staging: comedi: ni_daq_700: add AI subdevice

Add subdevice 1 as an analog input (AI) subdevice.  It currently only
supports basic, software-triggered acquisitions.

This is mostly the work of Fred Brooks (MODULE_AUTHOR), but he based his
update on an older version of the driver.  I applied the relevant
changes with a few tweaks: adding an explicit `udelay(1)` in a timeout
loop, replacing binary constants with hex, renaming functions, replacing
`printk()` calls, removing exported symbols, removing (very) incomplete
comedi "command" support, and making some coding-style changes.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_daq_700.c

 /*
  *     comedi/drivers/ni_daq_700.c
- *     Driver for DAQCard-700 DIO only
+ *     Driver for DAQCard-700 DIO/AI
  *     copied from 8255
  *
  *     COMEDI - Linux Control and Measurement Device Interface
@@ -29,14 +29,25 @@ Author: Fred Brooks <nsaspook@nsaspook.com>,
   based on ni_daq_dio24 by Daniel Vecino Castel <dvecino@able.es>
 Devices: [National Instruments] PCMCIA DAQ-Card-700 (ni_daq_700)
 Status: works
-Updated: Thu, 21 Feb 2008 12:07:20 +0000
+Updated: Wed, 19 Sep 2012 12:07:20 +0000
 
-The daqcard-700 appears in Comedi as a single digital I/O subdevice with
-16 channels.  The channel 0 corresponds to the daqcard-700's output
+The daqcard-700 appears in Comedi as a  digital I/O subdevice (0) with
+16 channels and a analog input subdevice (1) with 16 single-ended channels.
+
+Digital:  The channel 0 corresponds to the daqcard-700's output
 port, bit 0; channel 8 corresponds to the input port, bit 0.
 
-Direction configuration: channels 0-7 output, 8-15 input (8225 device
+Digital direction configuration: channels 0-7 output, 8-15 input (8225 device
 emu as port A output, port B input, port C N/A).
+
+Analog: The input  range is 0 to 4095 for -10 to +10 volts 
+IRQ is assigned but not used.
+
+Version 0.1	Original DIO only driver
+Version 0.2	DIO and basic AI analog input support on 16 se channels
+
+Manuals:	Register level:	http://www.ni.com/pdf/manuals/340698.pdf
+		User Manual:	http://www.ni.com/pdf/manuals/320676d.pdf
 */
 
 #include <linux/interrupt.h>
@@ -55,8 +66,21 @@ struct daq700_board {
 	const char *name;
 };
 
-#define DIO_W		0x04
-#define DIO_R		0x05
+/* daqcard700 registers */
+#define DIO_W		0x04	/* WO 8bit */
+#define DIO_R		0x05	/* RO 8bit */
+#define CMD_R1		0x00	/* WO 8bit */
+#define CMD_R2		0x07	/* RW 8bit */
+#define CMD_R3		0x05	/* W0 8bit */
+#define STA_R1		0x00	/* RO 8bit */
+#define STA_R2		0x01	/* RO 8bit */
+#define ADFIFO_R	0x02	/* RO 16bit */
+#define ADCLEAR_R	0x01	/* WO 8bit */
+#define CDA_R0		0x08	/* RW 8bit */
+#define CDA_R1		0x09	/* RW 8bit */
+#define CDA_R2		0x0A	/* RW 8bit */
+#define CMO_R		0x0B	/* RO 8bit */
+#define TIC_R		0x06	/* WO 8bit */
 
 static int daq700_dio_insn_bits(struct comedi_device *dev,
 				struct comedi_subdevice *s,
@@ -97,6 +121,87 @@ static int daq700_dio_insn_config(struct comedi_device *dev,
 	return insn->n;
 }
 
+static int daq700_ai_rinsn(struct comedi_device *dev,
+			   struct comedi_subdevice *s,
+			   struct comedi_insn *insn, unsigned int *data)
+{
+	int n, i, chan;
+	int d;
+	unsigned int status;
+	enum { TIMEOUT = 100 };
+
+	chan = CR_CHAN(insn->chanspec);
+	/* write channel to multiplexer */
+	/* set mask scan bit high to disable scanning */
+	outb(chan | 0x80, dev->iobase + CMD_R1);
+
+	/* convert n samples */
+	for (n = 0; n < insn->n; n++) {
+		/* trigger conversion with out0 L to H */
+		outb(0x00, dev->iobase + CMD_R2); /* enable ADC conversions */
+		outb(0x30, dev->iobase + CMO_R); /* mode 0 out0 L, from H */
+		/* mode 1 out0 H, L to H, start conversion */
+		outb(0x32, dev->iobase + CMO_R);
+		/* wait for conversion to end */
+		for (i = 0; i < TIMEOUT; i++) {
+			status = inb(dev->iobase + STA_R2);
+			if ((status & 0x03) != 0) {
+				dev_info(dev->class_dev,
+					 "Overflow/run Error\n");
+				return -EOVERFLOW;
+			}
+			status = inb(dev->iobase + STA_R1);
+			if ((status & 0x02) != 0) {
+				dev_info(dev->class_dev, "Data Error\n");
+				return -ENODATA;
+			}
+			if ((status & 0x11) == 0x01) {
+				/* ADC conversion complete */
+				break;
+			}
+			udelay(1);
+		}
+		if (i == TIMEOUT) {
+			dev_info(dev->class_dev,
+				 "timeout during ADC conversion\n");
+			return -ETIMEDOUT;
+		}
+		/* read data */
+		d = inw(dev->iobase + ADFIFO_R);
+		/* mangle the data as necessary */
+		/* Bipolar Offset Binary: 0 to 4095 for -10 to +10 */
+		d &= 0x0fff;
+		d ^= 0x0800;
+		data[n] = d;
+	}
+	return n;
+}
+
+/*
+ * Data acquisition is enabled.
+ * The counter 0 output is high.
+ * The I/O connector pin CLK1 drives counter 1 source.
+ * Multiple-channel scanning is disabled.
+ * All interrupts are disabled.
+ * The analog input range is set to +-10 V
+ * The analog input mode is single-ended.
+ * The analog input circuitry is initialized to channel 0.
+ * The A/D FIFO is cleared.
+ */
+static void daq700_ai_config(struct comedi_device *dev,
+			     struct comedi_subdevice *s)
+{			
+	unsigned long iobase = dev->iobase;
+
+	outb(0x80, iobase + CMD_R1);	/* disable scanning, ADC to chan 0 */
+	outb(0x00, iobase + CMD_R2);	/* clear all bits */
+	outb(0x00, iobase + CMD_R3);	/* set +-10 range */
+	outb(0x32, iobase + CMO_R);	/* config counter mode1, out0 to H */
+	outb(0x00, iobase + TIC_R);	/* clear counter interrupt */
+	outb(0x00, iobase + ADCLEAR_R);	/* clear the ADC FIFO */
+	inw(iobase + ADFIFO_R);		/* read 16bit junk from FIFO to clear */
+}
+
 static int daq700_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
 	const struct daq700_board *thisboard = comedi_board(dev);
@@ -116,7 +221,7 @@ static int daq700_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 
 	dev->board_name = thisboard->name;
 
-	ret = comedi_alloc_subdevices(dev, 1);
+	ret = comedi_alloc_subdevices(dev, 2);
 	if (ret)
 		return ret;
 
@@ -129,10 +234,20 @@ static int daq700_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	s->maxdata	= 1;
 	s->insn_bits	= daq700_dio_insn_bits;
 	s->insn_config	= daq700_dio_insn_config;
-
 	s->state	= 0;
 	s->io_bits	= 0x00ff;
 
+	/* DAQCard-700 ai */
+	s = &dev->subdevices[1];
+	s->type = COMEDI_SUBD_AI;
+	/* we support single-ended (ground)  */
+	s->subdev_flags = SDF_READABLE | SDF_GROUND;
+	s->n_chan = 16;
+	s->maxdata = (1 << 12) - 1;
+	s->range_table = &range_bipolar10;
+	s->insn_read = daq700_ai_rinsn;
+	daq700_ai_config(dev, s);
+
 	dev_info(dev->class_dev, "%s: %s, io 0x%lx\n",
 		dev->driver->driver_name,
 		dev->board_name,
@@ -246,5 +361,6 @@ module_exit(daq700_cs_exit);
 
 MODULE_AUTHOR("Fred Brooks <nsaspook@nsaspook.com>");
 MODULE_DESCRIPTION(
-	"Comedi driver for National Instruments PCMCIA DAQCard-700 DIO");
+	"Comedi driver for National Instruments PCMCIA DAQCard-700 DIO/AI");
+MODULE_VERSION("0.2.00");
 MODULE_LICENSE("GPL");