/*
    comedi/drivers/adv_pci1724.c
    This is a driver for the Advantech PCI-1724U card.

    Author:  Frank Mori Hess <fmh6jj@gmail.com>
    Copyright (C) 2013 GnuBIO Inc

    COMEDI - Linux Control and Measurement Device Interface
    Copyright (C) 1997-8 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: adv_1724
Description: Advantech PCI-1724U
Author: Frank Mori Hess <fmh6jj@gmail.com>
Status: works
Updated: 2013-02-09
Devices: [Advantech] PCI-1724U (adv_pci1724)

Subdevice 0 is the analog output.
Subdevice 1 is the offset calibration for the analog output.
Subdevice 2 is the gain calibration for the analog output.

The calibration offset and gains have quite a large effect
on the analog output, so it is possible to adjust the analog output to
have an output range significantly different from the board's
nominal output ranges.  For a calibrated +/- 10V range, the analog
output's offset will be set somewhere near mid-range (0x2000) and its
gain will be near maximum (0x3fff).

There is really no difference between the board's documented 0-20mA
versus 4-20mA output ranges.  To pick one or the other is simply a matter
of adjusting the offset and gain calibration until the board outputs in
the desired range.

Configuration options:
   None

Manual configuration of comedi devices is not supported by this driver;
supported PCI devices are configured as comedi devices automatically.

*/

#include <linux/pci.h>

#include "../comedidev.h"

#define PCI_VENDOR_ID_ADVANTECH	0x13fe

#define NUM_AO_CHANNELS 32

/* register offsets */
enum board_registers {
	DAC_CONTROL_REG = 0x0,
	SYNC_OUTPUT_REG = 0x4,
	EEPROM_CONTROL_REG = 0x8,
	SYNC_OUTPUT_TRIGGER_REG = 0xc,
	BOARD_ID_REG = 0x10
};

/* bit definitions for registers */
enum dac_control_contents {
	DAC_DATA_MASK = 0x3fff,
	DAC_DESTINATION_MASK = 0xc000,
	DAC_NORMAL_MODE = 0xc000,
	DAC_OFFSET_MODE = 0x8000,
	DAC_GAIN_MODE = 0x4000,
	DAC_CHANNEL_SELECT_MASK = 0xf0000,
	DAC_GROUP_SELECT_MASK = 0xf00000
};

static uint32_t dac_data_bits(uint16_t dac_data)
{
	return dac_data & DAC_DATA_MASK;
}

static uint32_t dac_channel_select_bits(unsigned channel)
{
	return (channel << 16) & DAC_CHANNEL_SELECT_MASK;
}

static uint32_t dac_group_select_bits(unsigned group)
{
	return (1 << (20 + group)) & DAC_GROUP_SELECT_MASK;
}

static uint32_t dac_channel_and_group_select_bits(unsigned comedi_channel)
{
	return dac_channel_select_bits(comedi_channel % 8) |
		dac_group_select_bits(comedi_channel / 8);
}

enum sync_output_contents {
	SYNC_MODE = 0x1,
	DAC_BUSY = 0x2, /* dac state machine is not ready */
};

enum sync_output_trigger_contents {
	SYNC_TRIGGER_BITS = 0x0 /* any value works */
};

enum board_id_contents {
	BOARD_ID_MASK = 0xf
};

static const struct comedi_lrange ao_ranges_1724 = { 4,
	{
		BIP_RANGE(10),
		RANGE_mA(0, 20),
		RANGE_mA(4, 20),
		RANGE_unitless(0, 1)
	}
};

static const struct comedi_lrange *const ao_range_list_1724[NUM_AO_CHANNELS] = {
	[0 ... NUM_AO_CHANNELS - 1] = &ao_ranges_1724,
};

/* this structure is for data unique to this hardware driver. */
struct adv_pci1724_private {
	int ao_value[NUM_AO_CHANNELS];
	int offset_value[NUM_AO_CHANNELS];
	int gain_value[NUM_AO_CHANNELS];
};

static int wait_for_dac_idle(struct comedi_device *dev)
{
	static const int timeout = 10000;
	int i;

	for (i = 0; i < timeout; ++i) {
		if ((inl(dev->iobase + SYNC_OUTPUT_REG) & DAC_BUSY) == 0)
			break;
		udelay(1);
	}
	if (i == timeout) {
		comedi_error(dev, "Timed out waiting for dac to become idle.");
		return -EIO;
	}
	return 0;
}

static int set_dac(struct comedi_device *dev, unsigned mode, unsigned channel,
		   unsigned data)
{
	int retval;
	unsigned control_bits;

	retval = wait_for_dac_idle(dev);
	if (retval < 0)
		return retval;

	control_bits = mode;
	control_bits |= dac_channel_and_group_select_bits(channel);
	control_bits |= dac_data_bits(data);
	outl(control_bits, dev->iobase + DAC_CONTROL_REG);
	return 0;
}

static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,
		    struct comedi_insn *insn, unsigned int *data)
{
	struct adv_pci1724_private *devpriv = dev->private;
	int channel = CR_CHAN(insn->chanspec);
	int retval;
	int i;

	/* turn off synchronous mode */
	outl(0, dev->iobase + SYNC_OUTPUT_REG);

	for (i = 0; i < insn->n; ++i) {
		retval = set_dac(dev, DAC_NORMAL_MODE, channel, data[i]);
		if (retval < 0)
			return retval;
		devpriv->ao_value[channel] = data[i];
	}
	return insn->n;
}

static int ao_readback_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data)
{
	struct adv_pci1724_private *devpriv = dev->private;
	int channel = CR_CHAN(insn->chanspec);
	int i;

	if (devpriv->ao_value[channel] < 0) {
		comedi_error(dev,
			     "Cannot read back channels which have not yet been written to.");
		return -EIO;
	}
	for (i = 0; i < insn->n; i++)
		data[i] = devpriv->ao_value[channel];

	return insn->n;
}

static int offset_write_insn(struct comedi_device *dev,
			     struct comedi_subdevice *s,
			     struct comedi_insn *insn, unsigned int *data)
{
	struct adv_pci1724_private *devpriv = dev->private;
	int channel = CR_CHAN(insn->chanspec);
	int retval;
	int i;

	/* turn off synchronous mode */
	outl(0, dev->iobase + SYNC_OUTPUT_REG);

	for (i = 0; i < insn->n; ++i) {
		retval = set_dac(dev, DAC_OFFSET_MODE, channel, data[i]);
		if (retval < 0)
			return retval;
		devpriv->offset_value[channel] = data[i];
	}

	return insn->n;
}

static int offset_read_insn(struct comedi_device *dev,
			    struct comedi_subdevice *s,
			    struct comedi_insn *insn, unsigned int *data)
{
	struct adv_pci1724_private *devpriv = dev->private;
	unsigned int channel = CR_CHAN(insn->chanspec);
	int i;

	if (devpriv->offset_value[channel] < 0) {
		comedi_error(dev,
			     "Cannot read back channels which have not yet been written to.");
		return -EIO;
	}
	for (i = 0; i < insn->n; i++)
		data[i] = devpriv->offset_value[channel];

	return insn->n;
}

static int gain_write_insn(struct comedi_device *dev,
			   struct comedi_subdevice *s,
			   struct comedi_insn *insn, unsigned int *data)
{
	struct adv_pci1724_private *devpriv = dev->private;
	int channel = CR_CHAN(insn->chanspec);
	int retval;
	int i;

	/* turn off synchronous mode */
	outl(0, dev->iobase + SYNC_OUTPUT_REG);

	for (i = 0; i < insn->n; ++i) {
		retval = set_dac(dev, DAC_GAIN_MODE, channel, data[i]);
		if (retval < 0)
			return retval;
		devpriv->gain_value[channel] = data[i];
	}

	return insn->n;
}

static int gain_read_insn(struct comedi_device *dev,
			  struct comedi_subdevice *s, struct comedi_insn *insn,
			  unsigned int *data)
{
	struct adv_pci1724_private *devpriv = dev->private;
	unsigned int channel = CR_CHAN(insn->chanspec);
	int i;

	if (devpriv->gain_value[channel] < 0) {
		comedi_error(dev,
			     "Cannot read back channels which have not yet been written to.");
		return -EIO;
	}
	for (i = 0; i < insn->n; i++)
		data[i] = devpriv->gain_value[channel];

	return insn->n;
}

/* Allocate and initialize the subdevice structures.
 */
static int setup_subdevices(struct comedi_device *dev)
{
	struct comedi_subdevice *s;
	int ret;

	ret = comedi_alloc_subdevices(dev, 3);
	if (ret)
		return ret;

	/* analog output subdevice */
	s = &dev->subdevices[0];
	s->type = COMEDI_SUBD_AO;
	s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_GROUND;
	s->n_chan = NUM_AO_CHANNELS;
	s->maxdata = 0x3fff;
	s->range_table_list = ao_range_list_1724;
	s->insn_read = ao_readback_insn;
	s->insn_write = ao_winsn;

	/* offset calibration */
	s = &dev->subdevices[1];
	s->type = COMEDI_SUBD_CALIB;
	s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
	s->n_chan = NUM_AO_CHANNELS;
	s->insn_read = offset_read_insn;
	s->insn_write = offset_write_insn;
	s->maxdata = 0x3fff;

	/* gain calibration */
	s = &dev->subdevices[2];
	s->type = COMEDI_SUBD_CALIB;
	s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
	s->n_chan = NUM_AO_CHANNELS;
	s->insn_read = gain_read_insn;
	s->insn_write = gain_write_insn;
	s->maxdata = 0x3fff;

	return 0;
}

static int adv_pci1724_auto_attach(struct comedi_device *dev,
				   unsigned long context_unused)
{
	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
	struct adv_pci1724_private *devpriv;
	int i;
	int retval;
	unsigned int board_id;

	devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL);
	if (!devpriv)
		return -ENOMEM;
	dev->private = devpriv;

	/* init software copies of output values to indicate we don't know
	 * what the output value is since it has never been written. */
	for (i = 0; i < NUM_AO_CHANNELS; ++i) {
		devpriv->ao_value[i] = -1;
		devpriv->offset_value[i] = -1;
		devpriv->gain_value[i] = -1;
	}

	retval = comedi_pci_enable(dev);
	if (retval)
		return retval;

	dev->iobase = pci_resource_start(pcidev, 2);
	board_id = inl(dev->iobase + BOARD_ID_REG) & BOARD_ID_MASK;
	dev_info(dev->class_dev, "board id: %d\n", board_id);

	retval = setup_subdevices(dev);
	if (retval < 0)
		return retval;

	dev_info(dev->class_dev, "%s (pci %s) attached, board id: %u\n",
		 dev->board_name, pci_name(pcidev), board_id);
	return 0;
}

static struct comedi_driver adv_pci1724_driver = {
	.driver_name = "adv_pci1724",
	.module = THIS_MODULE,
	.auto_attach = adv_pci1724_auto_attach,
	.detach = comedi_pci_disable,
};

static int adv_pci1724_pci_probe(struct pci_dev *dev,
				 const struct pci_device_id *id)
{
	return comedi_pci_auto_config(dev, &adv_pci1724_driver,
				      id->driver_data);
}

static DEFINE_PCI_DEVICE_TABLE(adv_pci1724_pci_table) = {
	{ PCI_DEVICE(PCI_VENDOR_ID_ADVANTECH, 0x1724) },
	{ 0 }
};
MODULE_DEVICE_TABLE(pci, adv_pci1724_pci_table);

static struct pci_driver adv_pci1724_pci_driver = {
	.name = "adv_pci1724",
	.id_table = adv_pci1724_pci_table,
	.probe = adv_pci1724_pci_probe,
	.remove = comedi_pci_auto_unconfig,
};

module_comedi_pci_driver(adv_pci1724_driver, adv_pci1724_pci_driver);

MODULE_AUTHOR("Frank Mori Hess <fmh6jj@gmail.com>");
MODULE_DESCRIPTION("Advantech PCI-1724U Comedi driver");
MODULE_LICENSE("GPL");