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Linux/drivers/rtc/rtc-max8925.c

  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         int                     irq;
 73 };
 74 
 75 static irqreturn_t rtc_update_handler(int irq, void *data)
 76 {
 77         struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
 78 
 79         /* disable ALARM0 except for 1SEC alarm */
 80         max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
 81         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
 82         return IRQ_HANDLED;
 83 }
 84 
 85 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
 86 {
 87         if (len < TIME_NUM)
 88                 return -EINVAL;
 89         tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
 90                         + (buf[RTC_YEAR2] & 0xf) * 100
 91                         + (buf[RTC_YEAR1] >> 4) * 10
 92                         + (buf[RTC_YEAR1] & 0xf);
 93         tm->tm_year -= 1900;
 94         tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
 95                         + (buf[RTC_MONTH] & 0x0f);
 96         tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
 97                         + (buf[RTC_DATE] & 0x0f);
 98         tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
 99         if (buf[RTC_HOUR] & HOUR_12) {
100                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
101                                 + (buf[RTC_HOUR] & 0x0f);
102                 if (buf[RTC_HOUR] & HOUR_AM_PM)
103                         tm->tm_hour += 12;
104         } else
105                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
106                                 + (buf[RTC_HOUR] & 0x0f);
107         tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
108                         + (buf[RTC_MIN] & 0x0f);
109         tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
110                         + (buf[RTC_SEC] & 0x0f);
111         return 0;
112 }
113 
114 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
115 {
116         unsigned char high, low;
117 
118         if (len < TIME_NUM)
119                 return -EINVAL;
120 
121         high = (tm->tm_year + 1900) / 1000;
122         low = (tm->tm_year + 1900) / 100;
123         low = low - high * 10;
124         buf[RTC_YEAR2] = (high << 4) + low;
125         high = (tm->tm_year + 1900) / 10;
126         low = tm->tm_year + 1900;
127         low = low - high * 10;
128         high = high - (high / 10) * 10;
129         buf[RTC_YEAR1] = (high << 4) + low;
130         high = tm->tm_mon / 10;
131         low = tm->tm_mon;
132         low = low - high * 10;
133         buf[RTC_MONTH] = (high << 4) + low;
134         high = tm->tm_mday / 10;
135         low = tm->tm_mday;
136         low = low - high * 10;
137         buf[RTC_DATE] = (high << 4) + low;
138         buf[RTC_WEEKDAY] = tm->tm_wday;
139         high = tm->tm_hour / 10;
140         low = tm->tm_hour;
141         low = low - high * 10;
142         buf[RTC_HOUR] = (high << 4) + low;
143         high = tm->tm_min / 10;
144         low = tm->tm_min;
145         low = low - high * 10;
146         buf[RTC_MIN] = (high << 4) + low;
147         high = tm->tm_sec / 10;
148         low = tm->tm_sec;
149         low = low - high * 10;
150         buf[RTC_SEC] = (high << 4) + low;
151         return 0;
152 }
153 
154 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
155 {
156         struct max8925_rtc_info *info = dev_get_drvdata(dev);
157         unsigned char buf[TIME_NUM];
158         int ret;
159 
160         ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
161         if (ret < 0)
162                 goto out;
163         ret = tm_calc(tm, buf, TIME_NUM);
164 out:
165         return ret;
166 }
167 
168 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
169 {
170         struct max8925_rtc_info *info = dev_get_drvdata(dev);
171         unsigned char buf[TIME_NUM];
172         int ret;
173 
174         ret = data_calc(buf, tm, TIME_NUM);
175         if (ret < 0)
176                 goto out;
177         ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
178 out:
179         return ret;
180 }
181 
182 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
183 {
184         struct max8925_rtc_info *info = dev_get_drvdata(dev);
185         unsigned char buf[TIME_NUM];
186         int ret;
187 
188         ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
189         if (ret < 0)
190                 goto out;
191         ret = tm_calc(&alrm->time, buf, TIME_NUM);
192         if (ret < 0)
193                 goto out;
194         ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
195         if (ret < 0)
196                 goto out;
197         if (ret & ALARM0_IRQ) {
198                 alrm->enabled = 0;
199         } else {
200                 ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
201                 if (ret < 0)
202                         goto out;
203                 if (!ret)
204                         alrm->enabled = 0;
205                 else
206                         alrm->enabled = 1;
207         }
208         ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
209         if (ret < 0)
210                 goto out;
211         if (ret & ALARM0_STATUS)
212                 alrm->pending = 1;
213         else
214                 alrm->pending = 0;
215         return 0;
216 out:
217         return ret;
218 }
219 
220 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
221 {
222         struct max8925_rtc_info *info = dev_get_drvdata(dev);
223         unsigned char buf[TIME_NUM];
224         int ret;
225 
226         ret = data_calc(buf, &alrm->time, TIME_NUM);
227         if (ret < 0)
228                 goto out;
229         ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
230         if (ret < 0)
231                 goto out;
232         if (alrm->enabled)
233                 /* only enable alarm on year/month/day/hour/min/sec */
234                 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
235         else
236                 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
237         if (ret < 0)
238                 goto out;
239 out:
240         return ret;
241 }
242 
243 static const struct rtc_class_ops max8925_rtc_ops = {
244         .read_time      = max8925_rtc_read_time,
245         .set_time       = max8925_rtc_set_time,
246         .read_alarm     = max8925_rtc_read_alarm,
247         .set_alarm      = max8925_rtc_set_alarm,
248 };
249 
250 static int max8925_rtc_probe(struct platform_device *pdev)
251 {
252         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
253         struct max8925_rtc_info *info;
254         int ret;
255 
256         info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
257                             GFP_KERNEL);
258         if (!info)
259                 return -ENOMEM;
260         info->chip = chip;
261         info->rtc = chip->rtc;
262         info->dev = &pdev->dev;
263         info->irq = platform_get_irq(pdev, 0);
264 
265         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
266                                         rtc_update_handler, IRQF_ONESHOT,
267                                         "rtc-alarm0", info);
268         if (ret < 0) {
269                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
270                         info->irq, ret);
271                 return ret;
272         }
273 
274         dev_set_drvdata(&pdev->dev, info);
275         /* XXX - isn't this redundant? */
276         platform_set_drvdata(pdev, info);
277 
278         device_init_wakeup(&pdev->dev, 1);
279 
280         info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
281                                         &max8925_rtc_ops, THIS_MODULE);
282         ret = PTR_ERR(info->rtc_dev);
283         if (IS_ERR(info->rtc_dev)) {
284                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
285                 return ret;
286         }
287 
288         return 0;
289 }
290 
291 #ifdef CONFIG_PM_SLEEP
292 static int max8925_rtc_suspend(struct device *dev)
293 {
294         struct platform_device *pdev = to_platform_device(dev);
295         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
296 
297         if (device_may_wakeup(dev))
298                 chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
299         return 0;
300 }
301 static int max8925_rtc_resume(struct device *dev)
302 {
303         struct platform_device *pdev = to_platform_device(dev);
304         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
305 
306         if (device_may_wakeup(dev))
307                 chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
308         return 0;
309 }
310 #endif
311 
312 static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
313 
314 static struct platform_driver max8925_rtc_driver = {
315         .driver         = {
316                 .name   = "max8925-rtc",
317                 .owner  = THIS_MODULE,
318                 .pm     = &max8925_rtc_pm_ops,
319         },
320         .probe          = max8925_rtc_probe,
321 };
322 
323 module_platform_driver(max8925_rtc_driver);
324 
325 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
326 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
327 MODULE_LICENSE("GPL");
328 
329 

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