blob: 7be38556aed0c5b0854a89704875218f15437b02 [file] [log] [blame]
Mark Brown502a0102009-07-27 14:46:12 +01001/*
2 * Watchdog driver for the wm831x PMICs
3 *
4 * Copyright (C) 2009 Wolfson Microelectronics
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation
9 */
10
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/types.h>
14#include <linux/kernel.h>
Mark Brown00411ee2011-10-04 16:43:40 +010015#include <linux/slab.h>
Mark Brown502a0102009-07-27 14:46:12 +010016#include <linux/platform_device.h>
17#include <linux/watchdog.h>
18#include <linux/uaccess.h>
19#include <linux/gpio.h>
20
21#include <linux/mfd/wm831x/core.h>
22#include <linux/mfd/wm831x/pdata.h>
23#include <linux/mfd/wm831x/watchdog.h>
24
25static int nowayout = WATCHDOG_NOWAYOUT;
26module_param(nowayout, int, 0);
27MODULE_PARM_DESC(nowayout,
28 "Watchdog cannot be stopped once started (default="
29 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
30
Mark Brown00411ee2011-10-04 16:43:40 +010031struct wm831x_wdt_drvdata {
32 struct watchdog_device wdt;
33 struct wm831x *wm831x;
34 struct mutex lock;
35 int update_gpio;
36 int update_state;
37};
Mark Brown502a0102009-07-27 14:46:12 +010038
39/* We can't use the sub-second values here but they're included
40 * for completeness. */
41static struct {
Mark Brown00411ee2011-10-04 16:43:40 +010042 unsigned int time; /* Seconds */
43 u16 val; /* WDOG_TO value */
Mark Brown502a0102009-07-27 14:46:12 +010044} wm831x_wdt_cfgs[] = {
45 { 1, 2 },
46 { 2, 3 },
47 { 4, 4 },
48 { 8, 5 },
49 { 16, 6 },
50 { 32, 7 },
51 { 33, 7 }, /* Actually 32.768s so include both, others round down */
52};
53
Mark Brown00411ee2011-10-04 16:43:40 +010054static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
Mark Brown502a0102009-07-27 14:46:12 +010055{
Mark Brown00411ee2011-10-04 16:43:40 +010056 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
57 struct wm831x *wm831x = driver_data->wm831x;
Mark Brown502a0102009-07-27 14:46:12 +010058 int ret;
59
Mark Brown00411ee2011-10-04 16:43:40 +010060 mutex_lock(&driver_data->lock);
Mark Brown502a0102009-07-27 14:46:12 +010061
62 ret = wm831x_reg_unlock(wm831x);
63 if (ret == 0) {
64 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
65 WM831X_WDOG_ENA, WM831X_WDOG_ENA);
66 wm831x_reg_lock(wm831x);
67 } else {
68 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
69 ret);
70 }
71
Mark Brown00411ee2011-10-04 16:43:40 +010072 mutex_unlock(&driver_data->lock);
Mark Brown502a0102009-07-27 14:46:12 +010073
74 return ret;
75}
76
Mark Brown00411ee2011-10-04 16:43:40 +010077static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
Mark Brown502a0102009-07-27 14:46:12 +010078{
Mark Brown00411ee2011-10-04 16:43:40 +010079 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
80 struct wm831x *wm831x = driver_data->wm831x;
Mark Brown502a0102009-07-27 14:46:12 +010081 int ret;
82
Mark Brown00411ee2011-10-04 16:43:40 +010083 mutex_lock(&driver_data->lock);
Mark Brown502a0102009-07-27 14:46:12 +010084
85 ret = wm831x_reg_unlock(wm831x);
86 if (ret == 0) {
87 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
88 WM831X_WDOG_ENA, 0);
89 wm831x_reg_lock(wm831x);
90 } else {
91 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
92 ret);
93 }
94
Mark Brown00411ee2011-10-04 16:43:40 +010095 mutex_unlock(&driver_data->lock);
Mark Brown502a0102009-07-27 14:46:12 +010096
97 return ret;
98}
99
Mark Brown00411ee2011-10-04 16:43:40 +0100100static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
Mark Brown502a0102009-07-27 14:46:12 +0100101{
Mark Brown00411ee2011-10-04 16:43:40 +0100102 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
103 struct wm831x *wm831x = driver_data->wm831x;
Mark Brown502a0102009-07-27 14:46:12 +0100104 int ret;
105 u16 reg;
106
Mark Brown00411ee2011-10-04 16:43:40 +0100107 mutex_lock(&driver_data->lock);
Mark Brown502a0102009-07-27 14:46:12 +0100108
Mark Brown00411ee2011-10-04 16:43:40 +0100109 if (driver_data->update_gpio) {
110 gpio_set_value_cansleep(driver_data->update_gpio,
111 driver_data->update_state);
112 driver_data->update_state = !driver_data->update_state;
Mark Brown502a0102009-07-27 14:46:12 +0100113 ret = 0;
114 goto out;
115 }
116
Mark Brown502a0102009-07-27 14:46:12 +0100117 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
118
119 if (!(reg & WM831X_WDOG_RST_SRC)) {
120 dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
121 ret = -EINVAL;
122 goto out;
123 }
124
125 reg |= WM831X_WDOG_RESET;
126
127 ret = wm831x_reg_unlock(wm831x);
128 if (ret == 0) {
129 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
130 wm831x_reg_lock(wm831x);
131 } else {
132 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
133 ret);
134 }
135
136out:
Mark Brown00411ee2011-10-04 16:43:40 +0100137 mutex_unlock(&driver_data->lock);
Mark Brown502a0102009-07-27 14:46:12 +0100138
139 return ret;
140}
141
Mark Brown00411ee2011-10-04 16:43:40 +0100142static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
143 unsigned int timeout)
Mark Brown502a0102009-07-27 14:46:12 +0100144{
Mark Brown00411ee2011-10-04 16:43:40 +0100145 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
146 struct wm831x *wm831x = driver_data->wm831x;
147 int ret, i;
Mark Brown502a0102009-07-27 14:46:12 +0100148
Mark Brown00411ee2011-10-04 16:43:40 +0100149 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
150 if (wm831x_wdt_cfgs[i].time == timeout)
151 break;
152 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
153 ret = -EINVAL;
Mark Brown502a0102009-07-27 14:46:12 +0100154
Mark Brown00411ee2011-10-04 16:43:40 +0100155 ret = wm831x_reg_unlock(wm831x);
156 if (ret == 0) {
157 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
158 WM831X_WDOG_TO_MASK,
159 wm831x_wdt_cfgs[i].val);
160 wm831x_reg_lock(wm831x);
161 } else {
162 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
163 ret);
Mark Brown502a0102009-07-27 14:46:12 +0100164 }
165
Mark Brown00411ee2011-10-04 16:43:40 +0100166 return ret;
Mark Brown502a0102009-07-27 14:46:12 +0100167}
168
Mark Brown00411ee2011-10-04 16:43:40 +0100169static const struct watchdog_info wm831x_wdt_info = {
Mark Brown502a0102009-07-27 14:46:12 +0100170 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
171 .identity = "WM831x Watchdog",
172};
173
Mark Brown00411ee2011-10-04 16:43:40 +0100174static const struct watchdog_ops wm831x_wdt_ops = {
Mark Brown502a0102009-07-27 14:46:12 +0100175 .owner = THIS_MODULE,
Mark Brown00411ee2011-10-04 16:43:40 +0100176 .start = wm831x_wdt_start,
177 .stop = wm831x_wdt_stop,
178 .ping = wm831x_wdt_ping,
179 .set_timeout = wm831x_wdt_set_timeout,
Mark Brown502a0102009-07-27 14:46:12 +0100180};
181
182static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
183{
Mark Brown00411ee2011-10-04 16:43:40 +0100184 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
Mark Brown502a0102009-07-27 14:46:12 +0100185 struct wm831x_pdata *chip_pdata;
186 struct wm831x_watchdog_pdata *pdata;
Mark Brown00411ee2011-10-04 16:43:40 +0100187 struct wm831x_wdt_drvdata *driver_data;
188 struct watchdog_device *wm831x_wdt;
189 int reg, ret, i;
Mark Brown502a0102009-07-27 14:46:12 +0100190
191 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
192 if (ret < 0) {
193 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
194 ret);
195 goto err;
196 }
197 reg = ret;
198
199 if (reg & WM831X_WDOG_DEBUG)
200 dev_warn(wm831x->dev, "Watchdog is paused\n");
201
Mark Brown00411ee2011-10-04 16:43:40 +0100202 driver_data = kzalloc(sizeof(*driver_data), GFP_KERNEL);
203 if (!driver_data) {
204 dev_err(wm831x->dev, "Unable to alloacate watchdog device\n");
205 ret = -ENOMEM;
206 goto err;
207 }
208
209 mutex_init(&driver_data->lock);
210 driver_data->wm831x = wm831x;
211
212 wm831x_wdt = &driver_data->wdt;
213
214 wm831x_wdt->info = &wm831x_wdt_info;
215 wm831x_wdt->ops = &wm831x_wdt_ops;
216 watchdog_set_drvdata(wm831x_wdt, driver_data);
217
218 if (nowayout)
219 wm831x_wdt->status |= WDOG_NO_WAY_OUT;
220
221 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
222 reg &= WM831X_WDOG_TO_MASK;
223 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
224 if (wm831x_wdt_cfgs[i].val == reg)
225 break;
226 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
227 dev_warn(wm831x->dev,
228 "Unknown watchdog timeout: %x\n", reg);
229 else
230 wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
231
Mark Brown502a0102009-07-27 14:46:12 +0100232 /* Apply any configuration */
233 if (pdev->dev.parent->platform_data) {
234 chip_pdata = pdev->dev.parent->platform_data;
235 pdata = chip_pdata->watchdog;
236 } else {
237 pdata = NULL;
238 }
239
240 if (pdata) {
241 reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
242 WM831X_WDOG_RST_SRC);
243
244 reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
245 reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
246 reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
247
248 if (pdata->update_gpio) {
249 ret = gpio_request(pdata->update_gpio,
250 "Watchdog update");
251 if (ret < 0) {
252 dev_err(wm831x->dev,
253 "Failed to request update GPIO: %d\n",
254 ret);
Mark Brown00411ee2011-10-04 16:43:40 +0100255 goto err_alloc;
Mark Brown502a0102009-07-27 14:46:12 +0100256 }
257
258 ret = gpio_direction_output(pdata->update_gpio, 0);
259 if (ret != 0) {
260 dev_err(wm831x->dev,
261 "gpio_direction_output returned: %d\n",
262 ret);
263 goto err_gpio;
264 }
265
Mark Brown00411ee2011-10-04 16:43:40 +0100266 driver_data->update_gpio = pdata->update_gpio;
Mark Brown502a0102009-07-27 14:46:12 +0100267
268 /* Make sure the watchdog takes hardware updates */
269 reg |= WM831X_WDOG_RST_SRC;
270 }
271
272 ret = wm831x_reg_unlock(wm831x);
273 if (ret == 0) {
274 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
275 wm831x_reg_lock(wm831x);
276 } else {
277 dev_err(wm831x->dev,
278 "Failed to unlock security key: %d\n", ret);
279 goto err_gpio;
280 }
281 }
282
Mark Brown00411ee2011-10-04 16:43:40 +0100283 ret = watchdog_register_device(&driver_data->wdt);
Mark Brown502a0102009-07-27 14:46:12 +0100284 if (ret != 0) {
Mark Brown00411ee2011-10-04 16:43:40 +0100285 dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
286 ret);
Mark Brown502a0102009-07-27 14:46:12 +0100287 goto err_gpio;
288 }
289
Mark Brown00411ee2011-10-04 16:43:40 +0100290 dev_set_drvdata(&pdev->dev, driver_data);
291
Mark Brown502a0102009-07-27 14:46:12 +0100292 return 0;
293
294err_gpio:
Mark Brown00411ee2011-10-04 16:43:40 +0100295 if (driver_data->update_gpio)
296 gpio_free(driver_data->update_gpio);
297err_alloc:
298 kfree(driver_data);
Mark Brown502a0102009-07-27 14:46:12 +0100299err:
300 return ret;
301}
302
303static int __devexit wm831x_wdt_remove(struct platform_device *pdev)
304{
Mark Brown00411ee2011-10-04 16:43:40 +0100305 struct wm831x_wdt_drvdata *driver_data = dev_get_drvdata(&pdev->dev);
Mark Brown502a0102009-07-27 14:46:12 +0100306
Mark Brown00411ee2011-10-04 16:43:40 +0100307 watchdog_unregister_device(&driver_data->wdt);
308
309 if (driver_data->update_gpio)
310 gpio_free(driver_data->update_gpio);
Mark Brown502a0102009-07-27 14:46:12 +0100311
312 return 0;
313}
314
315static struct platform_driver wm831x_wdt_driver = {
316 .probe = wm831x_wdt_probe,
317 .remove = __devexit_p(wm831x_wdt_remove),
318 .driver = {
319 .name = "wm831x-watchdog",
320 },
321};
322
323static int __init wm831x_wdt_init(void)
324{
325 return platform_driver_register(&wm831x_wdt_driver);
326}
327module_init(wm831x_wdt_init);
328
329static void __exit wm831x_wdt_exit(void)
330{
331 platform_driver_unregister(&wm831x_wdt_driver);
332}
333module_exit(wm831x_wdt_exit);
334
335MODULE_AUTHOR("Mark Brown");
336MODULE_DESCRIPTION("WM831x Watchdog");
337MODULE_LICENSE("GPL");
338MODULE_ALIAS("platform:wm831x-watchdog");