1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * RTC driver for Maxim MAX8925
4 *
5 * Copyright (C) 2009-2010 Marvell International Ltd.
6 * Haojian Zhuang <haojian.zhuang@marvell.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/i2c.h>
11 #include <linux/slab.h>
12 #include <linux/rtc.h>
13 #include <linux/platform_device.h>
14 #include <linux/mfd/max8925.h>
15
16 enum {
17 RTC_SEC = 0,
18 RTC_MIN,
19 RTC_HOUR,
20 RTC_WEEKDAY,
21 RTC_DATE,
22 RTC_MONTH,
23 RTC_YEAR1,
24 RTC_YEAR2,
25 };
26
27 #define MAX8925_RTC_SEC 0x00
28 #define MAX8925_RTC_MIN 0x01
29 #define MAX8925_RTC_HOUR 0x02
30 #define MAX8925_RTC_WEEKDAY 0x03
31 #define MAX8925_RTC_DATE 0x04
32 #define MAX8925_RTC_MONTH 0x05
33 #define MAX8925_RTC_YEAR1 0x06
34 #define MAX8925_RTC_YEAR2 0x07
35 #define MAX8925_ALARM0_SEC 0x08
36 #define MAX8925_ALARM0_MIN 0x09
37 #define MAX8925_ALARM0_HOUR 0x0a
38 #define MAX8925_ALARM0_WEEKDAY 0x0b
39 #define MAX8925_ALARM0_DATE 0x0c
40 #define MAX8925_ALARM0_MON 0x0d
41 #define MAX8925_ALARM0_YEAR1 0x0e
42 #define MAX8925_ALARM0_YEAR2 0x0f
43 #define MAX8925_ALARM1_SEC 0x10
44 #define MAX8925_ALARM1_MIN 0x11
45 #define MAX8925_ALARM1_HOUR 0x12
46 #define MAX8925_ALARM1_WEEKDAY 0x13
47 #define MAX8925_ALARM1_DATE 0x14
48 #define MAX8925_ALARM1_MON 0x15
49 #define MAX8925_ALARM1_YEAR1 0x16
50 #define MAX8925_ALARM1_YEAR2 0x17
51 #define MAX8925_RTC_CNTL 0x1b
52 #define MAX8925_RTC_STATUS 0x20
53
54 #define TIME_NUM 8
55 #define ALARM_1SEC (1 << 7)
56 #define HOUR_12 (1 << 7)
57 #define HOUR_AM_PM (1 << 5)
58 #define ALARM0_IRQ (1 << 3)
59 #define ALARM1_IRQ (1 << 2)
60 #define ALARM0_STATUS (1 << 2)
61 #define ALARM1_STATUS (1 << 1)
62
63
64 struct max8925_rtc_info {
65 struct rtc_device *rtc_dev;
66 struct max8925_chip *chip;
67 struct i2c_client *rtc;
68 struct device *dev;
69 int irq;
70 };
71
rtc_update_handler(int irq,void * data)72 static irqreturn_t rtc_update_handler(int irq, void *data)
73 {
74 struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
75
76 /* disable ALARM0 except for 1SEC alarm */
77 max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
78 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
79 return IRQ_HANDLED;
80 }
81
tm_calc(struct rtc_time * tm,unsigned char * buf,int len)82 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
83 {
84 if (len < TIME_NUM)
85 return -EINVAL;
86 tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
87 + (buf[RTC_YEAR2] & 0xf) * 100
88 + (buf[RTC_YEAR1] >> 4) * 10
89 + (buf[RTC_YEAR1] & 0xf);
90 tm->tm_year -= 1900;
91 tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
92 + (buf[RTC_MONTH] & 0x0f);
93 tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
94 + (buf[RTC_DATE] & 0x0f);
95 tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
96 if (buf[RTC_HOUR] & HOUR_12) {
97 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
98 + (buf[RTC_HOUR] & 0x0f);
99 if (buf[RTC_HOUR] & HOUR_AM_PM)
100 tm->tm_hour += 12;
101 } else
102 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
103 + (buf[RTC_HOUR] & 0x0f);
104 tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
105 + (buf[RTC_MIN] & 0x0f);
106 tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
107 + (buf[RTC_SEC] & 0x0f);
108 return 0;
109 }
110
data_calc(unsigned char * buf,struct rtc_time * tm,int len)111 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
112 {
113 unsigned char high, low;
114
115 if (len < TIME_NUM)
116 return -EINVAL;
117
118 high = (tm->tm_year + 1900) / 1000;
119 low = (tm->tm_year + 1900) / 100;
120 low = low - high * 10;
121 buf[RTC_YEAR2] = (high << 4) + low;
122 high = (tm->tm_year + 1900) / 10;
123 low = tm->tm_year + 1900;
124 low = low - high * 10;
125 high = high - (high / 10) * 10;
126 buf[RTC_YEAR1] = (high << 4) + low;
127 high = tm->tm_mon / 10;
128 low = tm->tm_mon;
129 low = low - high * 10;
130 buf[RTC_MONTH] = (high << 4) + low;
131 high = tm->tm_mday / 10;
132 low = tm->tm_mday;
133 low = low - high * 10;
134 buf[RTC_DATE] = (high << 4) + low;
135 buf[RTC_WEEKDAY] = tm->tm_wday;
136 high = tm->tm_hour / 10;
137 low = tm->tm_hour;
138 low = low - high * 10;
139 buf[RTC_HOUR] = (high << 4) + low;
140 high = tm->tm_min / 10;
141 low = tm->tm_min;
142 low = low - high * 10;
143 buf[RTC_MIN] = (high << 4) + low;
144 high = tm->tm_sec / 10;
145 low = tm->tm_sec;
146 low = low - high * 10;
147 buf[RTC_SEC] = (high << 4) + low;
148 return 0;
149 }
150
max8925_rtc_read_time(struct device * dev,struct rtc_time * tm)151 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
152 {
153 struct max8925_rtc_info *info = dev_get_drvdata(dev);
154 unsigned char buf[TIME_NUM];
155 int ret;
156
157 ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
158 if (ret < 0)
159 goto out;
160 ret = tm_calc(tm, buf, TIME_NUM);
161 out:
162 return ret;
163 }
164
max8925_rtc_set_time(struct device * dev,struct rtc_time * tm)165 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
166 {
167 struct max8925_rtc_info *info = dev_get_drvdata(dev);
168 unsigned char buf[TIME_NUM];
169 int ret;
170
171 ret = data_calc(buf, tm, TIME_NUM);
172 if (ret < 0)
173 goto out;
174 ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
175 out:
176 return ret;
177 }
178
max8925_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)179 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
180 {
181 struct max8925_rtc_info *info = dev_get_drvdata(dev);
182 unsigned char buf[TIME_NUM];
183 int ret;
184
185 ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
186 if (ret < 0)
187 goto out;
188 ret = tm_calc(&alrm->time, buf, TIME_NUM);
189 if (ret < 0)
190 goto out;
191 ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
192 if (ret < 0)
193 goto out;
194 if (ret & ALARM0_IRQ) {
195 alrm->enabled = 0;
196 } else {
197 ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
198 if (ret < 0)
199 goto out;
200 if (!ret)
201 alrm->enabled = 0;
202 else
203 alrm->enabled = 1;
204 }
205 ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
206 if (ret < 0)
207 goto out;
208 if (ret & ALARM0_STATUS)
209 alrm->pending = 1;
210 else
211 alrm->pending = 0;
212 return 0;
213 out:
214 return ret;
215 }
216
max8925_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)217 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
218 {
219 struct max8925_rtc_info *info = dev_get_drvdata(dev);
220 unsigned char buf[TIME_NUM];
221 int ret;
222
223 ret = data_calc(buf, &alrm->time, TIME_NUM);
224 if (ret < 0)
225 goto out;
226 ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
227 if (ret < 0)
228 goto out;
229 if (alrm->enabled)
230 /* only enable alarm on year/month/day/hour/min/sec */
231 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
232 else
233 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
234 out:
235 return ret;
236 }
237
238 static const struct rtc_class_ops max8925_rtc_ops = {
239 .read_time = max8925_rtc_read_time,
240 .set_time = max8925_rtc_set_time,
241 .read_alarm = max8925_rtc_read_alarm,
242 .set_alarm = max8925_rtc_set_alarm,
243 };
244
max8925_rtc_probe(struct platform_device * pdev)245 static int max8925_rtc_probe(struct platform_device *pdev)
246 {
247 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
248 struct max8925_rtc_info *info;
249 int ret;
250
251 info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
252 GFP_KERNEL);
253 if (!info)
254 return -ENOMEM;
255 info->chip = chip;
256 info->rtc = chip->rtc;
257 info->dev = &pdev->dev;
258 info->irq = platform_get_irq(pdev, 0);
259
260 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
261 rtc_update_handler, IRQF_ONESHOT,
262 "rtc-alarm0", info);
263 if (ret < 0) {
264 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
265 info->irq, ret);
266 return ret;
267 }
268
269 dev_set_drvdata(&pdev->dev, info);
270 /* XXX - isn't this redundant? */
271 platform_set_drvdata(pdev, info);
272
273 device_init_wakeup(&pdev->dev, 1);
274
275 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
276 &max8925_rtc_ops, THIS_MODULE);
277 ret = PTR_ERR(info->rtc_dev);
278 if (IS_ERR(info->rtc_dev)) {
279 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
280 return ret;
281 }
282
283 return 0;
284 }
285
286 #ifdef CONFIG_PM_SLEEP
max8925_rtc_suspend(struct device * dev)287 static int max8925_rtc_suspend(struct device *dev)
288 {
289 struct platform_device *pdev = to_platform_device(dev);
290 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
291
292 if (device_may_wakeup(dev))
293 chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
294 return 0;
295 }
max8925_rtc_resume(struct device * dev)296 static int max8925_rtc_resume(struct device *dev)
297 {
298 struct platform_device *pdev = to_platform_device(dev);
299 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
300
301 if (device_may_wakeup(dev))
302 chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
303 return 0;
304 }
305 #endif
306
307 static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
308
309 static struct platform_driver max8925_rtc_driver = {
310 .driver = {
311 .name = "max8925-rtc",
312 .pm = &max8925_rtc_pm_ops,
313 },
314 .probe = max8925_rtc_probe,
315 };
316
317 module_platform_driver(max8925_rtc_driver);
318
319 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
320 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
321 MODULE_LICENSE("GPL");
322
323