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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 <[email protected]>
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
24struct da9052_rtc {
25 struct rtc_device *rtc;
26 struct da9052 *da9052;
27};
28
29static 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
47static 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
56static 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
99static 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 alm_time = rtc_tm_to_time64(rtc_tm);
107
108 if (rtc_tm->tm_sec > 0) {
109 alm_time += 60 - rtc_tm->tm_sec;
110 rtc_time64_to_tm(alm_time, rtc_tm);
111 }
112 BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
113
114 rtc_tm->tm_year -= 100;
115 rtc_tm->tm_mon += 1;
116
117 ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
118 DA9052_RTC_MIN, rtc_tm->tm_min);
119 if (ret != 0) {
120 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
121 return ret;
122 }
123
124 v[0] = rtc_tm->tm_hour;
125 v[1] = rtc_tm->tm_mday;
126 v[2] = rtc_tm->tm_mon;
127
128 ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
129 if (ret < 0)
130 return ret;
131
132 ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
133 DA9052_RTC_YEAR, rtc_tm->tm_year);
134 if (ret != 0)
135 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
136
137 return ret;
138}
139
140static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
141{
142 int ret;
143
144 ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
145 if (ret < 0) {
146 rtc_err(rtc, "Failed to read ALM: %d\n", ret);
147 return ret;
148 }
149
150 return !!(ret&DA9052_ALARM_Y_ALARM_ON);
151}
152
153static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
154{
155 struct da9052_rtc *rtc = dev_get_drvdata(dev);
156 int ret;
157 uint8_t v[2][6];
158 int idx = 1;
159 int timeout = DA9052_GET_TIME_RETRIES;
160
161 ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
162 if (ret) {
163 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
164 return ret;
165 }
166
167 do {
168 ret = da9052_group_read(rtc->da9052,
169 DA9052_COUNT_S_REG, 6, &v[idx][0]);
170 if (ret) {
171 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
172 return ret;
173 }
174
175 if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
176 rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
177 rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1;
178 rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
179 rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
180 rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN;
181 rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC;
182
183 return 0;
184 }
185
186 idx = (1-idx);
187 msleep(20);
188
189 } while (timeout--);
190
191 rtc_err(rtc, "Timed out reading time\n");
192
193 return -EIO;
194}
195
196static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
197{
198 struct da9052_rtc *rtc;
199 uint8_t v[6];
200 int ret;
201
202 /* DA9052 only has 6 bits for year - to represent 2000-2063 */
203 if ((tm->tm_year < 100) || (tm->tm_year > 163))
204 return -EINVAL;
205
206 rtc = dev_get_drvdata(dev);
207
208 v[0] = tm->tm_sec;
209 v[1] = tm->tm_min;
210 v[2] = tm->tm_hour;
211 v[3] = tm->tm_mday;
212 v[4] = tm->tm_mon + 1;
213 v[5] = tm->tm_year - 100;
214
215 ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
216 if (ret < 0)
217 rtc_err(rtc, "failed to set RTC time: %d\n", ret);
218 return ret;
219}
220
221static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
222{
223 int ret;
224 struct rtc_time *tm = &alrm->time;
225 struct da9052_rtc *rtc = dev_get_drvdata(dev);
226
227 ret = da9052_read_alarm(rtc, tm);
228 if (ret < 0) {
229 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
230 return ret;
231 }
232
233 alrm->enabled = da9052_rtc_get_alarm_status(rtc);
234 return 0;
235}
236
237static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
238{
239 int ret;
240 struct rtc_time *tm = &alrm->time;
241 struct da9052_rtc *rtc = dev_get_drvdata(dev);
242
243 /* DA9052 only has 6 bits for year - to represent 2000-2063 */
244 if ((tm->tm_year < 100) || (tm->tm_year > 163))
245 return -EINVAL;
246
247 ret = da9052_rtc_enable_alarm(rtc, 0);
248 if (ret < 0)
249 return ret;
250
251 ret = da9052_set_alarm(rtc, tm);
252 if (ret < 0)
253 return ret;
254
255 ret = da9052_rtc_enable_alarm(rtc, 1);
256 return ret;
257}
258
259static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
260{
261 struct da9052_rtc *rtc = dev_get_drvdata(dev);
262
263 return da9052_rtc_enable_alarm(rtc, enabled);
264}
265
266static const struct rtc_class_ops da9052_rtc_ops = {
267 .read_time = da9052_rtc_read_time,
268 .set_time = da9052_rtc_set_time,
269 .read_alarm = da9052_rtc_read_alarm,
270 .set_alarm = da9052_rtc_set_alarm,
271 .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
272};
273
274static int da9052_rtc_probe(struct platform_device *pdev)
275{
276 struct da9052_rtc *rtc;
277 int ret;
278
279 rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
280 if (!rtc)
281 return -ENOMEM;
282
283 rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
284 platform_set_drvdata(pdev, rtc);
285
286 ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
287 if (ret < 0) {
288 rtc_err(rtc,
289 "Failed to setup RTC battery charging: %d\n", ret);
290 return ret;
291 }
292
293 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
294 DA9052_ALARM_Y_TICK_ON, 0);
295 if (ret != 0)
296 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
297
298 device_init_wakeup(&pdev->dev, true);
299 rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
300 if (IS_ERR(rtc->rtc))
301 return PTR_ERR(rtc->rtc);
302
303 rtc->rtc->ops = &da9052_rtc_ops;
304 rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
305 rtc->rtc->range_max = RTC_TIMESTAMP_END_2063;
306
307 ret = devm_rtc_register_device(rtc->rtc);
308 if (ret)
309 return ret;
310
311 ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
312 da9052_rtc_irq, rtc);
313 if (ret != 0) {
314 rtc_err(rtc, "irq registration failed: %d\n", ret);
315 return ret;
316 }
317
318 return 0;
319}
320
321static struct platform_driver da9052_rtc_driver = {
322 .probe = da9052_rtc_probe,
323 .driver = {
324 .name = "da9052-rtc",
325 },
326};
327
328module_platform_driver(da9052_rtc_driver);
329
330MODULE_AUTHOR("Anthony Olech <[email protected]>");
331MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
332MODULE_LICENSE("GPL");
333MODULE_ALIAS("platform:da9052-rtc");