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gma500: add an mmap ioctl
[linux-2.6/next.git] / drivers / rtc / rtc-stk17ta8.c
blob3b943673cd3e293c5c889078fd32a2f1bb01ecaa
1 /*
2 * A RTC driver for the Simtek STK17TA8
3 *
4 * By Thomas Hommel <thomas.hommel@ge.com>
5 *
6 * Based on the DS1553 driver from
7 * Atsushi Nemoto <anemo@mba.ocn.ne.jp>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14 #include <linux/bcd.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/gfp.h>
18 #include <linux/delay.h>
19 #include <linux/jiffies.h>
20 #include <linux/interrupt.h>
21 #include <linux/rtc.h>
22 #include <linux/platform_device.h>
23 #include <linux/io.h>
24
25 #define DRV_VERSION "0.1"
26
27 #define RTC_REG_SIZE 0x20000
28 #define RTC_OFFSET 0x1fff0
29
30 #define RTC_FLAGS (RTC_OFFSET + 0)
31 #define RTC_CENTURY (RTC_OFFSET + 1)
32 #define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
33 #define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
34 #define RTC_HOURS_ALARM (RTC_OFFSET + 4)
35 #define RTC_DATE_ALARM (RTC_OFFSET + 5)
36 #define RTC_INTERRUPTS (RTC_OFFSET + 6)
37 #define RTC_WATCHDOG (RTC_OFFSET + 7)
38 #define RTC_CALIBRATION (RTC_OFFSET + 8)
39 #define RTC_SECONDS (RTC_OFFSET + 9)
40 #define RTC_MINUTES (RTC_OFFSET + 10)
41 #define RTC_HOURS (RTC_OFFSET + 11)
42 #define RTC_DAY (RTC_OFFSET + 12)
43 #define RTC_DATE (RTC_OFFSET + 13)
44 #define RTC_MONTH (RTC_OFFSET + 14)
45 #define RTC_YEAR (RTC_OFFSET + 15)
46
47 #define RTC_SECONDS_MASK 0x7f
48 #define RTC_DAY_MASK 0x07
49 #define RTC_CAL_MASK 0x3f
50
51 /* Bits in the Calibration register */
52 #define RTC_STOP 0x80
53
54 /* Bits in the Flags register */
55 #define RTC_FLAGS_AF 0x40
56 #define RTC_FLAGS_PF 0x20
57 #define RTC_WRITE 0x02
58 #define RTC_READ 0x01
59
60 /* Bits in the Interrupts register */
61 #define RTC_INTS_AIE 0x40
62
63 struct rtc_plat_data {
64 struct rtc_device *rtc;
65 void __iomem *ioaddr;
66 unsigned long last_jiffies;
67 int irq;
68 unsigned int irqen;
69 int alrm_sec;
70 int alrm_min;
71 int alrm_hour;
72 int alrm_mday;
73 spinlock_t lock;
74 };
75
76 static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
77 {
78 struct platform_device *pdev = to_platform_device(dev);
79 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
80 void __iomem *ioaddr = pdata->ioaddr;
81 u8 flags;
82
83 flags = readb(pdata->ioaddr + RTC_FLAGS);
84 writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
85
86 writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
87 writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
88 writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
89 writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
90 writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
91 writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
92 writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
93 writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
94
95 writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
96 return 0;
97 }
98
99 static int stk17ta8_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 u8 flags;
107
108 /* give enough time to update RTC in case of continuous read */
109 if (pdata->last_jiffies == jiffies)
110 msleep(1);
111 pdata->last_jiffies = jiffies;
112
113 flags = readb(pdata->ioaddr + RTC_FLAGS);
114 writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
115 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
116 minute = readb(ioaddr + RTC_MINUTES);
117 hour = readb(ioaddr + RTC_HOURS);
118 day = readb(ioaddr + RTC_DATE);
119 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
120 month = readb(ioaddr + RTC_MONTH);
121 year = readb(ioaddr + RTC_YEAR);
122 century = readb(ioaddr + RTC_CENTURY);
123 writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
124 tm->tm_sec = bcd2bin(second);
125 tm->tm_min = bcd2bin(minute);
126 tm->tm_hour = bcd2bin(hour);
127 tm->tm_mday = bcd2bin(day);
128 tm->tm_wday = bcd2bin(week);
129 tm->tm_mon = bcd2bin(month) - 1;
130 /* year is 1900 + tm->tm_year */
131 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
132
133 if (rtc_valid_tm(tm) < 0) {
134 dev_err(dev, "retrieved date/time is not valid.\n");
135 rtc_time_to_tm(0, tm);
136 }
137 return 0;
138 }
139
140 static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
141 {
142 void __iomem *ioaddr = pdata->ioaddr;
143 unsigned long irqflags;
144 u8 flags;
145
146 spin_lock_irqsave(&pdata->lock, irqflags);
147
148 flags = readb(ioaddr + RTC_FLAGS);
149 writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
150
151 writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
152 0x80 : bin2bcd(pdata->alrm_mday),
153 ioaddr + RTC_DATE_ALARM);
154 writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
155 0x80 : bin2bcd(pdata->alrm_hour),
156 ioaddr + RTC_HOURS_ALARM);
157 writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
158 0x80 : bin2bcd(pdata->alrm_min),
159 ioaddr + RTC_MINUTES_ALARM);
160 writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
161 0x80 : bin2bcd(pdata->alrm_sec),
162 ioaddr + RTC_SECONDS_ALARM);
163 writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
164 readb(ioaddr + RTC_FLAGS); /* clear interrupts */
165 writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
166 spin_unlock_irqrestore(&pdata->lock, irqflags);
167 }
168
169 static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
170 {
171 struct platform_device *pdev = to_platform_device(dev);
172 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
173
174 if (pdata->irq <= 0)
175 return -EINVAL;
176 pdata->alrm_mday = alrm->time.tm_mday;
177 pdata->alrm_hour = alrm->time.tm_hour;
178 pdata->alrm_min = alrm->time.tm_min;
179 pdata->alrm_sec = alrm->time.tm_sec;
180 if (alrm->enabled)
181 pdata->irqen |= RTC_AF;
182 stk17ta8_rtc_update_alarm(pdata);
183 return 0;
184 }
185
186 static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
187 {
188 struct platform_device *pdev = to_platform_device(dev);
189 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
190
191 if (pdata->irq <= 0)
192 return -EINVAL;
193 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
194 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
195 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
196 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
197 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
198 return 0;
199 }
200
201 static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
202 {
203 struct platform_device *pdev = dev_id;
204 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
205 void __iomem *ioaddr = pdata->ioaddr;
206 unsigned long events = 0;
207
208 spin_lock(&pdata->lock);
209 /* read and clear interrupt */
210 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
211 events = RTC_IRQF;
212 if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
213 events |= RTC_UF;
214 else
215 events |= RTC_AF;
216 if (likely(pdata->rtc))
217 rtc_update_irq(pdata->rtc, 1, events);
218 }
219 spin_unlock(&pdata->lock);
220 return events ? IRQ_HANDLED : IRQ_NONE;
221 }
222
223 static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
224 unsigned int enabled)
225 {
226 struct platform_device *pdev = to_platform_device(dev);
227 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
228
229 if (pdata->irq <= 0)
230 return -EINVAL;
231 if (enabled)
232 pdata->irqen |= RTC_AF;
233 else
234 pdata->irqen &= ~RTC_AF;
235 stk17ta8_rtc_update_alarm(pdata);
236 return 0;
237 }
238
239 static const struct rtc_class_ops stk17ta8_rtc_ops = {
240 .read_time = stk17ta8_rtc_read_time,
241 .set_time = stk17ta8_rtc_set_time,
242 .read_alarm = stk17ta8_rtc_read_alarm,
243 .set_alarm = stk17ta8_rtc_set_alarm,
244 .alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable,
245 };
246
247 static ssize_t stk17ta8_nvram_read(struct file *filp, struct kobject *kobj,
248 struct bin_attribute *attr, char *buf,
249 loff_t pos, size_t size)
250 {
251 struct device *dev = container_of(kobj, struct device, kobj);
252 struct platform_device *pdev = to_platform_device(dev);
253 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
254 void __iomem *ioaddr = pdata->ioaddr;
255 ssize_t count;
256
257 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
258 *buf++ = readb(ioaddr + pos++);
259 return count;
260 }
261
262 static ssize_t stk17ta8_nvram_write(struct file *filp, struct kobject *kobj,
263 struct bin_attribute *attr, char *buf,
264 loff_t pos, size_t size)
265 {
266 struct device *dev = container_of(kobj, struct device, kobj);
267 struct platform_device *pdev = to_platform_device(dev);
268 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
269 void __iomem *ioaddr = pdata->ioaddr;
270 ssize_t count;
271
272 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
273 writeb(*buf++, ioaddr + pos++);
274 return count;
275 }
276
277 static struct bin_attribute stk17ta8_nvram_attr = {
278 .attr = {
279 .name = "nvram",
280 .mode = S_IRUGO | S_IWUSR,
281 },
282 .size = RTC_OFFSET,
283 .read = stk17ta8_nvram_read,
284 .write = stk17ta8_nvram_write,
285 };
286
287 static int __devinit stk17ta8_rtc_probe(struct platform_device *pdev)
288 {
289 struct resource *res;
290 unsigned int cal;
291 unsigned int flags;
292 struct rtc_plat_data *pdata;
293 void __iomem *ioaddr;
294 int ret = 0;
295
296 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297 if (!res)
298 return -ENODEV;
299
300 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
301 if (!pdata)
302 return -ENOMEM;
303 if (!devm_request_mem_region(&pdev->dev, res->start, RTC_REG_SIZE,
304 pdev->name))
305 return -EBUSY;
306 ioaddr = devm_ioremap(&pdev->dev, res->start, RTC_REG_SIZE);
307 if (!ioaddr)
308 return -ENOMEM;
309 pdata->ioaddr = ioaddr;
310 pdata->irq = platform_get_irq(pdev, 0);
311
312 /* turn RTC on if it was not on */
313 cal = readb(ioaddr + RTC_CALIBRATION);
314 if (cal & RTC_STOP) {
315 cal &= RTC_CAL_MASK;
316 flags = readb(ioaddr + RTC_FLAGS);
317 writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
318 writeb(cal, ioaddr + RTC_CALIBRATION);
319 writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
320 }
321 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
322 dev_warn(&pdev->dev, "voltage-low detected.\n");
323
324 spin_lock_init(&pdata->lock);
325 pdata->last_jiffies = jiffies;
326 platform_set_drvdata(pdev, pdata);
327 if (pdata->irq > 0) {
328 writeb(0, ioaddr + RTC_INTERRUPTS);
329 if (devm_request_irq(&pdev->dev, pdata->irq,
330 stk17ta8_rtc_interrupt,
331 IRQF_DISABLED | IRQF_SHARED,
332 pdev->name, pdev) < 0) {
333 dev_warn(&pdev->dev, "interrupt not available.\n");
334 pdata->irq = 0;
335 }
336 }
337
338 pdata->rtc = rtc_device_register(pdev->name, &pdev->dev,
339 &stk17ta8_rtc_ops, THIS_MODULE);
340 if (IS_ERR(pdata->rtc))
341 return PTR_ERR(pdata->rtc);
342
343 ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
344 if (ret)
345 rtc_device_unregister(pdata->rtc);
346 return ret;
347 }
348
349 static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
350 {
351 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
352
353 sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
354 rtc_device_unregister(pdata->rtc);
355 if (pdata->irq > 0)
356 writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
357 return 0;
358 }
359
360 /* work with hotplug and coldplug */
361 MODULE_ALIAS("platform:stk17ta8");
362
363 static struct platform_driver stk17ta8_rtc_driver = {
364 .probe = stk17ta8_rtc_probe,
365 .remove = __devexit_p(stk17ta8_rtc_remove),
366 .driver = {
367 .name = "stk17ta8",
368 .owner = THIS_MODULE,
369 },
370 };
371
372 static __init int stk17ta8_init(void)
373 {
374 return platform_driver_register(&stk17ta8_rtc_driver);
375 }
376
377 static __exit void stk17ta8_exit(void)
378 {
379 platform_driver_unregister(&stk17ta8_rtc_driver);
380 }
381
382 module_init(stk17ta8_init);
383 module_exit(stk17ta8_exit);
384
385 MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
386 MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
387 MODULE_LICENSE("GPL");
388 MODULE_VERSION(DRV_VERSION);
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