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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; | |
664a0d78 AJ |
34 | unsigned long jpast; |
35 | }; | |
36 | ||
37 | static const struct { | |
38 | u8 reg_val; | |
39 | int time; /* Seconds */ | |
40 | } da9052_wdt_maps[] = { | |
41 | { 1, 2 }, | |
42 | { 2, 4 }, | |
43 | { 3, 8 }, | |
44 | { 4, 16 }, | |
45 | { 5, 32 }, | |
46 | { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ | |
47 | { 6, 65 }, | |
48 | { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ | |
49 | { 7, 131 }, | |
50 | }; | |
51 | ||
52 | ||
664a0d78 AJ |
53 | static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev, |
54 | unsigned int timeout) | |
55 | { | |
56 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
57 | struct da9052 *da9052 = driver_data->da9052; | |
58 | int ret, i; | |
59 | ||
60 | /* | |
61 | * Disable the Watchdog timer before setting | |
62 | * new time out. | |
63 | */ | |
64 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
65 | DA9052_CONTROLD_TWDSCALE, 0); | |
66 | if (ret < 0) { | |
67 | dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", | |
68 | ret); | |
69 | return ret; | |
70 | } | |
71 | if (timeout) { | |
72 | /* | |
73 | * To change the timeout, da9052 needs to | |
74 | * be disabled for at least 150 us. | |
75 | */ | |
76 | udelay(150); | |
77 | ||
78 | /* Set the desired timeout */ | |
79 | for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) | |
80 | if (da9052_wdt_maps[i].time == timeout) | |
81 | break; | |
82 | ||
83 | if (i == ARRAY_SIZE(da9052_wdt_maps)) | |
84 | ret = -EINVAL; | |
85 | else | |
86 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
87 | DA9052_CONTROLD_TWDSCALE, | |
88 | da9052_wdt_maps[i].reg_val); | |
89 | if (ret < 0) { | |
90 | dev_err(da9052->dev, | |
91 | "Failed to update timescale bit, %d\n", ret); | |
92 | return ret; | |
93 | } | |
94 | ||
95 | wdt_dev->timeout = timeout; | |
96 | driver_data->jpast = jiffies; | |
97 | } | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
664a0d78 AJ |
102 | static int da9052_wdt_start(struct watchdog_device *wdt_dev) |
103 | { | |
104 | return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout); | |
105 | } | |
106 | ||
107 | static int da9052_wdt_stop(struct watchdog_device *wdt_dev) | |
108 | { | |
109 | return da9052_wdt_set_timeout(wdt_dev, 0); | |
110 | } | |
111 | ||
112 | static int da9052_wdt_ping(struct watchdog_device *wdt_dev) | |
113 | { | |
114 | struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); | |
115 | struct da9052 *da9052 = driver_data->da9052; | |
116 | unsigned long msec, jnow = jiffies; | |
117 | int ret; | |
118 | ||
119 | /* | |
120 | * We have a minimum time for watchdog window called TWDMIN. A write | |
121 | * to the watchdog before this elapsed time should cause an error. | |
122 | */ | |
123 | msec = (jnow - driver_data->jpast) * 1000/HZ; | |
124 | if (msec < DA9052_TWDMIN) | |
125 | mdelay(msec); | |
126 | ||
127 | /* Reset the watchdog timer */ | |
128 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
129 | DA9052_CONTROLD_WATCHDOG, 1 << 7); | |
130 | if (ret < 0) | |
131 | goto err_strobe; | |
132 | ||
133 | /* | |
134 | * FIXME: Reset the watchdog core, in general PMIC | |
135 | * is supposed to do this | |
136 | */ | |
137 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, | |
138 | DA9052_CONTROLD_WATCHDOG, 0 << 7); | |
139 | err_strobe: | |
140 | return ret; | |
141 | } | |
142 | ||
143 | static struct watchdog_info da9052_wdt_info = { | |
144 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
145 | .identity = "DA9052 Watchdog", | |
146 | }; | |
147 | ||
148 | static const struct watchdog_ops da9052_wdt_ops = { | |
149 | .owner = THIS_MODULE, | |
150 | .start = da9052_wdt_start, | |
151 | .stop = da9052_wdt_stop, | |
152 | .ping = da9052_wdt_ping, | |
153 | .set_timeout = da9052_wdt_set_timeout, | |
664a0d78 AJ |
154 | }; |
155 | ||
156 | ||
2d991a16 | 157 | static int da9052_wdt_probe(struct platform_device *pdev) |
664a0d78 AJ |
158 | { |
159 | struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent); | |
160 | struct da9052_wdt_data *driver_data; | |
161 | struct watchdog_device *da9052_wdt; | |
162 | int ret; | |
163 | ||
164 | driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data), | |
165 | GFP_KERNEL); | |
166 | if (!driver_data) { | |
664a0d78 AJ |
167 | ret = -ENOMEM; |
168 | goto err; | |
169 | } | |
170 | driver_data->da9052 = da9052; | |
171 | ||
172 | da9052_wdt = &driver_data->wdt; | |
173 | ||
174 | da9052_wdt->timeout = DA9052_DEF_TIMEOUT; | |
175 | da9052_wdt->info = &da9052_wdt_info; | |
176 | da9052_wdt->ops = &da9052_wdt_ops; | |
6551881c | 177 | da9052_wdt->parent = &pdev->dev; |
664a0d78 AJ |
178 | watchdog_set_drvdata(da9052_wdt, driver_data); |
179 | ||
664a0d78 AJ |
180 | ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, |
181 | DA9052_CONTROLD_TWDSCALE, 0); | |
182 | if (ret < 0) { | |
183 | dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n", | |
184 | ret); | |
185 | goto err; | |
186 | } | |
187 | ||
188 | ret = watchdog_register_device(&driver_data->wdt); | |
189 | if (ret != 0) { | |
190 | dev_err(da9052->dev, "watchdog_register_device() failed: %d\n", | |
191 | ret); | |
192 | goto err; | |
193 | } | |
194 | ||
552a9641 | 195 | platform_set_drvdata(pdev, driver_data); |
664a0d78 AJ |
196 | err: |
197 | return ret; | |
198 | } | |
199 | ||
4b12b896 | 200 | static int da9052_wdt_remove(struct platform_device *pdev) |
664a0d78 | 201 | { |
552a9641 | 202 | struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev); |
664a0d78 AJ |
203 | |
204 | watchdog_unregister_device(&driver_data->wdt); | |
664a0d78 AJ |
205 | |
206 | return 0; | |
207 | } | |
208 | ||
209 | static struct platform_driver da9052_wdt_driver = { | |
210 | .probe = da9052_wdt_probe, | |
82268714 | 211 | .remove = da9052_wdt_remove, |
664a0d78 AJ |
212 | .driver = { |
213 | .name = "da9052-watchdog", | |
214 | }, | |
215 | }; | |
216 | ||
217 | module_platform_driver(da9052_wdt_driver); | |
218 | ||
219 | MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); | |
220 | MODULE_DESCRIPTION("DA9052 SM Device Driver"); | |
221 | MODULE_LICENSE("GPL"); | |
222 | MODULE_ALIAS("platform:da9052-watchdog"); |