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authorMatthias Fuchs <matthias.fuchs@esd.eu>2012-01-14 02:25:25 +0000
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2012-02-12 10:11:27 +0100
commit2638b50b18ad78c8fc0433c05270d3c7d62a6e03 (patch)
treee1720092d32e09f98b7023c5ce842e44a7773836
parent82182720e799389aa86ae3dcc085f47f7b9dc161 (diff)
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mx28: fix i.MX28 spi driver
The generic spi flash driver (drivers/mtd/spi/spi_flash.c) uses the spi low level driver's spi_xfer() function with len=0 to deassert the SPI flash' chip select. But the i.MX28 spi driver rejects this call due to len=0. This patch implements an exception for len=0 with the SPI_XFER_END flag set. This results in an extra read with the chip select being deasserted afterwards. There seems to be no way to deassert the signal by hand. Signed-off-by: Matthias Fuchs <matthias.fuchs@esd.eu> Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
-rw-r--r--drivers/spi/mxs_spi.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index 4c27fef..adb9ca8 100644
--- a/drivers/spi/mxs_spi.c
+++ b/drivers/spi/mxs_spi.c
@@ -129,9 +129,15 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
int len = bitlen / 8;
const char *tx = dout;
char *rx = din;
-
- if (bitlen == 0)
- return 0;
+ char dummy;
+
+ if (bitlen == 0) {
+ if (flags & SPI_XFER_END) {
+ rx = &dummy;
+ len = 1;
+ } else
+ return 0;
+ }
if (!rx && !tx)
return 0;