tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) ST-Ericsson SA 2011-2013
3 *
4 * License Terms: GNU General Public License v2
5 *
6 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
7 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/moduleparam.h>
15#include <linux/miscdevice.h>
16#include <linux/err.h>
17#include <linux/uaccess.h>
18#include <linux/watchdog.h>
19#include <linux/platform_device.h>
20#include <linux/platform_data/ux500_wdt.h>
21
22#include <linux/mfd/dbx500-prcmu.h>
23
24#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
25
26#define WATCHDOG_MIN 0
27#define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */
28#define WATCHDOG_MAX32 4294967 /* 32 bit resolution in ms == 4294967.295 s */
29
30static unsigned int timeout = WATCHDOG_TIMEOUT;
31module_param(timeout, uint, 0);
32MODULE_PARM_DESC(timeout,
33 "Watchdog timeout in seconds. default="
34 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
35
36static bool nowayout = WATCHDOG_NOWAYOUT;
37module_param(nowayout, bool, 0);
38MODULE_PARM_DESC(nowayout,
39 "Watchdog cannot be stopped once started (default="
40 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
41
42static int ux500_wdt_start(struct watchdog_device *wdd)
43{
44 return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
45}
46
47static int ux500_wdt_stop(struct watchdog_device *wdd)
48{
49 return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
50}
51
52static int ux500_wdt_keepalive(struct watchdog_device *wdd)
53{
54 return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
55}
56
57static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
58 unsigned int timeout)
59{
60 ux500_wdt_stop(wdd);
61 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
62 ux500_wdt_start(wdd);
63
64 return 0;
65}
66
67static const struct watchdog_info ux500_wdt_info = {
68 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
69 .identity = "Ux500 WDT",
70 .firmware_version = 1,
71};
72
73static const struct watchdog_ops ux500_wdt_ops = {
74 .owner = THIS_MODULE,
75 .start = ux500_wdt_start,
76 .stop = ux500_wdt_stop,
77 .ping = ux500_wdt_keepalive,
78 .set_timeout = ux500_wdt_set_timeout,
79};
80
81static struct watchdog_device ux500_wdt = {
82 .info = &ux500_wdt_info,
83 .ops = &ux500_wdt_ops,
84 .min_timeout = WATCHDOG_MIN,
85 .max_timeout = WATCHDOG_MAX32,
86};
87
88static int ux500_wdt_probe(struct platform_device *pdev)
89{
90 int ret;
91 struct ux500_wdt_data *pdata = pdev->dev.platform_data;
92
93 if (pdata) {
94 if (pdata->timeout > 0)
95 timeout = pdata->timeout;
96 if (pdata->has_28_bits_resolution)
97 ux500_wdt.max_timeout = WATCHDOG_MAX28;
98 }
99
100 watchdog_set_nowayout(&ux500_wdt, nowayout);
101
102 /* disable auto off on sleep */
103 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
104
105 /* set HW initial value */
106 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
107
108 ret = watchdog_register_device(&ux500_wdt);
109 if (ret)
110 return ret;
111
112 dev_info(&pdev->dev, "initialized\n");
113
114 return 0;
115}
116
117static int ux500_wdt_remove(struct platform_device *dev)
118{
119 watchdog_unregister_device(&ux500_wdt);
120
121 return 0;
122}
123
124#ifdef CONFIG_PM
125static int ux500_wdt_suspend(struct platform_device *pdev,
126 pm_message_t state)
127{
128 if (watchdog_active(&ux500_wdt)) {
129 ux500_wdt_stop(&ux500_wdt);
130 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
131
132 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
133 ux500_wdt_start(&ux500_wdt);
134 }
135 return 0;
136}
137
138static int ux500_wdt_resume(struct platform_device *pdev)
139{
140 if (watchdog_active(&ux500_wdt)) {
141 ux500_wdt_stop(&ux500_wdt);
142 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
143
144 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
145 ux500_wdt_start(&ux500_wdt);
146 }
147 return 0;
148}
149#else
150#define ux500_wdt_suspend NULL
151#define ux500_wdt_resume NULL
152#endif
153
154static struct platform_driver ux500_wdt_driver = {
155 .probe = ux500_wdt_probe,
156 .remove = ux500_wdt_remove,
157 .suspend = ux500_wdt_suspend,
158 .resume = ux500_wdt_resume,
159 .driver = {
160 .owner = THIS_MODULE,
161 .name = "ux500_wdt",
162 },
163};
164
165module_platform_driver(ux500_wdt_driver);
166
167MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
168MODULE_DESCRIPTION("Ux500 Watchdog Driver");
169MODULE_LICENSE("GPL");
170MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
171MODULE_ALIAS("platform:ux500_wdt");