From b9d228f9e896df1af787b2f3467889ab0832370a Mon Sep 17 00:00:00 2001 From: Matthias Brugger Date: Wed, 13 Oct 2010 17:51:02 +0200 Subject: spi/atmel: let transfers through if not changing bits_per_word bits_per_word option in spi_transfer are allowed if it does not change the csr register. This is necessary for the driver in drivers/staging/iio/adis16260_core.c, as it uses this option. Signed-off-by: Matthias Brugger Signed-off-by: Grant Likely --- drivers/spi/atmel_spi.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/spi') diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index c4e04428992d..5c03a5bb168a 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -654,6 +654,8 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) struct spi_transfer *xfer; unsigned long flags; struct device *controller = spi->master->dev.parent; + u8 bits; + struct atmel_spi_device *asd; as = spi_master_get_devdata(spi->master); @@ -672,8 +674,18 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) return -EINVAL; } + if (xfer->bits_per_word) { + asd = spi->controller_state; + bits = (asd->csr >> 4) & 0xf; + if (bits != xfer->bits_per_word - 8) { + dev_dbg(&spi->dev, "you can't yet change " + "bit_per_word in transfers\n"); + return -ENOPROTOOPT; + } + } + /* FIXME implement these protocol options!! */ - if (xfer->bits_per_word || xfer->speed_hz) { + if (xfer->speed_hz) { dev_dbg(&spi->dev, "no protocol options yet\n"); return -ENOPROTOOPT; } -- cgit v1.2.3