1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Real time clock driver for DA9052
4 *
5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
6 *
7 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/rtc.h>
13 #include <linux/err.h>
14 #include <linux/delay.h>
15
16 #include <linux/mfd/da9052/da9052.h>
17 #include <linux/mfd/da9052/reg.h>
18
19 #define rtc_err(rtc, fmt, ...) \
20 dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
21
22 #define DA9052_GET_TIME_RETRIES 5
23
24 struct da9052_rtc {
25 struct rtc_device *rtc;
26 struct da9052 *da9052;
27 };
28
da9052_rtc_enable_alarm(struct da9052_rtc * rtc,bool enable)29 static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
30 {
31 int ret;
32 if (enable) {
33 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
34 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
35 DA9052_ALARM_Y_ALARM_ON);
36 if (ret != 0)
37 rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
38 } else {
39 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
40 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
41 if (ret != 0)
42 rtc_err(rtc, "Write error: %d\n", ret);
43 }
44 return ret;
45 }
46
da9052_rtc_irq(int irq,void * data)47 static irqreturn_t da9052_rtc_irq(int irq, void *data)
48 {
49 struct da9052_rtc *rtc = data;
50
51 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
52
53 return IRQ_HANDLED;
54 }
55
da9052_read_alarm(struct da9052_rtc * rtc,struct rtc_time * rtc_tm)56 static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
57 {
58 int ret;
59 uint8_t v[2][5];
60 int idx = 1;
61 int timeout = DA9052_GET_TIME_RETRIES;
62
63 ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
64 if (ret) {
65 rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
66 return ret;
67 }
68
69 do {
70 ret = da9052_group_read(rtc->da9052,
71 DA9052_ALARM_MI_REG, 5, &v[idx][0]);
72 if (ret) {
73 rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
74 return ret;
75 }
76
77 if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
78 rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
79 rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1;
80 rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
81 rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
82 rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN;
83 rtc_tm->tm_sec = 0;
84
85 ret = rtc_valid_tm(rtc_tm);
86 return ret;
87 }
88
89 idx = (1-idx);
90 msleep(20);
91
92 } while (timeout--);
93
94 rtc_err(rtc, "Timed out reading alarm time\n");
95
96 return -EIO;
97 }
98
da9052_set_alarm(struct da9052_rtc * rtc,struct rtc_time * rtc_tm)99 static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
100 {
101 struct da9052 *da9052 = rtc->da9052;
102 unsigned long alm_time;
103 int ret;
104 uint8_t v[3];
105
106 ret = rtc_tm_to_time(rtc_tm, &alm_time);
107 if (ret != 0)
108 return ret;
109
110 if (rtc_tm->tm_sec > 0) {
111 alm_time += 60 - rtc_tm->tm_sec;
112 rtc_time_to_tm(alm_time, rtc_tm);
113 }
114 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
115
116 rtc_tm->tm_year -= 100;
117 rtc_tm->tm_mon += 1;
118
119 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
120 DA9052_RTC_MIN, rtc_tm->tm_min);
121 if (ret != 0) {
122 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
123 return ret;
124 }
125
126 v[0] = rtc_tm->tm_hour;
127 v[1] = rtc_tm->tm_mday;
128 v[2] = rtc_tm->tm_mon;
129
130 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
131 if (ret < 0)
132 return ret;
133
134 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
135 DA9052_RTC_YEAR, rtc_tm->tm_year);
136 if (ret != 0)
137 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
138
139 return ret;
140 }
141
da9052_rtc_get_alarm_status(struct da9052_rtc * rtc)142 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
143 {
144 int ret;
145
146 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
147 if (ret < 0) {
148 rtc_err(rtc, "Failed to read ALM: %d\n", ret);
149 return ret;
150 }
151
152 return !!(ret&DA9052_ALARM_Y_ALARM_ON);
153 }
154
da9052_rtc_read_time(struct device * dev,struct rtc_time * rtc_tm)155 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
156 {
157 struct da9052_rtc *rtc = dev_get_drvdata(dev);
158 int ret;
159 uint8_t v[2][6];
160 int idx = 1;
161 int timeout = DA9052_GET_TIME_RETRIES;
162
163 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
164 if (ret) {
165 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
166 return ret;
167 }
168
169 do {
170 ret = da9052_group_read(rtc->da9052,
171 DA9052_COUNT_S_REG, 6, &v[idx][0]);
172 if (ret) {
173 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
174 return ret;
175 }
176
177 if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
178 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
179 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1;
180 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
181 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
182 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN;
183 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC;
184
185 return 0;
186 }
187
188 idx = (1-idx);
189 msleep(20);
190
191 } while (timeout--);
192
193 rtc_err(rtc, "Timed out reading time\n");
194
195 return -EIO;
196 }
197
da9052_rtc_set_time(struct device * dev,struct rtc_time * tm)198 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
199 {
200 struct da9052_rtc *rtc;
201 uint8_t v[6];
202 int ret;
203
204 /* DA9052 only has 6 bits for year - to represent 2000-2063 */
205 if ((tm->tm_year < 100) || (tm->tm_year > 163))
206 return -EINVAL;
207
208 rtc = dev_get_drvdata(dev);
209
210 v[0] = tm->tm_sec;
211 v[1] = tm->tm_min;
212 v[2] = tm->tm_hour;
213 v[3] = tm->tm_mday;
214 v[4] = tm->tm_mon + 1;
215 v[5] = tm->tm_year - 100;
216
217 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
218 if (ret < 0)
219 rtc_err(rtc, "failed to set RTC time: %d\n", ret);
220 return ret;
221 }
222
da9052_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)223 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
224 {
225 int ret;
226 struct rtc_time *tm = &alrm->time;
227 struct da9052_rtc *rtc = dev_get_drvdata(dev);
228
229 ret = da9052_read_alarm(rtc, tm);
230 if (ret < 0) {
231 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
232 return ret;
233 }
234
235 alrm->enabled = da9052_rtc_get_alarm_status(rtc);
236 return 0;
237 }
238
da9052_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)239 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
240 {
241 int ret;
242 struct rtc_time *tm = &alrm->time;
243 struct da9052_rtc *rtc = dev_get_drvdata(dev);
244
245 /* DA9052 only has 6 bits for year - to represent 2000-2063 */
246 if ((tm->tm_year < 100) || (tm->tm_year > 163))
247 return -EINVAL;
248
249 ret = da9052_rtc_enable_alarm(rtc, 0);
250 if (ret < 0)
251 return ret;
252
253 ret = da9052_set_alarm(rtc, tm);
254 if (ret < 0)
255 return ret;
256
257 ret = da9052_rtc_enable_alarm(rtc, 1);
258 return ret;
259 }
260
da9052_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)261 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
262 {
263 struct da9052_rtc *rtc = dev_get_drvdata(dev);
264
265 return da9052_rtc_enable_alarm(rtc, enabled);
266 }
267
268 static const struct rtc_class_ops da9052_rtc_ops = {
269 .read_time = da9052_rtc_read_time,
270 .set_time = da9052_rtc_set_time,
271 .read_alarm = da9052_rtc_read_alarm,
272 .set_alarm = da9052_rtc_set_alarm,
273 .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
274 };
275
da9052_rtc_probe(struct platform_device * pdev)276 static int da9052_rtc_probe(struct platform_device *pdev)
277 {
278 struct da9052_rtc *rtc;
279 int ret;
280
281 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
282 if (!rtc)
283 return -ENOMEM;
284
285 rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
286 platform_set_drvdata(pdev, rtc);
287
288 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
289 if (ret < 0) {
290 rtc_err(rtc,
291 "Failed to setup RTC battery charging: %d\n", ret);
292 return ret;
293 }
294
295 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
296 DA9052_ALARM_Y_TICK_ON, 0);
297 if (ret != 0)
298 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
299
300 device_init_wakeup(&pdev->dev, true);
301 rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
302 &da9052_rtc_ops, THIS_MODULE);
303
304 if (IS_ERR(rtc->rtc))
305 return PTR_ERR(rtc->rtc);
306
307 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
308 da9052_rtc_irq, rtc);
309 if (ret != 0) {
310 rtc_err(rtc, "irq registration failed: %d\n", ret);
311 return ret;
312 }
313
314 return 0;
315 }
316
317 static struct platform_driver da9052_rtc_driver = {
318 .probe = da9052_rtc_probe,
319 .driver = {
320 .name = "da9052-rtc",
321 },
322 };
323
324 module_platform_driver(da9052_rtc_driver);
325
326 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
327 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
328 MODULE_LICENSE("GPL");
329 MODULE_ALIAS("platform:da9052-rtc");
330
