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* 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.
*
* 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.
*/
#include "../comedidev.h"
#include "addi_watchdog.h"
/*
* Register offsets/defines for the addi-data watchdog
*/
#define ADDI_WDOG_REG 0x00
#define ADDI_WDOG_RELOAD_REG 0x04
#define ADDI_WDOG_TIMEBASE 0x08
#define ADDI_WDOG_CTRL_REG 0x0c
#define ADDI_WDOG_CTRL_ENABLE (1 << 0)
#define ADDI_WDOG_CTRL_SW_TRIG (1 << 9)
#define ADDI_WDOG_STATUS_REG 0x10
#define ADDI_WDOG_STATUS_ENABLED (1 << 0)
#define ADDI_WDOG_STATUS_SW_TRIG (1 << 1)
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_WDOG_CTRL_ENABLE;
reload = data[1] & s->maxdata;
outl(reload, spriv->iobase + ADDI_WDOG_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_WDOG_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_WDOG_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_WDOG_CTRL_SW_TRIG,
spriv->iobase + ADDI_WDOG_CTRL_REG);
}
return insn->n;
}
void addi_watchdog_reset(unsigned long iobase)
{
outl(0x0, iobase + ADDI_WDOG_CTRL_REG);
outl(0x0, iobase + ADDI_WDOG_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 = kzalloc(sizeof(*spriv), GFP_KERNEL);
if (!spriv)
return -ENOMEM;
spriv->iobase = iobase;
s->private = spriv;
s->type = COMEDI_SUBD_TIMER;
s->subdev_flags = SDF_WRITEABLE;
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");
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