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_wday = data[RTC_OFFSET_DOW];
79 tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_TC_MTH_MASK;
80 tm->tm_year = data[RTC_OFFSET_YEAR];
81
82 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
83 exit:
84 mutex_unlock(&rtc->lock);
85 return ret;
86 }
87
mtk_rtc_read_time(struct device * dev,struct rtc_time * tm)88 static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
89 {
90 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
91 int 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 start mon/wday from one, but tm_mon/tm_wday start from zero. */
100 tm->tm_mon--;
101 tm->tm_wday--;
102
103 exit:
104 return ret;
105 }
106
mtk_rtc_set_time(struct device * dev,struct rtc_time * tm)107 static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
108 {
109 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
110 int ret;
111 u16 data[RTC_OFFSET_COUNT];
112
113 tm->tm_mon++;
114 tm->tm_wday++;
115
116 data[RTC_OFFSET_SEC] = tm->tm_sec;
117 data[RTC_OFFSET_MIN] = tm->tm_min;
118 data[RTC_OFFSET_HOUR] = tm->tm_hour;
119 data[RTC_OFFSET_DOM] = tm->tm_mday;
120 data[RTC_OFFSET_DOW] = tm->tm_wday;
121 data[RTC_OFFSET_MTH] = tm->tm_mon;
122 data[RTC_OFFSET_YEAR] = tm->tm_year;
123
124 mutex_lock(&rtc->lock);
125 ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
126 data, RTC_OFFSET_COUNT);
127 if (ret < 0)
128 goto exit;
129
130 /* Time register write to hardware after call trigger function */
131 ret = mtk_rtc_write_trigger(rtc);
132
133 exit:
134 mutex_unlock(&rtc->lock);
135 return ret;
136 }
137
mtk_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alm)138 static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
139 {
140 struct rtc_time *tm = &alm->time;
141 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
142 u32 irqen, pdn2;
143 int ret;
144 u16 data[RTC_OFFSET_COUNT];
145
146 mutex_lock(&rtc->lock);
147 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen);
148 if (ret < 0)
149 goto err_exit;
150 ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2);
151 if (ret < 0)
152 goto err_exit;
153
154 ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
155 data, RTC_OFFSET_COUNT);
156 if (ret < 0)
157 goto err_exit;
158
159 alm->enabled = !!(irqen & RTC_IRQ_EN_AL);
160 alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
161 mutex_unlock(&rtc->lock);
162
163 tm->tm_sec = data[RTC_OFFSET_SEC] & RTC_AL_SEC_MASK;
164 tm->tm_min = data[RTC_OFFSET_MIN] & RTC_AL_MIN_MASK;
165 tm->tm_hour = data[RTC_OFFSET_HOUR] & RTC_AL_HOU_MASK;
166 tm->tm_mday = data[RTC_OFFSET_DOM] & RTC_AL_DOM_MASK;
167 tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK;
168 tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK;
169
170 tm->tm_mon--;
171
172 return 0;
173 err_exit:
174 mutex_unlock(&rtc->lock);
175 return ret;
176 }
177
mtk_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alm)178 static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
179 {
180 struct rtc_time *tm = &alm->time;
181 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
182 int ret;
183 u16 data[RTC_OFFSET_COUNT];
184
185 tm->tm_mon++;
186
187 mutex_lock(&rtc->lock);
188 ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
189 data, RTC_OFFSET_COUNT);
190 if (ret < 0)
191 goto exit;
192
193 data[RTC_OFFSET_SEC] = ((data[RTC_OFFSET_SEC] & ~(RTC_AL_SEC_MASK)) |
194 (tm->tm_sec & RTC_AL_SEC_MASK));
195 data[RTC_OFFSET_MIN] = ((data[RTC_OFFSET_MIN] & ~(RTC_AL_MIN_MASK)) |
196 (tm->tm_min & RTC_AL_MIN_MASK));
197 data[RTC_OFFSET_HOUR] = ((data[RTC_OFFSET_HOUR] & ~(RTC_AL_HOU_MASK)) |
198 (tm->tm_hour & RTC_AL_HOU_MASK));
199 data[RTC_OFFSET_DOM] = ((data[RTC_OFFSET_DOM] & ~(RTC_AL_DOM_MASK)) |
200 (tm->tm_mday & RTC_AL_DOM_MASK));
201 data[RTC_OFFSET_MTH] = ((data[RTC_OFFSET_MTH] & ~(RTC_AL_MTH_MASK)) |
202 (tm->tm_mon & RTC_AL_MTH_MASK));
203 data[RTC_OFFSET_YEAR] = ((data[RTC_OFFSET_YEAR] & ~(RTC_AL_YEA_MASK)) |
204 (tm->tm_year & RTC_AL_YEA_MASK));
205
206 if (alm->enabled) {
207 ret = regmap_bulk_write(rtc->regmap,
208 rtc->addr_base + RTC_AL_SEC,
209 data, RTC_OFFSET_COUNT);
210 if (ret < 0)
211 goto exit;
212 ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK,
213 RTC_AL_MASK_DOW);
214 if (ret < 0)
215 goto exit;
216 ret = regmap_update_bits(rtc->regmap,
217 rtc->addr_base + RTC_IRQ_EN,
218 RTC_IRQ_EN_ONESHOT_AL,
219 RTC_IRQ_EN_ONESHOT_AL);
220 if (ret < 0)
221 goto exit;
222 } else {
223 ret = regmap_update_bits(rtc->regmap,
224 rtc->addr_base + RTC_IRQ_EN,
225 RTC_IRQ_EN_ONESHOT_AL, 0);
226 if (ret < 0)
227 goto exit;
228 }
229
230 /* All alarm time register write to hardware after calling
231 * mtk_rtc_write_trigger. This can avoid race condition if alarm
232 * occur happen during writing alarm time register.
233 */
234 ret = mtk_rtc_write_trigger(rtc);
235 exit:
236 mutex_unlock(&rtc->lock);
237 return ret;
238 }
239
240 static const struct rtc_class_ops mtk_rtc_ops = {
241 .read_time = mtk_rtc_read_time,
242 .set_time = mtk_rtc_set_time,
243 .read_alarm = mtk_rtc_read_alarm,
244 .set_alarm = mtk_rtc_set_alarm,
245 };
246
mtk_rtc_probe(struct platform_device * pdev)247 static int mtk_rtc_probe(struct platform_device *pdev)
248 {
249 struct resource *res;
250 struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
251 struct mt6397_rtc *rtc;
252 int ret;
253
254 rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL);
255 if (!rtc)
256 return -ENOMEM;
257
258 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
259 if (!res)
260 return -EINVAL;
261 rtc->addr_base = res->start;
262
263 rtc->data = of_device_get_match_data(&pdev->dev);
264
265 rtc->irq = platform_get_irq(pdev, 0);
266 if (rtc->irq < 0)
267 return rtc->irq;
268
269 rtc->regmap = mt6397_chip->regmap;
270 mutex_init(&rtc->lock);
271
272 platform_set_drvdata(pdev, rtc);
273
274 rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
275 if (IS_ERR(rtc->rtc_dev))
276 return PTR_ERR(rtc->rtc_dev);
277
278 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
279 mtk_rtc_irq_handler_thread,
280 IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
281 "mt6397-rtc", rtc);
282
283 if (ret) {
284 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
285 rtc->irq, ret);
286 return ret;
287 }
288
289 device_init_wakeup(&pdev->dev, 1);
290
291 rtc->rtc_dev->ops = &mtk_rtc_ops;
292 rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900;
293 rtc->rtc_dev->range_max = mktime64(2027, 12, 31, 23, 59, 59);
294 rtc->rtc_dev->start_secs = mktime64(1968, 1, 2, 0, 0, 0);
295 rtc->rtc_dev->set_start_time = true;
296
297 return devm_rtc_register_device(rtc->rtc_dev);
298 }
299
300 #ifdef CONFIG_PM_SLEEP
mt6397_rtc_suspend(struct device * dev)301 static int mt6397_rtc_suspend(struct device *dev)
302 {
303 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
304
305 if (device_may_wakeup(dev))
306 enable_irq_wake(rtc->irq);
307
308 return 0;
309 }
310
mt6397_rtc_resume(struct device * dev)311 static int mt6397_rtc_resume(struct device *dev)
312 {
313 struct mt6397_rtc *rtc = dev_get_drvdata(dev);
314
315 if (device_may_wakeup(dev))
316 disable_irq_wake(rtc->irq);
317
318 return 0;
319 }
320 #endif
321
322 static SIMPLE_DEV_PM_OPS(mt6397_pm_ops, mt6397_rtc_suspend,
323 mt6397_rtc_resume);
324
325 static const struct mtk_rtc_data mt6358_rtc_data = {
326 .wrtgr = RTC_WRTGR_MT6358,
327 };
328
329 static const struct mtk_rtc_data mt6397_rtc_data = {
330 .wrtgr = RTC_WRTGR_MT6397,
331 };
332
333 static const struct of_device_id mt6397_rtc_of_match[] = {
334 { .compatible = "mediatek,mt6323-rtc", .data = &mt6397_rtc_data },
335 { .compatible = "mediatek,mt6358-rtc", .data = &mt6358_rtc_data },
336 { .compatible = "mediatek,mt6397-rtc", .data = &mt6397_rtc_data },
337 { }
338 };
339 MODULE_DEVICE_TABLE(of, mt6397_rtc_of_match);
340
341 static struct platform_driver mtk_rtc_driver = {
342 .driver = {
343 .name = "mt6397-rtc",
344 .of_match_table = mt6397_rtc_of_match,
345 .pm = &mt6397_pm_ops,
346 },
347 .probe = mtk_rtc_probe,
348 };
349
350 module_platform_driver(mtk_rtc_driver);
351
352 MODULE_LICENSE("GPL v2");
353 MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
354 MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");
355