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| author | Matthias Fuchs <matthias.fuchs@esd.eu> | 2012-01-14 02:25:25 +0000 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2012-02-12 10:11:27 +0100 |
| commit | 2638b50b18ad78c8fc0433c05270d3c7d62a6e03 (patch) | |
| tree | e1720092d32e09f98b7023c5ce842e44a7773836 /drivers/spi | |
| parent | 82182720e799389aa86ae3dcc085f47f7b9dc161 (diff) | |
| download | u-boot-imx-2638b50b18ad78c8fc0433c05270d3c7d62a6e03.zip u-boot-imx-2638b50b18ad78c8fc0433c05270d3c7d62a6e03.tar.gz u-boot-imx-2638b50b18ad78c8fc0433c05270d3c7d62a6e03.tar.bz2 | |
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>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/mxs_spi.c | 12 |
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; |