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rtc: DA9055 RTC driver
[~shefty/rdma-dev.git] / drivers / rtc / rtc-da9055.c
1 /*
2  * Real time clock driver for DA9055
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
19 #include <linux/mfd/da9055/core.h>
20 #include <linux/mfd/da9055/reg.h>
21 #include <linux/mfd/da9055/pdata.h>
22
23 struct da9055_rtc {
24         struct rtc_device *rtc;
25         struct da9055 *da9055;
26         int alarm_enable;
27 };
28
29 static int da9055_rtc_enable_alarm(struct da9055_rtc *rtc, bool enable)
30 {
31         int ret;
32         if (enable) {
33                 ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
34                                         DA9055_RTC_ALM_EN,
35                                         DA9055_RTC_ALM_EN);
36                 if (ret != 0)
37                         dev_err(rtc->da9055->dev, "Failed to enable ALM: %d\n",
38                                 ret);
39                 rtc->alarm_enable = 1;
40         } else {
41                 ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
42                                         DA9055_RTC_ALM_EN, 0);
43                 if (ret != 0)
44                         dev_err(rtc->da9055->dev,
45                                 "Failed to disable ALM: %d\n", ret);
46                 rtc->alarm_enable = 0;
47         }
48         return ret;
49 }
50
51 static irqreturn_t da9055_rtc_alm_irq(int irq, void *data)
52 {
53         struct da9055_rtc *rtc = data;
54
55         da9055_rtc_enable_alarm(rtc, 0);
56         rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
57
58         return IRQ_HANDLED;
59 }
60
61 static int da9055_read_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
62 {
63         int ret;
64         uint8_t v[5];
65
66         ret = da9055_group_read(da9055, DA9055_REG_ALARM_MI, 5, v);
67         if (ret != 0) {
68                 dev_err(da9055->dev, "Failed to group read ALM: %d\n", ret);
69                 return ret;
70         }
71
72         rtc_tm->tm_year = (v[4] & DA9055_RTC_ALM_YEAR) + 100;
73         rtc_tm->tm_mon  = (v[3] & DA9055_RTC_ALM_MONTH) - 1;
74         rtc_tm->tm_mday = v[2] & DA9055_RTC_ALM_DAY;
75         rtc_tm->tm_hour = v[1] & DA9055_RTC_ALM_HOUR;
76         rtc_tm->tm_min  = v[0] & DA9055_RTC_ALM_MIN;
77
78         return rtc_valid_tm(rtc_tm);
79 }
80
81 static int da9055_set_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
82 {
83         int ret;
84         uint8_t v[2];
85
86         rtc_tm->tm_year -= 100;
87         rtc_tm->tm_mon += 1;
88
89         ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MI,
90                                 DA9055_RTC_ALM_MIN, rtc_tm->tm_min);
91         if (ret != 0) {
92                 dev_err(da9055->dev, "Failed to write ALRM MIN: %d\n", ret);
93                 return ret;
94         }
95
96         v[0] = rtc_tm->tm_hour;
97         v[1] = rtc_tm->tm_mday;
98
99         ret = da9055_group_write(da9055, DA9055_REG_ALARM_H, 2, v);
100         if (ret < 0)
101                 return ret;
102
103         ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
104                                 DA9055_RTC_ALM_MONTH, rtc_tm->tm_mon);
105         if (ret < 0)
106                 dev_err(da9055->dev, "Failed to write ALM Month:%d\n", ret);
107
108         ret = da9055_reg_update(da9055, DA9055_REG_ALARM_Y,
109                                 DA9055_RTC_ALM_YEAR, rtc_tm->tm_year);
110         if (ret < 0)
111                 dev_err(da9055->dev, "Failed to write ALM Year:%d\n", ret);
112
113         return ret;
114 }
115
116 static int da9055_rtc_get_alarm_status(struct da9055 *da9055)
117 {
118         int ret;
119
120         ret = da9055_reg_read(da9055, DA9055_REG_ALARM_Y);
121         if (ret < 0) {
122                 dev_err(da9055->dev, "Failed to read ALM: %d\n", ret);
123                 return ret;
124         }
125         ret &= DA9055_RTC_ALM_EN;
126         return (ret > 0) ? 1 : 0;
127 }
128
129 static int da9055_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
130 {
131         struct da9055_rtc *rtc = dev_get_drvdata(dev);
132         uint8_t v[6];
133         int ret;
134
135         ret = da9055_reg_read(rtc->da9055, DA9055_REG_COUNT_S);
136         if (ret < 0)
137                 return ret;
138
139         /*
140          * Registers are only valid when RTC_READ
141          * status bit is asserted
142          */
143         if (!(ret & DA9055_RTC_READ))
144                 return -EBUSY;
145
146         ret = da9055_group_read(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
147         if (ret < 0) {
148                 dev_err(rtc->da9055->dev, "Failed to read RTC time : %d\n",
149                         ret);
150                 return ret;
151         }
152
153         rtc_tm->tm_year = (v[5] & DA9055_RTC_YEAR) + 100;
154         rtc_tm->tm_mon  = (v[4] & DA9055_RTC_MONTH) - 1;
155         rtc_tm->tm_mday = v[3] & DA9055_RTC_DAY;
156         rtc_tm->tm_hour = v[2] & DA9055_RTC_HOUR;
157         rtc_tm->tm_min  = v[1] & DA9055_RTC_MIN;
158         rtc_tm->tm_sec  = v[0] & DA9055_RTC_SEC;
159
160         return rtc_valid_tm(rtc_tm);
161 }
162
163 static int da9055_rtc_set_time(struct device *dev, struct rtc_time *tm)
164 {
165         struct da9055_rtc *rtc;
166         uint8_t v[6];
167
168         rtc = dev_get_drvdata(dev);
169
170         v[0] = tm->tm_sec;
171         v[1] = tm->tm_min;
172         v[2] = tm->tm_hour;
173         v[3] = tm->tm_mday;
174         v[4] = tm->tm_mon + 1;
175         v[5] = tm->tm_year - 100;
176
177         return da9055_group_write(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
178 }
179
180 static int da9055_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
181 {
182         int ret;
183         struct rtc_time *tm = &alrm->time;
184         struct da9055_rtc *rtc = dev_get_drvdata(dev);
185
186         ret = da9055_read_alarm(rtc->da9055, tm);
187
188         if (ret)
189                 return ret;
190
191         alrm->enabled = da9055_rtc_get_alarm_status(rtc->da9055);
192
193         return 0;
194 }
195
196 static int da9055_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
197 {
198         int ret;
199         struct rtc_time *tm = &alrm->time;
200         struct da9055_rtc *rtc = dev_get_drvdata(dev);
201
202         ret = da9055_rtc_enable_alarm(rtc, 0);
203         if (ret < 0)
204                 return ret;
205
206         ret = da9055_set_alarm(rtc->da9055, tm);
207         if (ret)
208                 return ret;
209
210         ret = da9055_rtc_enable_alarm(rtc, 1);
211
212         return ret;
213 }
214
215 static int da9055_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
216 {
217         struct da9055_rtc *rtc = dev_get_drvdata(dev);
218
219         return da9055_rtc_enable_alarm(rtc, enabled);
220 }
221
222 static const struct rtc_class_ops da9055_rtc_ops = {
223         .read_time      = da9055_rtc_read_time,
224         .set_time       = da9055_rtc_set_time,
225         .read_alarm     = da9055_rtc_read_alarm,
226         .set_alarm      = da9055_rtc_set_alarm,
227         .alarm_irq_enable = da9055_rtc_alarm_irq_enable,
228 };
229
230 static int __init da9055_rtc_device_init(struct da9055 *da9055,
231                                         struct da9055_pdata *pdata)
232 {
233         int ret;
234
235         /* Enable RTC and the internal Crystal */
236         ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
237                                 DA9055_RTC_EN, DA9055_RTC_EN);
238         if (ret < 0)
239                 return ret;
240         ret = da9055_reg_update(da9055, DA9055_REG_EN_32K,
241                                 DA9055_CRYSTAL_EN, DA9055_CRYSTAL_EN);
242         if (ret < 0)
243                 return ret;
244
245         /* Enable RTC in Power Down mode */
246         ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
247                                 DA9055_RTC_MODE_PD, DA9055_RTC_MODE_PD);
248         if (ret < 0)
249                 return ret;
250
251         /* Enable RTC in Reset mode */
252         if (pdata && pdata->reset_enable) {
253                 ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
254                                         DA9055_RTC_MODE_SD,
255                                         DA9055_RTC_MODE_SD <<
256                                         DA9055_RTC_MODE_SD_SHIFT);
257                 if (ret < 0)
258                         return ret;
259         }
260
261         /* Disable the RTC TICK ALM */
262         ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
263                                 DA9055_RTC_TICK_WAKE_MASK, 0);
264         if (ret < 0)
265                 return ret;
266
267         return 0;
268 }
269
270 static int da9055_rtc_probe(struct platform_device *pdev)
271 {
272         struct da9055_rtc *rtc;
273         struct da9055_pdata *pdata = NULL;
274         int ret, alm_irq;
275
276         rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9055_rtc), GFP_KERNEL);
277         if (!rtc)
278                 return -ENOMEM;
279
280         rtc->da9055 = dev_get_drvdata(pdev->dev.parent);
281         pdata = rtc->da9055->dev->platform_data;
282         platform_set_drvdata(pdev, rtc);
283
284         ret = da9055_rtc_device_init(rtc->da9055, pdata);
285         if (ret < 0)
286                 goto err_rtc;
287
288         ret = da9055_reg_read(rtc->da9055, DA9055_REG_ALARM_Y);
289         if (ret < 0)
290                 goto err_rtc;
291
292         if (ret & DA9055_RTC_ALM_EN)
293                 rtc->alarm_enable = 1;
294
295         device_init_wakeup(&pdev->dev, 1);
296
297         rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
298                                         &da9055_rtc_ops, THIS_MODULE);
299         if (IS_ERR(rtc->rtc)) {
300                 ret = PTR_ERR(rtc->rtc);
301                 goto err_rtc;
302         }
303
304         alm_irq = platform_get_irq_byname(pdev, "ALM");
305         alm_irq = regmap_irq_get_virq(rtc->da9055->irq_data, alm_irq);
306         ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL,
307                                         da9055_rtc_alm_irq,
308                                         IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
309                                         "ALM", rtc);
310         if (ret != 0)
311                 dev_err(rtc->da9055->dev, "irq registration failed: %d\n", ret);
312
313 err_rtc:
314         return ret;
315
316 }
317
318 static int da9055_rtc_remove(struct platform_device *pdev)
319 {
320         struct da9055_rtc *rtc = pdev->dev.platform_data;
321
322         rtc_device_unregister(rtc->rtc);
323         platform_set_drvdata(pdev, NULL);
324
325         return 0;
326 }
327
328 #ifdef CONFIG_PM
329 /* Turn off the alarm if it should not be a wake source. */
330 static int da9055_rtc_suspend(struct device *dev)
331 {
332         struct platform_device *pdev = to_platform_device(dev);
333         struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
334         int ret;
335
336         if (!device_may_wakeup(&pdev->dev)) {
337                 /* Disable the ALM IRQ */
338                 ret = da9055_rtc_enable_alarm(rtc, 0);
339                 if (ret < 0)
340                         dev_err(&pdev->dev, "Failed to disable RTC ALM\n");
341         }
342
343         return 0;
344 }
345
346 /* Enable the alarm if it should be enabled (in case it was disabled to
347  * prevent use as a wake source).
348  */
349 static int da9055_rtc_resume(struct device *dev)
350 {
351         struct platform_device *pdev = to_platform_device(dev);
352         struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
353         int ret;
354
355         if (!device_may_wakeup(&pdev->dev)) {
356                 if (rtc->alarm_enable) {
357                         ret = da9055_rtc_enable_alarm(rtc, 1);
358                         if (ret < 0)
359                                 dev_err(&pdev->dev,
360                                         "Failed to restart RTC ALM\n");
361                 }
362         }
363
364         return 0;
365 }
366
367 /* Unconditionally disable the alarm */
368 static int da9055_rtc_freeze(struct device *dev)
369 {
370         struct platform_device *pdev = to_platform_device(dev);
371         struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
372         int ret;
373
374         ret = da9055_rtc_enable_alarm(rtc, 0);
375         if (ret < 0)
376                 dev_err(&pdev->dev, "Failed to freeze RTC ALMs\n");
377
378         return 0;
379
380 }
381 #else
382 #define da9055_rtc_suspend NULL
383 #define da9055_rtc_resume NULL
384 #define da9055_rtc_freeze NULL
385 #endif
386
387 static const struct dev_pm_ops da9055_rtc_pm_ops = {
388         .suspend = da9055_rtc_suspend,
389         .resume = da9055_rtc_resume,
390
391         .freeze = da9055_rtc_freeze,
392         .thaw = da9055_rtc_resume,
393         .restore = da9055_rtc_resume,
394
395         .poweroff = da9055_rtc_suspend,
396 };
397
398 static struct platform_driver da9055_rtc_driver = {
399         .probe  = da9055_rtc_probe,
400         .remove = da9055_rtc_remove,
401         .driver = {
402                 .name   = "da9055-rtc",
403                 .owner  = THIS_MODULE,
404                 .pm = &da9055_rtc_pm_ops,
405         },
406 };
407
408 module_platform_driver(da9055_rtc_driver);
409
410 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
411 MODULE_DESCRIPTION("RTC driver for Dialog DA9055 PMIC");
412 MODULE_LICENSE("GPL");
413 MODULE_ALIAS("platform:da9055-rtc");