buf) {
+ if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
+ xfer->tx_nbits != SPI_NBITS_DUAL &&
+ xfer->tx_nbits != SPI_NBITS_QUAD)
+ return -EINVAL;
+ if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
+ !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
+ return -EINVAL;
+ if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
+ !(spi->mode & SPI_TX_QUAD))
+ return -EINVAL;
+ if ((spi->mode & SPI_3WIRE) &&
+ (xfer->tx_nbits != SPI_NBITS_SINGLE))
+ return -EINVAL;
+ }
/* check transfer rx_nbits */
- if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
- xfer->rx_nbits != SPI_NBITS_DUAL &&
- xfer->rx_nbits != SPI_NBITS_QUAD)
- return -EINVAL;
- if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
- !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
- return -EINVAL;
- if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
- !(spi->mode & SPI_RX_QUAD))
- return -EINVAL;
- if ((spi->mode & SPI_3WIRE) &&
- (xfer->rx_nbits != SPI_NBITS_SINGLE))
- return -EINVAL;
+ if (xfer->rx_buf) {
+ if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
+ xfer->rx_nbits != SPI_NBITS_DUAL &&
+ xfer->rx_nbits != SPI_NBITS_QUAD)
+ return -EINVAL;
+ if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
+ !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
+ return -EINVAL;
+ if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
+ !(spi->mode & SPI_RX_QUAD))
+ return -EINVAL;
+ if ((spi->mode & SPI_3WIRE) &&
+ (xfer->rx_nbits != SPI_NBITS_SINGLE))
+ return -EINVAL;
+ }
}
message->spi = spi;