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drm/i915: Remove redundant test in error path.
[linux-2.6/linux-2.6-openrd.git] / drivers / rtc / rtc-stk17ta8.c
blobf4cd46e15af98830ac3c580c52563119e7bc103e
1 /*
2 * A RTC driver for the Simtek STK17TA8
3 *
4 * By Thomas Hommel <thomas.hommel@gefanuc.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/delay.h>
18 #include <linux/jiffies.h>
19 #include <linux/interrupt.h>
20 #include <linux/rtc.h>
21 #include <linux/platform_device.h>
22 #include <linux/io.h>
23
24 #define DRV_VERSION "0.1"
25
26 #define RTC_REG_SIZE 0x20000
27 #define RTC_OFFSET 0x1fff0
28
29 #define RTC_FLAGS (RTC_OFFSET + 0)
30 #define RTC_CENTURY (RTC_OFFSET + 1)
31 #define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
32 #define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
33 #define RTC_HOURS_ALARM (RTC_OFFSET + 4)
34 #define RTC_DATE_ALARM (RTC_OFFSET + 5)
35 #define RTC_INTERRUPTS (RTC_OFFSET + 6)
36 #define RTC_WATCHDOG (RTC_OFFSET + 7)
37 #define RTC_CALIBRATION (RTC_OFFSET + 8)
38 #define RTC_SECONDS (RTC_OFFSET + 9)
39 #define RTC_MINUTES (RTC_OFFSET + 10)
40 #define RTC_HOURS (RTC_OFFSET + 11)
41 #define RTC_DAY (RTC_OFFSET + 12)
42 #define RTC_DATE (RTC_OFFSET + 13)
43 #define RTC_MONTH (RTC_OFFSET + 14)
44 #define RTC_YEAR (RTC_OFFSET + 15)
45
46 #define RTC_SECONDS_MASK 0x7f
47 #define RTC_DAY_MASK 0x07
48 #define RTC_CAL_MASK 0x3f
49
50 /* Bits in the Calibration register */
51 #define RTC_STOP 0x80
52
53 /* Bits in the Flags register */
54 #define RTC_FLAGS_AF 0x40
55 #define RTC_FLAGS_PF 0x20
56 #define RTC_WRITE 0x02
57 #define RTC_READ 0x01
58
59 /* Bits in the Interrupts register */
60 #define RTC_INTS_AIE 0x40
61
62 struct rtc_plat_data {
63 struct rtc_device *rtc;
64 void __iomem *ioaddr;
65 unsigned long baseaddr;
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 };
74
75 static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
76 {
77 struct platform_device *pdev = to_platform_device(dev);
78 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
79 void __iomem *ioaddr = pdata->ioaddr;
80 u8 flags;
81
82 flags = readb(pdata->ioaddr + RTC_FLAGS);
83 writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
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 writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
93
94 writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
95 return 0;
96 }
97
98 static int stk17ta8_rtc_read_time(struct device *dev, struct rtc_time *tm)
99 {
100 struct platform_device *pdev = to_platform_device(dev);
101 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
102 void __iomem *ioaddr = pdata->ioaddr;
103 unsigned int year, month, day, hour, minute, second, week;
104 unsigned int century;
105 u8 flags;
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
112 flags = readb(pdata->ioaddr + RTC_FLAGS);
113 writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
114 second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
115 minute = readb(ioaddr + RTC_MINUTES);
116 hour = readb(ioaddr + RTC_HOURS);
117 day = readb(ioaddr + RTC_DATE);
118 week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
119 month = readb(ioaddr + RTC_MONTH);
120 year = readb(ioaddr + RTC_YEAR);
121 century = readb(ioaddr + RTC_CENTURY);
122 writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
123 tm->tm_sec = bcd2bin(second);
124 tm->tm_min = bcd2bin(minute);
125 tm->tm_hour = bcd2bin(hour);
126 tm->tm_mday = bcd2bin(day);
127 tm->tm_wday = bcd2bin(week);
128 tm->tm_mon = bcd2bin(month) - 1;
129 /* year is 1900 + tm->tm_year */
130 tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
131
132 if (rtc_valid_tm(tm) < 0) {
133 dev_err(dev, "retrieved date/time is not valid.\n");
134 rtc_time_to_tm(0, tm);
135 }
136 return 0;
137 }
138
139 static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
140 {
141 void __iomem *ioaddr = pdata->ioaddr;
142 unsigned long irqflags;
143 u8 flags;
144
145 spin_lock_irqsave(&pdata->rtc->irq_lock, irqflags);
146
147 flags = readb(ioaddr + RTC_FLAGS);
148 writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
149
150 writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
151 0x80 : bin2bcd(pdata->alrm_mday),
152 ioaddr + RTC_DATE_ALARM);
153 writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
154 0x80 : bin2bcd(pdata->alrm_hour),
155 ioaddr + RTC_HOURS_ALARM);
156 writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
157 0x80 : bin2bcd(pdata->alrm_min),
158 ioaddr + RTC_MINUTES_ALARM);
159 writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
160 0x80 : bin2bcd(pdata->alrm_sec),
161 ioaddr + RTC_SECONDS_ALARM);
162 writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
163 readb(ioaddr + RTC_FLAGS); /* clear interrupts */
164 writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
165 spin_unlock_irqrestore(&pdata->rtc->irq_lock, irqflags);
166 }
167
168 static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
169 {
170 struct platform_device *pdev = to_platform_device(dev);
171 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
172
173 if (pdata->irq < 0)
174 return -EINVAL;
175 pdata->alrm_mday = alrm->time.tm_mday;
176 pdata->alrm_hour = alrm->time.tm_hour;
177 pdata->alrm_min = alrm->time.tm_min;
178 pdata->alrm_sec = alrm->time.tm_sec;
179 if (alrm->enabled)
180 pdata->irqen |= RTC_AF;
181 stk17ta8_rtc_update_alarm(pdata);
182 return 0;
183 }
184
185 static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
186 {
187 struct platform_device *pdev = to_platform_device(dev);
188 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
189
190 if (pdata->irq < 0)
191 return -EINVAL;
192 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
193 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
194 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
195 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
196 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
197 return 0;
198 }
199
200 static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
201 {
202 struct platform_device *pdev = dev_id;
203 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
204 void __iomem *ioaddr = pdata->ioaddr;
205 unsigned long events = RTC_IRQF;
206
207 /* read and clear interrupt */
208 if (!(readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF))
209 return IRQ_NONE;
210 if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
211 events |= RTC_UF;
212 else
213 events |= RTC_AF;
214 rtc_update_irq(pdata->rtc, 1, events);
215 return IRQ_HANDLED;
216 }
217
218 static int stk17ta8_rtc_ioctl(struct device *dev, unsigned int cmd,
219 unsigned long arg)
220 {
221 struct platform_device *pdev = to_platform_device(dev);
222 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
223
224 if (pdata->irq < 0)
225 return -ENOIOCTLCMD; /* fall back into rtc-dev's emulation */
226 switch (cmd) {
227 case RTC_AIE_OFF:
228 pdata->irqen &= ~RTC_AF;
229 stk17ta8_rtc_update_alarm(pdata);
230 break;
231 case RTC_AIE_ON:
232 pdata->irqen |= RTC_AF;
233 stk17ta8_rtc_update_alarm(pdata);
234 break;
235 default:
236 return -ENOIOCTLCMD;
237 }
238 return 0;
239 }
240
241 static const struct rtc_class_ops stk17ta8_rtc_ops = {
242 .read_time = stk17ta8_rtc_read_time,
243 .set_time = stk17ta8_rtc_set_time,
244 .read_alarm = stk17ta8_rtc_read_alarm,
245 .set_alarm = stk17ta8_rtc_set_alarm,
246 .ioctl = stk17ta8_rtc_ioctl,
247 };
248
249 static ssize_t stk17ta8_nvram_read(struct kobject *kobj,
250 struct bin_attribute *attr, char *buf,
251 loff_t pos, size_t size)
252 {
253 struct platform_device *pdev =
254 to_platform_device(container_of(kobj, struct device, kobj));
255 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
256 void __iomem *ioaddr = pdata->ioaddr;
257 ssize_t count;
258
259 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
260 *buf++ = readb(ioaddr + pos++);
261 return count;
262 }
263
264 static ssize_t stk17ta8_nvram_write(struct kobject *kobj,
265 struct bin_attribute *attr, char *buf,
266 loff_t pos, size_t size)
267 {
268 struct platform_device *pdev =
269 to_platform_device(container_of(kobj, struct device, kobj));
270 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
271 void __iomem *ioaddr = pdata->ioaddr;
272 ssize_t count;
273
274 for (count = 0; size > 0 && pos < RTC_OFFSET; count++, size--)
275 writeb(*buf++, ioaddr + pos++);
276 return count;
277 }
278
279 static struct bin_attribute stk17ta8_nvram_attr = {
280 .attr = {
281 .name = "nvram",
282 .mode = S_IRUGO | S_IWUSR,
283 },
284 .size = RTC_OFFSET,
285 .read = stk17ta8_nvram_read,
286 .write = stk17ta8_nvram_write,
287 };
288
289 static int __init stk17ta8_rtc_probe(struct platform_device *pdev)
290 {
291 struct rtc_device *rtc;
292 struct resource *res;
293 unsigned int cal;
294 unsigned int flags;
295 struct rtc_plat_data *pdata;
296 void __iomem *ioaddr = NULL;
297 int ret = 0;
298
299 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
300 if (!res)
301 return -ENODEV;
302
303 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
304 if (!pdata)
305 return -ENOMEM;
306 pdata->irq = -1;
307 if (!request_mem_region(res->start, RTC_REG_SIZE, pdev->name)) {
308 ret = -EBUSY;
309 goto out;
310 }
311 pdata->baseaddr = res->start;
312 ioaddr = ioremap(pdata->baseaddr, RTC_REG_SIZE);
313 if (!ioaddr) {
314 ret = -ENOMEM;
315 goto out;
316 }
317 pdata->ioaddr = ioaddr;
318 pdata->irq = platform_get_irq(pdev, 0);
319
320 /* turn RTC on if it was not on */
321 cal = readb(ioaddr + RTC_CALIBRATION);
322 if (cal & RTC_STOP) {
323 cal &= RTC_CAL_MASK;
324 flags = readb(ioaddr + RTC_FLAGS);
325 writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
326 writeb(cal, ioaddr + RTC_CALIBRATION);
327 writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
328 }
329 if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
330 dev_warn(&pdev->dev, "voltage-low detected.\n");
331
332 if (pdata->irq >= 0) {
333 writeb(0, ioaddr + RTC_INTERRUPTS);
334 if (request_irq(pdata->irq, stk17ta8_rtc_interrupt,
335 IRQF_DISABLED | IRQF_SHARED,
336 pdev->name, pdev) < 0) {
337 dev_warn(&pdev->dev, "interrupt not available.\n");
338 pdata->irq = -1;
339 }
340 }
341
342 rtc = rtc_device_register(pdev->name, &pdev->dev,
343 &stk17ta8_rtc_ops, THIS_MODULE);
344 if (IS_ERR(rtc)) {
345 ret = PTR_ERR(rtc);
346 goto out;
347 }
348 pdata->rtc = rtc;
349 pdata->last_jiffies = jiffies;
350 platform_set_drvdata(pdev, pdata);
351 ret = sysfs_create_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
352 if (ret)
353 goto out;
354 return 0;
355 out:
356 if (pdata->rtc)
357 rtc_device_unregister(pdata->rtc);
358 if (pdata->irq >= 0)
359 free_irq(pdata->irq, pdev);
360 if (ioaddr)
361 iounmap(ioaddr);
362 if (pdata->baseaddr)
363 release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
364 kfree(pdata);
365 return ret;
366 }
367
368 static int __devexit stk17ta8_rtc_remove(struct platform_device *pdev)
369 {
370 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
371
372 sysfs_remove_bin_file(&pdev->dev.kobj, &stk17ta8_nvram_attr);
373 rtc_device_unregister(pdata->rtc);
374 if (pdata->irq >= 0) {
375 writeb(0, pdata->ioaddr + RTC_INTERRUPTS);
376 free_irq(pdata->irq, pdev);
377 }
378 iounmap(pdata->ioaddr);
379 release_mem_region(pdata->baseaddr, RTC_REG_SIZE);
380 kfree(pdata);
381 return 0;
382 }
383
384 /* work with hotplug and coldplug */
385 MODULE_ALIAS("platform:stk17ta8");
386
387 static struct platform_driver stk17ta8_rtc_driver = {
388 .probe = stk17ta8_rtc_probe,
389 .remove = __devexit_p(stk17ta8_rtc_remove),
390 .driver = {
391 .name = "stk17ta8",
392 .owner = THIS_MODULE,
393 },
394 };
395
396 static __init int stk17ta8_init(void)
397 {
398 return platform_driver_register(&stk17ta8_rtc_driver);
399 }
400
401 static __exit void stk17ta8_exit(void)
402 {
403 return platform_driver_unregister(&stk17ta8_rtc_driver);
404 }
405
406 module_init(stk17ta8_init);
407 module_exit(stk17ta8_exit);
408
409 MODULE_AUTHOR("Thomas Hommel <thomas.hommel@gefanuc.com>");
410 MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
411 MODULE_LICENSE("GPL");
412 MODULE_VERSION(DRV_VERSION);
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