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staging: comedi: fix minimum AO period for NI 625x and NI 628x

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commit 34b55d8c48 upstream.

The minimum period was set to 357 ns, while the divider for these boards is 50
ns. This prevented to output at maximum speed as ni_ao_cmdtest() would return
357 but would not accept it.

Not sure why it was set to 357 ns (this was done before the git history,
which starts 5 years ago). My guess is that it comes from reading the
specification stating a 2.8 MHz rate (~ 357 ns). The latest
specification states a 2.86 MHz rate (~ 350 ns), which makes a lot
more sense.

Tested on a pci-6251.

Signed-off-by: Éric Piel <piel@delmic.com>
Acked-By: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Éric Piel 2012-12-19 13:03:13 +01:00 committed by Greg Kroah-Hartman
parent e7b67acb37
commit a72725d609
1 changed files with 8 additions and 8 deletions
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16
drivers/staging/comedi/drivers/ni_pcimio.c
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@ -1023,7 +1023,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_625x_ao,
.reg_type = ni_reg_625x,
.ao_unipolar = 0,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 8,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1042,7 +1042,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_625x_ao,
.reg_type = ni_reg_625x,
.ao_unipolar = 0,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 8,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1061,7 +1061,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_625x_ao,
.reg_type = ni_reg_625x,
.ao_unipolar = 0,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 8,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1097,7 +1097,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_625x_ao,
.reg_type = ni_reg_625x,
.ao_unipolar = 0,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 32,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1116,7 +1116,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_625x_ao,
.reg_type = ni_reg_625x,
.ao_unipolar = 0,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 32,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1152,7 +1152,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_628x_ao,
.reg_type = ni_reg_628x,
.ao_unipolar = 1,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 8,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1171,7 +1171,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_628x_ao,
.reg_type = ni_reg_628x,
.ao_unipolar = 1,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 8,
.caldac = {caldac_none},
.has_8255 = 0,
@ -1207,7 +1207,7 @@ static const struct ni_board_struct ni_boards[] = {
.ao_range_table = &range_ni_M_628x_ao,
.reg_type = ni_reg_628x,
.ao_unipolar = 1,
.ao_speed = 357,
.ao_speed = 350,
.num_p0_dio_channels = 32,
.caldac = {caldac_none},
.has_8255 = 0,