/*
 * adv_pci1724.c
 * Comedi 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.
 */

/*
 * Driver: adv_pci1724
 * Description: Advantech PCI-1724U
 * Devices: [Advantech] PCI-1724U (adv_pci1724)
 * Author: Frank Mori Hess <fmh6jj@gmail.com>
 * Updated: 2013-02-09
 * Status: works
 *
 * Configuration Options: not applicable, uses comedi PCI auto config
 *
 * 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.
 */

#include <linux/module.h>

#include "../comedi_pci.h"

/*
 * PCI bar 2 Register I/O map (dev->iobase)
 */
#define PCI1724_DAC_CTRL_REG		0x00
#define PCI1724_DAC_CTRL_GX(x)		BIT(20 + ((x) / 8))
#define PCI1724_DAC_CTRL_CX(x)		(((x) % 8) << 16)
#define PCI1724_DAC_CTRL_MODE(x)	(((x) & 0x3) << 14)
#define PCI1724_DAC_CTRL_MODE_GAIN	PCI1724_DAC_CTRL_MODE(1)
#define PCI1724_DAC_CTRL_MODE_OFFSET	PCI1724_DAC_CTRL_MODE(2)
#define PCI1724_DAC_CTRL_MODE_NORMAL	PCI1724_DAC_CTRL_MODE(3)
#define PCI1724_DAC_CTRL_MODE_MASK	PCI1724_DAC_CTRL_MODE(3)
#define PCI1724_DAC_CTRL_DATA(x)	(((x) & 0x3fff) << 0)
#define PCI1724_SYNC_CTRL_REG		0x04
#define PCI1724_SYNC_CTRL_DACSTAT	BIT(1)
#define PCI1724_SYNC_CTRL_SYN		BIT(0)
#define PCI1724_EEPROM_CTRL_REG		0x08
#define PCI1724_SYNC_TRIG_REG		0x0c  /* any value works */
#define PCI1724_BOARD_ID_REG		0x10
#define PCI1724_BOARD_ID_MASK		(0xf << 0)

static const struct comedi_lrange adv_pci1724_ao_ranges = {
	4, {
		BIP_RANGE(10),
		RANGE_mA(0, 20),
		RANGE_mA(4, 20),
		RANGE_unitless(0, 1)
	}
};

static int adv_pci1724_dac_idle(struct comedi_device *dev,
				struct comedi_subdevice *s,
				struct comedi_insn *insn,
				unsigned long context)
{
	unsigned int status;

	status = inl(dev->iobase + PCI1724_SYNC_CTRL_REG);
	if ((status & PCI1724_SYNC_CTRL_DACSTAT) == 0)
		return 0;
	return -EBUSY;
}

static int adv_pci1724_insn_write(struct comedi_device *dev,
				  struct comedi_subdevice *s,
				  struct comedi_insn *insn,
				  unsigned int *data)
{
	unsigned long mode = (unsigned long)s->private;
	unsigned int chan = CR_CHAN(insn->chanspec);
	unsigned int ctrl;
	int ret;
	int i;

	ctrl = PCI1724_DAC_CTRL_GX(chan) | PCI1724_DAC_CTRL_CX(chan) | mode;

	/* turn off synchronous mode */
	outl(0, dev->iobase + PCI1724_SYNC_CTRL_REG);

	for (i = 0; i < insn->n; ++i) {
		unsigned int val = data[i];

		ret = comedi_timeout(dev, s, insn, adv_pci1724_dac_idle, 0);
		if (ret)
			return ret;

		outl(ctrl | PCI1724_DAC_CTRL_DATA(val),
		     dev->iobase + PCI1724_DAC_CTRL_REG);

		s->readback[chan] = val;
	}

	return insn->n;
}

static int adv_pci1724_auto_attach(struct comedi_device *dev,
				   unsigned long context_unused)
{
	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
	struct comedi_subdevice *s;
	unsigned int board_id;
	int ret;

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

	dev->iobase = pci_resource_start(pcidev, 2);
	board_id = inl(dev->iobase + PCI1724_BOARD_ID_REG);
	dev_info(dev->class_dev, "board id: %d\n",
		 board_id & PCI1724_BOARD_ID_MASK);

	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	= 32;
	s->maxdata	= 0x3fff;
	s->range_table	= &adv_pci1724_ao_ranges;
	s->insn_write	= adv_pci1724_insn_write;
	s->private	= (void *)PCI1724_DAC_CTRL_MODE_NORMAL;

	ret = comedi_alloc_subdev_readback(s);
	if (ret)
		return ret;

	/* Offset Calibration subdevice */
	s = &dev->subdevices[1];
	s->type		= COMEDI_SUBD_CALIB;
	s->subdev_flags	= SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
	s->n_chan	= 32;
	s->maxdata	= 0x3fff;
	s->insn_write	= adv_pci1724_insn_write;
	s->private	= (void *)PCI1724_DAC_CTRL_MODE_OFFSET;

	ret = comedi_alloc_subdev_readback(s);
	if (ret)
		return ret;

	/* Gain Calibration subdevice */
	s = &dev->subdevices[2];
	s->type		= COMEDI_SUBD_CALIB;
	s->subdev_flags	= SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;
	s->n_chan	= 32;
	s->maxdata	= 0x3fff;
	s->insn_write	= adv_pci1724_insn_write;
	s->private	= (void *)PCI1724_DAC_CTRL_MODE_GAIN;

	return comedi_alloc_subdev_readback(s);
}

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

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 const struct pci_device_id 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");