1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2014-2015 MediaTek Inc.
4 * Author: Tianping.Fang <tianping.fang@mediatek.com>
5 */
6
7 #include <linux/err.h>
8 #include <linux/interrupt.h>
9 #include <linux/mfd/mt6397/core.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15 #include <linux/rtc.h>
16 #include <linux/mfd/mt6397/rtc.h>
17 #include <linux/mod_devicetable.h>
18
mtk_rtc_write_trigger(struct mt6397_rtc * rtc)19 static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
20 {
21 int ret;
22 u32 data;
23
24 ret = regmap_write(rtc->regmap, rtc->addr_base + rtc->data->wrtgr, 1);
25 if (ret < 0)
26 return ret;
27
28 ret = regmap_read_poll_timeout(rtc->regmap,
29 rtc->addr_base + RTC_BBPU, data,
30 !(data & RTC_BBPU_CBUSY),
31 MTK_RTC_POLL_DELAY_US,
32 MTK_RTC_POLL_TIMEOUT);
33 if (ret < 0)
34 dev_err(rtc->rtc_dev->dev.parent,
35 "failed to write WRTGR: %d\n", ret);
36
37 return ret;
38 }
39
mtk_rtc_irq_handler_thread(int irq,void * data)40 static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
41 {
42 struct mt6397_rtc *rtc = data;
43 u32 irqsta, irqen;
44 int ret;
45
46 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta);
47 if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) {
48 rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
49 irqen = irqsta & ~RTC_IRQ_EN_AL;
50 mutex_lock(&rtc->lock);
51 if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
52 irqen) == 0)
53 mtk_rtc_write_trigger(rtc);
54 mutex_unlock(&rtc->lock);
55
56 return IRQ_HANDLED;
57 }
58
59 return IRQ_NONE;
60 }
61
__mtk_rtc_read_time(struct mt6397_rtc * rtc,struct rtc_time * tm,int * sec)62 static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
63 struct rtc_time *tm, int *sec)
64 {
65 int ret;
66 u16 data[RTC_OFFSET_COUNT];
67
68 mutex_lock(&rtc->lock);
69 ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
70 data, RTC_OFFSET_COUNT);
71 if (ret < 0)
72 goto exit;
73
74 tm->tm_sec = data[RTC_OFFSET_SEC];
75 tm->tm_min = data[RTC_OFFSET_MIN];
76 tm->tm_hour = data[RTC_OFFSET_HOUR];
77 tm->tm_mday = data[RTC_OFFSET_DOM];
78 tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_TC_MTH_MASK;
79 tm->tm_year = data[RTC_OFFSET_YEAR];
80
81 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
82 exit:
83 mutex_unlock(&rtc->lock);
84 return ret;
85 }
86
mtk_rtc_read_time(struct device * dev,struct rtc_time * tm)87 static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
88 {
89 time64_t time;
90 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
91 int days, sec, ret;
92
93 do {
94 ret = __mtk_rtc_read_time(rtc, tm, &sec);
95 if (ret < 0)
96 goto exit;
97 } while (sec < tm->tm_sec);
98
99 /* HW register use 7 bits to store year data, minus
100 * RTC_MIN_YEAR_OFFSET before write year data to register, and plus
101 * RTC_MIN_YEAR_OFFSET back after read year from register
102 */
103 tm->tm_year += RTC_MIN_YEAR_OFFSET;
104
105 /* HW register start mon from one, but tm_mon start from zero. */
106 tm->tm_mon--;
107 time = rtc_tm_to_time64(tm);
108
109 /* rtc_tm_to_time64 covert Gregorian date to seconds since
110 * 01-01-1970 00:00:00, and this date is Thursday.
111 */
112 days = div_s64(time, 86400);
113 tm->tm_wday = (days + 4) % 7;
114
115 exit:
116 return ret;
117 }
118
mtk_rtc_set_time(struct device * dev,struct rtc_time * tm)119 static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
120 {
121 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
122 int ret;
123 u16 data[RTC_OFFSET_COUNT];
124
125 tm->tm_year -= RTC_MIN_YEAR_OFFSET;
126 tm->tm_mon++;
127
128 data[RTC_OFFSET_SEC] = tm->tm_sec;
129 data[RTC_OFFSET_MIN] = tm->tm_min;
130 data[RTC_OFFSET_HOUR] = tm->tm_hour;
131 data[RTC_OFFSET_DOM] = tm->tm_mday;
132 data[RTC_OFFSET_MTH] = tm->tm_mon;
133 data[RTC_OFFSET_YEAR] = tm->tm_year;
134
135 mutex_lock(&rtc->lock);
136 ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
137 data, RTC_OFFSET_COUNT);
138 if (ret < 0)
139 goto exit;
140
141 /* Time register write to hardware after call trigger function */
142 ret = mtk_rtc_write_trigger(rtc);
143
144 exit:
145 mutex_unlock(&rtc->lock);
146 return ret;
147 }
148
mtk_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)149 static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
150 {
151 struct rtc_time *tm = &alm->time;
152 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
153 u32 irqen, pdn2;
154 int ret;
155 u16 data[RTC_OFFSET_COUNT];
156
157 mutex_lock(&rtc->lock);
158 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen);
159 if (ret < 0)
160 goto err_exit;
161 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2);
162 if (ret < 0)
163 goto err_exit;
164
165 ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
166 data, RTC_OFFSET_COUNT);
167 if (ret < 0)
168 goto err_exit;
169
170 alm->enabled = !!(irqen & RTC_IRQ_EN_AL);
171 alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
172 mutex_unlock(&rtc->lock);
173
174 tm->tm_sec = data[RTC_OFFSET_SEC] & RTC_AL_SEC_MASK;
175 tm->tm_min = data[RTC_OFFSET_MIN] & RTC_AL_MIN_MASK;
176 tm->tm_hour = data[RTC_OFFSET_HOUR] & RTC_AL_HOU_MASK;
177 tm->tm_mday = data[RTC_OFFSET_DOM] & RTC_AL_DOM_MASK;
178 tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK;
179 tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK;
180
181 tm->tm_year += RTC_MIN_YEAR_OFFSET;
182 tm->tm_mon--;
183
184 return 0;
185 err_exit:
186 mutex_unlock(&rtc->lock);
187 return ret;
188 }
189
mtk_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)190 static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
191 {
192 struct rtc_time *tm = &alm->time;
193 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
194 int ret;
195 u16 data[RTC_OFFSET_COUNT];
196
197 tm->tm_year -= RTC_MIN_YEAR_OFFSET;
198 tm->tm_mon++;
199
200 mutex_lock(&rtc->lock);
201 ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
202 data, RTC_OFFSET_COUNT);
203 if (ret < 0)
204 goto exit;
205
206 data[RTC_OFFSET_SEC] = ((data[RTC_OFFSET_SEC] & ~(RTC_AL_SEC_MASK)) |
207 (tm->tm_sec & RTC_AL_SEC_MASK));
208 data[RTC_OFFSET_MIN] = ((data[RTC_OFFSET_MIN] & ~(RTC_AL_MIN_MASK)) |
209 (tm->tm_min & RTC_AL_MIN_MASK));
210 data[RTC_OFFSET_HOUR] = ((data[RTC_OFFSET_HOUR] & ~(RTC_AL_HOU_MASK)) |
211 (tm->tm_hour & RTC_AL_HOU_MASK));
212 data[RTC_OFFSET_DOM] = ((data[RTC_OFFSET_DOM] & ~(RTC_AL_DOM_MASK)) |
213 (tm->tm_mday & RTC_AL_DOM_MASK));
214 data[RTC_OFFSET_MTH] = ((data[RTC_OFFSET_MTH] & ~(RTC_AL_MTH_MASK)) |
215 (tm->tm_mon & RTC_AL_MTH_MASK));
216 data[RTC_OFFSET_YEAR] = ((data[RTC_OFFSET_YEAR] & ~(RTC_AL_YEA_MASK)) |
217 (tm->tm_year & RTC_AL_YEA_MASK));
218
219 if (alm->enabled) {
220 ret = regmap_bulk_write(rtc->regmap,
221 rtc->addr_base + RTC_AL_SEC,
222 data, RTC_OFFSET_COUNT);
223 if (ret < 0)
224 goto exit;
225 ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK,
226 RTC_AL_MASK_DOW);
227 if (ret < 0)
228 goto exit;
229 ret = regmap_update_bits(rtc->regmap,
230 rtc->addr_base + RTC_IRQ_EN,
231 RTC_IRQ_EN_ONESHOT_AL,
232 RTC_IRQ_EN_ONESHOT_AL);
233 if (ret < 0)
234 goto exit;
235 } else {
236 ret = regmap_update_bits(rtc->regmap,
237 rtc->addr_base + RTC_IRQ_EN,
238 RTC_IRQ_EN_ONESHOT_AL, 0);
239 if (ret < 0)
240 goto exit;
241 }
242
243 /* All alarm time register write to hardware after calling
244 * mtk_rtc_write_trigger. This can avoid race condition if alarm
245 * occur happen during writing alarm time register.
246 */
247 ret = mtk_rtc_write_trigger(rtc);
248 exit:
249 mutex_unlock(&rtc->lock);
250 return ret;
251 }
252
253 static const struct rtc_class_ops mtk_rtc_ops = {
254 .read_time = mtk_rtc_read_time,
255 .set_time = mtk_rtc_set_time,
256 .read_alarm = mtk_rtc_read_alarm,
257 .set_alarm = mtk_rtc_set_alarm,
258 };
259
mtk_rtc_probe(struct platform_device * pdev)260 static int mtk_rtc_probe(struct platform_device *pdev)
261 {
262 struct resource *res;
263 struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
264 struct mt6397_rtc *rtc;
265 int ret;
266
267 rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL);
268 if (!rtc)
269 return -ENOMEM;
270
271 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
272 if (!res)
273 return -EINVAL;
274 rtc->addr_base = res->start;
275
276 rtc->data = of_device_get_match_data(&pdev->dev);
277
278 rtc->irq = platform_get_irq(pdev, 0);
279 if (rtc->irq < 0)
280 return rtc->irq;
281
282 rtc->regmap = mt6397_chip->regmap;
283 mutex_init(&rtc->lock);
284
285 platform_set_drvdata(pdev, rtc);
286
287 rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
288 if (IS_ERR(rtc->rtc_dev))
289 return PTR_ERR(rtc->rtc_dev);
290
291 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
292 mtk_rtc_irq_handler_thread,
293 IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
294 "mt6397-rtc", rtc);
295
296 if (ret) {
297 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
298 rtc->irq, ret);
299 return ret;
300 }
301
302 device_init_wakeup(&pdev->dev, 1);
303
304 rtc->rtc_dev->ops = &mtk_rtc_ops;
305
306 return devm_rtc_register_device(rtc->rtc_dev);
307 }
308
309 #ifdef CONFIG_PM_SLEEP
mt6397_rtc_suspend(struct device * dev)310 static int mt6397_rtc_suspend(struct device *dev)
311 {
312 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
313
314 if (device_may_wakeup(dev))
315 enable_irq_wake(rtc->irq);
316
317 return 0;
318 }
319
mt6397_rtc_resume(struct device * dev)320 static int mt6397_rtc_resume(struct device *dev)
321 {
322 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
323
324 if (device_may_wakeup(dev))
325 disable_irq_wake(rtc->irq);
326
327 return 0;
328 }
329 #endif
330
331 static SIMPLE_DEV_PM_OPS(mt6397_pm_ops, mt6397_rtc_suspend,
332 mt6397_rtc_resume);
333
334 static const struct mtk_rtc_data mt6358_rtc_data = {
335 .wrtgr = RTC_WRTGR_MT6358,
336 };
337
338 static const struct mtk_rtc_data mt6397_rtc_data = {
339 .wrtgr = RTC_WRTGR_MT6397,
340 };
341
342 static const struct of_device_id mt6397_rtc_of_match[] = {
343 { .compatible = "mediatek,mt6323-rtc", .data = &mt6397_rtc_data },
344 { .compatible = "mediatek,mt6358-rtc", .data = &mt6358_rtc_data },
345 { .compatible = "mediatek,mt6397-rtc", .data = &mt6397_rtc_data },
346 { }
347 };
348 MODULE_DEVICE_TABLE(of, mt6397_rtc_of_match);
349
350 static struct platform_driver mtk_rtc_driver = {
351 .driver = {
352 .name = "mt6397-rtc",
353 .of_match_table = mt6397_rtc_of_match,
354 .pm = &mt6397_pm_ops,
355 },
356 .probe = mtk_rtc_probe,
357 };
358
359 module_platform_driver(mtk_rtc_driver);
360
361 MODULE_LICENSE("GPL v2");
362 MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
363 MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");
364