Version:  2.0.40 2.2.26 2.4.37 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7

Linux/drivers/watchdog/da9052_wdt.c

  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>
 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         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 
 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 
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,
154 };
155 
156 
157 static int da9052_wdt_probe(struct platform_device *pdev)
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) {
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;
177         da9052_wdt->parent = &pdev->dev;
178         watchdog_set_drvdata(da9052_wdt, driver_data);
179 
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 
195         platform_set_drvdata(pdev, driver_data);
196 err:
197         return ret;
198 }
199 
200 static int da9052_wdt_remove(struct platform_device *pdev)
201 {
202         struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev);
203 
204         watchdog_unregister_device(&driver_data->wdt);
205 
206         return 0;
207 }
208 
209 static struct platform_driver da9052_wdt_driver = {
210         .probe = da9052_wdt_probe,
211         .remove = da9052_wdt_remove,
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");
223 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us