[PATCH 3.4 32/44] staging: comedi: das08: Correct AI encoding for das08jr-16-ao

Greg Kroah-Hartman
2014-07-08T00:03:31Z

From: Ian Abbott <abbotti@mev.co.uk>

commit e6391a182865efc896cb2a8d79e07b7ac2f45b48 upstream.

The element of `das08_boards[]` for the 'das08jr-16-ao' board has the
`ai_encoding` member set to `das08_encode12`. It should be set to
`das08_encode16` same as the 'das08jr/16' board. After all, this board
has 16-bit AI resolution.

The description of the A/D LSB register at offset 0 seems incorrect in
the user manual "cio-das08jr-16-ao.pdf" as it implies that the AI
resolution is only 12 bits. The diagrams of the A/D LSB and MSB
registers show 15 data bits and a sign bit, which matches what the
software expects for the `das08_encode16` AI encoding method.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/comedi/drivers/das08.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/comedi/drivers/das08.c
+++ b/drivers/staging/comedi/drivers/das08.c
@@ -385,7 +385,7 @@ static const struct das08_board_struct d
.ai = das08_ai_rinsn,
.ai_nbits = 16,
.ai_pg = das08_pg_none,
- .ai_encoding = das08_encode12,
+ .ai_encoding = das08_encode16,
.ao = das08jr_ao_winsn,
.ao_nbits = 16,
.di = das08jr_di_rbits,