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
ds1286_rtc_read(struct ds1286_priv * priv,int reg)33 static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
34 {
35 return __raw_readl(&priv->rtcregs[reg]) & 0xff;
36 }
37
ds1286_rtc_write(struct ds1286_priv * priv,u8 data,int reg)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
ds1286_alarm_irq_enable(struct device * dev,unsigned int enabled)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
ds1286_ioctl(struct device * dev,unsigned int cmd,unsigned long arg)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
ds1286_proc(struct device * dev,struct seq_file * seq)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
ds1286_read_time(struct device * dev,struct rtc_time * tm)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
ds1286_set_time(struct device * dev,struct rtc_time * tm)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
ds1286_read_alarm(struct device * dev,struct rtc_wkalrm * alm)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
ds1286_set_alarm(struct device * dev,struct rtc_wkalrm * alm)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
ds1286_probe(struct platform_device * pdev)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 = resource_size(res);
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
ds1286_remove(struct platform_device * pdev)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 module_platform_driver(ds1286_platform_driver);
400
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");
406