Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / drivers / rtc / rtc-ds1286.c
1 /*
2  * DS1286 Real Time Clock interface for Linux
3  *
4  * Copyright (C) 1998, 1999, 2000 Ralf Baechle
5  * Copyright (C) 2008 Thomas Bogendoerfer
6  *
7  * Based on code written by Paul Gortmaker.
8  *
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.
13  */
14
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>
20 #include <linux/io.h>
21 #include <linux/slab.h>
22
23 #define DRV_VERSION             "1.0"
24
25 struct ds1286_priv {
26         struct rtc_device *rtc;
27         u32 __iomem *rtcregs;
28         size_t size;
29         unsigned long baseaddr;
30         spinlock_t lock;
31 };
32
33 static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
34 {
35         return __raw_readl(&priv->rtcregs[reg]) & 0xff;
36 }
37
38 static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg)
39 {
40         __raw_writel(data, &priv->rtcregs[reg]);
41 }
42
43
44 static int ds1286_alarm_irq_enable(struct device *dev, unsigned int enabled)
45 {
46         struct ds1286_priv *priv = dev_get_drvdata(dev);
47         unsigned long flags;
48         unsigned char val;
49
50         /* Allow or mask alarm interrupts */
51         spin_lock_irqsave(&priv->lock, flags);
52         val = ds1286_rtc_read(priv, RTC_CMD);
53         if (enabled)
54                 val &=  ~RTC_TDM;
55         else
56                 val |=  RTC_TDM;
57         ds1286_rtc_write(priv, val, RTC_CMD);
58         spin_unlock_irqrestore(&priv->lock, flags);
59
60         return 0;
61 }
62
63 #ifdef CONFIG_RTC_INTF_DEV
64
65 static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
66 {
67         struct ds1286_priv *priv = dev_get_drvdata(dev);
68         unsigned long flags;
69         unsigned char val;
70
71         switch (cmd) {
72         case RTC_WIE_OFF:
73                 /* Mask watchdog int. enab. bit */
74                 spin_lock_irqsave(&priv->lock, flags);
75                 val = ds1286_rtc_read(priv, RTC_CMD);
76                 val |= RTC_WAM;
77                 ds1286_rtc_write(priv, val, RTC_CMD);
78                 spin_unlock_irqrestore(&priv->lock, flags);
79                 break;
80         case RTC_WIE_ON:
81                 /* Allow watchdog interrupts.   */
82                 spin_lock_irqsave(&priv->lock, flags);
83                 val = ds1286_rtc_read(priv, RTC_CMD);
84                 val &= ~RTC_WAM;
85                 ds1286_rtc_write(priv, val, RTC_CMD);
86                 spin_unlock_irqrestore(&priv->lock, flags);
87                 break;
88         default:
89                 return -ENOIOCTLCMD;
90         }
91         return 0;
92 }
93
94 #else
95 #define ds1286_ioctl    NULL
96 #endif
97
98 #ifdef CONFIG_PROC_FS
99
100 static int ds1286_proc(struct device *dev, struct seq_file *seq)
101 {
102         struct ds1286_priv *priv = dev_get_drvdata(dev);
103         unsigned char month, cmd, amode;
104         const char *s;
105
106         month = ds1286_rtc_read(priv, RTC_MONTH);
107         seq_printf(seq,
108                    "oscillator\t: %s\n"
109                    "square_wave\t: %s\n",
110                    (month & RTC_EOSC) ? "disabled" : "enabled",
111                    (month & RTC_ESQW) ? "disabled" : "enabled");
112
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);
116         switch (amode) {
117         case 7:
118                 s = "each minute";
119                 break;
120         case 3:
121                 s = "minutes match";
122                 break;
123         case 1:
124                 s = "hours and minutes match";
125                 break;
126         case 0:
127                 s = "days, hours and minutes match";
128                 break;
129         default:
130                 s = "invalid";
131                 break;
132         }
133         seq_printf(seq, "alarm_mode\t: %s\n", s);
134
135         cmd = ds1286_rtc_read(priv, RTC_CMD);
136         seq_printf(seq,
137                    "alarm_enable\t: %s\n"
138                    "wdog_alarm\t: %s\n"
139                    "alarm_mask\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");
151         return 0;
152 }
153
154 #else
155 #define ds1286_proc     NULL
156 #endif
157
158 static int ds1286_read_time(struct device *dev, struct rtc_time *tm)
159 {
160         struct ds1286_priv *priv = dev_get_drvdata(dev);
161         unsigned char save_control;
162         unsigned long flags;
163         unsigned long uip_watchdog = jiffies;
164
165         /*
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.
173          */
174
175         if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)
176                 while (time_before(jiffies, uip_watchdog + 2*HZ/100))
177                         barrier();
178
179         /*
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.
184          */
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);
188
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);
195
196         ds1286_rtc_write(priv, save_control, RTC_CMD);
197         spin_unlock_irqrestore(&priv->lock, flags);
198
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);
205
206         /*
207          * Account for differences between how the RTC uses the values
208          * and how they are defined in a struct rtc_time;
209          */
210         if (tm->tm_year < 45)
211                 tm->tm_year += 30;
212         tm->tm_year += 40;
213         if (tm->tm_year < 70)
214                 tm->tm_year += 100;
215
216         tm->tm_mon--;
217
218         return rtc_valid_tm(tm);
219 }
220
221 static int ds1286_set_time(struct device *dev, struct rtc_time *tm)
222 {
223         struct ds1286_priv *priv = dev_get_drvdata(dev);
224         unsigned char mon, day, hrs, min, sec;
225         unsigned char save_control;
226         unsigned int yrs;
227         unsigned long flags;
228
229         yrs = tm->tm_year + 1900;
230         mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
231         day = tm->tm_mday;
232         hrs = tm->tm_hour;
233         min = tm->tm_min;
234         sec = tm->tm_sec;
235
236         if (yrs < 1970)
237                 return -EINVAL;
238
239         yrs -= 1940;
240         if (yrs > 255)    /* They are unsigned */
241                 return -EINVAL;
242
243         if (yrs >= 100)
244                 yrs -= 100;
245
246         sec = bin2bcd(sec);
247         min = bin2bcd(min);
248         hrs = bin2bcd(hrs);
249         day = bin2bcd(day);
250         mon = bin2bcd(mon);
251         yrs = bin2bcd(yrs);
252
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);
256
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);
264
265         ds1286_rtc_write(priv, save_control, RTC_CMD);
266         spin_unlock_irqrestore(&priv->lock, flags);
267         return 0;
268 }
269
270 static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
271 {
272         struct ds1286_priv *priv = dev_get_drvdata(dev);
273         unsigned char cmd;
274         unsigned long flags;
275
276         /*
277          * Only the values that we read from the RTC are set. That
278          * means only tm_wday, tm_hour, tm_min.
279          */
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);
286
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;
290         return 0;
291 }
292
293 static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
294 {
295         struct ds1286_priv *priv = dev_get_drvdata(dev);
296         unsigned char hrs, min, sec;
297
298         hrs = alm->time.tm_hour;
299         min = alm->time.tm_min;
300         sec = alm->time.tm_sec;
301
302         if (hrs >= 24)
303                 hrs = 0xff;
304
305         if (min >= 60)
306                 min = 0xff;
307
308         if (sec != 0)
309                 return -EINVAL;
310
311         min = bin2bcd(min);
312         hrs = bin2bcd(hrs);
313
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);
318
319         return 0;
320 }
321
322 static const struct rtc_class_ops ds1286_ops = {
323         .ioctl          = ds1286_ioctl,
324         .proc           = ds1286_proc,
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,
330 };
331
332 static int __devinit ds1286_probe(struct platform_device *pdev)
333 {
334         struct rtc_device *rtc;
335         struct resource *res;
336         struct ds1286_priv *priv;
337         int ret = 0;
338
339         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
340         if (!res)
341                 return -ENODEV;
342         priv = kzalloc(sizeof(struct ds1286_priv), GFP_KERNEL);
343         if (!priv)
344                 return -ENOMEM;
345
346         priv->size = res->end - res->start + 1;
347         if (!request_mem_region(res->start, priv->size, pdev->name)) {
348                 ret = -EBUSY;
349                 goto out;
350         }
351         priv->baseaddr = res->start;
352         priv->rtcregs = ioremap(priv->baseaddr, priv->size);
353         if (!priv->rtcregs) {
354                 ret = -ENOMEM;
355                 goto out;
356         }
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);
361         if (IS_ERR(rtc)) {
362                 ret = PTR_ERR(rtc);
363                 goto out;
364         }
365         priv->rtc = rtc;
366         return 0;
367
368 out:
369         if (priv->rtc)
370                 rtc_device_unregister(priv->rtc);
371         if (priv->rtcregs)
372                 iounmap(priv->rtcregs);
373         if (priv->baseaddr)
374                 release_mem_region(priv->baseaddr, priv->size);
375         kfree(priv);
376         return ret;
377 }
378
379 static int __devexit ds1286_remove(struct platform_device *pdev)
380 {
381         struct ds1286_priv *priv = platform_get_drvdata(pdev);
382
383         rtc_device_unregister(priv->rtc);
384         iounmap(priv->rtcregs);
385         release_mem_region(priv->baseaddr, priv->size);
386         kfree(priv);
387         return 0;
388 }
389
390 static struct platform_driver ds1286_platform_driver = {
391         .driver         = {
392                 .name   = "rtc-ds1286",
393                 .owner  = THIS_MODULE,
394         },
395         .probe          = ds1286_probe,
396         .remove         = __devexit_p(ds1286_remove),
397 };
398
399 static int __init ds1286_init(void)
400 {
401         return platform_driver_register(&ds1286_platform_driver);
402 }
403
404 static void __exit ds1286_exit(void)
405 {
406         platform_driver_unregister(&ds1286_platform_driver);
407 }
408
409 MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
410 MODULE_DESCRIPTION("DS1286 RTC driver");
411 MODULE_LICENSE("GPL");
412 MODULE_VERSION(DRV_VERSION);
413 MODULE_ALIAS("platform:rtc-ds1286");
414
415 module_init(ds1286_init);
416 module_exit(ds1286_exit);