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664a0d78 AJ |
1 | /* |
2 | * System monitoring driver for DA9052 PMICs. | |
3 | * | |
4 | * Copyright(c) 2012 Dialog Semiconductor Ltd. | |
5 | * | |
6 | * Author: Anthony Olech <Anthony.Olech@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/delay.h> | |
17 | #include <linux/uaccess.h> | |
18 | #include <linux/platform_device.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/watchdog.h> | |
21 | #include <linux/types.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/jiffies.h> | |
664a0d78 AJ |
24 | |
25 | #include <linux/mfd/da9052/reg.h> | |
26 | #include <linux/mfd/da9052/da9052.h> | |
27 | ||
28 | #define DA9052_DEF_TIMEOUT 4 | |
29 | #define DA9052_TWDMIN 256 | |
30 | ||
31 | struct da9052_wdt_data { | |
32 | struct watchdog_device wdt; | |
33 | struct da9052 *da9052; | |
34 | struct kref kref; | |
35 | unsigned long jpast; | |
36 | }; | |
37 | ||
38 | static const struct { | |
39 | u8 reg_val; | |
40 | int time; /* Seconds */ | |
41 | } da9052_wdt_maps[] = { | |
42 | { 1, 2 }, | |
43 | { 2, 4 }, | |
44 | { 3, 8 }, | |
45 | { 4, 16 }, | |
46 | { 5, 32 }, | |
47 | { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ | |
48 | { 6, 65 }, | |
49 | { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ | |
50 | { 7, 131 }, | |
51 | }; | |
52 | ||
53 | ||
54 | static void da9052_wdt_release_resources(struct kref *r) | |
55 | { | |
664a0d78 AJ |
56 | } |
57 | ||
58 | static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev, | |
59 | unsigned int timeout) | |
60 | { | |
61 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
62 | struct da9052 *da9052 = driver_data->da9052; | |
63 | int ret, i; | |
64 | ||
65 | /* | |
66 | * Disable the Watchdog timer before setting | |
67 | * new time out. | |
68 | */ | |
69 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
70 | DA9052_CONTROLD_TWDSCALE, 0); | |
71 | if (ret < 0) { | |
72 | dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", | |
73 | ret); | |
74 | return ret; | |
75 | } | |
76 | if (timeout) { | |
77 | /* | |
78 | * To change the timeout, da9052 needs to | |
79 | * be disabled for at least 150 us. | |
80 | */ | |
81 | udelay(150); | |
82 | ||
83 | /* Set the desired timeout */ | |
84 | for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) | |
85 | if (da9052_wdt_maps[i].time == timeout) | |
86 | break; | |
87 | ||
88 | if (i == ARRAY_SIZE(da9052_wdt_maps)) | |
89 | ret = -EINVAL; | |
90 | else | |
91 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
92 | DA9052_CONTROLD_TWDSCALE, | |
93 | da9052_wdt_maps[i].reg_val); | |
94 | if (ret < 0) { | |
95 | dev_err(da9052->dev, | |
96 | "Failed to update timescale bit, %d\n", ret); | |
97 | return ret; | |
98 | } | |
99 | ||
100 | wdt_dev->timeout = timeout; | |
101 | driver_data->jpast = jiffies; | |
102 | } | |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
107 | static void da9052_wdt_ref(struct watchdog_device *wdt_dev) | |
108 | { | |
109 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
110 | ||
111 | kref_get(&driver_data->kref); | |
112 | } | |
113 | ||
114 | static void da9052_wdt_unref(struct watchdog_device *wdt_dev) | |
115 | { | |
116 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
117 | ||
118 | kref_put(&driver_data->kref, da9052_wdt_release_resources); | |
119 | } | |
120 | ||
121 | static int da9052_wdt_start(struct watchdog_device *wdt_dev) | |
122 | { | |
123 | return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
124 | } | |
125 | ||
126 | static int da9052_wdt_stop(struct watchdog_device *wdt_dev) | |
127 | { | |
128 | return da9052_wdt_set_timeout(wdt_dev, 0); | |
129 | } | |
130 | ||
131 | static int da9052_wdt_ping(struct watchdog_device *wdt_dev) | |
132 | { | |
133 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
134 | struct da9052 *da9052 = driver_data->da9052; | |
135 | unsigned long msec, jnow = jiffies; | |
136 | int ret; | |
137 | ||
138 | /* | |
139 | * We have a minimum time for watchdog window called TWDMIN. A write | |
140 | * to the watchdog before this elapsed time should cause an error. | |
141 | */ | |
142 | msec = (jnow - driver_data->jpast) * 1000/HZ; | |
143 | if (msec < DA9052_TWDMIN) | |
144 | mdelay(msec); | |
145 | ||
146 | /* Reset the watchdog timer */ | |
147 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
148 | DA9052_CONTROLD_WATCHDOG, 1 << 7); | |
149 | if (ret < 0) | |
150 | goto err_strobe; | |
151 | ||
152 | /* | |
153 | * FIXME: Reset the watchdog core, in general PMIC | |
154 | * is supposed to do this | |
155 | */ | |
156 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
157 | DA9052_CONTROLD_WATCHDOG, 0 << 7); | |
158 | err_strobe: | |
159 | return ret; | |
160 | } | |
161 | ||
162 | static struct watchdog_info da9052_wdt_info = { | |
163 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
164 | .identity = "DA9052 Watchdog", | |
165 | }; | |
166 | ||
167 | static const struct watchdog_ops da9052_wdt_ops = { | |
168 | .owner = THIS_MODULE, | |
169 | .start = da9052_wdt_start, | |
170 | .stop = da9052_wdt_stop, | |
171 | .ping = da9052_wdt_ping, | |
172 | .set_timeout = da9052_wdt_set_timeout, | |
173 | .ref = da9052_wdt_ref, | |
174 | .unref = da9052_wdt_unref, | |
175 | }; | |
176 | ||
177 | ||
2d991a16 | 178 | static int da9052_wdt_probe(struct platform_device *pdev) |
664a0d78 AJ |
179 | { |
180 | struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent); | |
181 | struct da9052_wdt_data *driver_data; | |
182 | struct watchdog_device *da9052_wdt; | |
183 | int ret; | |
184 | ||
185 | driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data), | |
186 | GFP_KERNEL); | |
187 | if (!driver_data) { | |
188 | dev_err(da9052->dev, "Unable to alloacate watchdog device\n"); | |
189 | ret = -ENOMEM; | |
190 | goto err; | |
191 | } | |
192 | driver_data->da9052 = da9052; | |
193 | ||
194 | da9052_wdt = &driver_data->wdt; | |
195 | ||
196 | da9052_wdt->timeout = DA9052_DEF_TIMEOUT; | |
197 | da9052_wdt->info = &da9052_wdt_info; | |
198 | da9052_wdt->ops = &da9052_wdt_ops; | |
199 | watchdog_set_drvdata(da9052_wdt, driver_data); | |
200 | ||
201 | kref_init(&driver_data->kref); | |
202 | ||
203 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
204 | DA9052_CONTROLD_TWDSCALE, 0); | |
205 | if (ret < 0) { | |
206 | dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n", | |
207 | ret); | |
208 | goto err; | |
209 | } | |
210 | ||
211 | ret = watchdog_register_device(&driver_data->wdt); | |
212 | if (ret != 0) { | |
213 | dev_err(da9052->dev, "watchdog_register_device() failed: %d\n", | |
214 | ret); | |
215 | goto err; | |
216 | } | |
217 | ||
552a9641 | 218 | platform_set_drvdata(pdev, driver_data); |
664a0d78 AJ |
219 | err: |
220 | return ret; | |
221 | } | |
222 | ||
4b12b896 | 223 | static int da9052_wdt_remove(struct platform_device *pdev) |
664a0d78 | 224 | { |
552a9641 | 225 | struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev); |
664a0d78 AJ |
226 | |
227 | watchdog_unregister_device(&driver_data->wdt); | |
228 | kref_put(&driver_data->kref, da9052_wdt_release_resources); | |
229 | ||
230 | return 0; | |
231 | } | |
232 | ||
233 | static struct platform_driver da9052_wdt_driver = { | |
234 | .probe = da9052_wdt_probe, | |
82268714 | 235 | .remove = da9052_wdt_remove, |
664a0d78 AJ |
236 | .driver = { |
237 | .name = "da9052-watchdog", | |
238 | }, | |
239 | }; | |
240 | ||
241 | module_platform_driver(da9052_wdt_driver); | |
242 | ||
243 | MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); | |
244 | MODULE_DESCRIPTION("DA9052 SM Device Driver"); | |
245 | MODULE_LICENSE("GPL"); | |
246 | MODULE_ALIAS("platform:da9052-watchdog"); |