2 * COMEDI driver for the watchdog subdevice found on some addi-data boards
3 * Copyright (c) 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
5 * Based on implementations in various addi-data COMEDI drivers.
7 * COMEDI - Linux Control and Measurement Device Interface
8 * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include "../comedidev.h"
26 #include "addi_watchdog.h"
29 * Register offsets/defines for the addi-data watchdog
31 #define ADDI_WDOG_REG 0x00
32 #define ADDI_WDOG_RELOAD_REG 0x04
33 #define ADDI_WDOG_TIMEBASE 0x08
34 #define ADDI_WDOG_CTRL_REG 0x0c
35 #define ADDI_WDOG_CTRL_ENABLE (1 << 0)
36 #define ADDI_WDOG_CTRL_SW_TRIG (1 << 9)
37 #define ADDI_WDOG_STATUS_REG 0x10
38 #define ADDI_WDOG_STATUS_ENABLED (1 << 0)
39 #define ADDI_WDOG_STATUS_SW_TRIG (1 << 1)
41 struct addi_watchdog_private
{
43 unsigned int wdog_ctrl
;
47 * The watchdog subdevice is configured with two INSN_CONFIG instructions:
49 * Enable the watchdog and set the reload timeout:
50 * data[0] = INSN_CONFIG_ARM
51 * data[1] = timeout reload value
53 * Disable the watchdog:
54 * data[0] = INSN_CONFIG_DISARM
56 static int addi_watchdog_insn_config(struct comedi_device
*dev
,
57 struct comedi_subdevice
*s
,
58 struct comedi_insn
*insn
,
61 struct addi_watchdog_private
*spriv
= s
->private;
66 spriv
->wdog_ctrl
= ADDI_WDOG_CTRL_ENABLE
;
67 reload
= data
[1] & s
->maxdata
;
68 outl(reload
, spriv
->iobase
+ ADDI_WDOG_RELOAD_REG
);
70 /* Time base is 20ms, let the user know the timeout */
71 dev_info(dev
->class_dev
, "watchdog enabled, timeout:%dms\n",
74 case INSN_CONFIG_DISARM
:
81 outl(spriv
->wdog_ctrl
, spriv
->iobase
+ ADDI_WDOG_CTRL_REG
);
86 static int addi_watchdog_insn_read(struct comedi_device
*dev
,
87 struct comedi_subdevice
*s
,
88 struct comedi_insn
*insn
,
91 struct addi_watchdog_private
*spriv
= s
->private;
94 for (i
= 0; i
< insn
->n
; i
++)
95 data
[i
] = inl(spriv
->iobase
+ ADDI_WDOG_STATUS_REG
);
100 static int addi_watchdog_insn_write(struct comedi_device
*dev
,
101 struct comedi_subdevice
*s
,
102 struct comedi_insn
*insn
,
105 struct addi_watchdog_private
*spriv
= s
->private;
108 if (spriv
->wdog_ctrl
== 0) {
109 dev_warn(dev
->class_dev
, "watchdog is disabled\n");
113 /* "ping" the watchdog */
114 for (i
= 0; i
< insn
->n
; i
++) {
115 outl(spriv
->wdog_ctrl
| ADDI_WDOG_CTRL_SW_TRIG
,
116 spriv
->iobase
+ ADDI_WDOG_CTRL_REG
);
122 void addi_watchdog_reset(unsigned long iobase
)
124 outl(0x0, iobase
+ ADDI_WDOG_CTRL_REG
);
125 outl(0x0, iobase
+ ADDI_WDOG_RELOAD_REG
);
127 EXPORT_SYMBOL_GPL(addi_watchdog_reset
);
129 int addi_watchdog_init(struct comedi_subdevice
*s
, unsigned long iobase
)
131 struct addi_watchdog_private
*spriv
;
133 spriv
= kzalloc(sizeof(*spriv
), GFP_KERNEL
);
137 spriv
->iobase
= iobase
;
141 s
->type
= COMEDI_SUBD_TIMER
;
142 s
->subdev_flags
= SDF_WRITEABLE
;
145 s
->insn_config
= addi_watchdog_insn_config
;
146 s
->insn_read
= addi_watchdog_insn_read
;
147 s
->insn_write
= addi_watchdog_insn_write
;
151 EXPORT_SYMBOL_GPL(addi_watchdog_init
);
153 static int __init
addi_watchdog_module_init(void)
157 module_init(addi_watchdog_module_init
);
159 static void __exit
addi_watchdog_module_exit(void)
162 module_exit(addi_watchdog_module_exit
);
164 MODULE_DESCRIPTION("ADDI-DATA Watchdog subdevice");
165 MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
166 MODULE_LICENSE("GPL");