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[pohmelfs.git] / drivers / rtc / rtc-max8925.c
blob2d71943bc436ad9719d364d99361dd62f92268eb
1 /*
2 * RTC driver for Maxim MAX8925
3 *
4 * Copyright (C) 2009-2010 Marvell International Ltd.
5 * Haojian Zhuang <haojian.zhuang@marvell.com>
6 *
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.
10 */
11
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>
18
19 enum {
20 RTC_SEC = 0,
21 RTC_MIN,
22 RTC_HOUR,
23 RTC_WEEKDAY,
24 RTC_DATE,
25 RTC_MONTH,
26 RTC_YEAR1,
27 RTC_YEAR2,
28 };
29
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
56
57 #define TIME_NUM 8
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)
65
66
67 struct max8925_rtc_info {
68 struct rtc_device *rtc_dev;
69 struct max8925_chip *chip;
70 struct i2c_client *rtc;
71 struct device *dev;
72 };
73
74 static irqreturn_t rtc_update_handler(int irq, void *data)
75 {
76 struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
77
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);
81 return IRQ_HANDLED;
82 }
83
84 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
85 {
86 if (len < TIME_NUM)
87 return -EINVAL;
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);
92 tm->tm_year -= 1900;
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)
102 tm->tm_hour += 12;
103 } else
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);
110 return 0;
111 }
112
113 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
114 {
115 unsigned char high, low;
116
117 if (len < TIME_NUM)
118 return -EINVAL;
119
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;
130 low = tm->tm_mon;
131 low = low - high * 10;
132 buf[RTC_MONTH] = (high << 4) + low;
133 high = tm->tm_mday / 10;
134 low = tm->tm_mday;
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;
139 low = tm->tm_hour;
140 low = low - high * 10;
141 buf[RTC_HOUR] = (high << 4) + low;
142 high = tm->tm_min / 10;
143 low = tm->tm_min;
144 low = low - high * 10;
145 buf[RTC_MIN] = (high << 4) + low;
146 high = tm->tm_sec / 10;
147 low = tm->tm_sec;
148 low = low - high * 10;
149 buf[RTC_SEC] = (high << 4) + low;
150 return 0;
151 }
152
153 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
154 {
155 struct max8925_rtc_info *info = dev_get_drvdata(dev);
156 unsigned char buf[TIME_NUM];
157 int ret;
158
159 ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
160 if (ret < 0)
161 goto out;
162 ret = tm_calc(tm, buf, TIME_NUM);
163 out:
164 return ret;
165 }
166
167 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
168 {
169 struct max8925_rtc_info *info = dev_get_drvdata(dev);
170 unsigned char buf[TIME_NUM];
171 int ret;
172
173 ret = data_calc(buf, tm, TIME_NUM);
174 if (ret < 0)
175 goto out;
176 ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
177 out:
178 return ret;
179 }
180
181 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
182 {
183 struct max8925_rtc_info *info = dev_get_drvdata(dev);
184 unsigned char buf[TIME_NUM];
185 int ret;
186
187 ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
188 if (ret < 0)
189 goto out;
190 ret = tm_calc(&alrm->time, buf, TIME_NUM);
191 if (ret < 0)
192 goto out;
193 ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
194 if (ret < 0)
195 goto out;
196 if ((ret & ALARM0_IRQ) == 0)
197 alrm->enabled = 1;
198 else
199 alrm->enabled = 0;
200 ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
201 if (ret < 0)
202 goto out;
203 if (ret & ALARM0_STATUS)
204 alrm->pending = 1;
205 else
206 alrm->pending = 0;
207 out:
208 return ret;
209 }
210
211 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
212 {
213 struct max8925_rtc_info *info = dev_get_drvdata(dev);
214 unsigned char buf[TIME_NUM];
215 int ret;
216
217 ret = data_calc(buf, &alrm->time, TIME_NUM);
218 if (ret < 0)
219 goto out;
220 ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
221 if (ret < 0)
222 goto out;
223 /* only enable alarm on year/month/day/hour/min/sec */
224 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
225 if (ret < 0)
226 goto out;
227 out:
228 return ret;
229 }
230
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,
236 };
237
238 static int __devinit max8925_rtc_probe(struct platform_device *pdev)
239 {
240 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
241 struct max8925_rtc_info *info;
242 int irq, ret;
243
244 info = kzalloc(sizeof(struct max8925_rtc_info), GFP_KERNEL);
245 if (!info)
246 return -ENOMEM;
247 info->chip = chip;
248 info->rtc = chip->rtc;
249 info->dev = &pdev->dev;
250 irq = chip->irq_base + MAX8925_IRQ_RTC_ALARM0;
251
252 ret = request_threaded_irq(irq, NULL, rtc_update_handler,
253 IRQF_ONESHOT, "rtc-alarm0", info);
254 if (ret < 0) {
255 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
256 irq, ret);
257 goto out_irq;
258 }
259
260 dev_set_drvdata(&pdev->dev, info);
261 /* XXX - isn't this redundant? */
262 platform_set_drvdata(pdev, info);
263
264 device_init_wakeup(&pdev->dev, 1);
265
266 info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev,
267 &max8925_rtc_ops, THIS_MODULE);
268 ret = PTR_ERR(info->rtc_dev);
269 if (IS_ERR(info->rtc_dev)) {
270 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
271 goto out_rtc;
272 }
273
274 return 0;
275 out_rtc:
276 platform_set_drvdata(pdev, NULL);
277 free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
278 out_irq:
279 kfree(info);
280 return ret;
281 }
282
283 static int __devexit max8925_rtc_remove(struct platform_device *pdev)
284 {
285 struct max8925_rtc_info *info = platform_get_drvdata(pdev);
286
287 if (info) {
288 free_irq(info->chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
289 rtc_device_unregister(info->rtc_dev);
290 kfree(info);
291 }
292 return 0;
293 }
294
295 #ifdef CONFIG_PM_SLEEP
296 static int max8925_rtc_suspend(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 static int max8925_rtc_resume(struct device *dev)
306 {
307 struct platform_device *pdev = to_platform_device(dev);
308 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
309
310 if (device_may_wakeup(dev))
311 chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
312 return 0;
313 }
314 #endif
315
316 static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
317
318 static struct platform_driver max8925_rtc_driver = {
319 .driver = {
320 .name = "max8925-rtc",
321 .owner = THIS_MODULE,
322 .pm = &max8925_rtc_pm_ops,
323 },
324 .probe = max8925_rtc_probe,
325 .remove = __devexit_p(max8925_rtc_remove),
326 };
327
328 module_platform_driver(max8925_rtc_driver);
329
330 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
331 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
332 MODULE_LICENSE("GPL");
333