Staging: comedi: add 8255 driver

The classic in digital I/O.

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/8255.c

+/*
+    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);

drivers/staging/comedi/drivers/8255.h

+/*
+    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