[PATCH 13/35] staging: comedi: das1800: refactor 'range_ai' boardinfo

[H Hartley Sweeten]

The boards supported by this driver have analog inputs with gains of
1, 10, 50, and 250 ("01" type) or 1, 2, 4, and 8 ("02" type).

Replace the 'range_ai' member of the boardinfo with a bit-field flag,
'das1801_range' and only set it for the "01" type boards. Remove the
unnecessary initialization for the "02" type boards.

For aesthetics, rename the comedi_lrange arrays and document the gain.

Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/staging/comedi/drivers/das1800.c | 67 +++++++++++++-------------------
 1 file changed, 28 insertions(+), 39 deletions(-)

diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 88ba051..44a5ac1 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -174,39 +174,38 @@ enum {
 	das1802hr, das1802hr_da, das1801hc, das1802hc, das1801ao, das1802ao
 };
 
-/* analog input ranges */
-static const struct comedi_lrange range_ai_das1801 = {
+static const struct comedi_lrange das1801_ai_range = {
 	8, {
-		BIP_RANGE(5),
-		BIP_RANGE(1),
-		BIP_RANGE(0.1),
-		BIP_RANGE(0.02),
-		UNI_RANGE(5),
-		UNI_RANGE(1),
-		UNI_RANGE(0.1),
-		UNI_RANGE(0.02)
+		BIP_RANGE(5),		/* bipolar gain = 1 */
+		BIP_RANGE(1),		/* bipolar gain = 10 */
+		BIP_RANGE(0.1),		/* bipolar gain = 50 */
+		BIP_RANGE(0.02),	/* bipolar gain = 250 */
+		UNI_RANGE(5),		/* unipolar gain = 1 */
+		UNI_RANGE(1),		/* unipolar gain = 10 */
+		UNI_RANGE(0.1),		/* unipolar gain = 50 */
+		UNI_RANGE(0.02)		/* unipolar gain = 250 */
 	}
 };
 
-static const struct comedi_lrange range_ai_das1802 = {
+static const struct comedi_lrange das1802_ai_range = {
 	8, {
-		BIP_RANGE(10),
-		BIP_RANGE(5),
-		BIP_RANGE(2.5),
-		BIP_RANGE(1.25),
-		UNI_RANGE(10),
-		UNI_RANGE(5),
-		UNI_RANGE(2.5),
-		UNI_RANGE(1.25)
+		BIP_RANGE(10),		/* bipolar gain = 1 */
+		BIP_RANGE(5),		/* bipolar gain = 2 */
+		BIP_RANGE(2.5),		/* bipolar gain = 4 */
+		BIP_RANGE(1.25),	/* bipolar gain = 8 */
+		UNI_RANGE(10),		/* unipolar gain = 1 */
+		UNI_RANGE(5),		/* unipolar gain = 2 */
+		UNI_RANGE(2.5),		/* unipolar gain = 4 */
+		UNI_RANGE(1.25)		/* unipolar gain = 8 */
 	}
 };
 
 struct das1800_board {
 	const char *name;
 	int ai_speed;		/* max conversion period in nanoseconds */
-	const struct comedi_lrange *range_ai;	/* available input ranges */
 	unsigned int is_16bit:1;
 	unsigned int has_64_ai_chan:1;
+	unsigned int das1801_range:1;
 	unsigned int has_ao:1;
 	unsigned int has_wform_ao:1;
 	unsigned int has_4_ao_chan:1;
@@ -221,98 +220,87 @@ static const struct das1800_board das1800_boards[] = {
 	{
 		.name		= "das-1701st",
 		.ai_speed	= 6250,
-		.range_ai	= &range_ai_das1801,
+		.das1801_range	= 1,
 	}, {
 		.name		= "das-1701st-da",
 		.ai_speed	= 6250,
-		.range_ai	= &range_ai_das1801,
+		.das1801_range	= 1,
 		.has_ao		= 1,
 		.has_4_ao_chan	= 1,
 	}, {
 		.name		= "das-1702st",
 		.ai_speed	= 6250,
-		.range_ai	= &range_ai_das1802,
 	}, {
 		.name		= "das-1702st-da",
 		.ai_speed	= 6250,
-		.range_ai	= &range_ai_das1802,
 		.has_ao		= 1,
 		.has_4_ao_chan	= 1,
 	}, {
 		.name		= "das-1702hr",
 		.ai_speed	= 20000,
-		.range_ai	= &range_ai_das1802,
 		.is_16bit	= 1,
 	}, {
 		.name		= "das-1702hr-da",
 		.ai_speed	= 20000,
-		.range_ai	= &range_ai_das1802,
 		.is_16bit	= 1,
 		.has_ao		= 1,
 	}, {
 		.name		= "das-1701ao",
 		.ai_speed	= 6250,
-		.range_ai	= &range_ai_das1801,
+		.das1801_range	= 1,
 		.has_wform_ao	= 1,
 	}, {
 		.name		= "das-1702ao",
 		.ai_speed	= 6250,
-		.range_ai	= &range_ai_das1802,
 		.has_wform_ao	= 1,
 	}, {
 		.name		= "das-1801st",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1801,
+		.das1801_range	= 1,
 	}, {
 		.name		= "das-1801st-da",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1801,
+		.das1801_range	= 1,
 		.has_ao		= 1,
 		.has_4_ao_chan	= 1,
 	}, {
 		.name		= "das-1802st",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1802,
 	}, {
 		.name		= "das-1802st-da",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1802,
 		.has_ao		= 1,
 		.has_4_ao_chan	= 1,
 	}, {
 		.name		= "das-1802hr",
 		.ai_speed	= 10000,
-		.range_ai	= &range_ai_das1802,
 		.is_16bit	= 1,
 	}, {
 		.name		= "das-1802hr-da",
 		.ai_speed	= 10000,
-		.range_ai	= &range_ai_das1802,
 		.is_16bit	= 1,
 		.has_ao		= 1,
 	}, {
 		.name		= "das-1801hc",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1801,
 		.has_64_ai_chan	= 1,
+		.das1801_range	= 1,
 		.has_ao		= 1,
 		.has_8_do_chan	= 1,
 	}, {
 		.name		= "das-1802hc",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1802,
 		.has_64_ai_chan	= 1,
 		.has_ao		= 1,
 		.has_8_do_chan	= 1,
 	}, {
 		.name		= "das-1801ao",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1801,
+		.das1801_range	= 1,
 		.has_wform_ao	= 1,
 	}, {
 		.name		= "das-1802ao",
 		.ai_speed	= 3000,
-		.range_ai	= &range_ai_das1802,
 		.has_wform_ao	= 1,
 	},
 };
@@ -1261,7 +1249,8 @@ static int das1800_attach(struct comedi_device *dev,
 		s->subdev_flags	|= SDF_COMMON;
 	s->n_chan	= (board->has_64_ai_chan) ? 64 : 16;
 	s->maxdata	= (board->is_16bit) ? 0xffff : 0x0fff;
-	s->range_table	= board->range_ai;
+	s->range_table	= (board->das1801_range) ? &das1801_ai_range
+						 : &das1802_ai_range;
 	s->insn_read	= das1800_ai_insn_read;
 	if (dev->irq) {
 		dev->read_subdev = s;
-- 
2.6.3