1/*
2 * Copyright (C) Nokia Corporation
3 *
4 * Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <linux/module.h>
22#include <linux/types.h>
23#include <linux/slab.h>
24#include <linux/kernel.h>
25#include <linux/watchdog.h>
26#include <linux/platform_device.h>
27#include <linux/i2c/twl.h>
28
29#define TWL4030_WATCHDOG_CFG_REG_OFFS	0x3
30
31static bool nowayout = WATCHDOG_NOWAYOUT;
32module_param(nowayout, bool, 0);
33MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
34	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
35
36static int twl4030_wdt_write(unsigned char val)
37{
38	return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val,
39					TWL4030_WATCHDOG_CFG_REG_OFFS);
40}
41
42static int twl4030_wdt_start(struct watchdog_device *wdt)
43{
44	return twl4030_wdt_write(wdt->timeout + 1);
45}
46
47static int twl4030_wdt_stop(struct watchdog_device *wdt)
48{
49	return twl4030_wdt_write(0);
50}
51
52static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
53				   unsigned int timeout)
54{
55	wdt->timeout = timeout;
56	return 0;
57}
58
59static const struct watchdog_info twl4030_wdt_info = {
60	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
61	.identity = "TWL4030 Watchdog",
62};
63
64static const struct watchdog_ops twl4030_wdt_ops = {
65	.owner		= THIS_MODULE,
66	.start		= twl4030_wdt_start,
67	.stop		= twl4030_wdt_stop,
68	.set_timeout	= twl4030_wdt_set_timeout,
69};
70
71static int twl4030_wdt_probe(struct platform_device *pdev)
72{
73	int ret = 0;
74	struct watchdog_device *wdt;
75
76	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
77	if (!wdt)
78		return -ENOMEM;
79
80	wdt->info		= &twl4030_wdt_info;
81	wdt->ops		= &twl4030_wdt_ops;
82	wdt->status		= 0;
83	wdt->timeout		= 30;
84	wdt->min_timeout	= 1;
85	wdt->max_timeout	= 30;
86
87	watchdog_set_nowayout(wdt, nowayout);
88	platform_set_drvdata(pdev, wdt);
89
90	twl4030_wdt_stop(wdt);
91
92	ret = watchdog_register_device(wdt);
93	if (ret)
94		return ret;
95
96	return 0;
97}
98
99static int twl4030_wdt_remove(struct platform_device *pdev)
100{
101	struct watchdog_device *wdt = platform_get_drvdata(pdev);
102
103	watchdog_unregister_device(wdt);
104
105	return 0;
106}
107
108#ifdef CONFIG_PM
109static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
110{
111	struct watchdog_device *wdt = platform_get_drvdata(pdev);
112	if (watchdog_active(wdt))
113		return twl4030_wdt_stop(wdt);
114
115	return 0;
116}
117
118static int twl4030_wdt_resume(struct platform_device *pdev)
119{
120	struct watchdog_device *wdt = platform_get_drvdata(pdev);
121	if (watchdog_active(wdt))
122		return twl4030_wdt_start(wdt);
123
124	return 0;
125}
126#else
127#define twl4030_wdt_suspend        NULL
128#define twl4030_wdt_resume         NULL
129#endif
130
131static const struct of_device_id twl_wdt_of_match[] = {
132	{ .compatible = "ti,twl4030-wdt", },
133	{ },
134};
135MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
136
137static struct platform_driver twl4030_wdt_driver = {
138	.probe		= twl4030_wdt_probe,
139	.remove		= twl4030_wdt_remove,
140	.suspend	= twl4030_wdt_suspend,
141	.resume		= twl4030_wdt_resume,
142	.driver		= {
143		.name		= "twl4030_wdt",
144		.of_match_table	= twl_wdt_of_match,
145	},
146};
147
148module_platform_driver(twl4030_wdt_driver);
149
150MODULE_AUTHOR("Nokia Corporation");
151MODULE_LICENSE("GPL");
152MODULE_ALIAS("platform:twl4030_wdt");
153
154