staging: comedi: addi_apci_3120: fix apci3120_ao_insn_write()

The comedi core expects (*insn_write) functions to write insn->n values and
return the number of values written or an errno. This function currently
returns insn->n but it only writes a single data value.

Fix the function to work like the core expects.

There are two registers used to update the analog outputs. Offset 0x08 is
used to update channels 0-3 and offset 0x0a to update channels 4-7. Bits
14 and 15 in each register set the mux to select which channel to update.
The lower 14 bits are the value used to set the DAC.

For aesthetics, tidy up the defines used for the register offsets and bits
in the registers.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

@@ -96,24 +96,12 @@ This program is distributed in the hope that it will be useful, but WITHOUT ANY
 #define	APCI3120_SET4DIGITALOUTPUTON	1
 #define APCI3120_SET4DIGITALOUTPUTOFF	0
 
-/* analog output SELECT BIT */
-#define APCI3120_ANALOG_OP_CHANNEL_1	0x0000
-#define APCI3120_ANALOG_OP_CHANNEL_2	0x4000
-#define APCI3120_ANALOG_OP_CHANNEL_3	0x8000
-#define APCI3120_ANALOG_OP_CHANNEL_4	0xc000
-#define APCI3120_ANALOG_OP_CHANNEL_5	0x0000
-#define APCI3120_ANALOG_OP_CHANNEL_6	0x4000
-#define APCI3120_ANALOG_OP_CHANNEL_7	0x8000
-#define APCI3120_ANALOG_OP_CHANNEL_8	0xc000
-
 /* Enable external trigger bit in nWrAddress */
 #define APCI3120_ENABLE_EXT_TRIGGER	0x8000
 
 /* ANALOG OUTPUT AND INPUT DEFINE */
 #define APCI3120_UNIPOLAR		0x80
 #define APCI3120_BIPOLAR		0x00
-#define APCI3120_ANALOG_OUTPUT_1	0x08
-#define APCI3120_ANALOG_OUTPUT_2	0x0a
 #define APCI3120_1_GAIN			0x00
 #define APCI3120_2_GAIN			0x10
 #define APCI3120_5_GAIN			0x20
@@ -1923,31 +1911,20 @@ static int apci3120_ao_insn_write(struct comedi_device *dev,
 				  struct comedi_insn *insn,
 				  unsigned int *data)
 {
-	unsigned int ui_Channel;
-	int ret;
-
-	ui_Channel = CR_CHAN(insn->chanspec);
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	int i;
 
-	data[0] = ((((ui_Channel & 0x03) << 14) & 0xC000) | data[0]);
+	for (i = 0; i < insn->n; i++) {
+		unsigned int val = data[i];
+		int ret;
 
 		ret = comedi_timeout(dev, s, insn, apci3120_ao_ready, 0);
 		if (ret)
 			return ret;
 
-	if (ui_Channel <= 3)
-		/*
-		 * for channel 0-3 out at the register 1 (wrDac1-8) data[i]
-		 * typecasted to ushort since word write is to be done
-		 */
-		outw((unsigned short) data[0],
-		     dev->iobase + APCI3120_ANALOG_OUTPUT_1);
-	else
-		/*
-		 * for channel 4-7 out at the register 2 (wrDac5-8) data[i]
-		 * typecasted to ushort since word write is to be done
-		 */
-		outw((unsigned short) data[0],
-		     dev->iobase + APCI3120_ANALOG_OUTPUT_2);
+		outw(APCI3120_AO_MUX(chan) | APCI3120_AO_DATA(val),
+		     dev->iobase + APCI3120_AO_REG(chan));
+	}
 
 	return insn->n;
 }

drivers/staging/comedi/drivers/addi_apci_3120.c

@@ -7,6 +7,22 @@
 #include "comedi_fc.h"
 #include "amcc_s5933.h"
 
+/*
+ * PCI BAR 0 register map (devpriv->amcc)
+ * see amcc_s5933.h for register and bit defines
+ */
+
+/*
+ * PCI BAR 1 register map (dev->iobase)
+ */
+#define APCI3120_AO_REG(x)			(0x08 + (((x) / 4) * 2))
+#define APCI3120_AO_MUX(x)			(((x) & 0x3) << 14)
+#define APCI3120_AO_DATA(x)			((x) << 0)
+
+/*
+ * PCI BAR 2 register map (devpriv->addon)
+ */
+
 enum apci3120_boardid {
 	BOARD_APCI3120,
 	BOARD_APCI3001,