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2a7b753a MW |
1 | /* |
2 | * Copyright (C) 2015 Zodiac Inflight Innovations | |
3 | * | |
4 | * Author: Martyn Welch <martyn.welch@collabora.co.uk> | |
5 | * | |
6 | * Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>: | |
7 | * | |
8 | * Copyright (C) Nokia Corporation | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License as published by | |
12 | * the Free Software Foundation; either version 2 of the License, or | |
13 | * (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | */ | |
20 | ||
21 | #include <linux/i2c.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/sysfs.h> | |
26 | #include <linux/types.h> | |
27 | #include <linux/version.h> | |
28 | #include <linux/watchdog.h> | |
29 | ||
30 | #define ZIIRAVE_TIMEOUT_MIN 3 | |
31 | #define ZIIRAVE_TIMEOUT_MAX 255 | |
32 | ||
33 | #define ZIIRAVE_PING_VALUE 0x0 | |
34 | ||
35 | #define ZIIRAVE_STATE_INITIAL 0x0 | |
36 | #define ZIIRAVE_STATE_OFF 0x1 | |
37 | #define ZIIRAVE_STATE_ON 0x2 | |
38 | ||
0ce72f35 | 39 | static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL, |
2a7b753a MW |
40 | "host request", NULL, "illegal configuration", |
41 | "illegal instruction", "illegal trap", | |
42 | "unknown"}; | |
43 | ||
44 | #define ZIIRAVE_WDT_FIRM_VER_MAJOR 0x1 | |
45 | #define ZIIRAVE_WDT_BOOT_VER_MAJOR 0x3 | |
46 | #define ZIIRAVE_WDT_RESET_REASON 0x5 | |
47 | #define ZIIRAVE_WDT_STATE 0x6 | |
48 | #define ZIIRAVE_WDT_TIMEOUT 0x7 | |
49 | #define ZIIRAVE_WDT_TIME_LEFT 0x8 | |
50 | #define ZIIRAVE_WDT_PING 0x9 | |
51 | #define ZIIRAVE_WDT_RESET_DURATION 0xa | |
52 | ||
53 | struct ziirave_wdt_rev { | |
54 | unsigned char major; | |
55 | unsigned char minor; | |
56 | }; | |
57 | ||
58 | struct ziirave_wdt_data { | |
59 | struct watchdog_device wdd; | |
60 | struct ziirave_wdt_rev bootloader_rev; | |
61 | struct ziirave_wdt_rev firmware_rev; | |
62 | int reset_reason; | |
63 | }; | |
64 | ||
65 | static int wdt_timeout; | |
66 | module_param(wdt_timeout, int, 0); | |
67 | MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds"); | |
68 | ||
69 | static int reset_duration; | |
70 | module_param(reset_duration, int, 0); | |
71 | MODULE_PARM_DESC(reset_duration, | |
72 | "Watchdog reset pulse duration in milliseconds"); | |
73 | ||
74 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
75 | module_param(nowayout, bool, 0); | |
76 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started default=" | |
77 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
78 | ||
79 | static int ziirave_wdt_revision(struct i2c_client *client, | |
80 | struct ziirave_wdt_rev *rev, u8 command) | |
81 | { | |
82 | int ret; | |
83 | ||
84 | ret = i2c_smbus_read_byte_data(client, command); | |
85 | if (ret < 0) | |
86 | return ret; | |
87 | ||
88 | rev->major = ret; | |
89 | ||
90 | ret = i2c_smbus_read_byte_data(client, command + 1); | |
91 | if (ret < 0) | |
92 | return ret; | |
93 | ||
94 | rev->minor = ret; | |
95 | ||
96 | return 0; | |
97 | } | |
98 | ||
99 | static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state) | |
100 | { | |
101 | struct i2c_client *client = to_i2c_client(wdd->parent); | |
102 | ||
103 | return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state); | |
104 | } | |
105 | ||
106 | static int ziirave_wdt_start(struct watchdog_device *wdd) | |
107 | { | |
108 | return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON); | |
109 | } | |
110 | ||
111 | static int ziirave_wdt_stop(struct watchdog_device *wdd) | |
112 | { | |
113 | return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF); | |
114 | } | |
115 | ||
116 | static int ziirave_wdt_ping(struct watchdog_device *wdd) | |
117 | { | |
118 | struct i2c_client *client = to_i2c_client(wdd->parent); | |
119 | ||
120 | return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING, | |
121 | ZIIRAVE_PING_VALUE); | |
122 | } | |
123 | ||
124 | static int ziirave_wdt_set_timeout(struct watchdog_device *wdd, | |
125 | unsigned int timeout) | |
126 | { | |
127 | struct i2c_client *client = to_i2c_client(wdd->parent); | |
128 | int ret; | |
129 | ||
130 | ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout); | |
131 | if (!ret) | |
132 | wdd->timeout = timeout; | |
133 | ||
134 | return ret; | |
135 | } | |
136 | ||
137 | static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd) | |
138 | { | |
139 | struct i2c_client *client = to_i2c_client(wdd->parent); | |
140 | int ret; | |
141 | ||
142 | ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT); | |
143 | if (ret < 0) | |
144 | ret = 0; | |
145 | ||
146 | return ret; | |
147 | } | |
148 | ||
149 | static const struct watchdog_info ziirave_wdt_info = { | |
150 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, | |
151 | .identity = "Zodiac RAVE Watchdog", | |
152 | }; | |
153 | ||
154 | static const struct watchdog_ops ziirave_wdt_ops = { | |
155 | .owner = THIS_MODULE, | |
156 | .start = ziirave_wdt_start, | |
157 | .stop = ziirave_wdt_stop, | |
158 | .ping = ziirave_wdt_ping, | |
159 | .set_timeout = ziirave_wdt_set_timeout, | |
160 | .get_timeleft = ziirave_wdt_get_timeleft, | |
161 | }; | |
162 | ||
163 | static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev, | |
164 | struct device_attribute *attr, | |
165 | char *buf) | |
166 | { | |
167 | struct i2c_client *client = to_i2c_client(dev->parent); | |
168 | struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client); | |
169 | ||
170 | return sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major, | |
171 | w_priv->firmware_rev.minor); | |
172 | } | |
173 | ||
174 | static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm, | |
175 | NULL); | |
176 | ||
177 | static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev, | |
178 | struct device_attribute *attr, | |
179 | char *buf) | |
180 | { | |
181 | struct i2c_client *client = to_i2c_client(dev->parent); | |
182 | struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client); | |
183 | ||
184 | return sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major, | |
185 | w_priv->bootloader_rev.minor); | |
186 | } | |
187 | ||
188 | static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot, | |
189 | NULL); | |
190 | ||
191 | static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev, | |
192 | struct device_attribute *attr, | |
193 | char *buf) | |
194 | { | |
195 | struct i2c_client *client = to_i2c_client(dev->parent); | |
196 | struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client); | |
197 | ||
198 | return sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]); | |
199 | } | |
200 | ||
201 | static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason, | |
202 | NULL); | |
203 | ||
204 | static struct attribute *ziirave_wdt_attrs[] = { | |
205 | &dev_attr_firmware_version.attr, | |
206 | &dev_attr_bootloader_version.attr, | |
207 | &dev_attr_reset_reason.attr, | |
208 | NULL | |
209 | }; | |
2c2f3080 | 210 | ATTRIBUTE_GROUPS(ziirave_wdt); |
2a7b753a MW |
211 | |
212 | static int ziirave_wdt_init_duration(struct i2c_client *client) | |
213 | { | |
214 | int ret; | |
215 | ||
216 | if (!reset_duration) { | |
217 | /* See if the reset pulse duration is provided in an of_node */ | |
218 | if (!client->dev.of_node) | |
219 | ret = -ENODEV; | |
220 | else | |
221 | ret = of_property_read_u32(client->dev.of_node, | |
222 | "reset-duration-ms", | |
223 | &reset_duration); | |
224 | if (ret) { | |
225 | dev_info(&client->dev, | |
226 | "Unable to set reset pulse duration, using default\n"); | |
227 | return 0; | |
228 | } | |
229 | } | |
230 | ||
231 | if (reset_duration < 1 || reset_duration > 255) | |
232 | return -EINVAL; | |
233 | ||
234 | dev_info(&client->dev, "Setting reset duration to %dms", | |
235 | reset_duration); | |
236 | ||
237 | return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION, | |
238 | reset_duration); | |
239 | } | |
240 | ||
241 | static int ziirave_wdt_probe(struct i2c_client *client, | |
242 | const struct i2c_device_id *id) | |
243 | { | |
244 | int ret; | |
245 | struct ziirave_wdt_data *w_priv; | |
246 | int val; | |
247 | ||
248 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
249 | return -ENODEV; | |
250 | ||
251 | w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL); | |
252 | if (!w_priv) | |
253 | return -ENOMEM; | |
254 | ||
255 | w_priv->wdd.info = &ziirave_wdt_info; | |
256 | w_priv->wdd.ops = &ziirave_wdt_ops; | |
257 | w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN; | |
258 | w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX; | |
259 | w_priv->wdd.parent = &client->dev; | |
2c2f3080 | 260 | w_priv->wdd.groups = ziirave_wdt_groups; |
2a7b753a MW |
261 | |
262 | ret = watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev); | |
263 | if (ret) { | |
264 | dev_info(&client->dev, | |
265 | "Unable to select timeout value, using default\n"); | |
266 | } | |
267 | ||
268 | /* | |
269 | * The default value set in the watchdog should be perfectly valid, so | |
270 | * pass that in if we haven't provided one via the module parameter or | |
271 | * of property. | |
272 | */ | |
273 | if (w_priv->wdd.timeout == 0) { | |
274 | val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT); | |
275 | if (val < 0) | |
276 | return val; | |
277 | ||
278 | if (val < ZIIRAVE_TIMEOUT_MIN) | |
279 | return -ENODEV; | |
280 | ||
281 | w_priv->wdd.timeout = val; | |
282 | } else { | |
283 | ret = ziirave_wdt_set_timeout(&w_priv->wdd, | |
284 | w_priv->wdd.timeout); | |
285 | if (ret) | |
286 | return ret; | |
287 | ||
288 | dev_info(&client->dev, "Timeout set to %ds.", | |
289 | w_priv->wdd.timeout); | |
290 | } | |
291 | ||
292 | watchdog_set_nowayout(&w_priv->wdd, nowayout); | |
293 | ||
294 | i2c_set_clientdata(client, w_priv); | |
295 | ||
296 | /* If in unconfigured state, set to stopped */ | |
297 | val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE); | |
298 | if (val < 0) | |
299 | return val; | |
300 | ||
301 | if (val == ZIIRAVE_STATE_INITIAL) | |
302 | ziirave_wdt_stop(&w_priv->wdd); | |
303 | ||
304 | ret = ziirave_wdt_init_duration(client); | |
305 | if (ret) | |
306 | return ret; | |
307 | ||
308 | ret = ziirave_wdt_revision(client, &w_priv->firmware_rev, | |
309 | ZIIRAVE_WDT_FIRM_VER_MAJOR); | |
310 | if (ret) | |
311 | return ret; | |
312 | ||
313 | ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev, | |
314 | ZIIRAVE_WDT_BOOT_VER_MAJOR); | |
315 | if (ret) | |
316 | return ret; | |
317 | ||
318 | w_priv->reset_reason = i2c_smbus_read_byte_data(client, | |
319 | ZIIRAVE_WDT_RESET_REASON); | |
320 | if (w_priv->reset_reason < 0) | |
321 | return w_priv->reset_reason; | |
322 | ||
323 | if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) || | |
324 | !ziirave_reasons[w_priv->reset_reason]) | |
325 | return -ENODEV; | |
326 | ||
327 | ret = watchdog_register_device(&w_priv->wdd); | |
2a7b753a | 328 | |
2c2f3080 | 329 | return ret; |
2a7b753a MW |
330 | } |
331 | ||
332 | static int ziirave_wdt_remove(struct i2c_client *client) | |
333 | { | |
334 | struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client); | |
335 | ||
2a7b753a MW |
336 | watchdog_unregister_device(&w_priv->wdd); |
337 | ||
338 | return 0; | |
339 | } | |
340 | ||
341 | static struct i2c_device_id ziirave_wdt_id[] = { | |
342 | { "ziirave-wdt", 0 }, | |
343 | { } | |
344 | }; | |
345 | MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id); | |
346 | ||
347 | static const struct of_device_id zrv_wdt_of_match[] = { | |
348 | { .compatible = "zii,rave-wdt", }, | |
349 | { }, | |
350 | }; | |
351 | MODULE_DEVICE_TABLE(of, zrv_wdt_of_match); | |
352 | ||
353 | static struct i2c_driver ziirave_wdt_driver = { | |
354 | .driver = { | |
355 | .name = "ziirave_wdt", | |
356 | .of_match_table = zrv_wdt_of_match, | |
357 | }, | |
358 | .probe = ziirave_wdt_probe, | |
359 | .remove = ziirave_wdt_remove, | |
360 | .id_table = ziirave_wdt_id, | |
361 | }; | |
362 | ||
363 | module_i2c_driver(ziirave_wdt_driver); | |
364 | ||
365 | MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.co.uk"); | |
366 | MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver"); | |
367 | MODULE_LICENSE("GPL"); |