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Linux/drivers/rtc/rtc-da9052.c

  1 /*
  2  * Real time clock driver for DA9052
  3  *
  4  * Copyright(c) 2012 Dialog Semiconductor Ltd.
  5  *
  6  * Author: Dajun Dajun Chen <dajun.chen@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/platform_device.h>
 17 #include <linux/rtc.h>
 18 #include <linux/err.h>
 19 #include <linux/delay.h>
 20 
 21 #include <linux/mfd/da9052/da9052.h>
 22 #include <linux/mfd/da9052/reg.h>
 23 
 24 #define rtc_err(rtc, fmt, ...) \
 25                 dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
 26 
 27 #define DA9052_GET_TIME_RETRIES 5
 28 
 29 struct da9052_rtc {
 30         struct rtc_device *rtc;
 31         struct da9052 *da9052;
 32 };
 33 
 34 static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
 35 {
 36         int ret;
 37         if (enable) {
 38                 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
 39                                 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
 40                                 DA9052_ALARM_Y_ALARM_ON);
 41                 if (ret != 0)
 42                         rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
 43         } else {
 44                 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
 45                         DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
 46                 if (ret != 0)
 47                         rtc_err(rtc, "Write error: %d\n", ret);
 48         }
 49         return ret;
 50 }
 51 
 52 static irqreturn_t da9052_rtc_irq(int irq, void *data)
 53 {
 54         struct da9052_rtc *rtc = data;
 55 
 56         rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
 57 
 58         return IRQ_HANDLED;
 59 }
 60 
 61 static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
 62 {
 63         int ret;
 64         uint8_t v[2][5];
 65         int idx = 1;
 66         int timeout = DA9052_GET_TIME_RETRIES;
 67 
 68         ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
 69         if (ret) {
 70                 rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
 71                 return ret;
 72         }
 73 
 74         do {
 75                 ret = da9052_group_read(rtc->da9052,
 76                                         DA9052_ALARM_MI_REG, 5, &v[idx][0]);
 77                 if (ret) {
 78                         rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
 79                         return ret;
 80                 }
 81 
 82                 if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
 83                         rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
 84                         rtc_tm->tm_mon  = (v[0][3] & DA9052_RTC_MONTH) - 1;
 85                         rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
 86                         rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
 87                         rtc_tm->tm_min  = v[0][0] & DA9052_RTC_MIN;
 88 
 89                         ret = rtc_valid_tm(rtc_tm);
 90                         return ret;
 91                 }
 92 
 93                 idx = (1-idx);
 94                 msleep(20);
 95 
 96         } while (timeout--);
 97 
 98         rtc_err(rtc, "Timed out reading alarm time\n");
 99 
100         return -EIO;
101 }
102 
103 static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
104 {
105         struct da9052 *da9052 = rtc->da9052;
106         unsigned long alm_time;
107         int ret;
108         uint8_t v[3];
109 
110         ret = rtc_tm_to_time(rtc_tm, &alm_time);
111         if (ret != 0)
112                 return ret;
113 
114         if (rtc_tm->tm_sec > 0) {
115                 alm_time += 60 - rtc_tm->tm_sec;
116                 rtc_time_to_tm(alm_time, rtc_tm);
117         }
118         BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
119 
120         rtc_tm->tm_year -= 100;
121         rtc_tm->tm_mon += 1;
122 
123         ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
124                                 DA9052_RTC_MIN, rtc_tm->tm_min);
125         if (ret != 0) {
126                 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
127                 return ret;
128         }
129 
130         v[0] = rtc_tm->tm_hour;
131         v[1] = rtc_tm->tm_mday;
132         v[2] = rtc_tm->tm_mon;
133 
134         ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
135         if (ret < 0)
136                 return ret;
137 
138         ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
139                                 DA9052_RTC_YEAR, rtc_tm->tm_year);
140         if (ret != 0)
141                 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
142 
143         return ret;
144 }
145 
146 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
147 {
148         int ret;
149 
150         ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
151         if (ret < 0) {
152                 rtc_err(rtc, "Failed to read ALM: %d\n", ret);
153                 return ret;
154         }
155 
156         return !!(ret&DA9052_ALARM_Y_ALARM_ON);
157 }
158 
159 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
160 {
161         struct da9052_rtc *rtc = dev_get_drvdata(dev);
162         int ret;
163         uint8_t v[2][6];
164         int idx = 1;
165         int timeout = DA9052_GET_TIME_RETRIES;
166 
167         ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
168         if (ret) {
169                 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
170                 return ret;
171         }
172 
173         do {
174                 ret = da9052_group_read(rtc->da9052,
175                                         DA9052_COUNT_S_REG, 6, &v[idx][0]);
176                 if (ret) {
177                         rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
178                         return ret;
179                 }
180 
181                 if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
182                         rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
183                         rtc_tm->tm_mon  = (v[0][4] & DA9052_RTC_MONTH) - 1;
184                         rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
185                         rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
186                         rtc_tm->tm_min  = v[0][1] & DA9052_RTC_MIN;
187                         rtc_tm->tm_sec  = v[0][0] & DA9052_RTC_SEC;
188 
189                         ret = rtc_valid_tm(rtc_tm);
190                         return ret;
191                 }
192 
193                 idx = (1-idx);
194                 msleep(20);
195 
196         } while (timeout--);
197 
198         rtc_err(rtc, "Timed out reading time\n");
199 
200         return -EIO;
201 }
202 
203 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
204 {
205         struct da9052_rtc *rtc;
206         uint8_t v[6];
207         int ret;
208 
209         /* DA9052 only has 6 bits for year - to represent 2000-2063 */
210         if ((tm->tm_year < 100) || (tm->tm_year > 163))
211                 return -EINVAL;
212 
213         rtc = dev_get_drvdata(dev);
214 
215         v[0] = tm->tm_sec;
216         v[1] = tm->tm_min;
217         v[2] = tm->tm_hour;
218         v[3] = tm->tm_mday;
219         v[4] = tm->tm_mon + 1;
220         v[5] = tm->tm_year - 100;
221 
222         ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
223         if (ret < 0)
224                 rtc_err(rtc, "failed to set RTC time: %d\n", ret);
225         return ret;
226 }
227 
228 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
229 {
230         int ret;
231         struct rtc_time *tm = &alrm->time;
232         struct da9052_rtc *rtc = dev_get_drvdata(dev);
233 
234         ret = da9052_read_alarm(rtc, tm);
235         if (ret < 0) {
236                 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
237                 return ret;
238         }
239 
240         alrm->enabled = da9052_rtc_get_alarm_status(rtc);
241         return 0;
242 }
243 
244 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
245 {
246         int ret;
247         struct rtc_time *tm = &alrm->time;
248         struct da9052_rtc *rtc = dev_get_drvdata(dev);
249 
250         /* DA9052 only has 6 bits for year - to represent 2000-2063 */
251         if ((tm->tm_year < 100) || (tm->tm_year > 163))
252                 return -EINVAL;
253 
254         ret = da9052_rtc_enable_alarm(rtc, 0);
255         if (ret < 0)
256                 return ret;
257 
258         ret = da9052_set_alarm(rtc, tm);
259         if (ret < 0)
260                 return ret;
261 
262         ret = da9052_rtc_enable_alarm(rtc, 1);
263         return ret;
264 }
265 
266 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
267 {
268         struct da9052_rtc *rtc = dev_get_drvdata(dev);
269 
270         return da9052_rtc_enable_alarm(rtc, enabled);
271 }
272 
273 static const struct rtc_class_ops da9052_rtc_ops = {
274         .read_time      = da9052_rtc_read_time,
275         .set_time       = da9052_rtc_set_time,
276         .read_alarm     = da9052_rtc_read_alarm,
277         .set_alarm      = da9052_rtc_set_alarm,
278         .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
279 };
280 
281 static int da9052_rtc_probe(struct platform_device *pdev)
282 {
283         struct da9052_rtc *rtc;
284         int ret;
285 
286         rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
287         if (!rtc)
288                 return -ENOMEM;
289 
290         rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
291         platform_set_drvdata(pdev, rtc);
292 
293         ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
294         if (ret < 0) {
295                 rtc_err(rtc,
296                         "Failed to setup RTC battery charging: %d\n", ret);
297                 return ret;
298         }
299 
300         ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
301                                 DA9052_ALARM_Y_TICK_ON, 0);
302         if (ret != 0)
303                 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
304 
305         ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
306                                 da9052_rtc_irq, rtc);
307         if (ret != 0) {
308                 rtc_err(rtc, "irq registration failed: %d\n", ret);
309                 return ret;
310         }
311 
312         device_init_wakeup(&pdev->dev, true);
313 
314         rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
315                                        &da9052_rtc_ops, THIS_MODULE);
316         return PTR_ERR_OR_ZERO(rtc->rtc);
317 }
318 
319 static struct platform_driver da9052_rtc_driver = {
320         .probe  = da9052_rtc_probe,
321         .driver = {
322                 .name   = "da9052-rtc",
323         },
324 };
325 
326 module_platform_driver(da9052_rtc_driver);
327 
328 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
329 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
330 MODULE_LICENSE("GPL");
331 MODULE_ALIAS("platform:da9052-rtc");
332 

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