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312b00e1 AJ |
1 | /* |
2 | * System monitoring driver for DA9055 PMICs. | |
3 | * | |
4 | * Copyright(c) 2012 Dialog Semiconductor Ltd. | |
5 | * | |
6 | * Author: David Dajun Chen <dchen@diasemi.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/types.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/watchdog.h> | |
21 | #include <linux/delay.h> | |
22 | ||
23 | #include <linux/mfd/da9055/core.h> | |
24 | #include <linux/mfd/da9055/reg.h> | |
25 | ||
26 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
27 | module_param(nowayout, bool, 0); | |
28 | MODULE_PARM_DESC(nowayout, | |
29 | "Watchdog cannot be stopped once started (default=" | |
30 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
31 | ||
32 | #define DA9055_DEF_TIMEOUT 4 | |
33 | #define DA9055_TWDMIN 256 | |
34 | ||
35 | struct da9055_wdt_data { | |
36 | struct watchdog_device wdt; | |
37 | struct da9055 *da9055; | |
312b00e1 AJ |
38 | }; |
39 | ||
40 | static const struct { | |
41 | u8 reg_val; | |
42 | int user_time; /* In seconds */ | |
43 | } da9055_wdt_maps[] = { | |
44 | { 0, 0 }, | |
45 | { 1, 2 }, | |
46 | { 2, 4 }, | |
47 | { 3, 8 }, | |
48 | { 4, 16 }, | |
49 | { 5, 32 }, | |
50 | { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ | |
51 | { 6, 65 }, | |
52 | { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ | |
53 | { 7, 131 }, | |
54 | }; | |
55 | ||
56 | static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
57 | unsigned int timeout) | |
58 | { | |
59 | struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
60 | struct da9055 *da9055 = driver_data->da9055; | |
61 | int ret, i; | |
62 | ||
63 | for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++) | |
64 | if (da9055_wdt_maps[i].user_time == timeout) | |
65 | break; | |
66 | ||
67 | if (i == ARRAY_SIZE(da9055_wdt_maps)) | |
68 | ret = -EINVAL; | |
69 | else | |
70 | ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B, | |
71 | DA9055_TWDSCALE_MASK, | |
72 | da9055_wdt_maps[i].reg_val << | |
73 | DA9055_TWDSCALE_SHIFT); | |
98e4a293 | 74 | if (ret < 0) { |
312b00e1 AJ |
75 | dev_err(da9055->dev, |
76 | "Failed to update timescale bit, %d\n", ret); | |
98e4a293 AL |
77 | return ret; |
78 | } | |
312b00e1 AJ |
79 | |
80 | wdt_dev->timeout = timeout; | |
81 | ||
98e4a293 | 82 | return 0; |
312b00e1 AJ |
83 | } |
84 | ||
85 | static int da9055_wdt_ping(struct watchdog_device *wdt_dev) | |
86 | { | |
87 | struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
88 | struct da9055 *da9055 = driver_data->da9055; | |
312b00e1 AJ |
89 | |
90 | /* | |
91 | * We have a minimum time for watchdog window called TWDMIN. A write | |
92 | * to the watchdog before this elapsed time will cause an error. | |
93 | */ | |
94 | mdelay(DA9055_TWDMIN); | |
95 | ||
96 | /* Reset the watchdog timer */ | |
98e4a293 AL |
97 | return da9055_reg_update(da9055, DA9055_REG_CONTROL_E, |
98 | DA9055_WATCHDOG_MASK, 1); | |
312b00e1 AJ |
99 | } |
100 | ||
312b00e1 AJ |
101 | static int da9055_wdt_start(struct watchdog_device *wdt_dev) |
102 | { | |
103 | return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
104 | } | |
105 | ||
106 | static int da9055_wdt_stop(struct watchdog_device *wdt_dev) | |
107 | { | |
108 | return da9055_wdt_set_timeout(wdt_dev, 0); | |
109 | } | |
110 | ||
111 | static struct watchdog_info da9055_wdt_info = { | |
112 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
113 | .identity = "DA9055 Watchdog", | |
114 | }; | |
115 | ||
116 | static const struct watchdog_ops da9055_wdt_ops = { | |
117 | .owner = THIS_MODULE, | |
118 | .start = da9055_wdt_start, | |
119 | .stop = da9055_wdt_stop, | |
120 | .ping = da9055_wdt_ping, | |
121 | .set_timeout = da9055_wdt_set_timeout, | |
312b00e1 AJ |
122 | }; |
123 | ||
124 | static int da9055_wdt_probe(struct platform_device *pdev) | |
125 | { | |
126 | struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent); | |
127 | struct da9055_wdt_data *driver_data; | |
128 | struct watchdog_device *da9055_wdt; | |
129 | int ret; | |
130 | ||
131 | driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data), | |
132 | GFP_KERNEL); | |
8deea830 | 133 | if (!driver_data) |
312b00e1 | 134 | return -ENOMEM; |
312b00e1 AJ |
135 | |
136 | driver_data->da9055 = da9055; | |
137 | ||
138 | da9055_wdt = &driver_data->wdt; | |
139 | ||
140 | da9055_wdt->timeout = DA9055_DEF_TIMEOUT; | |
141 | da9055_wdt->info = &da9055_wdt_info; | |
142 | da9055_wdt->ops = &da9055_wdt_ops; | |
6551881c | 143 | da9055_wdt->parent = &pdev->dev; |
312b00e1 AJ |
144 | watchdog_set_nowayout(da9055_wdt, nowayout); |
145 | watchdog_set_drvdata(da9055_wdt, driver_data); | |
146 | ||
312b00e1 AJ |
147 | ret = da9055_wdt_stop(da9055_wdt); |
148 | if (ret < 0) { | |
149 | dev_err(&pdev->dev, "Failed to stop watchdog, %d\n", ret); | |
150 | goto err; | |
151 | } | |
152 | ||
76692c94 | 153 | platform_set_drvdata(pdev, driver_data); |
312b00e1 AJ |
154 | |
155 | ret = watchdog_register_device(&driver_data->wdt); | |
156 | if (ret != 0) | |
157 | dev_err(da9055->dev, "watchdog_register_device() failed: %d\n", | |
158 | ret); | |
159 | ||
160 | err: | |
161 | return ret; | |
162 | } | |
163 | ||
164 | static int da9055_wdt_remove(struct platform_device *pdev) | |
165 | { | |
76692c94 | 166 | struct da9055_wdt_data *driver_data = platform_get_drvdata(pdev); |
312b00e1 AJ |
167 | |
168 | watchdog_unregister_device(&driver_data->wdt); | |
312b00e1 AJ |
169 | |
170 | return 0; | |
171 | } | |
172 | ||
173 | static struct platform_driver da9055_wdt_driver = { | |
174 | .probe = da9055_wdt_probe, | |
175 | .remove = da9055_wdt_remove, | |
176 | .driver = { | |
177 | .name = "da9055-watchdog", | |
178 | }, | |
179 | }; | |
180 | ||
181 | module_platform_driver(da9055_wdt_driver); | |
182 | ||
183 | MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>"); | |
184 | MODULE_DESCRIPTION("DA9055 watchdog"); | |
185 | MODULE_LICENSE("GPL"); | |
186 | MODULE_ALIAS("platform:da9055-watchdog"); |