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12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/rtc.h>
17#include <linux/mfd/abx500.h>
18#include <linux/mfd/abx500/ab8500.h>
19#include <linux/delay.h>
20#include <linux/of.h>
21
22#define AB8500_RTC_SOFF_STAT_REG 0x00
23#define AB8500_RTC_CC_CONF_REG 0x01
24#define AB8500_RTC_READ_REQ_REG 0x02
25#define AB8500_RTC_WATCH_TSECMID_REG 0x03
26#define AB8500_RTC_WATCH_TSECHI_REG 0x04
27#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
28#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
29#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
30#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
31#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
32#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
33#define AB8500_RTC_STAT_REG 0x0B
34#define AB8500_RTC_BKUP_CHG_REG 0x0C
35#define AB8500_RTC_FORCE_BKUP_REG 0x0D
36#define AB8500_RTC_CALIB_REG 0x0E
37#define AB8500_RTC_SWITCH_STAT_REG 0x0F
38
39
40#define RTC_READ_REQUEST 0x01
41#define RTC_WRITE_REQUEST 0x02
42
43
44#define RTC_ALARM_ENA 0x04
45#define RTC_STATUS_DATA 0x01
46
47#define COUNTS_PER_SEC (0xF000 / 60)
48#define AB8500_RTC_EPOCH 2000
49
50static const u8 ab8500_rtc_time_regs[] = {
51 AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
52 AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
53 AB8500_RTC_WATCH_TSECMID_REG
54};
55
56static const u8 ab8500_rtc_alarm_regs[] = {
57 AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
58 AB8500_RTC_ALRM_MIN_LOW_REG
59};
60
61
62static unsigned long get_elapsed_seconds(int year)
63{
64 unsigned long secs;
65 struct rtc_time tm = {
66 .tm_year = year - 1900,
67 .tm_mday = 1,
68 };
69
70
71
72
73
74 rtc_tm_to_time(&tm, &secs);
75 return secs;
76}
77
78static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
79{
80 unsigned long timeout = jiffies + HZ;
81 int retval, i;
82 unsigned long mins, secs;
83 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
84 u8 value;
85
86
87 retval = abx500_set_register_interruptible(dev,
88 AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
89 if (retval < 0)
90 return retval;
91
92
93 while (time_before(jiffies, timeout)) {
94 retval = abx500_get_register_interruptible(dev,
95 AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
96 if (retval < 0)
97 return retval;
98
99 if (!(value & RTC_READ_REQUEST))
100 break;
101
102 usleep_range(1000, 5000);
103 }
104
105
106 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
107 retval = abx500_get_register_interruptible(dev,
108 AB8500_RTC, ab8500_rtc_time_regs[i], &value);
109 if (retval < 0)
110 return retval;
111 buf[i] = value;
112 }
113
114 mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
115
116 secs = (buf[3] << 8) | buf[4];
117 secs = secs / COUNTS_PER_SEC;
118 secs = secs + (mins * 60);
119
120
121 secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
122
123 rtc_time_to_tm(secs, tm);
124 return rtc_valid_tm(tm);
125}
126
127static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
128{
129 int retval, i;
130 unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
131 unsigned long no_secs, no_mins, secs = 0;
132
133 if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
134 dev_dbg(dev, "year should be equal to or greater than %d\n",
135 AB8500_RTC_EPOCH);
136 return -EINVAL;
137 }
138
139
140 rtc_tm_to_time(tm, &secs);
141
142
143
144
145
146 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
147
148 no_mins = secs / 60;
149
150 no_secs = secs % 60;
151
152 no_secs = no_secs * COUNTS_PER_SEC;
153
154 buf[4] = no_secs & 0xFF;
155 buf[3] = (no_secs >> 8) & 0xFF;
156
157 buf[2] = no_mins & 0xFF;
158 buf[1] = (no_mins >> 8) & 0xFF;
159 buf[0] = (no_mins >> 16) & 0xFF;
160
161 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
162 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
163 ab8500_rtc_time_regs[i], buf[i]);
164 if (retval < 0)
165 return retval;
166 }
167
168
169 return abx500_set_register_interruptible(dev, AB8500_RTC,
170 AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
171}
172
173static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
174{
175 int retval, i;
176 u8 rtc_ctrl, value;
177 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
178 unsigned long secs, mins;
179
180
181 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
182 AB8500_RTC_STAT_REG, &rtc_ctrl);
183 if (retval < 0)
184 return retval;
185
186 if (rtc_ctrl & RTC_ALARM_ENA)
187 alarm->enabled = 1;
188 else
189 alarm->enabled = 0;
190
191 alarm->pending = 0;
192
193 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
194 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
195 ab8500_rtc_alarm_regs[i], &value);
196 if (retval < 0)
197 return retval;
198 buf[i] = value;
199 }
200
201 mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
202 secs = mins * 60;
203
204
205 secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
206
207 rtc_time_to_tm(secs, &alarm->time);
208
209 return rtc_valid_tm(&alarm->time);
210}
211
212static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
213{
214 return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
215 AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
216 enabled ? RTC_ALARM_ENA : 0);
217}
218
219static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
220{
221 int retval, i;
222 unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
223 unsigned long mins, secs = 0, cursec = 0;
224 struct rtc_time curtm;
225
226 if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
227 dev_dbg(dev, "year should be equal to or greater than %d\n",
228 AB8500_RTC_EPOCH);
229 return -EINVAL;
230 }
231
232
233 rtc_tm_to_time(&alarm->time, &secs);
234
235
236
237
238
239
240 ab8500_rtc_read_time(dev, &curtm);
241 rtc_tm_to_time(&curtm, &cursec);
242 if ((secs - cursec) < 59) {
243 dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
244 return -EINVAL;
245 }
246
247
248
249
250
251 secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
252
253 mins = secs / 60;
254
255 buf[2] = mins & 0xFF;
256 buf[1] = (mins >> 8) & 0xFF;
257 buf[0] = (mins >> 16) & 0xFF;
258
259
260 for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
261 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
262 ab8500_rtc_alarm_regs[i], buf[i]);
263 if (retval < 0)
264 return retval;
265 }
266
267 return ab8500_rtc_irq_enable(dev, alarm->enabled);
268}
269
270
271static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
272{
273 int retval;
274 u8 rtccal = 0;
275
276
277
278
279
280
281
282
283 if ((calibration < -127) || (calibration > 127)) {
284 dev_err(dev, "RtcCalibration value outside permitted range\n");
285 return -EINVAL;
286 }
287
288
289
290
291
292
293 if (calibration >= 0)
294 rtccal = 0x7F & calibration;
295 else
296 rtccal = ~(calibration - 1) | 0x80;
297
298 retval = abx500_set_register_interruptible(dev, AB8500_RTC,
299 AB8500_RTC_CALIB_REG, rtccal);
300
301 return retval;
302}
303
304static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
305{
306 int retval;
307 u8 rtccal = 0;
308
309 retval = abx500_get_register_interruptible(dev, AB8500_RTC,
310 AB8500_RTC_CALIB_REG, &rtccal);
311 if (retval >= 0) {
312
313
314
315
316
317 if (rtccal & 0x80)
318 *calibration = 0 - (rtccal & 0x7F);
319 else
320 *calibration = 0x7F & rtccal;
321 }
322
323 return retval;
324}
325
326static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
327 struct device_attribute *attr,
328 const char *buf, size_t count)
329{
330 int retval;
331 int calibration = 0;
332
333 if (sscanf(buf, " %i ", &calibration) != 1) {
334 dev_err(dev, "Failed to store RTC calibration attribute\n");
335 return -EINVAL;
336 }
337
338 retval = ab8500_rtc_set_calibration(dev, calibration);
339
340 return retval ? retval : count;
341}
342
343static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
344 struct device_attribute *attr, char *buf)
345{
346 int retval = 0;
347 int calibration = 0;
348
349 retval = ab8500_rtc_get_calibration(dev, &calibration);
350 if (retval < 0) {
351 dev_err(dev, "Failed to read RTC calibration attribute\n");
352 sprintf(buf, "0\n");
353 return retval;
354 }
355
356 return sprintf(buf, "%d\n", calibration);
357}
358
359static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
360 ab8500_sysfs_show_rtc_calibration,
361 ab8500_sysfs_store_rtc_calibration);
362
363static int ab8500_sysfs_rtc_register(struct device *dev)
364{
365 return device_create_file(dev, &dev_attr_rtc_calibration);
366}
367
368static void ab8500_sysfs_rtc_unregister(struct device *dev)
369{
370 device_remove_file(dev, &dev_attr_rtc_calibration);
371}
372
373static irqreturn_t rtc_alarm_handler(int irq, void *data)
374{
375 struct rtc_device *rtc = data;
376 unsigned long events = RTC_IRQF | RTC_AF;
377
378 dev_dbg(&rtc->dev, "%s\n", __func__);
379 rtc_update_irq(rtc, 1, events);
380
381 return IRQ_HANDLED;
382}
383
384static const struct rtc_class_ops ab8500_rtc_ops = {
385 .read_time = ab8500_rtc_read_time,
386 .set_time = ab8500_rtc_set_time,
387 .read_alarm = ab8500_rtc_read_alarm,
388 .set_alarm = ab8500_rtc_set_alarm,
389 .alarm_irq_enable = ab8500_rtc_irq_enable,
390};
391
392static int ab8500_rtc_probe(struct platform_device *pdev)
393{
394 int err;
395 struct rtc_device *rtc;
396 u8 rtc_ctrl;
397 int irq;
398
399 irq = platform_get_irq_byname(pdev, "ALARM");
400 if (irq < 0)
401 return irq;
402
403
404 err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
405 AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
406 if (err < 0)
407 return err;
408
409
410 usleep_range(1000, 5000);
411
412 err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
413 AB8500_RTC_STAT_REG, &rtc_ctrl);
414 if (err < 0)
415 return err;
416
417
418 if (!(rtc_ctrl & RTC_STATUS_DATA)) {
419 dev_err(&pdev->dev, "RTC supply failure\n");
420 return -ENODEV;
421 }
422
423 device_init_wakeup(&pdev->dev, true);
424
425 rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
426 THIS_MODULE);
427 if (IS_ERR(rtc)) {
428 dev_err(&pdev->dev, "Registration failed\n");
429 err = PTR_ERR(rtc);
430 return err;
431 }
432
433 err = request_threaded_irq(irq, NULL, rtc_alarm_handler,
434 IRQF_NO_SUSPEND | IRQF_ONESHOT, "ab8500-rtc", rtc);
435 if (err < 0) {
436 rtc_device_unregister(rtc);
437 return err;
438 }
439
440 platform_set_drvdata(pdev, rtc);
441
442 err = ab8500_sysfs_rtc_register(&pdev->dev);
443 if (err) {
444 dev_err(&pdev->dev, "sysfs RTC failed to register\n");
445 return err;
446 }
447
448 return 0;
449}
450
451static int ab8500_rtc_remove(struct platform_device *pdev)
452{
453 struct rtc_device *rtc = platform_get_drvdata(pdev);
454 int irq = platform_get_irq_byname(pdev, "ALARM");
455
456 ab8500_sysfs_rtc_unregister(&pdev->dev);
457
458 free_irq(irq, rtc);
459 rtc_device_unregister(rtc);
460 platform_set_drvdata(pdev, NULL);
461
462 return 0;
463}
464
465static struct platform_driver ab8500_rtc_driver = {
466 .driver = {
467 .name = "ab8500-rtc",
468 .owner = THIS_MODULE,
469 },
470 .probe = ab8500_rtc_probe,
471 .remove = ab8500_rtc_remove,
472};
473
474module_platform_driver(ab8500_rtc_driver);
475
476MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
477MODULE_DESCRIPTION("AB8500 RTC Driver");
478MODULE_LICENSE("GPL v2");
479
