1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (C) ST-Ericsson SA 2011-2013 |
4 | * |
5 | * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson |
6 | * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson |
7 | */ |
8 | |
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/kernel.h> |
13 | #include <linux/moduleparam.h> |
14 | #include <linux/err.h> |
15 | #include <linux/uaccess.h> |
16 | #include <linux/watchdog.h> |
17 | #include <linux/platform_device.h> |
18 | |
19 | #include <linux/mfd/dbx500-prcmu.h> |
20 | |
21 | #define WATCHDOG_TIMEOUT 600 /* 10 minutes */ |
22 | |
23 | #define WATCHDOG_MIN 0 |
24 | #define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */ |
25 | |
26 | static unsigned int timeout = WATCHDOG_TIMEOUT; |
27 | module_param(timeout, uint, 0); |
28 | MODULE_PARM_DESC(timeout, |
29 | "Watchdog timeout in seconds. default=" |
30 | __MODULE_STRING(WATCHDOG_TIMEOUT) "." ); |
31 | |
32 | static bool nowayout = WATCHDOG_NOWAYOUT; |
33 | module_param(nowayout, bool, 0); |
34 | MODULE_PARM_DESC(nowayout, |
35 | "Watchdog cannot be stopped once started (default=" |
36 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")" ); |
37 | |
38 | static int db8500_wdt_start(struct watchdog_device *wdd) |
39 | { |
40 | return prcmu_enable_a9wdog(PRCMU_WDOG_ALL); |
41 | } |
42 | |
43 | static int db8500_wdt_stop(struct watchdog_device *wdd) |
44 | { |
45 | return prcmu_disable_a9wdog(PRCMU_WDOG_ALL); |
46 | } |
47 | |
48 | static int db8500_wdt_keepalive(struct watchdog_device *wdd) |
49 | { |
50 | return prcmu_kick_a9wdog(PRCMU_WDOG_ALL); |
51 | } |
52 | |
53 | static int db8500_wdt_set_timeout(struct watchdog_device *wdd, |
54 | unsigned int timeout) |
55 | { |
56 | db8500_wdt_stop(wdd); |
57 | prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); |
58 | db8500_wdt_start(wdd); |
59 | |
60 | return 0; |
61 | } |
62 | |
63 | static const struct watchdog_info db8500_wdt_info = { |
64 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
65 | .identity = "DB8500 WDT" , |
66 | .firmware_version = 1, |
67 | }; |
68 | |
69 | static const struct watchdog_ops db8500_wdt_ops = { |
70 | .owner = THIS_MODULE, |
71 | .start = db8500_wdt_start, |
72 | .stop = db8500_wdt_stop, |
73 | .ping = db8500_wdt_keepalive, |
74 | .set_timeout = db8500_wdt_set_timeout, |
75 | }; |
76 | |
77 | static struct watchdog_device db8500_wdt = { |
78 | .info = &db8500_wdt_info, |
79 | .ops = &db8500_wdt_ops, |
80 | .min_timeout = WATCHDOG_MIN, |
81 | .max_timeout = WATCHDOG_MAX28, |
82 | }; |
83 | |
84 | static int db8500_wdt_probe(struct platform_device *pdev) |
85 | { |
86 | struct device *dev = &pdev->dev; |
87 | int ret; |
88 | |
89 | timeout = 600; /* Default to 10 minutes */ |
90 | db8500_wdt.parent = dev; |
91 | watchdog_set_nowayout(wdd: &db8500_wdt, nowayout); |
92 | |
93 | /* disable auto off on sleep */ |
94 | prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false); |
95 | |
96 | /* set HW initial value */ |
97 | prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); |
98 | |
99 | ret = devm_watchdog_register_device(dev, &db8500_wdt); |
100 | if (ret) |
101 | return ret; |
102 | |
103 | dev_info(dev, "initialized\n" ); |
104 | |
105 | return 0; |
106 | } |
107 | |
108 | static int db8500_wdt_suspend(struct platform_device *pdev, |
109 | pm_message_t state) |
110 | { |
111 | if (watchdog_active(wdd: &db8500_wdt)) { |
112 | db8500_wdt_stop(wdd: &db8500_wdt); |
113 | prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true); |
114 | |
115 | prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); |
116 | db8500_wdt_start(wdd: &db8500_wdt); |
117 | } |
118 | return 0; |
119 | } |
120 | |
121 | static int db8500_wdt_resume(struct platform_device *pdev) |
122 | { |
123 | if (watchdog_active(wdd: &db8500_wdt)) { |
124 | db8500_wdt_stop(wdd: &db8500_wdt); |
125 | prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false); |
126 | |
127 | prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000); |
128 | db8500_wdt_start(wdd: &db8500_wdt); |
129 | } |
130 | return 0; |
131 | } |
132 | |
133 | static struct platform_driver db8500_wdt_driver = { |
134 | .probe = db8500_wdt_probe, |
135 | .suspend = pm_ptr(db8500_wdt_suspend), |
136 | .resume = pm_ptr(db8500_wdt_resume), |
137 | .driver = { |
138 | .name = "db8500_wdt" , |
139 | }, |
140 | }; |
141 | |
142 | module_platform_driver(db8500_wdt_driver); |
143 | |
144 | MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>" ); |
145 | MODULE_DESCRIPTION("DB8500 Watchdog Driver" ); |
146 | MODULE_LICENSE("GPL" ); |
147 | MODULE_ALIAS("platform:db8500_wdt" ); |
148 | |