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SPI controller drivers: check for unsupported modes

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Minor SPI controller driver updates: make the setup() methods reject
spi->mode bits they don't support, by masking aginst the inverse of bits
they *do* support.  This insures against misbehavior later when new mode
bits get added.

Most controllers can't support SPI_LSB_FIRST; more handle SPI_CS_HIGH.
Support for all four SPI clock/transfer modes is routine.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Brownell
2007-07-17 04:04:02 -07:00
committed by Linus Torvalds
parent ff294cba8a
commit dccd573bb0
10 changed files with 66 additions and 21 deletions
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24
drivers/spi/spi_imx.c
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@@ -1163,6 +1163,9 @@ msg_rejected:
return -EINVAL;
}
/* the spi->mode bits understood by this driver: */
#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
/* On first setup bad values must free chip_data memory since will cause
spi_new_device to fail. Bad value setup from protocol driver are simply not
applied and notified to the calling driver. */
@@ -1174,6 +1177,12 @@ static int setup(struct spi_device *spi)
u32 tmp;
int status = 0;
if (spi->mode & ~MODEBITS) {
dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
spi->mode & ~MODEBITS);
return -EINVAL;
}
/* Get controller data */
chip_info = spi->controller_data;
@@ -1245,21 +1254,6 @@ static int setup(struct spi_device *spi)
/* SPI mode */
tmp = spi->mode;
if (tmp & SPI_LSB_FIRST) {
status = -EINVAL;
if (first_setup) {
dev_err(&spi->dev,
"setup - "
"HW doesn't support LSB first transfer\n");
goto err_first_setup;
} else {
dev_err(&spi->dev,
"setup - "
"HW doesn't support LSB first transfer, "
"default to MSB first\n");
spi->mode &= ~SPI_LSB_FIRST;
}
}
if (tmp & SPI_CS_HIGH) {
u32_EDIT(chip->control,
SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);