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Linux 2.6.34-rc3
[pohmelfs.git] / drivers / rtc / rtc-ds1553.c
blobed1ef7c9cc069fc2d2634429827f66c783734aa6
1 /*
2 * An rtc driver for the Dallas DS1553
3 *
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/bcd.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/delay.h>
15 #include <linux/jiffies.h>
16 #include <linux/interrupt.h>
17 #include <linux/rtc.h>
18 #include <linux/platform_device.h>
19 #include <linux/io.h>
20
21 #define DRV_VERSION "0.3"
22
23 #define RTC_REG_SIZE 0x2000
24 #define RTC_OFFSET 0x1ff0
25
26 #define RTC_FLAGS (RTC_OFFSET + 0)
27 #define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
28 #define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
29 #define RTC_HOURS_ALARM (RTC_OFFSET + 4)
30 #define RTC_DATE_ALARM (RTC_OFFSET + 5)
31 #define RTC_INTERRUPTS (RTC_OFFSET + 6)
32 #define RTC_WATCHDOG (RTC_OFFSET + 7)
33 #define RTC_CONTROL (RTC_OFFSET + 8)
34 #define RTC_CENTURY (RTC_OFFSET + 8)
35 #define RTC_SECONDS (RTC_OFFSET + 9)
36 #define RTC_MINUTES (RTC_OFFSET + 10)
37 #define RTC_HOURS (RTC_OFFSET + 11)
38 #define RTC_DAY (RTC_OFFSET + 12)
39 #define RTC_DATE (RTC_OFFSET + 13)
40 #define RTC_MONTH (RTC_OFFSET + 14)
41 #define RTC_YEAR (RTC_OFFSET + 15)
42
43 #define RTC_CENTURY_MASK 0x3f
44 #define RTC_SECONDS_MASK 0x7f
45 #define RTC_DAY_MASK 0x07
46
47 /* Bits in the Control/Century register */
48 #define RTC_WRITE 0x80
49 #define RTC_READ 0x40
50
51 /* Bits in the Seconds register */
52 #define RTC_STOP 0x80
53
54 /* Bits in the Flags register */
55 #define RTC_FLAGS_AF 0x40
56 #define RTC_FLAGS_BLF 0x10
57
58 /* Bits in the Interrupts register */
59 #define RTC_INTS_AE 0x80
60
61 struct rtc_plat_data {
62 struct rtc_device *rtc;
63 void __iomem *ioaddr;
64 unsigned long last_jiffies;
65 int irq;
66 unsigned int irqen;
67 int alrm_sec;
68 int alrm_min;
69 int alrm_hour;
70 int alrm_mday;
71 spinlock_t lock;
72 };
73
74 static int ds1553_rtc_set_time(struct device *dev, struct rtc_time *tm)
75 {
76 struct platform_device *pdev = to_platform_device(dev);
77 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
78 void __iomem *ioaddr = pdata->ioaddr;
79 u8 century;
80
81 century = bin2bcd((tm->tm_year + 1900) / 100);
82
83 writeb(RTC_WRITE, pdata->ioaddr + RTC_CONTROL);
84
85 writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
86 writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
87 writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
88 writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
89 writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
90 writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
91 writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
92
93 /* RTC_CENTURY and RTC_CONTROL share same register */
94 writeb(RTC_WRITE | (century & RTC_CENTURY_MASK), ioaddr + RTC_CENTURY);
95 writeb(century & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
96 return 0;
97 }
98
99 static int ds1553_rtc_read_time(struct device *dev, struct rtc_time *tm)
100 {
101 struct platform_device *pdev = to_platform_device(dev);
102 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
103 void __iomem *ioaddr = pdata->ioaddr;
104 unsigned int year, month, day, hour, minute, second, week;
105 unsigned int century;
106
107 /* give enough time to update RTC in case of continuous read */
108 if (pdata->last_jiffies == jiffies)
109 msleep(1);
110 pdata->last_jiffies = jiffies;
111 writeb(RTC_READ, ioaddr + RTC_CONTROL);
112 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
113 minute = readb(ioaddr + RTC_MINUTES);
114 hour = readb(ioaddr + RTC_HOURS);
115 day = readb(ioaddr + RTC_DATE);
116 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
117 month = readb(ioaddr + RTC_MONTH);
118 year = readb(ioaddr + RTC_YEAR);
119 century = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
120 writeb(0, ioaddr + RTC_CONTROL);
121 tm->tm_sec = bcd2bin(second);
122 tm->tm_min = bcd2bin(minute);
123 tm->tm_hour = bcd2bin(hour);
124 tm->tm_mday = bcd2bin(day);
125 tm->tm_wday = bcd2bin(week);
126 tm->tm_mon = bcd2bin(month) - 1;
127 /* year is 1900 + tm->tm_year */
128 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
129
130 if (rtc_valid_tm(tm) < 0) {
131 dev_err(dev, "retrieved date/time is not valid.\n");
132 rtc_time_to_tm(0, tm);
133 }
134 return 0;
135 }
136
137 static void ds1553_rtc_update_alarm(struct rtc_plat_data *pdata)
138 {
139 void __iomem *ioaddr = pdata->ioaddr;
140 unsigned long flags;
141
142 spin_lock_irqsave(&pdata->lock, flags);
143 writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
144 0x80 : bin2bcd(pdata->alrm_mday),
145 ioaddr + RTC_DATE_ALARM);
146 writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
147 0x80 : bin2bcd(pdata->alrm_hour),
148 ioaddr + RTC_HOURS_ALARM);
149 writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
150 0x80 : bin2bcd(pdata->alrm_min),
151 ioaddr + RTC_MINUTES_ALARM);
152 writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
153 0x80 : bin2bcd(pdata->alrm_sec),
154 ioaddr + RTC_SECONDS_ALARM);
155 writeb(pdata->irqen ? RTC_INTS_AE : 0, ioaddr + RTC_INTERRUPTS);
156 readb(ioaddr + RTC_FLAGS); /* clear interrupts */
157 spin_unlock_irqrestore(&pdata->lock, flags);
158 }
159
160 static int ds1553_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
161 {
162 struct platform_device *pdev = to_platform_device(dev);
163 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
164
165 if (pdata->irq <= 0)
166 return -EINVAL;
167 pdata->alrm_mday = alrm->time.tm_mday;
168 pdata->alrm_hour = alrm->time.tm_hour;
169 pdata->alrm_min = alrm->time.tm_min;
170 pdata->alrm_sec = alrm->time.tm_sec;
171 if (alrm->enabled)
172 pdata->irqen |= RTC_AF;
173 ds1553_rtc_update_alarm(pdata);
174 return 0;
175 }
176
177 static int ds1553_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
178 {
179 struct platform_device *pdev = to_platform_device(dev);
180 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
181
182 if (pdata->irq <= 0)
183 return -EINVAL;
184 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
185 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
186 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
187 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
188 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
189 return 0;
190 }
191
192 static irqreturn_t ds1553_rtc_interrupt(int irq, void *dev_id)
193 {
194 struct platform_device *pdev = dev_id;
195 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
196 void __iomem *ioaddr = pdata->ioaddr;
197 unsigned long events = 0;
198
199 spin_lock(&pdata->lock);
200 /* read and clear interrupt */
201 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
202 events = RTC_IRQF;
203 if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
204 events |= RTC_UF;
205 else
206 events |= RTC_AF;
207 if (likely(pdata->rtc))
208 rtc_update_irq(pdata->rtc, 1, events);
209 }
210 spin_unlock(&pdata->lock);
211 return events ? IRQ_HANDLED : IRQ_NONE;
212 }
213
214 static int ds1553_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
215 {
216 struct platform_device *pdev = to_platform_device(dev);
217 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
218
219 if (pdata->irq <= 0)
220 return -EINVAL;
221 if (enabled)
222 pdata->irqen |= RTC_AF;
223 else
224 pdata->irqen &= ~RTC_AF;
225 ds1553_rtc_update_alarm(pdata);
226 return 0;
227 }
228
229 static int ds1553_rtc_update_irq_enable(struct device *dev,
230 unsigned int enabled)
231 {
232 struct platform_device *pdev = to_platform_device(dev);
233 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
234
235 if (pdata->irq <= 0)
236 return -EINVAL;
237 if (enabled)
238 pdata->irqen |= RTC_UF;
239 else
240 pdata->irqen &= ~RTC_UF;
241 ds1553_rtc_update_alarm(pdata);
242 return 0;
243 }
244
245 static const struct rtc_class_ops ds1553_rtc_ops = {
246 .read_time = ds1553_rtc_read_time,
247 .set_time = ds1553_rtc_set_time,
248 .read_alarm = ds1553_rtc_read_alarm,
249 .set_alarm = ds1553_rtc_set_alarm,
250 .alarm_irq_enable = ds1553_rtc_alarm_irq_enable,
251 .update_irq_enable = ds1553_rtc_update_irq_enable,
252 };
253
254 static ssize_t ds1553_nvram_read(struct kobject *kobj,
255 struct bin_attribute *bin_attr,
256 char *buf, loff_t pos, size_t size)
257 {
258 struct device *dev = container_of(kobj, struct device, kobj);
259 struct platform_device *pdev = to_platform_device(dev);
260 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
261 void __iomem *ioaddr = pdata->ioaddr;
262 ssize_t count;
263
264 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
265 *buf++ = readb(ioaddr + pos++);
266 return count;
267 }
268
269 static ssize_t ds1553_nvram_write(struct kobject *kobj,
270 struct bin_attribute *bin_attr,
271 char *buf, loff_t pos, size_t size)
272 {
273 struct device *dev = container_of(kobj, struct device, kobj);
274 struct platform_device *pdev = to_platform_device(dev);
275 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
276 void __iomem *ioaddr = pdata->ioaddr;
277 ssize_t count;
278
279 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
280 writeb(*buf++, ioaddr + pos++);
281 return count;
282 }
283
284 static struct bin_attribute ds1553_nvram_attr = {
285 .attr = {
286 .name = "nvram",
287 .mode = S_IRUGO | S_IWUSR,
288 },
289 .size = RTC_OFFSET,
290 .read = ds1553_nvram_read,
291 .write = ds1553_nvram_write,
292 };
293
294 static int __devinit ds1553_rtc_probe(struct platform_device *pdev)
295 {
296 struct rtc_device *rtc;
297 struct resource *res;
298 unsigned int cen, sec;
299 struct rtc_plat_data *pdata;
300 void __iomem *ioaddr;
301 int ret = 0;
302
303 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
304 if (!res)
305 return -ENODEV;
306 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
307 if (!pdata)
308 return -ENOMEM;
309 if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
310 pdev->name))
311 return -EBUSY;
312
313 ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
314 if (!ioaddr)
315 return -ENOMEM;
316 pdata->ioaddr = ioaddr;
317 pdata->irq = platform_get_irq(pdev, 0);
318
319 /* turn RTC on if it was not on */
320 sec = readb(ioaddr + RTC_SECONDS);
321 if (sec & RTC_STOP) {
322 sec &= RTC_SECONDS_MASK;
323 cen = readb(ioaddr + RTC_CENTURY) & RTC_CENTURY_MASK;
324 writeb(RTC_WRITE, ioaddr + RTC_CONTROL);
325 writeb(sec, ioaddr + RTC_SECONDS);
326 writeb(cen & RTC_CENTURY_MASK, ioaddr + RTC_CONTROL);
327 }
328 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_BLF)
329 dev_warn(&pdev->dev, "voltage-low detected.\n");
330
331 spin_lock_init(&pdata->lock);
332 pdata->last_jiffies = jiffies;
333 platform_set_drvdata(pdev, pdata);
334 if (pdata->irq > 0) {
335 writeb(0, ioaddr + RTC_INTERRUPTS);
336 if (devm_request_irq(&pdev->dev, pdata->irq,
337 ds1553_rtc_interrupt,
338 IRQF_DISABLED, pdev->name, pdev) < 0) {
339 dev_warn(&pdev->dev, "interrupt not available.\n");
340 pdata->irq = 0;
341 }
342 }
343
344 rtc = rtc_device_register(pdev->name, &pdev->dev,
345 &ds1553_rtc_ops, THIS_MODULE);
346 if (IS_ERR(rtc))
347 return PTR_ERR(rtc);
348 pdata->rtc = rtc;
349
350 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
351 if (ret)
352 rtc_device_unregister(rtc);
353 return ret;
354 }
355
356 static int __devexit ds1553_rtc_remove(struct platform_device *pdev)
357 {
358 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
359
360 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1553_nvram_attr);
361 rtc_device_unregister(pdata->rtc);
362 if (pdata->irq > 0)
363 writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
364 return 0;
365 }
366
367 /* work with hotplug and coldplug */
368 MODULE_ALIAS("platform:rtc-ds1553");
369
370 static struct platform_driver ds1553_rtc_driver = {
371 .probe = ds1553_rtc_probe,
372 .remove = __devexit_p(ds1553_rtc_remove),
373 .driver = {
374 .name = "rtc-ds1553",
375 .owner = THIS_MODULE,
376 },
377 };
378
379 static __init int ds1553_init(void)
380 {
381 return platform_driver_register(&ds1553_rtc_driver);
382 }
383
384 static __exit void ds1553_exit(void)
385 {
386 platform_driver_unregister(&ds1553_rtc_driver);
387 }
388
389 module_init(ds1553_init);
390 module_exit(ds1553_exit);
391
392 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
393 MODULE_DESCRIPTION("Dallas DS1553 RTC driver");
394 MODULE_LICENSE("GPL");
395 MODULE_VERSION(DRV_VERSION);