Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[linux-2.6.git] / drivers / rtc / rtc-rs5c372.c
1 /*
2  * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
3  *
4  * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
5  * Copyright (C) 2006 Tower Technologies
6  * Copyright (C) 2008 Paul Mundt
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12
13 #include <linux/i2c.h>
14 #include <linux/rtc.h>
15 #include <linux/bcd.h>
16 #include <linux/slab.h>
17
18 #define DRV_VERSION "0.6"
19
20
21 /*
22  * Ricoh has a family of I2C based RTCs, which differ only slightly from
23  * each other.  Differences center on pinout (e.g. how many interrupts,
24  * output clock, etc) and how the control registers are used.  The '372
25  * is significant only because that's the one this driver first supported.
26  */
27 #define RS5C372_REG_SECS        0
28 #define RS5C372_REG_MINS        1
29 #define RS5C372_REG_HOURS       2
30 #define RS5C372_REG_WDAY        3
31 #define RS5C372_REG_DAY         4
32 #define RS5C372_REG_MONTH       5
33 #define RS5C372_REG_YEAR        6
34 #define RS5C372_REG_TRIM        7
35 #       define RS5C372_TRIM_XSL         0x80
36 #       define RS5C372_TRIM_MASK        0x7F
37
38 #define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
39 #define RS5C_REG_ALARM_A_HOURS  9
40 #define RS5C_REG_ALARM_A_WDAY   10
41
42 #define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
43 #define RS5C_REG_ALARM_B_HOURS  12
44 #define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
45
46 #define RS5C_REG_CTRL1          14
47 #       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
48 #       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
49 #       define RV5C387_CTRL1_24         (1 << 5)
50 #       define RS5C372A_CTRL1_SL1       (1 << 5)
51 #       define RS5C_CTRL1_CT_MASK       (7 << 0)
52 #       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
53 #       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
54 #define RS5C_REG_CTRL2          15
55 #       define RS5C372_CTRL2_24         (1 << 5)
56 #       define R2025_CTRL2_XST          (1 << 5)
57 #       define RS5C_CTRL2_XSTP          (1 << 4)        /* only if !R2025S/D */
58 #       define RS5C_CTRL2_CTFG          (1 << 2)
59 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
60 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
61
62
63 /* to read (style 1) or write registers starting at R */
64 #define RS5C_ADDR(R)            (((R) << 4) | 0)
65
66
67 enum rtc_type {
68         rtc_undef = 0,
69         rtc_r2025sd,
70         rtc_rs5c372a,
71         rtc_rs5c372b,
72         rtc_rv5c386,
73         rtc_rv5c387a,
74 };
75
76 static const struct i2c_device_id rs5c372_id[] = {
77         { "r2025sd", rtc_r2025sd },
78         { "rs5c372a", rtc_rs5c372a },
79         { "rs5c372b", rtc_rs5c372b },
80         { "rv5c386", rtc_rv5c386 },
81         { "rv5c387a", rtc_rv5c387a },
82         { }
83 };
84 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
85
86 /* REVISIT:  this assumes that:
87  *  - we're in the 21st century, so it's safe to ignore the century
88  *    bit for rv5c38[67] (REG_MONTH bit 7);
89  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
90  */
91 struct rs5c372 {
92         struct i2c_client       *client;
93         struct rtc_device       *rtc;
94         enum rtc_type           type;
95         unsigned                time24:1;
96         unsigned                has_irq:1;
97         unsigned                smbus:1;
98         char                    buf[17];
99         char                    *regs;
100 };
101
102 static int rs5c_get_regs(struct rs5c372 *rs5c)
103 {
104         struct i2c_client       *client = rs5c->client;
105         struct i2c_msg          msgs[] = {
106                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
107         };
108
109         /* This implements the third reading method from the datasheet, using
110          * an internal address that's reset after each transaction (by STOP)
111          * to 0x0f ... so we read extra registers, and skip the first one.
112          *
113          * The first method doesn't work with the iop3xx adapter driver, on at
114          * least 80219 chips; this works around that bug.
115          *
116          * The third method on the other hand doesn't work for the SMBus-only
117          * configurations, so we use the the first method there, stripping off
118          * the extra register in the process.
119          */
120         if (rs5c->smbus) {
121                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
122                 int size = sizeof(rs5c->buf) - 1;
123
124                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
125                                                   rs5c->buf + 1) != size) {
126                         dev_warn(&client->dev, "can't read registers\n");
127                         return -EIO;
128                 }
129         } else {
130                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
131                         dev_warn(&client->dev, "can't read registers\n");
132                         return -EIO;
133                 }
134         }
135
136         dev_dbg(&client->dev,
137                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
138                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
139                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
140                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
141                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
142                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
143
144         return 0;
145 }
146
147 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
148 {
149         unsigned        hour;
150
151         if (rs5c->time24)
152                 return bcd2bin(reg & 0x3f);
153
154         hour = bcd2bin(reg & 0x1f);
155         if (hour == 12)
156                 hour = 0;
157         if (reg & 0x20)
158                 hour += 12;
159         return hour;
160 }
161
162 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
163 {
164         if (rs5c->time24)
165                 return bin2bcd(hour);
166
167         if (hour > 12)
168                 return 0x20 | bin2bcd(hour - 12);
169         if (hour == 12)
170                 return 0x20 | bin2bcd(12);
171         if (hour == 0)
172                 return bin2bcd(12);
173         return bin2bcd(hour);
174 }
175
176 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
177 {
178         struct rs5c372  *rs5c = i2c_get_clientdata(client);
179         int             status = rs5c_get_regs(rs5c);
180
181         if (status < 0)
182                 return status;
183
184         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
185         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
186         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
187
188         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
189         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
190
191         /* tm->tm_mon is zero-based */
192         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
193
194         /* year is 1900 + tm->tm_year */
195         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
196
197         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
198                 "mday=%d, mon=%d, year=%d, wday=%d\n",
199                 __func__,
200                 tm->tm_sec, tm->tm_min, tm->tm_hour,
201                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
202
203         /* rtc might need initialization */
204         return rtc_valid_tm(tm);
205 }
206
207 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
208 {
209         struct rs5c372  *rs5c = i2c_get_clientdata(client);
210         unsigned char   buf[8];
211         int             addr;
212
213         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
214                 "mday=%d, mon=%d, year=%d, wday=%d\n",
215                 __func__,
216                 tm->tm_sec, tm->tm_min, tm->tm_hour,
217                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
218
219         addr   = RS5C_ADDR(RS5C372_REG_SECS);
220         buf[0] = bin2bcd(tm->tm_sec);
221         buf[1] = bin2bcd(tm->tm_min);
222         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
223         buf[3] = bin2bcd(tm->tm_wday);
224         buf[4] = bin2bcd(tm->tm_mday);
225         buf[5] = bin2bcd(tm->tm_mon + 1);
226         buf[6] = bin2bcd(tm->tm_year - 100);
227
228         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
229                 dev_err(&client->dev, "%s: write error\n", __func__);
230                 return -EIO;
231         }
232
233         return 0;
234 }
235
236 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
237 #define NEED_TRIM
238 #endif
239
240 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
241 #define NEED_TRIM
242 #endif
243
244 #ifdef  NEED_TRIM
245 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
246 {
247         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
248         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
249
250         if (osc)
251                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
252
253         if (trim) {
254                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
255                 tmp &= RS5C372_TRIM_MASK;
256                 if (tmp & 0x3e) {
257                         int t = tmp & 0x3f;
258
259                         if (tmp & 0x40)
260                                 t = (~t | (s8)0xc0) + 1;
261                         else
262                                 t = t - 1;
263
264                         tmp = t * 2;
265                 } else
266                         tmp = 0;
267                 *trim = tmp;
268         }
269
270         return 0;
271 }
272 #endif
273
274 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
275 {
276         return rs5c372_get_datetime(to_i2c_client(dev), tm);
277 }
278
279 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
280 {
281         return rs5c372_set_datetime(to_i2c_client(dev), tm);
282 }
283
284 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
285
286 static int
287 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
288 {
289         struct i2c_client       *client = to_i2c_client(dev);
290         struct rs5c372          *rs5c = i2c_get_clientdata(client);
291         unsigned char           buf;
292         int                     status, addr;
293
294         buf = rs5c->regs[RS5C_REG_CTRL1];
295         switch (cmd) {
296         case RTC_UIE_OFF:
297         case RTC_UIE_ON:
298                 /* some 327a modes use a different IRQ pin for 1Hz irqs */
299                 if (rs5c->type == rtc_rs5c372a
300                                 && (buf & RS5C372A_CTRL1_SL1))
301                         return -ENOIOCTLCMD;
302         case RTC_AIE_OFF:
303         case RTC_AIE_ON:
304                 /* these irq management calls only make sense for chips
305                  * which are wired up to an IRQ.
306                  */
307                 if (!rs5c->has_irq)
308                         return -ENOIOCTLCMD;
309                 break;
310         default:
311                 return -ENOIOCTLCMD;
312         }
313
314         status = rs5c_get_regs(rs5c);
315         if (status < 0)
316                 return status;
317
318         addr = RS5C_ADDR(RS5C_REG_CTRL1);
319         switch (cmd) {
320         case RTC_AIE_OFF:       /* alarm off */
321                 buf &= ~RS5C_CTRL1_AALE;
322                 break;
323         case RTC_AIE_ON:        /* alarm on */
324                 buf |= RS5C_CTRL1_AALE;
325                 break;
326         case RTC_UIE_OFF:       /* update off */
327                 buf &= ~RS5C_CTRL1_CT_MASK;
328                 break;
329         case RTC_UIE_ON:        /* update on */
330                 buf &= ~RS5C_CTRL1_CT_MASK;
331                 buf |= RS5C_CTRL1_CT4;
332                 break;
333         }
334
335         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
336                 printk(KERN_WARNING "%s: can't update alarm\n",
337                         rs5c->rtc->name);
338                 status = -EIO;
339         } else
340                 rs5c->regs[RS5C_REG_CTRL1] = buf;
341
342         return status;
343 }
344
345 #else
346 #define rs5c_rtc_ioctl  NULL
347 #endif
348
349
350 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
351  * which only exposes a polled programming interface; and since
352  * these calls map directly to those EFI requests; we don't demand
353  * we have an IRQ for this chip when we go through this API.
354  *
355  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
356  * though, managed through RTC_AIE_{ON,OFF} requests.
357  */
358
359 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
360 {
361         struct i2c_client       *client = to_i2c_client(dev);
362         struct rs5c372          *rs5c = i2c_get_clientdata(client);
363         int                     status;
364
365         status = rs5c_get_regs(rs5c);
366         if (status < 0)
367                 return status;
368
369         /* report alarm time */
370         t->time.tm_sec = 0;
371         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
372         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
373         t->time.tm_mday = -1;
374         t->time.tm_mon = -1;
375         t->time.tm_year = -1;
376         t->time.tm_wday = -1;
377         t->time.tm_yday = -1;
378         t->time.tm_isdst = -1;
379
380         /* ... and status */
381         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
382         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
383
384         return 0;
385 }
386
387 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
388 {
389         struct i2c_client       *client = to_i2c_client(dev);
390         struct rs5c372          *rs5c = i2c_get_clientdata(client);
391         int                     status, addr, i;
392         unsigned char           buf[3];
393
394         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
395         if (t->time.tm_mday != -1
396                         || t->time.tm_mon != -1
397                         || t->time.tm_year != -1)
398                 return -EINVAL;
399
400         /* REVISIT: round up tm_sec */
401
402         /* if needed, disable irq (clears pending status) */
403         status = rs5c_get_regs(rs5c);
404         if (status < 0)
405                 return status;
406         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
407                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
408                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
409                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
410                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
411                         return -EIO;
412                 }
413                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
414         }
415
416         /* set alarm */
417         buf[0] = bin2bcd(t->time.tm_min);
418         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
419         buf[2] = 0x7f;  /* any/all days */
420
421         for (i = 0; i < sizeof(buf); i++) {
422                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
423                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
424                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
425                         return -EIO;
426                 }
427         }
428
429         /* ... and maybe enable its irq */
430         if (t->enabled) {
431                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
432                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
433                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
434                         printk(KERN_WARNING "%s: can't enable alarm\n",
435                                 rs5c->rtc->name);
436                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
437         }
438
439         return 0;
440 }
441
442 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
443
444 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
445 {
446         int err, osc, trim;
447
448         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
449         if (err == 0) {
450                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
451                                 osc / 1000, osc % 1000);
452                 seq_printf(seq, "trim\t\t: %d\n", trim);
453         }
454
455         return 0;
456 }
457
458 #else
459 #define rs5c372_rtc_proc        NULL
460 #endif
461
462 static const struct rtc_class_ops rs5c372_rtc_ops = {
463         .proc           = rs5c372_rtc_proc,
464         .ioctl          = rs5c_rtc_ioctl,
465         .read_time      = rs5c372_rtc_read_time,
466         .set_time       = rs5c372_rtc_set_time,
467         .read_alarm     = rs5c_read_alarm,
468         .set_alarm      = rs5c_set_alarm,
469 };
470
471 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
472
473 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
474                                 struct device_attribute *attr, char *buf)
475 {
476         int err, trim;
477
478         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
479         if (err)
480                 return err;
481
482         return sprintf(buf, "%d\n", trim);
483 }
484 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
485
486 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
487                                 struct device_attribute *attr, char *buf)
488 {
489         int err, osc;
490
491         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
492         if (err)
493                 return err;
494
495         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
496 }
497 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
498
499 static int rs5c_sysfs_register(struct device *dev)
500 {
501         int err;
502
503         err = device_create_file(dev, &dev_attr_trim);
504         if (err)
505                 return err;
506         err = device_create_file(dev, &dev_attr_osc);
507         if (err)
508                 device_remove_file(dev, &dev_attr_trim);
509
510         return err;
511 }
512
513 static void rs5c_sysfs_unregister(struct device *dev)
514 {
515         device_remove_file(dev, &dev_attr_trim);
516         device_remove_file(dev, &dev_attr_osc);
517 }
518
519 #else
520 static int rs5c_sysfs_register(struct device *dev)
521 {
522         return 0;
523 }
524
525 static void rs5c_sysfs_unregister(struct device *dev)
526 {
527         /* nothing */
528 }
529 #endif  /* SYSFS */
530
531 static struct i2c_driver rs5c372_driver;
532
533 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
534 {
535         unsigned char buf[2];
536         int addr, i, ret = 0;
537
538         if (rs5c372->type == rtc_r2025sd) {
539                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
540                         return ret;
541                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
542         } else {
543                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
544                         return ret;
545                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
546         }
547
548         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
549         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
550         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
551
552         /* use 24hr mode */
553         switch (rs5c372->type) {
554         case rtc_rs5c372a:
555         case rtc_rs5c372b:
556                 buf[1] |= RS5C372_CTRL2_24;
557                 rs5c372->time24 = 1;
558                 break;
559         case rtc_r2025sd:
560         case rtc_rv5c386:
561         case rtc_rv5c387a:
562                 buf[0] |= RV5C387_CTRL1_24;
563                 rs5c372->time24 = 1;
564                 break;
565         default:
566                 /* impossible */
567                 break;
568         }
569
570         for (i = 0; i < sizeof(buf); i++) {
571                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
572                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
573                 if (unlikely(ret < 0))
574                         return ret;
575         }
576
577         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
578         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
579
580         return 0;
581 }
582
583 static int rs5c372_probe(struct i2c_client *client,
584                          const struct i2c_device_id *id)
585 {
586         int err = 0;
587         int smbus_mode = 0;
588         struct rs5c372 *rs5c372;
589         struct rtc_time tm;
590
591         dev_dbg(&client->dev, "%s\n", __func__);
592
593         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
594                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
595                 /*
596                  * If we don't have any master mode adapter, try breaking
597                  * it down in to the barest of capabilities.
598                  */
599                 if (i2c_check_functionality(client->adapter,
600                                 I2C_FUNC_SMBUS_BYTE_DATA |
601                                 I2C_FUNC_SMBUS_I2C_BLOCK))
602                         smbus_mode = 1;
603                 else {
604                         /* Still no good, give up */
605                         err = -ENODEV;
606                         goto exit;
607                 }
608         }
609
610         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
611                 err = -ENOMEM;
612                 goto exit;
613         }
614
615         rs5c372->client = client;
616         i2c_set_clientdata(client, rs5c372);
617         rs5c372->type = id->driver_data;
618
619         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
620         rs5c372->regs = &rs5c372->buf[1];
621         rs5c372->smbus = smbus_mode;
622
623         err = rs5c_get_regs(rs5c372);
624         if (err < 0)
625                 goto exit_kfree;
626
627         /* clock may be set for am/pm or 24 hr time */
628         switch (rs5c372->type) {
629         case rtc_rs5c372a:
630         case rtc_rs5c372b:
631                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
632                  * so does periodic irq, except some 327a modes.
633                  */
634                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
635                         rs5c372->time24 = 1;
636                 break;
637         case rtc_r2025sd:
638         case rtc_rv5c386:
639         case rtc_rv5c387a:
640                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
641                         rs5c372->time24 = 1;
642                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
643                  * irq, on both 386 and 387
644                  */
645                 break;
646         default:
647                 dev_err(&client->dev, "unknown RTC type\n");
648                 goto exit_kfree;
649         }
650
651         /* if the oscillator lost power and no other software (like
652          * the bootloader) set it up, do it here.
653          *
654          * The R2025S/D does this a little differently than the other
655          * parts, so we special case that..
656          */
657         err = rs5c_oscillator_setup(rs5c372);
658         if (unlikely(err < 0)) {
659                 dev_err(&client->dev, "setup error\n");
660                 goto exit_kfree;
661         }
662
663         if (rs5c372_get_datetime(client, &tm) < 0)
664                 dev_warn(&client->dev, "clock needs to be set\n");
665
666         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
667                         ({ char *s; switch (rs5c372->type) {
668                         case rtc_r2025sd:       s = "r2025sd"; break;
669                         case rtc_rs5c372a:      s = "rs5c372a"; break;
670                         case rtc_rs5c372b:      s = "rs5c372b"; break;
671                         case rtc_rv5c386:       s = "rv5c386"; break;
672                         case rtc_rv5c387a:      s = "rv5c387a"; break;
673                         default:                s = "chip"; break;
674                         }; s;}),
675                         rs5c372->time24 ? "24hr" : "am/pm"
676                         );
677
678         /* REVISIT use client->irq to register alarm irq ... */
679
680         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
681                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
682
683         if (IS_ERR(rs5c372->rtc)) {
684                 err = PTR_ERR(rs5c372->rtc);
685                 goto exit_kfree;
686         }
687
688         err = rs5c_sysfs_register(&client->dev);
689         if (err)
690                 goto exit_devreg;
691
692         return 0;
693
694 exit_devreg:
695         rtc_device_unregister(rs5c372->rtc);
696
697 exit_kfree:
698         kfree(rs5c372);
699
700 exit:
701         return err;
702 }
703
704 static int rs5c372_remove(struct i2c_client *client)
705 {
706         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
707
708         rtc_device_unregister(rs5c372->rtc);
709         rs5c_sysfs_unregister(&client->dev);
710         kfree(rs5c372);
711         return 0;
712 }
713
714 static struct i2c_driver rs5c372_driver = {
715         .driver         = {
716                 .name   = "rtc-rs5c372",
717         },
718         .probe          = rs5c372_probe,
719         .remove         = rs5c372_remove,
720         .id_table       = rs5c372_id,
721 };
722
723 static __init int rs5c372_init(void)
724 {
725         return i2c_add_driver(&rs5c372_driver);
726 }
727
728 static __exit void rs5c372_exit(void)
729 {
730         i2c_del_driver(&rs5c372_driver);
731 }
732
733 module_init(rs5c372_init);
734 module_exit(rs5c372_exit);
735
736 MODULE_AUTHOR(
737                 "Pavel Mironchik <pmironchik@optifacio.net>, "
738                 "Alessandro Zummo <a.zummo@towertech.it>, "
739                 "Paul Mundt <lethal@linux-sh.org>");
740 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
741 MODULE_LICENSE("GPL");
742 MODULE_VERSION(DRV_VERSION);