aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/staging/comedi/drivers/addi_watchdog.c
blob: c5b082d4e51e3ccce736af728d8a5e17d6dfb5f0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * COMEDI driver for the watchdog subdevice found on some addi-data boards
 * Copyright (c) 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
 *
 * Based on implementations in various addi-data COMEDI drivers.
 *
 * 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.
 */

#include <linux/module.h>
#include "../comedidev.h"
#include "addi_tcw.h"
#include "addi_watchdog.h"

struct addi_watchdog_private {
	unsigned long iobase;
	unsigned int wdog_ctrl;
};

/*
 * The watchdog subdevice is configured with two INSN_CONFIG instructions:
 *
 * Enable the watchdog and set the reload timeout:
 *	data[0] = INSN_CONFIG_ARM
 *	data[1] = timeout reload value
 *
 * Disable the watchdog:
 *	data[0] = INSN_CONFIG_DISARM
 */
static int addi_watchdog_insn_config(struct comedi_device *dev,
				     struct comedi_subdevice *s,
				     struct comedi_insn *insn,
				     unsigned int *data)
{
	struct addi_watchdog_private *spriv = s->private;
	unsigned int reload;

	switch (data[0]) {
	case INSN_CONFIG_ARM:
		spriv->wdog_ctrl = ADDI_TCW_CTRL_ENA;
		reload = data[1] & s->maxdata;
		outl(reload, spriv->iobase + ADDI_TCW_RELOAD_REG);

		/* Time base is 20ms, let the user know the timeout */
		dev_info(dev->class_dev, "watchdog enabled, timeout:%dms\n",
			20 * reload + 20);
		break;
	case INSN_CONFIG_DISARM:
		spriv->wdog_ctrl = 0;
		break;
	default:
		return -EINVAL;
	}

	outl(spriv->wdog_ctrl, spriv->iobase + ADDI_TCW_CTRL_REG);

	return insn->n;
}

static int addi_watchdog_insn_read(struct comedi_device *dev,
				   struct comedi_subdevice *s,
				   struct comedi_insn *insn,
				   unsigned int *data)
{
	struct addi_watchdog_private *spriv = s->private;
	int i;

	for (i = 0; i < insn->n; i++)
		data[i] = inl(spriv->iobase + ADDI_TCW_STATUS_REG);

	return insn->n;
}

static int addi_watchdog_insn_write(struct comedi_device *dev,
				    struct comedi_subdevice *s,
				    struct comedi_insn *insn,
				    unsigned int *data)
{
	struct addi_watchdog_private *spriv = s->private;
	int i;

	if (spriv->wdog_ctrl == 0) {
		dev_warn(dev->class_dev, "watchdog is disabled\n");
		return -EINVAL;
	}

	/* "ping" the watchdog */
	for (i = 0; i < insn->n; i++) {
		outl(spriv->wdog_ctrl | ADDI_TCW_CTRL_TRIG,
		     spriv->iobase + ADDI_TCW_CTRL_REG);
	}

	return insn->n;
}

void addi_watchdog_reset(unsigned long iobase)
{
	outl(0x0, iobase + ADDI_TCW_CTRL_REG);
	outl(0x0, iobase + ADDI_TCW_RELOAD_REG);
}
EXPORT_SYMBOL_GPL(addi_watchdog_reset);

int addi_watchdog_init(struct comedi_subdevice *s, unsigned long iobase)
{
	struct addi_watchdog_private *spriv;

	spriv = comedi_alloc_spriv(s, sizeof(*spriv));
	if (!spriv)
		return -ENOMEM;

	spriv->iobase = iobase;

	s->type		= COMEDI_SUBD_TIMER;
	s->subdev_flags	= SDF_WRITABLE;
	s->n_chan	= 1;
	s->maxdata	= 0xff;
	s->insn_config	= addi_watchdog_insn_config;
	s->insn_read	= addi_watchdog_insn_read;
	s->insn_write	= addi_watchdog_insn_write;

	return 0;
}
EXPORT_SYMBOL_GPL(addi_watchdog_init);

static int __init addi_watchdog_module_init(void)
{
	return 0;
}
module_init(addi_watchdog_module_init);

static void __exit addi_watchdog_module_exit(void)
{
}
module_exit(addi_watchdog_module_exit);

MODULE_DESCRIPTION("ADDI-DATA Watchdog subdevice");
MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_LICENSE("GPL");