Staging: comedi: add 8255 driver

/*

    comedi/drivers/8255.c

    Driver for 8255

    COMEDI - Linux Control and Measurement Device Interface

    Copyright (C) 1998 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: 8255

Description: generic 8255 support

Devices: [standard] 8255 (8255)

Author: ds

Status: works

Updated: Fri,  7 Jun 2002 12:56:45 -0700

The classic in digital I/O.  The 8255 appears in Comedi as a single

digital I/O subdevice with 24 channels.  The channel 0 corresponds

to the 8255's port A, bit 0; channel 23 corresponds to port C, bit

7.  Direction configuration is done in blocks, with channels 0-7,

8-15, 16-19, and 20-23 making up the 4 blocks.  The only 8255 mode

supported is mode 0.

You should enable compilation this driver if you plan to use a board

that has an 8255 chip.  For multifunction boards, the main driver will

configure the 8255 subdevice automatically.

This driver also works independently with ISA and PCI cards that

directly map the 8255 registers to I/O ports, including cards with

multiple 8255 chips.  To configure the driver for such a card, the

option list should be a list of the I/O port bases for each of the

8255 chips.  For example,

  comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c

Note that most PCI 8255 boards do NOT work with this driver, and

need a separate driver as a wrapper.  For those that do work, the

I/O port base address can be found in the output of 'lspci -v'.

*/

/*

   This file contains an exported subdevice for driving an 8255.

   To use this subdevice as part of another driver, you need to

   set up the subdevice in the attach function of the driver by

   calling:

     subdev_8255_init(device, subdevice, callback_function, arg)

   device and subdevice are pointers to the device and subdevice

   structures.  callback_function will be called to provide the

   low-level input/output to the device, i.e., actual register

   access.  callback_function will be called with the value of arg

   as the last parameter.  If the 8255 device is mapped as 4

   consecutive I/O ports, you can use NULL for callback_function

   and the I/O port base for arg, and an internal function will

   handle the register access.

   In addition, if the main driver handles interrupts, you can

   enable commands on the subdevice by calling subdev_8255_init_irq()

   instead.  Then, when you get an interrupt that is likely to be

   from the 8255, you should call subdev_8255_interrupt(), which

   will copy the latched value to a Comedi buffer.

 */

#include "../comedidev.h"

#include <linux/ioport.h>

#define _8255_SIZE 4

#define _8255_DATA 0

#define _8255_CR 3

#define CR_C_LO_IO	0x01

#define CR_B_IO		0x02

#define CR_B_MODE	0x04

#define CR_C_HI_IO	0x08

#define CR_A_IO		0x10

#define CR_A_MODE(a)	((a)<<5)

#define CR_CW		0x80

struct subdev_8255_struct {

	unsigned long cb_arg;

	int (*cb_func) (int, int, int, unsigned long);

	int have_irq;

};

#define CALLBACK_ARG	(((struct subdev_8255_struct *)s->private)->cb_arg)

#define CALLBACK_FUNC	(((struct subdev_8255_struct *)s->private)->cb_func)

#define subdevpriv	((struct subdev_8255_struct *)s->private)

static int dev_8255_attach(comedi_device * dev, comedi_devconfig * it);

static int dev_8255_detach(comedi_device * dev);

static comedi_driver driver_8255 = {

      driver_name:"8255",

      module:THIS_MODULE,

      attach:dev_8255_attach,

      detach:dev_8255_detach,

};

COMEDI_INITCLEANUP(driver_8255);

static void do_config(comedi_device * dev, comedi_subdevice * s);

void subdev_8255_interrupt(comedi_device * dev, comedi_subdevice * s)

{

	sampl_t d;

	d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);

	d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);

	comedi_buf_put(s->async, d);

	s->async->events |= COMEDI_CB_EOS;

	comedi_event(dev, s);

}

static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)

{

	unsigned long iobase = arg;

	if (dir) {

		outb(data, iobase + port);

		return 0;

	} else {

		return inb(iobase + port);

	}

}

static int subdev_8255_insn(comedi_device * dev, comedi_subdevice * s,

	comedi_insn * insn, lsampl_t * data)

{

	if (data[0]) {

		s->state &= ~data[0];

		s->state |= (data[0] & data[1]);

		if (data[0] & 0xff)

			CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,

				CALLBACK_ARG);

		if (data[0] & 0xff00)

			CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,

				CALLBACK_ARG);

		if (data[0] & 0xff0000)

			CALLBACK_FUNC(1, _8255_DATA + 2,

				(s->state >> 16) & 0xff, CALLBACK_ARG);

	}

	data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);

	data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);

	data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16);

	return 2;

}

static int subdev_8255_insn_config(comedi_device * dev, comedi_subdevice * s,

	comedi_insn * insn, lsampl_t * data)

{

	unsigned int mask;

	unsigned int bits;

	mask = 1 << CR_CHAN(insn->chanspec);

	if (mask & 0x0000ff) {

		bits = 0x0000ff;

	} else if (mask & 0x00ff00) {

		bits = 0x00ff00;

	} else if (mask & 0x0f0000) {

		bits = 0x0f0000;

	} else {

		bits = 0xf00000;

	}

	switch (data[0]) {

	case INSN_CONFIG_DIO_INPUT:

		s->io_bits &= ~bits;

		break;

	case INSN_CONFIG_DIO_OUTPUT:

		s->io_bits |= bits;

		break;

	case INSN_CONFIG_DIO_QUERY:

		data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;

		return insn->n;

		break;

	default:

		return -EINVAL;

	}

	do_config(dev, s);

	return 1;

}

static void do_config(comedi_device * dev, comedi_subdevice * s)

{

	int config;

	config = CR_CW;

	/* 1 in io_bits indicates output, 1 in config indicates input */

	if (!(s->io_bits & 0x0000ff))

		config |= CR_A_IO;

	if (!(s->io_bits & 0x00ff00))

		config |= CR_B_IO;

	if (!(s->io_bits & 0x0f0000))

		config |= CR_C_LO_IO;

	if (!(s->io_bits & 0xf00000))

		config |= CR_C_HI_IO;

	CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG);

}

static int subdev_8255_cmdtest(comedi_device * dev, comedi_subdevice * s,

	comedi_cmd * cmd)

{

	int err = 0;

	unsigned int tmp;

	/* step 1 */

	tmp = cmd->start_src;

	cmd->start_src &= TRIG_NOW;

	if (!cmd->start_src || tmp != cmd->start_src)

		err++;

	tmp = cmd->scan_begin_src;

	cmd->scan_begin_src &= TRIG_EXT;

	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)

		err++;

	tmp = cmd->convert_src;

	cmd->convert_src &= TRIG_FOLLOW;

	if (!cmd->convert_src || tmp != cmd->convert_src)

		err++;

	tmp = cmd->scan_end_src;

	cmd->scan_end_src &= TRIG_COUNT;

	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)

		err++;

	tmp = cmd->stop_src;

	cmd->stop_src &= TRIG_NONE;

	if (!cmd->stop_src || tmp != cmd->stop_src)

		err++;

	if (err)

		return 1;

	/* step 2 */

	if (err)

		return 2;

	/* step 3 */

	if (cmd->start_arg != 0) {

		cmd->start_arg = 0;

		err++;

	}

	if (cmd->scan_begin_arg != 0) {

		cmd->scan_begin_arg = 0;

		err++;

	}

	if (cmd->convert_arg != 0) {

		cmd->convert_arg = 0;

		err++;

	}

	if (cmd->scan_end_arg != 1) {

		cmd->scan_end_arg = 1;

		err++;

	}

	if (cmd->stop_arg != 0) {

		cmd->stop_arg = 0;

		err++;

	}

	if (err)

		return 3;

	/* step 4 */

	if (err)

		return 4;

	return 0;

}

static int subdev_8255_cmd(comedi_device * dev, comedi_subdevice * s)

{

	/* FIXME */

	return 0;

}

static int subdev_8255_cancel(comedi_device * dev, comedi_subdevice * s)

{

	/* FIXME */

	return 0;

}

int subdev_8255_init(comedi_device * dev, comedi_subdevice * s, int (*cb) (int,

		int, int, unsigned long), unsigned long arg)

{

	s->type = COMEDI_SUBD_DIO;

	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;

	s->n_chan = 24;

	s->range_table = &range_digital;

	s->maxdata = 1;

	s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);

	if (!s->private)

		return -ENOMEM;

	CALLBACK_ARG = arg;

	if (cb == NULL) {

		CALLBACK_FUNC = subdev_8255_cb;

	} else {

		CALLBACK_FUNC = cb;

	}

	s->insn_bits = subdev_8255_insn;

	s->insn_config = subdev_8255_insn_config;

	s->state = 0;

	s->io_bits = 0;

	do_config(dev, s);

	return 0;

}

int subdev_8255_init_irq(comedi_device * dev, comedi_subdevice * s,

	int (*cb) (int, int, int, unsigned long), unsigned long arg)

{

	int ret;

	ret = subdev_8255_init(dev, s, cb, arg);

	if (ret < 0)

		return ret;

	s->do_cmdtest = subdev_8255_cmdtest;

	s->do_cmd = subdev_8255_cmd;

	s->cancel = subdev_8255_cancel;

	subdevpriv->have_irq = 1;

	return 0;

}

void subdev_8255_cleanup(comedi_device * dev, comedi_subdevice * s)

{

	if (s->private) {

		if (subdevpriv->have_irq) {

		}

		kfree(s->private);

	}

}

/*

   Start of the 8255 standalone device

 */

static int dev_8255_attach(comedi_device * dev, comedi_devconfig * it)

{

	int ret;

	unsigned long iobase;

	int i;

	printk("comedi%d: 8255:", dev->minor);

	dev->board_name = "8255";

	for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {

		iobase = it->options[i];

		if (!iobase)

			break;

	}

	if (i == 0) {

		printk(" no devices specified\n");

		return -EINVAL;

	}

	if ((ret = alloc_subdevices(dev, i)) < 0)

		return ret;

	for (i = 0; i < dev->n_subdevices; i++) {

		iobase = it->options[i];

		printk(" 0x%04lx", iobase);

		if (!request_region(iobase, _8255_SIZE, "8255")) {

			printk(" (I/O port conflict)");

			dev->subdevices[i].type = COMEDI_SUBD_UNUSED;

		} else {

			subdev_8255_init(dev, dev->subdevices + i, NULL,

				iobase);

		}

	}

	printk("\n");

	return 0;

}

static int dev_8255_detach(comedi_device * dev)

{

	int i;

	unsigned long iobase;

	comedi_subdevice *s;

	printk("comedi%d: 8255: remove\n", dev->minor);

	for (i = 0; i < dev->n_subdevices; i++) {

		s = dev->subdevices + i;

		if (s->type != COMEDI_SUBD_UNUSED) {

			iobase = CALLBACK_ARG;

			release_region(iobase, _8255_SIZE);

		}

		subdev_8255_cleanup(dev, s);

	}

	return 0;

}

EXPORT_SYMBOL(subdev_8255_init);

EXPORT_SYMBOL(subdev_8255_init_irq);

EXPORT_SYMBOL(subdev_8255_cleanup);

EXPORT_SYMBOL(subdev_8255_interrupt);

/*

    module/8255.h

    Header file for 8255

    COMEDI - Linux Control and Measurement Device Interface

    Copyright (C) 1998 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.

*/

#ifndef _8255_H

#define _8255_H

#include "../comedidev.h"

#if defined(CONFIG_COMEDI_8255) || defined(CONFIG_COMEDI_8255_MODULE)

int subdev_8255_init(comedi_device * dev, comedi_subdevice * s,

	int (*cb) (int, int, int, unsigned long), unsigned long arg);

int subdev_8255_init_irq(comedi_device * dev, comedi_subdevice * s,

	int (*cb) (int, int, int, unsigned long), unsigned long arg);

void subdev_8255_cleanup(comedi_device * dev, comedi_subdevice * s);

void subdev_8255_interrupt(comedi_device * dev, comedi_subdevice * s);

#else

static inline int subdev_8255_init(comedi_device * dev, comedi_subdevice * s,

	void *x, unsigned long y)

{

	printk("8255 support not configured -- disabling subdevice\n");

	s->type = COMEDI_SUBD_UNUSED;

	return 0;

}

static inline void subdev_8255_cleanup(comedi_device * dev,

	comedi_subdevice * s)

{

}

#endif

#endif