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authorDavid Brownell <david-b@pacbell.net>2007-07-17 04:04:02 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-17 10:23:04 -0700
commitdccd573bb02aa011a4a7146c02c409ac0bd722a0 (patch)
tree743eeca4fbbea8272ca4f341b806d776e404d704 /drivers/spi/spi_bitbang.c
parentff294cba8a62fa8334b88692da6d48683900f015 (diff)
downloadop-kernel-dev-dccd573bb02aa011a4a7146c02c409ac0bd722a0.zip
op-kernel-dev-dccd573bb02aa011a4a7146c02c409ac0bd722a0.tar.gz
SPI controller drivers: check for unsupported modes
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>
Diffstat (limited to 'drivers/spi/spi_bitbang.c')
-rw-r--r--drivers/spi/spi_bitbang.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
index 88425e1..0c85c98 100644
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -187,12 +187,10 @@ int spi_bitbang_setup(struct spi_device *spi)
bitbang = spi_master_get_devdata(spi->master);
- /* REVISIT: some systems will want to support devices using lsb-first
- * bit encodings on the wire. In pure software that would be trivial,
- * just bitbang_txrx_le_cphaX() routines shifting the other way, and
- * some hardware controllers also have this support.
+ /* Bitbangers can support SPI_CS_HIGH, SPI_3WIRE, and so on;
+ * add those to master->flags, and provide the other support.
*/
- if ((spi->mode & SPI_LSB_FIRST) != 0)
+ if ((spi->mode & ~(SPI_CPOL|SPI_CPHA|bitbang->flags)) != 0)
return -EINVAL;
if (!cs) {
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