Staging: comedi: add pcmad driver

Hardware driver for Winsystems PCM-A/D12 and PCM-A/D16

From: David Schleef <ds@schleef.org>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/pcmad.c

@@ -0,0 +1,173 @@
+/*
+    comedi/drivers/pcmad.c
+    Hardware driver for Winsystems PCM-A/D12 and PCM-A/D16
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 2000,2001 David A. Schleef <ds@schleef.org>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+/*
+Driver: pcmad
+Description: Winsystems PCM-A/D12, PCM-A/D16
+Author: ds
+Devices: [Winsystems] PCM-A/D12 (pcmad12), PCM-A/D16 (pcmad16)
+Status: untested
+
+This driver was written on a bet that I couldn't write a driver
+in less than 2 hours.  I won the bet, but never got paid.  =(
+
+Configuration options:
+  [0] - I/O port base
+  [1] - unused
+  [2] - Analog input reference
+          0 = single ended
+          1 = differential
+  [3] - Analog input encoding (must match jumpers)
+          0 = straight binary
+          1 = two's complement
+*/
+
+#include "../comedidev.h"
+
+#include <linux/ioport.h>
+
+#define PCMAD_SIZE		4
+
+#define PCMAD_STATUS		0
+#define PCMAD_LSB		1
+#define PCMAD_MSB		2
+#define PCMAD_CONVERT		1
+
+struct pcmad_board_struct {
+	const char *name;
+	int n_ai_bits;
+};
+static const struct pcmad_board_struct pcmad_boards[] = {
+	{
+	      name:	"pcmad12",
+	      n_ai_bits:12,
+		},
+	{
+	      name:	"pcmad16",
+	      n_ai_bits:16,
+		},
+};
+
+#define this_board ((const struct pcmad_board_struct *)(dev->board_ptr))
+#define n_pcmad_boards (sizeof(pcmad_boards)/sizeof(pcmad_boards[0]))
+
+struct pcmad_priv_struct {
+	int differential;
+	int twos_comp;
+};
+#define devpriv ((struct pcmad_priv_struct *)dev->private)
+
+static int pcmad_attach(comedi_device * dev, comedi_devconfig * it);
+static int pcmad_detach(comedi_device * dev);
+static comedi_driver driver_pcmad = {
+      driver_name:"pcmad",
+      module:THIS_MODULE,
+      attach:pcmad_attach,
+      detach:pcmad_detach,
+      board_name:&pcmad_boards[0].name,
+      num_names:n_pcmad_boards,
+      offset:sizeof(pcmad_boards[0]),
+};
+
+COMEDI_INITCLEANUP(driver_pcmad);
+
+#define TIMEOUT	100
+
+static int pcmad_ai_insn_read(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int i;
+	int chan;
+	int n;
+
+	chan = CR_CHAN(insn->chanspec);
+
+	for (n = 0; n < insn->n; n++) {
+		outb(chan, dev->iobase + PCMAD_CONVERT);
+
+		for (i = 0; i < TIMEOUT; i++) {
+			if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
+				break;
+		}
+		data[n] = inb(dev->iobase + PCMAD_LSB);
+		data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
+
+		if (devpriv->twos_comp) {
+			data[n] ^= (1 << (this_board->n_ai_bits - 1));
+		}
+	}
+
+	return n;
+}
+
+/*
+ * options:
+ * 0	i/o base
+ * 1	unused
+ * 2	0=single ended 1=differential
+ * 3	0=straight binary 1=two's comp
+ */
+static int pcmad_attach(comedi_device * dev, comedi_devconfig * it)
+{
+	int ret;
+	comedi_subdevice *s;
+	unsigned long iobase;
+
+	iobase = it->options[0];
+	printk("comedi%d: pcmad: 0x%04lx ", dev->minor, iobase);
+	if (!request_region(iobase, PCMAD_SIZE, "pcmad")) {
+		printk("I/O port conflict\n");
+		return -EIO;
+	}
+	dev->iobase = iobase;
+
+	if ((ret = alloc_subdevices(dev, 1)) < 0)
+		return ret;
+	if ((ret = alloc_private(dev, sizeof(struct pcmad_priv_struct))) < 0)
+		return ret;
+
+	dev->board_name = this_board->name;
+
+	s = dev->subdevices + 0;
+	s->type = COMEDI_SUBD_AI;
+	s->subdev_flags = SDF_READABLE | AREF_GROUND;
+	s->n_chan = 16;		/* XXX */
+	s->len_chanlist = 1;
+	s->insn_read = pcmad_ai_insn_read;
+	s->maxdata = (1 << this_board->n_ai_bits) - 1;
+	s->range_table = &range_unknown;
+
+	return 0;
+}
+
+static int pcmad_detach(comedi_device * dev)
+{
+	printk("comedi%d: pcmad: remove\n", dev->minor);
+
+	if (dev->irq) {
+		free_irq(dev->irq, dev);
+	}
+	if (dev->iobase)
+		release_region(dev->iobase, PCMAD_SIZE);
+
+	return 0;
+}