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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Real time clock driver for DA9055
4 *
5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
6 *
7 * Author: Dajun Dajun Chen <[email protected]>
8 */
9
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/rtc.h>
13
14#include <linux/mfd/da9055/core.h>
15#include <linux/mfd/da9055/reg.h>
16#include <linux/mfd/da9055/pdata.h>
17
18struct da9055_rtc {
19 struct rtc_device *rtc;
20 struct da9055 *da9055;
21 int alarm_enable;
22};
23
24static int da9055_rtc_enable_alarm(struct da9055_rtc *rtc, bool enable)
25{
26 int ret;
27 if (enable) {
28 ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
29 DA9055_RTC_ALM_EN,
30 DA9055_RTC_ALM_EN);
31 if (ret != 0)
32 dev_err(rtc->da9055->dev, "Failed to enable ALM: %d\n",
33 ret);
34 rtc->alarm_enable = 1;
35 } else {
36 ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
37 DA9055_RTC_ALM_EN, 0);
38 if (ret != 0)
39 dev_err(rtc->da9055->dev,
40 "Failed to disable ALM: %d\n", ret);
41 rtc->alarm_enable = 0;
42 }
43 return ret;
44}
45
46static irqreturn_t da9055_rtc_alm_irq(int irq, void *data)
47{
48 struct da9055_rtc *rtc = data;
49
50 da9055_rtc_enable_alarm(rtc, 0);
51 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
52
53 return IRQ_HANDLED;
54}
55
56static int da9055_read_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
57{
58 int ret;
59 uint8_t v[5];
60
61 ret = da9055_group_read(da9055, DA9055_REG_ALARM_MI, 5, v);
62 if (ret != 0) {
63 dev_err(da9055->dev, "Failed to group read ALM: %d\n", ret);
64 return ret;
65 }
66
67 rtc_tm->tm_year = (v[4] & DA9055_RTC_ALM_YEAR) + 100;
68 rtc_tm->tm_mon = (v[3] & DA9055_RTC_ALM_MONTH) - 1;
69 rtc_tm->tm_mday = v[2] & DA9055_RTC_ALM_DAY;
70 rtc_tm->tm_hour = v[1] & DA9055_RTC_ALM_HOUR;
71 rtc_tm->tm_min = v[0] & DA9055_RTC_ALM_MIN;
72 rtc_tm->tm_sec = 0;
73
74 return rtc_valid_tm(rtc_tm);
75}
76
77static int da9055_set_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
78{
79 int ret;
80 uint8_t v[2];
81
82 rtc_tm->tm_year -= 100;
83 rtc_tm->tm_mon += 1;
84
85 ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MI,
86 DA9055_RTC_ALM_MIN, rtc_tm->tm_min);
87 if (ret != 0) {
88 dev_err(da9055->dev, "Failed to write ALRM MIN: %d\n", ret);
89 return ret;
90 }
91
92 v[0] = rtc_tm->tm_hour;
93 v[1] = rtc_tm->tm_mday;
94
95 ret = da9055_group_write(da9055, DA9055_REG_ALARM_H, 2, v);
96 if (ret < 0)
97 return ret;
98
99 ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
100 DA9055_RTC_ALM_MONTH, rtc_tm->tm_mon);
101 if (ret < 0)
102 dev_err(da9055->dev, "Failed to write ALM Month:%d\n", ret);
103
104 ret = da9055_reg_update(da9055, DA9055_REG_ALARM_Y,
105 DA9055_RTC_ALM_YEAR, rtc_tm->tm_year);
106 if (ret < 0)
107 dev_err(da9055->dev, "Failed to write ALM Year:%d\n", ret);
108
109 return ret;
110}
111
112static int da9055_rtc_get_alarm_status(struct da9055 *da9055)
113{
114 int ret;
115
116 ret = da9055_reg_read(da9055, DA9055_REG_ALARM_Y);
117 if (ret < 0) {
118 dev_err(da9055->dev, "Failed to read ALM: %d\n", ret);
119 return ret;
120 }
121 ret &= DA9055_RTC_ALM_EN;
122 return (ret > 0) ? 1 : 0;
123}
124
125static int da9055_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
126{
127 struct da9055_rtc *rtc = dev_get_drvdata(dev);
128 uint8_t v[6];
129 int ret;
130
131 ret = da9055_reg_read(rtc->da9055, DA9055_REG_COUNT_S);
132 if (ret < 0)
133 return ret;
134
135 /*
136 * Registers are only valid when RTC_READ
137 * status bit is asserted
138 */
139 if (!(ret & DA9055_RTC_READ))
140 return -EBUSY;
141
142 ret = da9055_group_read(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
143 if (ret < 0) {
144 dev_err(rtc->da9055->dev, "Failed to read RTC time : %d\n",
145 ret);
146 return ret;
147 }
148
149 rtc_tm->tm_year = (v[5] & DA9055_RTC_YEAR) + 100;
150 rtc_tm->tm_mon = (v[4] & DA9055_RTC_MONTH) - 1;
151 rtc_tm->tm_mday = v[3] & DA9055_RTC_DAY;
152 rtc_tm->tm_hour = v[2] & DA9055_RTC_HOUR;
153 rtc_tm->tm_min = v[1] & DA9055_RTC_MIN;
154 rtc_tm->tm_sec = v[0] & DA9055_RTC_SEC;
155
156 return 0;
157}
158
159static int da9055_rtc_set_time(struct device *dev, struct rtc_time *tm)
160{
161 struct da9055_rtc *rtc;
162 uint8_t v[6];
163
164 rtc = dev_get_drvdata(dev);
165
166 v[0] = tm->tm_sec;
167 v[1] = tm->tm_min;
168 v[2] = tm->tm_hour;
169 v[3] = tm->tm_mday;
170 v[4] = tm->tm_mon + 1;
171 v[5] = tm->tm_year - 100;
172
173 return da9055_group_write(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
174}
175
176static int da9055_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
177{
178 int ret;
179 struct rtc_time *tm = &alrm->time;
180 struct da9055_rtc *rtc = dev_get_drvdata(dev);
181
182 ret = da9055_read_alarm(rtc->da9055, tm);
183
184 if (ret)
185 return ret;
186
187 alrm->enabled = da9055_rtc_get_alarm_status(rtc->da9055);
188
189 return 0;
190}
191
192static int da9055_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
193{
194 int ret;
195 struct rtc_time *tm = &alrm->time;
196 struct da9055_rtc *rtc = dev_get_drvdata(dev);
197
198 ret = da9055_rtc_enable_alarm(rtc, 0);
199 if (ret < 0)
200 return ret;
201
202 ret = da9055_set_alarm(rtc->da9055, tm);
203 if (ret)
204 return ret;
205
206 ret = da9055_rtc_enable_alarm(rtc, 1);
207
208 return ret;
209}
210
211static int da9055_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
212{
213 struct da9055_rtc *rtc = dev_get_drvdata(dev);
214
215 return da9055_rtc_enable_alarm(rtc, enabled);
216}
217
218static const struct rtc_class_ops da9055_rtc_ops = {
219 .read_time = da9055_rtc_read_time,
220 .set_time = da9055_rtc_set_time,
221 .read_alarm = da9055_rtc_read_alarm,
222 .set_alarm = da9055_rtc_set_alarm,
223 .alarm_irq_enable = da9055_rtc_alarm_irq_enable,
224};
225
226static int da9055_rtc_device_init(struct da9055 *da9055,
227 struct da9055_pdata *pdata)
228{
229 int ret;
230
231 /* Enable RTC and the internal Crystal */
232 ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
233 DA9055_RTC_EN, DA9055_RTC_EN);
234 if (ret < 0)
235 return ret;
236 ret = da9055_reg_update(da9055, DA9055_REG_EN_32K,
237 DA9055_CRYSTAL_EN, DA9055_CRYSTAL_EN);
238 if (ret < 0)
239 return ret;
240
241 /* Enable RTC in Power Down mode */
242 ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
243 DA9055_RTC_MODE_PD, DA9055_RTC_MODE_PD);
244 if (ret < 0)
245 return ret;
246
247 /* Enable RTC in Reset mode */
248 if (pdata && pdata->reset_enable) {
249 ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
250 DA9055_RTC_MODE_SD,
251 DA9055_RTC_MODE_SD <<
252 DA9055_RTC_MODE_SD_SHIFT);
253 if (ret < 0)
254 return ret;
255 }
256
257 /* Disable the RTC TICK ALM */
258 ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
259 DA9055_RTC_TICK_WAKE_MASK, 0);
260 if (ret < 0)
261 return ret;
262
263 return 0;
264}
265
266static int da9055_rtc_probe(struct platform_device *pdev)
267{
268 struct da9055_rtc *rtc;
269 struct da9055_pdata *pdata = NULL;
270 int ret, alm_irq;
271
272 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9055_rtc), GFP_KERNEL);
273 if (!rtc)
274 return -ENOMEM;
275
276 rtc->da9055 = dev_get_drvdata(pdev->dev.parent);
277 pdata = dev_get_platdata(rtc->da9055->dev);
278 platform_set_drvdata(pdev, rtc);
279
280 ret = da9055_rtc_device_init(rtc->da9055, pdata);
281 if (ret < 0)
282 goto err_rtc;
283
284 ret = da9055_reg_read(rtc->da9055, DA9055_REG_ALARM_Y);
285 if (ret < 0)
286 goto err_rtc;
287
288 if (ret & DA9055_RTC_ALM_EN)
289 rtc->alarm_enable = 1;
290
291 device_init_wakeup(&pdev->dev, true);
292
293 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
294 &da9055_rtc_ops, THIS_MODULE);
295 if (IS_ERR(rtc->rtc)) {
296 ret = PTR_ERR(rtc->rtc);
297 goto err_rtc;
298 }
299
300 alm_irq = platform_get_irq_byname(pdev, "ALM");
301 if (alm_irq < 0)
302 return alm_irq;
303
304 ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL,
305 da9055_rtc_alm_irq,
306 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
307 "ALM", rtc);
308 if (ret != 0)
309 dev_err(rtc->da9055->dev, "irq registration failed: %d\n", ret);
310
311err_rtc:
312 return ret;
313
314}
315
316#ifdef CONFIG_PM
317/* Turn off the alarm if it should not be a wake source. */
318static int da9055_rtc_suspend(struct device *dev)
319{
320 struct platform_device *pdev = to_platform_device(dev);
321 struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
322 int ret;
323
324 if (!device_may_wakeup(&pdev->dev)) {
325 /* Disable the ALM IRQ */
326 ret = da9055_rtc_enable_alarm(rtc, 0);
327 if (ret < 0)
328 dev_err(&pdev->dev, "Failed to disable RTC ALM\n");
329 }
330
331 return 0;
332}
333
334/* Enable the alarm if it should be enabled (in case it was disabled to
335 * prevent use as a wake source).
336 */
337static int da9055_rtc_resume(struct device *dev)
338{
339 struct platform_device *pdev = to_platform_device(dev);
340 struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
341 int ret;
342
343 if (!device_may_wakeup(&pdev->dev)) {
344 if (rtc->alarm_enable) {
345 ret = da9055_rtc_enable_alarm(rtc, 1);
346 if (ret < 0)
347 dev_err(&pdev->dev,
348 "Failed to restart RTC ALM\n");
349 }
350 }
351
352 return 0;
353}
354
355/* Unconditionally disable the alarm */
356static int da9055_rtc_freeze(struct device *dev)
357{
358 struct platform_device *pdev = to_platform_device(dev);
359 struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
360 int ret;
361
362 ret = da9055_rtc_enable_alarm(rtc, 0);
363 if (ret < 0)
364 dev_err(&pdev->dev, "Failed to freeze RTC ALMs\n");
365
366 return 0;
367
368}
369#else
370#define da9055_rtc_suspend NULL
371#define da9055_rtc_resume NULL
372#define da9055_rtc_freeze NULL
373#endif
374
375static const struct dev_pm_ops da9055_rtc_pm_ops = {
376 .suspend = da9055_rtc_suspend,
377 .resume = da9055_rtc_resume,
378
379 .freeze = da9055_rtc_freeze,
380 .thaw = da9055_rtc_resume,
381 .restore = da9055_rtc_resume,
382
383 .poweroff = da9055_rtc_suspend,
384};
385
386static struct platform_driver da9055_rtc_driver = {
387 .probe = da9055_rtc_probe,
388 .driver = {
389 .name = "da9055-rtc",
390 .pm = &da9055_rtc_pm_ops,
391 },
392};
393
394module_platform_driver(da9055_rtc_driver);
395
396MODULE_AUTHOR("David Dajun Chen <[email protected]>");
397MODULE_DESCRIPTION("RTC driver for Dialog DA9055 PMIC");
398MODULE_LICENSE("GPL");
399MODULE_ALIAS("platform:da9055-rtc");