2 * RTC driver for Maxim MAX8925
4 * Copyright (C) 2009-2010 Marvell International Ltd.
5 * Haojian Zhuang <haojian.zhuang@marvell.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/module.h>
13 #include <linux/i2c.h>
14 #include <linux/slab.h>
15 #include <linux/rtc.h>
16 #include <linux/platform_device.h>
17 #include <linux/mfd/max8925.h>
30 #define MAX8925_RTC_SEC 0x00
31 #define MAX8925_RTC_MIN 0x01
32 #define MAX8925_RTC_HOUR 0x02
33 #define MAX8925_RTC_WEEKDAY 0x03
34 #define MAX8925_RTC_DATE 0x04
35 #define MAX8925_RTC_MONTH 0x05
36 #define MAX8925_RTC_YEAR1 0x06
37 #define MAX8925_RTC_YEAR2 0x07
38 #define MAX8925_ALARM0_SEC 0x08
39 #define MAX8925_ALARM0_MIN 0x09
40 #define MAX8925_ALARM0_HOUR 0x0a
41 #define MAX8925_ALARM0_WEEKDAY 0x0b
42 #define MAX8925_ALARM0_DATE 0x0c
43 #define MAX8925_ALARM0_MON 0x0d
44 #define MAX8925_ALARM0_YEAR1 0x0e
45 #define MAX8925_ALARM0_YEAR2 0x0f
46 #define MAX8925_ALARM1_SEC 0x10
47 #define MAX8925_ALARM1_MIN 0x11
48 #define MAX8925_ALARM1_HOUR 0x12
49 #define MAX8925_ALARM1_WEEKDAY 0x13
50 #define MAX8925_ALARM1_DATE 0x14
51 #define MAX8925_ALARM1_MON 0x15
52 #define MAX8925_ALARM1_YEAR1 0x16
53 #define MAX8925_ALARM1_YEAR2 0x17
54 #define MAX8925_RTC_CNTL 0x1b
55 #define MAX8925_RTC_STATUS 0x20
58 #define ALARM_1SEC (1 << 7)
59 #define HOUR_12 (1 << 7)
60 #define HOUR_AM_PM (1 << 5)
61 #define ALARM0_IRQ (1 << 3)
62 #define ALARM1_IRQ (1 << 2)
63 #define ALARM0_STATUS (1 << 2)
64 #define ALARM1_STATUS (1 << 1)
67 struct max8925_rtc_info {
68 struct rtc_device *rtc_dev;
69 struct max8925_chip *chip;
70 struct i2c_client *rtc;
74 static irqreturn_t rtc_update_handler(int irq, void *data)
76 struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
78 /* disable ALARM0 except for 1SEC alarm */
79 max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
80 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
84 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
88 tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
89 + (buf[RTC_YEAR2] & 0xf) * 100
90 + (buf[RTC_YEAR1] >> 4) * 10
91 + (buf[RTC_YEAR1] & 0xf);
93 tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
94 + (buf[RTC_MONTH] & 0x0f);
95 tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
96 + (buf[RTC_DATE] & 0x0f);
97 tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
98 if (buf[RTC_HOUR] & HOUR_12) {
99 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
100 + (buf[RTC_HOUR] & 0x0f);
101 if (buf[RTC_HOUR] & HOUR_AM_PM)
104 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
105 + (buf[RTC_HOUR] & 0x0f);
106 tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
107 + (buf[RTC_MIN] & 0x0f);
108 tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
109 + (buf[RTC_SEC] & 0x0f);
113 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
115 unsigned char high, low;
120 high = (tm->tm_year + 1900) / 1000;
121 low = (tm->tm_year + 1900) / 100;
122 low = low - high * 10;
123 buf[RTC_YEAR2] = (high << 4) + low;
124 high = (tm->tm_year + 1900) / 10;
125 low = tm->tm_year + 1900;
126 low = low - high * 10;
127 high = high - (high / 10) * 10;
128 buf[RTC_YEAR1] = (high << 4) + low;
129 high = tm->tm_mon / 10;
131 low = low - high * 10;
132 buf[RTC_MONTH] = (high << 4) + low;
133 high = tm->tm_mday / 10;
135 low = low - high * 10;
136 buf[RTC_DATE] = (high << 4) + low;
137 buf[RTC_WEEKDAY] = tm->tm_wday;
138 high = tm->tm_hour / 10;
140 low = low - high * 10;
141 buf[RTC_HOUR] = (high << 4) + low;
142 high = tm->tm_min / 10;
144 low = low - high * 10;
145 buf[RTC_MIN] = (high << 4) + low;
146 high = tm->tm_sec / 10;
148 low = low - high * 10;
149 buf[RTC_SEC] = (high << 4) + low;
153 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
155 struct max8925_rtc_info *info = dev_get_drvdata(dev);
156 unsigned char buf[TIME_NUM];
159 ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
162 ret = tm_calc(tm, buf, TIME_NUM);
167 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
169 struct max8925_rtc_info *info = dev_get_drvdata(dev);
170 unsigned char buf[TIME_NUM];
173 ret = data_calc(buf, tm, TIME_NUM);
176 ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
181 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
183 struct max8925_rtc_info *info = dev_get_drvdata(dev);
184 unsigned char buf[TIME_NUM];
187 ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
190 ret = tm_calc(&alrm->time, buf, TIME_NUM);
193 ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
196 if ((ret & ALARM0_IRQ) == 0)
200 ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
203 if (ret & ALARM0_STATUS)
211 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
213 struct max8925_rtc_info *info = dev_get_drvdata(dev);
214 unsigned char buf[TIME_NUM];
217 ret = data_calc(buf, &alrm->time, TIME_NUM);
220 ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
223 /* only enable alarm on year/month/day/hour/min/sec */
224 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
231 static const struct rtc_class_ops max8925_rtc_ops = {
232 .read_time = max8925_rtc_read_time,
233 .set_time = max8925_rtc_set_time,
234 .read_alarm = max8925_rtc_read_alarm,
235 .set_alarm = max8925_rtc_set_alarm,
238 static int __devinit max8925_rtc_probe(struct platform_device *pdev)
240 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
241 struct max8925_rtc_info *info;
244 info = kzalloc(sizeof(struct max8925_rtc_info), GFP_KERNEL);
248 info->rtc = chip->rtc;
249 info->dev = &pdev->dev;
250 irq = chip->irq_base + MAX8925_IRQ_RTC_ALARM0;
252 ret = request_threaded_irq(irq, NULL, rtc_update_handler,
253 IRQF_ONESHOT, "rtc-alarm0", info);
255 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
260 dev_set_drvdata(&pdev->dev, info);
261 /* XXX - isn't this redundant? */
262 platform_set_drvdata(pdev, info);
264 info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev,
265 &max8925_rtc_ops, THIS_MODULE);
266 ret = PTR_ERR(info->rtc_dev);
267 if (IS_ERR(info->rtc_dev)) {
268 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
274 platform_set_drvdata(pdev, NULL);
275 free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
281 static int __devexit max8925_rtc_remove(struct platform_device *pdev)
283 struct max8925_rtc_info *info = platform_get_drvdata(pdev);
286 free_irq(info->chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
287 rtc_device_unregister(info->rtc_dev);
293 static struct platform_driver max8925_rtc_driver = {
295 .name = "max8925-rtc",
296 .owner = THIS_MODULE,
298 .probe = max8925_rtc_probe,
299 .remove = __devexit_p(max8925_rtc_remove),
302 static int __init max8925_rtc_init(void)
304 return platform_driver_register(&max8925_rtc_driver);
306 module_init(max8925_rtc_init);
308 static void __exit max8925_rtc_exit(void)
310 platform_driver_unregister(&max8925_rtc_driver);
312 module_exit(max8925_rtc_exit);
314 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
315 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
316 MODULE_LICENSE("GPL");