rtc: Add max77660 rtc driver
[linux-3.10.git] / drivers / rtc / rtc-tps80031.c
1 /*
2  * rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver
3  *
4  * RTC driver for TI TPS80031/TPS80032 Fully Integrated
5  * Power Management with Power Path and Battery Charger
6  *
7  * Copyright (c) 2012, NVIDIA Corporation.
8  *
9  * Author: Laxman Dewangan <ldewangan@nvidia.com>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation version 2.
14  *
15  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
16  * whether express or implied; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23  * 02111-1307, USA
24  */
25
26 #include <linux/bcd.h>
27 #include <linux/device.h>
28 #include <linux/err.h>
29 #include <linux/init.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/mfd/tps80031.h>
33 #include <linux/platform_device.h>
34 #include <linux/pm.h>
35 #include <linux/rtc.h>
36 #include <linux/slab.h>
37
38 #define ENABLE_ALARM_INT                        0x08
39 #define ALARM_INT_STATUS                        0x40
40
41 /**
42  * Setting bit to 1 in STOP_RTC will run the RTC and
43  * setting this bit to 0 will freeze RTC.
44  */
45 #define STOP_RTC                                0x1
46
47 /* Power on reset Values of RTC registers */
48 #define TPS80031_RTC_POR_YEAR                   0
49 #define TPS80031_RTC_POR_MONTH                  1
50 #define TPS80031_RTC_POR_DAY                    1
51
52 /* Numbers of registers for time and alarms */
53 #define TPS80031_RTC_TIME_NUM_REGS              7
54 #define TPS80031_RTC_ALARM_NUM_REGS             6
55
56 /**
57  * PMU RTC have only 2 nibbles to store year information, so using an
58  * offset of 100 to set the base year as 2000 for our driver.
59  */
60 #define RTC_YEAR_OFFSET 100
61
62 struct tps80031_rtc {
63         struct rtc_device       *rtc;
64         int                     irq;
65 };
66
67 static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm)
68 {
69         u8 buff[TPS80031_RTC_TIME_NUM_REGS];
70         int ret;
71
72         ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
73                         TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff);
74         if (ret < 0) {
75                 dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret);
76                 return ret;
77         }
78
79         tm->tm_sec = bcd2bin(buff[0]);
80         tm->tm_min = bcd2bin(buff[1]);
81         tm->tm_hour = bcd2bin(buff[2]);
82         tm->tm_mday = bcd2bin(buff[3]);
83         tm->tm_mon = bcd2bin(buff[4]) - 1;
84         tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
85         tm->tm_wday = bcd2bin(buff[6]);
86         return 0;
87 }
88
89 static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm)
90 {
91         u8 buff[7];
92         int ret;
93
94         buff[0] = bin2bcd(tm->tm_sec);
95         buff[1] = bin2bcd(tm->tm_min);
96         buff[2] = bin2bcd(tm->tm_hour);
97         buff[3] = bin2bcd(tm->tm_mday);
98         buff[4] = bin2bcd(tm->tm_mon + 1);
99         buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET);
100         buff[6] = bin2bcd(tm->tm_wday);
101
102         /* Stop RTC while updating the RTC time registers */
103         ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
104                                 TPS80031_RTC_CTRL_REG, STOP_RTC);
105         if (ret < 0) {
106                 dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret);
107                 return ret;
108         }
109
110         ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
111                         TPS80031_SECONDS_REG,
112                         TPS80031_RTC_TIME_NUM_REGS, buff);
113         if (ret < 0) {
114                 dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret);
115                 return ret;
116         }
117
118         ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
119                                 TPS80031_RTC_CTRL_REG, STOP_RTC);
120         if (ret < 0)
121                 dev_err(dev->parent, "Start RTC failed, err = %d\n", ret);
122         return ret;
123 }
124
125 static int tps80031_rtc_alarm_irq_enable(struct device *dev,
126                                          unsigned int enable)
127 {
128         int ret;
129
130         if (enable)
131                 ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
132                                 TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
133         else
134                 ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
135                                 TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
136         if (ret < 0) {
137                 dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret);
138                 return ret;
139         }
140         return 0;
141 }
142
143 static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
144 {
145         u8 buff[TPS80031_RTC_ALARM_NUM_REGS];
146         int ret;
147
148         buff[0] = bin2bcd(alrm->time.tm_sec);
149         buff[1] = bin2bcd(alrm->time.tm_min);
150         buff[2] = bin2bcd(alrm->time.tm_hour);
151         buff[3] = bin2bcd(alrm->time.tm_mday);
152         buff[4] = bin2bcd(alrm->time.tm_mon + 1);
153         buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET);
154         ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
155                         TPS80031_ALARM_SECONDS_REG,
156                         TPS80031_RTC_ALARM_NUM_REGS, buff);
157         if (ret < 0) {
158                 dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret);
159                 return ret;
160         }
161         return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled);
162 }
163
164 static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
165 {
166         u8 buff[6];
167         int ret;
168
169         ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
170                         TPS80031_ALARM_SECONDS_REG,
171                         TPS80031_RTC_ALARM_NUM_REGS, buff);
172         if (ret < 0) {
173                 dev_err(dev->parent,
174                         "reading RTC_ALARM failed, err = %d\n", ret);
175                 return ret;
176         }
177
178         alrm->time.tm_sec = bcd2bin(buff[0]);
179         alrm->time.tm_min = bcd2bin(buff[1]);
180         alrm->time.tm_hour = bcd2bin(buff[2]);
181         alrm->time.tm_mday = bcd2bin(buff[3]);
182         alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
183         alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
184         return 0;
185 }
186
187 static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc)
188 {
189         int ret;
190         u8 buf;
191
192         /**
193          * As per datasheet, A dummy read of this  RTC_STATUS_REG register
194          * is necessary before each I2C read in order to update the status
195          * register value.
196          */
197         ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1,
198                                 TPS80031_RTC_STATUS_REG, &buf);
199         if (ret < 0) {
200                 dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret);
201                 return ret;
202         }
203
204         /* clear Alarm status bits.*/
205         ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
206                         TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS);
207         if (ret < 0) {
208                 dev_err(dev, "clear Alarm INT failed, err = %d\n", ret);
209                 return ret;
210         }
211         return 0;
212 }
213
214 static irqreturn_t tps80031_rtc_irq(int irq, void *data)
215 {
216         struct device *dev = data;
217         struct tps80031_rtc *rtc = dev_get_drvdata(dev);
218         int ret;
219
220         ret = clear_alarm_int_status(dev, rtc);
221         if (ret < 0)
222                 return ret;
223
224         rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
225         return IRQ_HANDLED;
226 }
227
228 static const struct rtc_class_ops tps80031_rtc_ops = {
229         .read_time = tps80031_rtc_read_time,
230         .set_time = tps80031_rtc_set_time,
231         .set_alarm = tps80031_rtc_set_alarm,
232         .read_alarm = tps80031_rtc_read_alarm,
233         .alarm_irq_enable = tps80031_rtc_alarm_irq_enable,
234 };
235
236 static int tps80031_rtc_probe(struct platform_device *pdev)
237 {
238         struct tps80031_rtc *rtc;
239         struct rtc_time tm;
240         int ret;
241
242         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
243         if (!rtc)
244                 return -ENOMEM;
245
246         rtc->irq = platform_get_irq(pdev, 0);
247         platform_set_drvdata(pdev, rtc);
248
249         /* Start RTC */
250         ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1,
251                         TPS80031_RTC_CTRL_REG, STOP_RTC);
252         if (ret < 0) {
253                 dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret);
254                 return ret;
255         }
256
257         /* If RTC have POR values, set time 01:01:2000 */
258         tps80031_rtc_read_time(&pdev->dev, &tm);
259         if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) &&
260                 (tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) &&
261                 (tm.tm_mday == TPS80031_RTC_POR_DAY)) {
262                 tm.tm_year = 2000;
263                 tm.tm_mday = 1;
264                 tm.tm_mon = 1;
265                 ret = tps80031_rtc_set_time(&pdev->dev, &tm);
266                 if (ret < 0) {
267                         dev_err(&pdev->dev,
268                                 "RTC set time failed, err = %d\n", ret);
269                         return ret;
270                 }
271         }
272
273         /* Clear alarm intretupt status if it is there */
274         ret = clear_alarm_int_status(&pdev->dev, rtc);
275         if (ret < 0) {
276                 dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret);
277                 return ret;
278         }
279
280         rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
281                                &tps80031_rtc_ops, THIS_MODULE);
282         if (IS_ERR(rtc->rtc)) {
283                 ret = PTR_ERR(rtc->rtc);
284                 dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret);
285                 return ret;
286         }
287
288         ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
289                         tps80031_rtc_irq,
290                         IRQF_ONESHOT | IRQF_EARLY_RESUME,
291                         dev_name(&pdev->dev), rtc);
292         if (ret < 0) {
293                 dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
294                          rtc->irq, ret);
295                 return ret;
296         }
297         device_set_wakeup_capable(&pdev->dev, 1);
298         return 0;
299 }
300
301 static int tps80031_rtc_remove(struct platform_device *pdev)
302 {
303         return 0;
304 }
305
306 #ifdef CONFIG_PM_SLEEP
307 static int tps80031_rtc_suspend(struct device *dev)
308 {
309         struct tps80031_rtc *rtc = dev_get_drvdata(dev);
310
311         if (device_may_wakeup(dev))
312                 enable_irq_wake(rtc->irq);
313         return 0;
314 }
315
316 static int tps80031_rtc_resume(struct device *dev)
317 {
318         struct tps80031_rtc *rtc = dev_get_drvdata(dev);
319
320         if (device_may_wakeup(dev))
321                 disable_irq_wake(rtc->irq);
322         return 0;
323 };
324 #endif
325
326 static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend,
327                         tps80031_rtc_resume);
328
329 static struct platform_driver tps80031_rtc_driver = {
330         .driver = {
331                 .name   = "tps80031-rtc",
332                 .owner  = THIS_MODULE,
333                 .pm     = &tps80031_pm_ops,
334         },
335         .probe  = tps80031_rtc_probe,
336         .remove = tps80031_rtc_remove,
337 };
338
339 module_platform_driver(tps80031_rtc_driver);
340
341 MODULE_ALIAS("platform:tps80031-rtc");
342 MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver");
343 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
344 MODULE_LICENSE("GPL v2");