staging: comedi: ni_labpc: introduce labpc_range_is_unipolar()

Introduce a helper function to determine if a range selection is
bipolar or unipolar.

This allows removing the static data 'labpc_range_is_unipolar' and
'labpc_plus_is_unipolar' as well as the boardinfo 'ai_range_is_unipolar'.

For consistency, also use the helper in labpc_ao_winsn() when
checking the range.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_labpc.c

@@ -215,11 +215,6 @@ enum scan_mode {
 	MODE_MULT_CHAN_DOWN,
 };
 
-static const int labpc_plus_is_unipolar[] = {
-	0, 0, 0, 0, 0, 0, 0, 0,
-	1, 1, 1, 1, 1, 1, 1, 1,
-};
-
 static const int labpc_plus_ai_gain_bits[] = {
 	0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
 	0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
@@ -246,12 +241,6 @@ static const struct comedi_lrange range_labpc_plus_ai = {
 	}
 };
 
-const int labpc_1200_is_unipolar[] = {
-	0, 0, 0, 0, 0, 0, 0,
-	1, 1, 1, 1, 1, 1, 1,
-};
-EXPORT_SYMBOL_GPL(labpc_1200_is_unipolar);
-
 const int labpc_1200_ai_gain_bits[] = {
 	0x00, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
 	0x00, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70,
@@ -278,7 +267,6 @@ const struct comedi_lrange range_labpc_1200_ai = {
 };
 EXPORT_SYMBOL_GPL(range_labpc_1200_ai);
 
-#define AO_RANGE_IS_UNIPOLAR 0x1
 static const struct comedi_lrange range_labpc_ao = {
 	2, {
 		BIP_RANGE(5),
@@ -317,7 +305,6 @@ static const struct labpc_boardinfo labpc_boards[] = {
 		.has_ao			= 1,
 		.ai_range_table		= &range_labpc_1200_ai,
 		.ai_range_code		= labpc_1200_ai_gain_bits,
-		.ai_range_is_unipolar	= labpc_1200_is_unipolar,
 		.ai_scan_up		= 1,
 	}, {
 		.name			= "lab-pc-1200ai",
@@ -326,7 +313,6 @@ static const struct labpc_boardinfo labpc_boards[] = {
 		.register_layout	= labpc_1200_layout,
 		.ai_range_table		= &range_labpc_1200_ai,
 		.ai_range_code		= labpc_1200_ai_gain_bits,
-		.ai_range_is_unipolar	= labpc_1200_is_unipolar,
 		.ai_scan_up		= 1,
 	}, {
 		.name			= "lab-pc+",
@@ -336,7 +322,6 @@ static const struct labpc_boardinfo labpc_boards[] = {
 		.has_ao			= 1,
 		.ai_range_table		= &range_labpc_plus_ai,
 		.ai_range_code		= labpc_plus_ai_gain_bits,
-		.ai_range_is_unipolar	= labpc_plus_is_unipolar,
 	},
 #ifdef CONFIG_COMEDI_PCI_DRIVERS
 	{
@@ -348,7 +333,6 @@ static const struct labpc_boardinfo labpc_boards[] = {
 		.has_ao			= 1,
 		.ai_range_table		= &range_labpc_1200_ai,
 		.ai_range_code		= labpc_1200_ai_gain_bits,
-		.ai_range_is_unipolar	= labpc_1200_is_unipolar,
 		.ai_scan_up		= 1,
 		.has_mmio		= 1,
 	},
@@ -360,6 +344,18 @@ static const int dma_buffer_size = 0xff00;
 /* 2 bytes per sample */
 static const int sample_size = 2;
 
+static bool labpc_range_is_unipolar(struct comedi_subdevice *s,
+				    unsigned int range)
+{
+	const struct comedi_lrange *lrange = s->range_table;
+	const struct comedi_krange *krange = &lrange->range[range];
+
+	if (krange->min < 0)
+		return false;
+	else
+		return true;
+}
+
 static void labpc_clear_adc_fifo(const struct comedi_device *dev)
 {
 	struct labpc_private *devpriv = dev->private;
@@ -409,7 +405,7 @@ static int labpc_ai_rinsn(struct comedi_device *dev, struct comedi_subdevice *s,
 		else
 			devpriv->cmd6 &= ~ADC_COMMON_BIT;
 		/* bipolar or unipolar range? */
-		if (board->ai_range_is_unipolar[range])
+		if (labpc_range_is_unipolar(s, range))
 			devpriv->cmd6 |= ADC_UNIP_BIT;
 		else
 			devpriv->cmd6 &= ~ADC_UNIP_BIT;
@@ -938,7 +934,7 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
 		else
 			devpriv->cmd6 &= ~ADC_COMMON_BIT;
 		/*  bipolar or unipolar range? */
-		if (board->ai_range_is_unipolar[range])
+		if (labpc_range_is_unipolar(s, range))
 			devpriv->cmd6 |= ADC_UNIP_BIT;
 		else
 			devpriv->cmd6 &= ~ADC_UNIP_BIT;
@@ -1363,7 +1359,7 @@ static int labpc_ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
 	/* set range */
 	if (board->register_layout == labpc_1200_layout) {
 		range = CR_RANGE(insn->chanspec);
-		if (range & AO_RANGE_IS_UNIPOLAR)
+		if (labpc_range_is_unipolar(s, range))
 			devpriv->cmd6 |= DAC_UNIP_BIT(channel);
 		else
 			devpriv->cmd6 &= ~DAC_UNIP_BIT(channel);

drivers/staging/comedi/drivers/ni_labpc.h

@@ -44,7 +44,6 @@ struct labpc_boardinfo {
 	int has_ao;		/*  has analog output true/false */
 	const struct comedi_lrange *ai_range_table;
 	const int *ai_range_code;
-	const int *ai_range_is_unipolar;
 
 	/*  board can auto scan up in ai channels, not just down */
 	unsigned ai_scan_up:1;
@@ -105,7 +104,6 @@ int labpc_common_attach(struct comedi_device *dev, unsigned long iobase,
 			unsigned int irq, unsigned int dma);
 void labpc_common_detach(struct comedi_device *dev);
 
-extern const int labpc_1200_is_unipolar[];
 extern const int labpc_1200_ai_gain_bits[];
 extern const struct comedi_lrange range_labpc_1200_ai;
 

drivers/staging/comedi/drivers/ni_labpc_cs.c

@@ -83,7 +83,6 @@ static const struct labpc_boardinfo labpc_cs_boards[] = {
 		.has_ao			= 1,
 		.ai_range_table		= &range_labpc_1200_ai,
 		.ai_range_code		= labpc_1200_ai_gain_bits,
-		.ai_range_is_unipolar	= labpc_1200_is_unipolar,
 	},
 };