26c81f233606ebe043360cf349196f5ed7557670
[linux-3.10.git] / drivers / rtc / rtc-isl1208.c
1 /*
2  * Intersil ISL1208 rtc class driver
3  *
4  * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
5  *
6  *  This program is free software; you can redistribute  it and/or modify it
7  *  under  the terms of  the GNU General  Public License as published by the
8  *  Free Software Foundation;  either version 2 of the  License, or (at your
9  *  option) any later version.
10  *
11  */
12
13 #include <linux/module.h>
14 #include <linux/i2c.h>
15 #include <linux/bcd.h>
16 #include <linux/rtc.h>
17
18 #define DRV_VERSION "0.3"
19
20 /* Register map */
21 /* rtc section */
22 #define ISL1208_REG_SC  0x00
23 #define ISL1208_REG_MN  0x01
24 #define ISL1208_REG_HR  0x02
25 #define ISL1208_REG_HR_MIL     (1<<7)   /* 24h/12h mode */
26 #define ISL1208_REG_HR_PM      (1<<5)   /* PM/AM bit in 12h mode */
27 #define ISL1208_REG_DT  0x03
28 #define ISL1208_REG_MO  0x04
29 #define ISL1208_REG_YR  0x05
30 #define ISL1208_REG_DW  0x06
31 #define ISL1208_RTC_SECTION_LEN 7
32
33 /* control/status section */
34 #define ISL1208_REG_SR  0x07
35 #define ISL1208_REG_SR_ARST    (1<<7)   /* auto reset */
36 #define ISL1208_REG_SR_XTOSCB  (1<<6)   /* crystal oscillator */
37 #define ISL1208_REG_SR_WRTC    (1<<4)   /* write rtc */
38 #define ISL1208_REG_SR_ALM     (1<<2)   /* alarm */
39 #define ISL1208_REG_SR_BAT     (1<<1)   /* battery */
40 #define ISL1208_REG_SR_RTCF    (1<<0)   /* rtc fail */
41 #define ISL1208_REG_INT 0x08
42 #define ISL1208_REG_INT_ALME   (1<<6)   /* alarm enable */
43 #define ISL1208_REG_INT_IM     (1<<7)   /* interrupt/alarm mode */
44 #define ISL1208_REG_09  0x09    /* reserved */
45 #define ISL1208_REG_ATR 0x0a
46 #define ISL1208_REG_DTR 0x0b
47
48 /* alarm section */
49 #define ISL1208_REG_SCA 0x0c
50 #define ISL1208_REG_MNA 0x0d
51 #define ISL1208_REG_HRA 0x0e
52 #define ISL1208_REG_DTA 0x0f
53 #define ISL1208_REG_MOA 0x10
54 #define ISL1208_REG_DWA 0x11
55 #define ISL1208_ALARM_SECTION_LEN 6
56
57 /* user section */
58 #define ISL1208_REG_USR1 0x12
59 #define ISL1208_REG_USR2 0x13
60 #define ISL1208_USR_SECTION_LEN 2
61
62 static struct i2c_driver isl1208_driver;
63
64 /* block read */
65 static int
66 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
67                       unsigned len)
68 {
69         u8 reg_addr[1] = { reg };
70         struct i2c_msg msgs[2] = {
71                 {
72                         .addr = client->addr,
73                         .len = sizeof(reg_addr),
74                         .buf = reg_addr
75                 },
76                 {
77                         .addr = client->addr,
78                         .flags = I2C_M_RD,
79                         .len = len,
80                         .buf = buf
81                 }
82         };
83         int ret;
84
85         BUG_ON(reg > ISL1208_REG_USR2);
86         BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
87
88         ret = i2c_transfer(client->adapter, msgs, 2);
89         if (ret > 0)
90                 ret = 0;
91         return ret;
92 }
93
94 /* block write */
95 static int
96 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
97                      unsigned len)
98 {
99         u8 i2c_buf[ISL1208_REG_USR2 + 2];
100         struct i2c_msg msgs[1] = {
101                 {
102                         .addr = client->addr,
103                         .len = len + 1,
104                         .buf = i2c_buf
105                 }
106         };
107         int ret;
108
109         BUG_ON(reg > ISL1208_REG_USR2);
110         BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
111
112         i2c_buf[0] = reg;
113         memcpy(&i2c_buf[1], &buf[0], len);
114
115         ret = i2c_transfer(client->adapter, msgs, 1);
116         if (ret > 0)
117                 ret = 0;
118         return ret;
119 }
120
121 /* simple check to see wether we have a isl1208 */
122 static int
123 isl1208_i2c_validate_client(struct i2c_client *client)
124 {
125         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
126         u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
127                 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
128         };
129         int i;
130         int ret;
131
132         ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
133         if (ret < 0)
134                 return ret;
135
136         for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
137                 if (regs[i] & zero_mask[i])     /* check if bits are cleared */
138                         return -ENODEV;
139         }
140
141         return 0;
142 }
143
144 static int
145 isl1208_i2c_get_sr(struct i2c_client *client)
146 {
147         int sr = i2c_smbus_read_byte_data(client, ISL1208_REG_SR);
148         if (sr < 0)
149                 return -EIO;
150
151         return sr;
152 }
153
154 static int
155 isl1208_i2c_get_atr(struct i2c_client *client)
156 {
157         int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
158         if (atr < 0)
159                 return atr;
160
161         /* The 6bit value in the ATR register controls the load
162          * capacitance C_load * in steps of 0.25pF
163          *
164          * bit (1<<5) of the ATR register is inverted
165          *
166          * C_load(ATR=0x20) =  4.50pF
167          * C_load(ATR=0x00) = 12.50pF
168          * C_load(ATR=0x1f) = 20.25pF
169          *
170          */
171
172         atr &= 0x3f;            /* mask out lsb */
173         atr ^= 1 << 5;          /* invert 6th bit */
174         atr += 2 * 9;           /* add offset of 4.5pF; unit[atr] = 0.25pF */
175
176         return atr;
177 }
178
179 static int
180 isl1208_i2c_get_dtr(struct i2c_client *client)
181 {
182         int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
183         if (dtr < 0)
184                 return -EIO;
185
186         /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */
187         dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1);
188
189         return dtr;
190 }
191
192 static int
193 isl1208_i2c_get_usr(struct i2c_client *client)
194 {
195         u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
196         int ret;
197
198         ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf,
199                                     ISL1208_USR_SECTION_LEN);
200         if (ret < 0)
201                 return ret;
202
203         return (buf[1] << 8) | buf[0];
204 }
205
206 static int
207 isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
208 {
209         u8 buf[ISL1208_USR_SECTION_LEN];
210
211         buf[0] = usr & 0xff;
212         buf[1] = (usr >> 8) & 0xff;
213
214         return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf,
215                                     ISL1208_USR_SECTION_LEN);
216 }
217
218 static int
219 isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable)
220 {
221         int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
222
223         if (icr < 0) {
224                 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
225                 return icr;
226         }
227
228         if (enable)
229                 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM;
230         else
231                 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM);
232
233         icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr);
234         if (icr < 0) {
235                 dev_err(&client->dev, "%s: writing INT failed\n", __func__);
236                 return icr;
237         }
238
239         return 0;
240 }
241
242 static int
243 isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
244 {
245         struct i2c_client *const client = to_i2c_client(dev);
246         int sr, dtr, atr, usr;
247
248         sr = isl1208_i2c_get_sr(client);
249         if (sr < 0) {
250                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
251                 return sr;
252         }
253
254         seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
255                    (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
256                    (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
257                    (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
258                    (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
259                    (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
260                    (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr);
261
262         seq_printf(seq, "batt_status\t: %s\n",
263                    (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
264
265         dtr = isl1208_i2c_get_dtr(client);
266         if (dtr >= 0 - 1)
267                 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
268
269         atr = isl1208_i2c_get_atr(client);
270         if (atr >= 0)
271                 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
272                            atr >> 2, (atr & 0x3) * 25);
273
274         usr = isl1208_i2c_get_usr(client);
275         if (usr >= 0)
276                 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
277
278         return 0;
279 }
280
281 static int
282 isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
283 {
284         int sr;
285         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
286
287         sr = isl1208_i2c_get_sr(client);
288         if (sr < 0) {
289                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
290                 return -EIO;
291         }
292
293         sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
294         if (sr < 0) {
295                 dev_err(&client->dev, "%s: reading RTC section failed\n",
296                         __func__);
297                 return sr;
298         }
299
300         tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]);
301         tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]);
302
303         /* HR field has a more complex interpretation */
304         {
305                 const u8 _hr = regs[ISL1208_REG_HR];
306                 if (_hr & ISL1208_REG_HR_MIL)   /* 24h format */
307                         tm->tm_hour = bcd2bin(_hr & 0x3f);
308                 else {
309                         /* 12h format */
310                         tm->tm_hour = bcd2bin(_hr & 0x1f);
311                         if (_hr & ISL1208_REG_HR_PM)    /* PM flag set */
312                                 tm->tm_hour += 12;
313                 }
314         }
315
316         tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]);
317         tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
318         tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100;
319         tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]);
320
321         return 0;
322 }
323
324 static int
325 isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
326 {
327         struct rtc_time *const tm = &alarm->time;
328         u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
329         int icr, yr, sr = isl1208_i2c_get_sr(client);
330
331         if (sr < 0) {
332                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
333                 return sr;
334         }
335
336         sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
337                                    ISL1208_ALARM_SECTION_LEN);
338         if (sr < 0) {
339                 dev_err(&client->dev, "%s: reading alarm section failed\n",
340                         __func__);
341                 return sr;
342         }
343
344         /* MSB of each alarm register is an enable bit */
345         tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f);
346         tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f);
347         tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f);
348         tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f);
349         tm->tm_mon =
350                 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1;
351         tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03);
352
353         /* The alarm doesn't store the year so get it from the rtc section */
354         yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR);
355         if (yr < 0) {
356                 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__);
357                 return yr;
358         }
359         tm->tm_year = bcd2bin(yr) + 100;
360
361         icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT);
362         if (icr < 0) {
363                 dev_err(&client->dev, "%s: reading INT failed\n", __func__);
364                 return icr;
365         }
366         alarm->enabled = !!(icr & ISL1208_REG_INT_ALME);
367
368         return 0;
369 }
370
371 static int
372 isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
373 {
374         struct rtc_time *alarm_tm = &alarm->time;
375         u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
376         const int offs = ISL1208_REG_SCA;
377         unsigned long rtc_secs, alarm_secs;
378         struct rtc_time rtc_tm;
379         int err, enable;
380
381         err = isl1208_i2c_read_time(client, &rtc_tm);
382         if (err)
383                 return err;
384         err = rtc_tm_to_time(&rtc_tm, &rtc_secs);
385         if (err)
386                 return err;
387         err = rtc_tm_to_time(alarm_tm, &alarm_secs);
388         if (err)
389                 return err;
390
391         /* If the alarm time is before the current time disable the alarm */
392         if (!alarm->enabled || alarm_secs <= rtc_secs)
393                 enable = 0x00;
394         else
395                 enable = 0x80;
396
397         /* Program the alarm and enable it for each setting */
398         regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable;
399         regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable;
400         regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) |
401                 ISL1208_REG_HR_MIL | enable;
402
403         regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable;
404         regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable;
405         regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable;
406
407         /* write ALARM registers */
408         err = isl1208_i2c_set_regs(client, offs, regs,
409                                   ISL1208_ALARM_SECTION_LEN);
410         if (err < 0) {
411                 dev_err(&client->dev, "%s: writing ALARM section failed\n",
412                         __func__);
413                 return err;
414         }
415
416         err = isl1208_rtc_toggle_alarm(client, enable);
417         if (err)
418                 return err;
419
420         return 0;
421 }
422
423 static int
424 isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
425 {
426         return isl1208_i2c_read_time(to_i2c_client(dev), tm);
427 }
428
429 static int
430 isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
431 {
432         int sr;
433         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
434
435         /* The clock has an 8 bit wide bcd-coded register (they never learn)
436          * for the year. tm_year is an offset from 1900 and we are interested
437          * in the 2000-2099 range, so any value less than 100 is invalid.
438          */
439         if (tm->tm_year < 100)
440                 return -EINVAL;
441
442         regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec);
443         regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min);
444         regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL;
445
446         regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday);
447         regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1);
448         regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100);
449
450         regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7);
451
452         sr = isl1208_i2c_get_sr(client);
453         if (sr < 0) {
454                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
455                 return sr;
456         }
457
458         /* set WRTC */
459         sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
460                                        sr | ISL1208_REG_SR_WRTC);
461         if (sr < 0) {
462                 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
463                 return sr;
464         }
465
466         /* write RTC registers */
467         sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
468         if (sr < 0) {
469                 dev_err(&client->dev, "%s: writing RTC section failed\n",
470                         __func__);
471                 return sr;
472         }
473
474         /* clear WRTC again */
475         sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR,
476                                        sr & ~ISL1208_REG_SR_WRTC);
477         if (sr < 0) {
478                 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
479                 return sr;
480         }
481
482         return 0;
483 }
484
485
486 static int
487 isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
488 {
489         return isl1208_i2c_set_time(to_i2c_client(dev), tm);
490 }
491
492 static int
493 isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
494 {
495         return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
496 }
497
498 static int
499 isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
500 {
501         return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm);
502 }
503
504 static irqreturn_t
505 isl1208_rtc_interrupt(int irq, void *data)
506 {
507         unsigned long timeout = jiffies + msecs_to_jiffies(1000);
508         struct i2c_client *client = data;
509         int handled = 0, sr, err;
510
511         /*
512          * I2C reads get NAK'ed if we read straight away after an interrupt?
513          * Using a mdelay/msleep didn't seem to help either, so we work around
514          * this by continually trying to read the register for a short time.
515          */
516         while (1) {
517                 sr = isl1208_i2c_get_sr(client);
518                 if (sr >= 0)
519                         break;
520
521                 if (time_after(jiffies, timeout)) {
522                         dev_err(&client->dev, "%s: reading SR failed\n",
523                                 __func__);
524                         return sr;
525                 }
526         }
527
528         if (sr & ISL1208_REG_SR_ALM) {
529                 dev_dbg(&client->dev, "alarm!\n");
530
531                 /* Clear the alarm */
532                 sr &= ~ISL1208_REG_SR_ALM;
533                 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
534                 if (sr < 0)
535                         dev_err(&client->dev, "%s: writing SR failed\n",
536                                 __func__);
537                 else
538                         handled = 1;
539
540                 /* Disable the alarm */
541                 err = isl1208_rtc_toggle_alarm(client, 0);
542                 if (err)
543                         return err;
544         }
545
546         return handled ? IRQ_HANDLED : IRQ_NONE;
547 }
548
549 static const struct rtc_class_ops isl1208_rtc_ops = {
550         .proc = isl1208_rtc_proc,
551         .read_time = isl1208_rtc_read_time,
552         .set_time = isl1208_rtc_set_time,
553         .read_alarm = isl1208_rtc_read_alarm,
554         .set_alarm = isl1208_rtc_set_alarm,
555 };
556
557 /* sysfs interface */
558
559 static ssize_t
560 isl1208_sysfs_show_atrim(struct device *dev,
561                          struct device_attribute *attr, char *buf)
562 {
563         int atr = isl1208_i2c_get_atr(to_i2c_client(dev));
564         if (atr < 0)
565                 return atr;
566
567         return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25);
568 }
569
570 static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
571
572 static ssize_t
573 isl1208_sysfs_show_dtrim(struct device *dev,
574                          struct device_attribute *attr, char *buf)
575 {
576         int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
577         if (dtr < 0)
578                 return dtr;
579
580         return sprintf(buf, "%d ppm\n", dtr);
581 }
582
583 static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
584
585 static ssize_t
586 isl1208_sysfs_show_usr(struct device *dev,
587                        struct device_attribute *attr, char *buf)
588 {
589         int usr = isl1208_i2c_get_usr(to_i2c_client(dev));
590         if (usr < 0)
591                 return usr;
592
593         return sprintf(buf, "0x%.4x\n", usr);
594 }
595
596 static ssize_t
597 isl1208_sysfs_store_usr(struct device *dev,
598                         struct device_attribute *attr,
599                         const char *buf, size_t count)
600 {
601         int usr = -1;
602
603         if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
604                 if (sscanf(buf, "%x", &usr) != 1)
605                         return -EINVAL;
606         } else {
607                 if (sscanf(buf, "%d", &usr) != 1)
608                         return -EINVAL;
609         }
610
611         if (usr < 0 || usr > 0xffff)
612                 return -EINVAL;
613
614         return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
615 }
616
617 static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
618                    isl1208_sysfs_store_usr);
619
620 static struct attribute *isl1208_rtc_attrs[] = {
621         &dev_attr_atrim.attr,
622         &dev_attr_dtrim.attr,
623         &dev_attr_usr.attr,
624         NULL
625 };
626
627 static const struct attribute_group isl1208_rtc_sysfs_files = {
628         .attrs  = isl1208_rtc_attrs,
629 };
630
631 static int
632 isl1208_probe(struct i2c_client *client, const struct i2c_device_id *id)
633 {
634         int rc = 0;
635         struct rtc_device *rtc;
636
637         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
638                 return -ENODEV;
639
640         if (isl1208_i2c_validate_client(client) < 0)
641                 return -ENODEV;
642
643         dev_info(&client->dev,
644                  "chip found, driver version " DRV_VERSION "\n");
645
646         if (client->irq > 0) {
647                 rc = request_threaded_irq(client->irq, NULL,
648                                           isl1208_rtc_interrupt,
649                                           IRQF_SHARED,
650                                           isl1208_driver.driver.name, client);
651                 if (!rc) {
652                         device_init_wakeup(&client->dev, 1);
653                         enable_irq_wake(client->irq);
654                 } else {
655                         dev_err(&client->dev,
656                                 "Unable to request irq %d, no alarm support\n",
657                                 client->irq);
658                         client->irq = 0;
659                 }
660         }
661
662         rtc = rtc_device_register(isl1208_driver.driver.name,
663                                   &client->dev, &isl1208_rtc_ops,
664                                   THIS_MODULE);
665         if (IS_ERR(rtc)) {
666                 rc = PTR_ERR(rtc);
667                 goto exit_free_irq;
668         }
669
670         i2c_set_clientdata(client, rtc);
671
672         rc = isl1208_i2c_get_sr(client);
673         if (rc < 0) {
674                 dev_err(&client->dev, "reading status failed\n");
675                 goto exit_unregister;
676         }
677
678         if (rc & ISL1208_REG_SR_RTCF)
679                 dev_warn(&client->dev, "rtc power failure detected, "
680                          "please set clock.\n");
681
682         rc = sysfs_create_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
683         if (rc)
684                 goto exit_unregister;
685
686         return 0;
687
688 exit_unregister:
689         rtc_device_unregister(rtc);
690 exit_free_irq:
691         if (client->irq)
692                 free_irq(client->irq, client);
693
694         return rc;
695 }
696
697 static int
698 isl1208_remove(struct i2c_client *client)
699 {
700         struct rtc_device *rtc = i2c_get_clientdata(client);
701
702         sysfs_remove_group(&client->dev.kobj, &isl1208_rtc_sysfs_files);
703         rtc_device_unregister(rtc);
704         if (client->irq)
705                 free_irq(client->irq, client);
706
707         return 0;
708 }
709
710 static const struct i2c_device_id isl1208_id[] = {
711         { "isl1208", 0 },
712         { "isl1218", 0 },
713         { }
714 };
715 MODULE_DEVICE_TABLE(i2c, isl1208_id);
716
717 static struct i2c_driver isl1208_driver = {
718         .driver = {
719                    .name = "rtc-isl1208",
720                    },
721         .probe = isl1208_probe,
722         .remove = isl1208_remove,
723         .id_table = isl1208_id,
724 };
725
726 module_i2c_driver(isl1208_driver);
727
728 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
729 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
730 MODULE_LICENSE("GPL");
731 MODULE_VERSION(DRV_VERSION);