2 * DS1286 Real Time Clock interface for Linux
4 * Copyright (C) 1998, 1999, 2000 Ralf Baechle
5 * Copyright (C) 2008 Thomas Bogendoerfer
7 * Based on code written by Paul Gortmaker.
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
15 #include <linux/module.h>
16 #include <linux/rtc.h>
17 #include <linux/platform_device.h>
18 #include <linux/bcd.h>
19 #include <linux/ds1286.h>
21 #include <linux/slab.h>
23 #define DRV_VERSION "1.0"
26 struct rtc_device *rtc;
29 unsigned long baseaddr;
33 static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
35 return __raw_readl(&priv->rtcregs[reg]) & 0xff;
38 static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg)
40 __raw_writel(data, &priv->rtcregs[reg]);
44 static int ds1286_alarm_irq_enable(struct device *dev, unsigned int enabled)
46 struct ds1286_priv *priv = dev_get_drvdata(dev);
50 /* Allow or mask alarm interrupts */
51 spin_lock_irqsave(&priv->lock, flags);
52 val = ds1286_rtc_read(priv, RTC_CMD);
57 ds1286_rtc_write(priv, val, RTC_CMD);
58 spin_unlock_irqrestore(&priv->lock, flags);
63 #ifdef CONFIG_RTC_INTF_DEV
65 static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
67 struct ds1286_priv *priv = dev_get_drvdata(dev);
73 /* Mask watchdog int. enab. bit */
74 spin_lock_irqsave(&priv->lock, flags);
75 val = ds1286_rtc_read(priv, RTC_CMD);
77 ds1286_rtc_write(priv, val, RTC_CMD);
78 spin_unlock_irqrestore(&priv->lock, flags);
81 /* Allow watchdog interrupts. */
82 spin_lock_irqsave(&priv->lock, flags);
83 val = ds1286_rtc_read(priv, RTC_CMD);
85 ds1286_rtc_write(priv, val, RTC_CMD);
86 spin_unlock_irqrestore(&priv->lock, flags);
95 #define ds1286_ioctl NULL
100 static int ds1286_proc(struct device *dev, struct seq_file *seq)
102 struct ds1286_priv *priv = dev_get_drvdata(dev);
103 unsigned char month, cmd, amode;
106 month = ds1286_rtc_read(priv, RTC_MONTH);
109 "square_wave\t: %s\n",
110 (month & RTC_EOSC) ? "disabled" : "enabled",
111 (month & RTC_ESQW) ? "disabled" : "enabled");
113 amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) |
114 ((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) |
115 ((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7);
124 s = "hours and minutes match";
127 s = "days, hours and minutes match";
133 seq_printf(seq, "alarm_mode\t: %s\n", s);
135 cmd = ds1286_rtc_read(priv, RTC_CMD);
137 "alarm_enable\t: %s\n"
140 "wdog_alarm_mask\t: %s\n"
141 "interrupt_mode\t: %s\n"
142 "INTB_mode\t: %s_active\n"
143 "interrupt_pins\t: %s\n",
144 (cmd & RTC_TDF) ? "yes" : "no",
145 (cmd & RTC_WAF) ? "yes" : "no",
146 (cmd & RTC_TDM) ? "disabled" : "enabled",
147 (cmd & RTC_WAM) ? "disabled" : "enabled",
148 (cmd & RTC_PU_LVL) ? "pulse" : "level",
149 (cmd & RTC_IBH_LO) ? "low" : "high",
150 (cmd & RTC_IPSW) ? "unswapped" : "swapped");
155 #define ds1286_proc NULL
158 static int ds1286_read_time(struct device *dev, struct rtc_time *tm)
160 struct ds1286_priv *priv = dev_get_drvdata(dev);
161 unsigned char save_control;
163 unsigned long uip_watchdog = jiffies;
166 * read RTC once any update in progress is done. The update
167 * can take just over 2ms. We wait 10 to 20ms. There is no need to
168 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
169 * If you need to know *exactly* when a second has started, enable
170 * periodic update complete interrupts, (via ioctl) and then
171 * immediately read /dev/rtc which will block until you get the IRQ.
172 * Once the read clears, read the RTC time (again via ioctl). Easy.
175 if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)
176 while (time_before(jiffies, uip_watchdog + 2*HZ/100))
180 * Only the values that we read from the RTC are set. We leave
181 * tm_wday, tm_yday and tm_isdst untouched. Even though the
182 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
183 * by the RTC when initially set to a non-zero value.
185 spin_lock_irqsave(&priv->lock, flags);
186 save_control = ds1286_rtc_read(priv, RTC_CMD);
187 ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
189 tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS);
190 tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES);
191 tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f;
192 tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE);
193 tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f;
194 tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR);
196 ds1286_rtc_write(priv, save_control, RTC_CMD);
197 spin_unlock_irqrestore(&priv->lock, flags);
199 tm->tm_sec = bcd2bin(tm->tm_sec);
200 tm->tm_min = bcd2bin(tm->tm_min);
201 tm->tm_hour = bcd2bin(tm->tm_hour);
202 tm->tm_mday = bcd2bin(tm->tm_mday);
203 tm->tm_mon = bcd2bin(tm->tm_mon);
204 tm->tm_year = bcd2bin(tm->tm_year);
207 * Account for differences between how the RTC uses the values
208 * and how they are defined in a struct rtc_time;
210 if (tm->tm_year < 45)
213 if (tm->tm_year < 70)
218 return rtc_valid_tm(tm);
221 static int ds1286_set_time(struct device *dev, struct rtc_time *tm)
223 struct ds1286_priv *priv = dev_get_drvdata(dev);
224 unsigned char mon, day, hrs, min, sec;
225 unsigned char save_control;
229 yrs = tm->tm_year + 1900;
230 mon = tm->tm_mon + 1; /* tm_mon starts at zero */
240 if (yrs > 255) /* They are unsigned */
253 spin_lock_irqsave(&priv->lock, flags);
254 save_control = ds1286_rtc_read(priv, RTC_CMD);
255 ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
257 ds1286_rtc_write(priv, yrs, RTC_YEAR);
258 ds1286_rtc_write(priv, mon, RTC_MONTH);
259 ds1286_rtc_write(priv, day, RTC_DATE);
260 ds1286_rtc_write(priv, hrs, RTC_HOURS);
261 ds1286_rtc_write(priv, min, RTC_MINUTES);
262 ds1286_rtc_write(priv, sec, RTC_SECONDS);
263 ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND);
265 ds1286_rtc_write(priv, save_control, RTC_CMD);
266 spin_unlock_irqrestore(&priv->lock, flags);
270 static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
272 struct ds1286_priv *priv = dev_get_drvdata(dev);
277 * Only the values that we read from the RTC are set. That
278 * means only tm_wday, tm_hour, tm_min.
280 spin_lock_irqsave(&priv->lock, flags);
281 alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f;
282 alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x1f;
283 alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x07;
284 cmd = ds1286_rtc_read(priv, RTC_CMD);
285 spin_unlock_irqrestore(&priv->lock, flags);
287 alm->time.tm_min = bcd2bin(alm->time.tm_min);
288 alm->time.tm_hour = bcd2bin(alm->time.tm_hour);
289 alm->time.tm_sec = 0;
293 static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
295 struct ds1286_priv *priv = dev_get_drvdata(dev);
296 unsigned char hrs, min, sec;
298 hrs = alm->time.tm_hour;
299 min = alm->time.tm_min;
300 sec = alm->time.tm_sec;
314 spin_lock(&priv->lock);
315 ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM);
316 ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM);
317 spin_unlock(&priv->lock);
322 static const struct rtc_class_ops ds1286_ops = {
323 .ioctl = ds1286_ioctl,
325 .read_time = ds1286_read_time,
326 .set_time = ds1286_set_time,
327 .read_alarm = ds1286_read_alarm,
328 .set_alarm = ds1286_set_alarm,
329 .alarm_irq_enable = ds1286_alarm_irq_enable,
332 static int __devinit ds1286_probe(struct platform_device *pdev)
334 struct rtc_device *rtc;
335 struct resource *res;
336 struct ds1286_priv *priv;
339 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
342 priv = kzalloc(sizeof(struct ds1286_priv), GFP_KERNEL);
346 priv->size = resource_size(res);
347 if (!request_mem_region(res->start, priv->size, pdev->name)) {
351 priv->baseaddr = res->start;
352 priv->rtcregs = ioremap(priv->baseaddr, priv->size);
353 if (!priv->rtcregs) {
357 spin_lock_init(&priv->lock);
358 platform_set_drvdata(pdev, priv);
359 rtc = rtc_device_register("ds1286", &pdev->dev,
360 &ds1286_ops, THIS_MODULE);
370 rtc_device_unregister(priv->rtc);
372 iounmap(priv->rtcregs);
374 release_mem_region(priv->baseaddr, priv->size);
379 static int __devexit ds1286_remove(struct platform_device *pdev)
381 struct ds1286_priv *priv = platform_get_drvdata(pdev);
383 rtc_device_unregister(priv->rtc);
384 iounmap(priv->rtcregs);
385 release_mem_region(priv->baseaddr, priv->size);
390 static struct platform_driver ds1286_platform_driver = {
392 .name = "rtc-ds1286",
393 .owner = THIS_MODULE,
395 .probe = ds1286_probe,
396 .remove = __devexit_p(ds1286_remove),
399 module_platform_driver(ds1286_platform_driver);
401 MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
402 MODULE_DESCRIPTION("DS1286 RTC driver");
403 MODULE_LICENSE("GPL");
404 MODULE_VERSION(DRV_VERSION);
405 MODULE_ALIAS("platform:rtc-ds1286");