Staging: comedi: add cb_pcimdda driver

Driver for Measurement Computing PCIM-DDA06-16

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

drivers/staging/comedi/drivers/cb_pcimdda.c

+/*
+    comedi/drivers/cb_pcimdda.c
+    Computer Boards PCIM-DDA06-16 Comedi driver
+    Author: Calin Culianu <calin@ajvar.org>
+
+    COMEDI - Linux Control and Measurement Device Interface
+    Copyright (C) 2000 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: cb_pcimdda
+Description: Measurement Computing PCIM-DDA06-16
+Devices: [Measurement Computing] PCIM-DDA06-16 (cb_pcimdda)
+Author: Calin Culianu <calin@ajvar.org>
+Updated: Mon, 14 Apr 2008 15:15:51 +0100
+Status: works
+
+All features of the PCIM-DDA06-16 board are supported.  This board
+has 6 16-bit AO channels, and the usual 8255 DIO setup.  (24 channels,
+configurable in banks of 8 and 4, etc.).  This board does not support commands.
+
+The board has a peculiar way of specifying AO gain/range settings -- You have
+1 jumper bank on the card, which either makes all 6 AO channels either
+5 Volt unipolar, 5V bipolar, 10 Volt unipolar or 10V bipolar.
+
+Since there is absolutely _no_ way to tell in software how this jumper is set
+(well, at least according  to the rather thin spec. from Measurement Computing
+ that comes with the board), the driver assumes the jumper is at its factory
+default setting of +/-5V.
+
+Also of note is the fact that this board features another jumper, whose
+state is also completely invisible to software.  It toggles two possible AO
+output modes on the board:
+
+  - Update Mode: Writing to an AO channel instantaneously updates the actual
+    signal output by the DAC on the board (this is the factory default).
+  - Simultaneous XFER Mode: Writing to an AO channel has no effect until
+    you read from any one of the AO channels.  This is useful for loading
+    all 6 AO values, and then reading from any one of the AO channels on the
+    device to instantly update all 6 AO values in unison.  Useful for some
+    control apps, I would assume?  If your jumper is in this setting, then you
+    need to issue your comedi_data_write()s to load all the values you want,
+    then issue one comedi_data_read() on any channel on the AO subdevice
+    to initiate the simultaneous XFER.
+
+Configuration Options:
+  [0] PCI bus (optional)
+  [1] PCI slot (optional)
+  [2] analog output range jumper setting
+      0 == +/- 5 V
+      1 == +/- 10 V
+*/
+
+/*
+    This is a driver for the Computer Boards PCIM-DDA06-16 Analog Output
+    card.  This board has a unique register layout and as such probably
+    deserves its own driver file.
+
+    It is theoretically possible to integrate this board into the cb_pcidda
+    file, but since that isn't my code, I didn't want to significantly
+    modify that file to support this board (I thought it impolite to do so).
+
+    At any rate, if you feel ambitious, please feel free to take
+    the code out of this file and combine it with a more unified driver
+    file.
+
+    I would like to thank Timothy Curry <Timothy.Curry@rdec.redstone.army.mil>
+    for lending me a board so that I could write this driver.
+
+    -Calin Culianu <calin@ajvar.org>
+ */
+
+#include "../comedidev.h"
+
+#include "comedi_pci.h"
+
+#include "8255.h"
+
+/* device ids of the cards we support -- currently only 1 card supported */
+#define PCI_ID_PCIM_DDA06_16 0x0053
+
+/*
+ * This is straight from skel.c -- I did this in case this source file
+ * will someday support more than 1 board...
+ */
+typedef struct board_struct {
+	const char *name;
+	unsigned short device_id;
+	int ao_chans;
+	int ao_bits;
+	int dio_chans;
+	int dio_method;
+	int dio_offset;		/* how many bytes into the BADR are the DIO ports */
+	int regs_badrindex;	/* IO Region for the control, analog output,
+				   and DIO registers */
+	int reg_sz;		/* number of bytes of registers in io region */
+} board;
+
+enum DIO_METHODS {
+	DIO_NONE = 0,
+	DIO_8255,
+	DIO_INTERNAL		/* unimplemented */
+};
+
+static const board boards[] = {
+	{
+	      name:	"cb_pcimdda06-16",
+	      device_id:PCI_ID_PCIM_DDA06_16,
+	      ao_chans:6,
+	      ao_bits:	16,
+	      dio_chans:24,
+	      dio_method:DIO_8255,
+	      dio_offset:12,
+	      regs_badrindex:3,
+	      reg_sz:	16,
+		}
+};
+
+/*
+ * Useful for shorthand access to the particular board structure
+ */
+#define thisboard    ((const board *)dev->board_ptr)
+
+/* Number of boards in boards[] */
+#define N_BOARDS	(sizeof(boards) / sizeof(board))
+#define REG_SZ (thisboard->reg_sz)
+#define REGS_BADRINDEX (thisboard->regs_badrindex)
+
+/* This is used by modprobe to translate PCI IDs to drivers.  Should
+ * only be used for PCI and ISA-PnP devices */
+/* Please add your PCI vendor ID to comedidev.h, and it will be forwarded
+ * upstream. */
+static DEFINE_PCI_DEVICE_TABLE(pci_table) = {
+	{PCI_VENDOR_ID_COMPUTERBOARDS, PCI_ID_PCIM_DDA06_16, PCI_ANY_ID,
+		PCI_ANY_ID, 0, 0, 0},
+	{0}
+};
+
+MODULE_DEVICE_TABLE(pci, pci_table);
+
+/* this structure is for data unique to this hardware driver.  If
+   several hardware drivers keep similar information in this structure,
+   feel free to suggest moving the variable to the comedi_device struct.  */
+typedef struct {
+	unsigned long registers;	/* set by probe */
+	unsigned long dio_registers;
+	char attached_to_8255;	/* boolean */
+	char attached_successfully;	/* boolean */
+	/* would be useful for a PCI device */
+	struct pci_dev *pci_dev;
+
+#define MAX_AO_READBACK_CHANNELS 6
+	/* Used for AO readback */
+	lsampl_t ao_readback[MAX_AO_READBACK_CHANNELS];
+
+} private;
+
+/*
+ * most drivers define the following macro to make it easy to
+ * access the private structure.
+ */
+#define devpriv ((private *)dev->private)
+
+/*
+ * The comedi_driver structure tells the Comedi core module
+ * which functions to call to configure/deconfigure (attach/detach)
+ * the board, and also about the kernel module that contains
+ * the device code.
+ */
+static int attach(comedi_device * dev, comedi_devconfig * it);
+static int detach(comedi_device * dev);
+static comedi_driver cb_pcimdda_driver = {
+      driver_name:"cb_pcimdda",
+      module:THIS_MODULE,
+      attach:attach,
+      detach:detach,
+};
+
+MODULE_AUTHOR("Calin A. Culianu <calin@rtlab.org>");
+MODULE_DESCRIPTION("Comedi low-level driver for the Computerboards PCIM-DDA "
+	"series.  Currently only supports PCIM-DDA06-16 (which "
+	"also happens to be the only board in this series. :) ) ");
+MODULE_LICENSE("GPL");
+COMEDI_PCI_INITCLEANUP_NOMODULE(cb_pcimdda_driver, pci_table);
+
+static int ao_winsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+static int ao_rinsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data);
+
+/*---------------------------------------------------------------------------
+  HELPER FUNCTION DECLARATIONS
+-----------------------------------------------------------------------------*/
+
+/* returns a maxdata value for a given n_bits */
+static inline lsampl_t figure_out_maxdata(int bits)
+{
+	return (((lsampl_t) 1 << bits) - 1);
+}
+
+/*
+ *  Probes for a supported device.
+ *
+ *  Prerequisite: private be allocated already inside dev
+ *
+ *  If the device is found, it returns 0 and has the following side effects:
+ *
+ *  o  assigns a struct pci_dev * to dev->private->pci_dev
+ *  o  assigns a struct board * to dev->board_ptr
+ *  o  sets dev->private->registers
+ *  o  sets dev->private->dio_registers
+ *
+ *  Otherwise, returns a -errno on error
+ */
+static int probe(comedi_device * dev, const comedi_devconfig * it);
+
+/*---------------------------------------------------------------------------
+  FUNCTION DEFINITIONS
+-----------------------------------------------------------------------------*/
+
+/*
+ * Attach is called by the Comedi core to configure the driver
+ * for a particular board.  If you specified a board_name array
+ * in the driver structure, dev->board_ptr contains that
+ * address.
+ */
+static int attach(comedi_device * dev, comedi_devconfig * it)
+{
+	comedi_subdevice *s;
+	int err;
+
+/*
+ * Allocate the private structure area.  alloc_private() is a
+ * convenient macro defined in comedidev.h.
+ * if this function fails (returns negative) then the private area is
+ * kfree'd by comedi
+ */
+	if (alloc_private(dev, sizeof(private)) < 0)
+		return -ENOMEM;
+
+/*
+ * If you can probe the device to determine what device in a series
+ * it is, this is the place to do it.  Otherwise, dev->board_ptr
+ * should already be initialized.
+ */
+	if ((err = probe(dev, it)))
+		return err;
+
+/* Output some info */
+	printk("comedi%d: %s: ", dev->minor, thisboard->name);
+
+/*
+ * Initialize dev->board_name.  Note that we can use the "thisboard"
+ * macro now, since we just initialized it in the last line.
+ */
+	dev->board_name = thisboard->name;
+
+/*
+ * Allocate the subdevice structures.  alloc_subdevice() is a
+ * convenient macro defined in comedidev.h.
+ */
+	if (alloc_subdevices(dev, 2) < 0)
+		return -ENOMEM;
+
+	s = dev->subdevices + 0;
+
+	/* analog output subdevice */
+	s->type = COMEDI_SUBD_AO;
+	s->subdev_flags = SDF_WRITABLE | SDF_READABLE;
+	s->n_chan = thisboard->ao_chans;
+	s->maxdata = figure_out_maxdata(thisboard->ao_bits);
+	/* this is hard-coded here */
+	if (it->options[2]) {
+		s->range_table = &range_bipolar10;
+	} else {
+		s->range_table = &range_bipolar5;
+	}
+	s->insn_write = &ao_winsn;
+	s->insn_read = &ao_rinsn;
+
+	s = dev->subdevices + 1;
+	/* digital i/o subdevice */
+	if (thisboard->dio_chans) {
+		switch (thisboard->dio_method) {
+		case DIO_8255:
+			/* this is a straight 8255, so register us with the 8255 driver */
+			subdev_8255_init(dev, s, NULL, devpriv->dio_registers);
+			devpriv->attached_to_8255 = 1;
+			break;
+		case DIO_INTERNAL:
+		default:
+			printk("DIO_INTERNAL not implemented yet!\n");
+			return -ENXIO;
+			break;
+		}
+	} else {
+		s->type = COMEDI_SUBD_UNUSED;
+	}
+
+	devpriv->attached_successfully = 1;
+
+	printk("attached\n");
+
+	return 1;
+}
+
+/*
+ * _detach is called to deconfigure a device.  It should deallocate
+ * resources.
+ * This function is also called when _attach() fails, so it should be
+ * careful not to release resources that were not necessarily
+ * allocated by _attach().  dev->private and dev->subdevices are
+ * deallocated automatically by the core.
+ */
+static int detach(comedi_device * dev)
+{
+	if (devpriv) {
+
+		if (dev->subdevices && devpriv->attached_to_8255) {
+			/* de-register us from the 8255 driver */
+			subdev_8255_cleanup(dev, dev->subdevices + 2);
+			devpriv->attached_to_8255 = 0;
+		}
+
+		if (devpriv->pci_dev) {
+			if (devpriv->registers) {
+				comedi_pci_disable(devpriv->pci_dev);
+			}
+			pci_dev_put(devpriv->pci_dev);
+		}
+
+		if (devpriv->attached_successfully && thisboard)
+			printk("comedi%d: %s: detached\n", dev->minor,
+				thisboard->name);
+
+	}
+
+	return 0;
+}
+
+static int ao_winsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int i;
+	int chan = CR_CHAN(insn->chanspec);
+	unsigned long offset = devpriv->registers + chan * 2;
+
+	/* Writing a list of values to an AO channel is probably not
+	 * very useful, but that's how the interface is defined. */
+	for (i = 0; i < insn->n; i++) {
+		/*  first, load the low byte */
+		outb((char)(data[i] & 0x00ff), offset);
+		/*  next, write the high byte -- only after this is written is
+		   the channel voltage updated in the DAC, unless
+		   we're in simultaneous xfer mode (jumper on card)
+		   then a rinsn is necessary to actually update the DAC --
+		   see ao_rinsn() below... */
+		outb((char)(data[i] >> 8 & 0x00ff), offset + 1);
+
+		/* for testing only.. the actual rinsn SHOULD do an inw!
+		   (see the stuff about simultaneous XFER mode on this board) */
+		devpriv->ao_readback[chan] = data[i];
+	}
+
+	/* return the number of samples read/written */
+	return i;
+}
+
+/* AO subdevices should have a read insn as well as a write insn.
+
+   Usually this means copying a value stored in devpriv->ao_readback.
+   However, since this board has this jumper setting called "Simultaneous
+   Xfer mode" (off by default), we will support it.  Simultaneaous xfer
+   mode is accomplished by loading ALL the values you want for AO in all the
+   channels, then READing off one of the AO registers to initiate the
+   instantaneous simultaneous update of all DAC outputs, which makes
+   all AO channels update simultaneously.  This is useful for some control
+   applications, I would imagine.
+*/
+static int ao_rinsn(comedi_device * dev, comedi_subdevice * s,
+	comedi_insn * insn, lsampl_t * data)
+{
+	int i;
+	int chan = CR_CHAN(insn->chanspec);
+
+	for (i = 0; i < insn->n; i++) {
+		inw(devpriv->registers + chan * 2);
+		/* should I set data[i] to the result of the actual read on the register
+		   or the cached lsampl_t in devpriv->ao_readback[]? */
+		data[i] = devpriv->ao_readback[chan];
+	}
+
+	return i;
+}
+
+/*---------------------------------------------------------------------------
+  HELPER FUNCTION DEFINITIONS
+-----------------------------------------------------------------------------*/
+
+/*
+ *  Probes for a supported device.
+ *
+ *  Prerequisite: private be allocated already inside dev
+ *
+ *  If the device is found, it returns 0 and has the following side effects:
+ *
+ *  o  assigns a struct pci_dev * to dev->private->pci_dev
+ *  o  assigns a struct board * to dev->board_ptr
+ *  o  sets dev->private->registers
+ *  o  sets dev->private->dio_registers
+ *
+ *  Otherwise, returns a -errno on error
+ */
+static int probe(comedi_device * dev, const comedi_devconfig * it)
+{
+	struct pci_dev *pcidev;
+	int index;
+	unsigned long registers;
+
+	for (pcidev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
+		pcidev != NULL;
+		pcidev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, pcidev)) {
+		// is it not a computer boards card?
+		if (pcidev->vendor != PCI_VENDOR_ID_COMPUTERBOARDS)
+			continue;
+		// loop through cards supported by this driver
+		for (index = 0; index < N_BOARDS; index++) {
+			if (boards[index].device_id != pcidev->device)
+				continue;
+			// was a particular bus/slot requested?
+			if (it->options[0] || it->options[1]) {
+				// are we on the wrong bus/slot?
+				if (pcidev->bus->number != it->options[0] ||
+					PCI_SLOT(pcidev->devfn) !=
+					it->options[1]) {
+					continue;
+				}
+			}
+			/* found ! */
+
+			devpriv->pci_dev = pcidev;
+			dev->board_ptr = boards + index;
+			if (comedi_pci_enable(pcidev, thisboard->name)) {
+				printk("cb_pcimdda: Failed to enable PCI device and request regions\n");
+				return -EIO;
+			}
+			registers =
+				pci_resource_start(devpriv->pci_dev,
+				REGS_BADRINDEX);
+			devpriv->registers = registers;
+			devpriv->dio_registers
+				= devpriv->registers + thisboard->dio_offset;
+			return 0;
+		}
+	}
+
+	printk("cb_pcimdda: No supported ComputerBoards/MeasurementComputing "
+		"card found at the requested position\n");
+	return -ENODEV;
+}