From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Fuchs Date: Sat, 14 Jan 2012 13:25:25 +0100 Subject: [U-Boot] [PATCH] mx28: fix i.MX28 spi driver Message-ID: <4F117435.7080807@esd.eu> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de 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 --- 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;