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