8b561958fb1e62056c62ef2aabe37742ab2cd395
[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
17 #define DRV_VERSION "0.6"
18
19
20 /*
21  * Ricoh has a family of I2C based RTCs, which differ only slightly from
22  * each other.  Differences center on pinout (e.g. how many interrupts,
23  * output clock, etc) and how the control registers are used.  The '372
24  * is significant only because that's the one this driver first supported.
25  */
26 #define RS5C372_REG_SECS        0
27 #define RS5C372_REG_MINS        1
28 #define RS5C372_REG_HOURS       2
29 #define RS5C372_REG_WDAY        3
30 #define RS5C372_REG_DAY         4
31 #define RS5C372_REG_MONTH       5
32 #define RS5C372_REG_YEAR        6
33 #define RS5C372_REG_TRIM        7
34 #       define RS5C372_TRIM_XSL         0x80
35 #       define RS5C372_TRIM_MASK        0x7F
36
37 #define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
38 #define RS5C_REG_ALARM_A_HOURS  9
39 #define RS5C_REG_ALARM_A_WDAY   10
40
41 #define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
42 #define RS5C_REG_ALARM_B_HOURS  12
43 #define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
44
45 #define RS5C_REG_CTRL1          14
46 #       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
47 #       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
48 #       define RV5C387_CTRL1_24         (1 << 5)
49 #       define RS5C372A_CTRL1_SL1       (1 << 5)
50 #       define RS5C_CTRL1_CT_MASK       (7 << 0)
51 #       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
52 #       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
53 #define RS5C_REG_CTRL2          15
54 #       define RS5C372_CTRL2_24         (1 << 5)
55 #       define R2025_CTRL2_XST          (1 << 5)
56 #       define RS5C_CTRL2_XSTP          (1 << 4)        /* only if !R2025S/D */
57 #       define RS5C_CTRL2_CTFG          (1 << 2)
58 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
59 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
60
61
62 /* to read (style 1) or write registers starting at R */
63 #define RS5C_ADDR(R)            (((R) << 4) | 0)
64
65
66 enum rtc_type {
67         rtc_undef = 0,
68         rtc_r2025sd,
69         rtc_rs5c372a,
70         rtc_rs5c372b,
71         rtc_rv5c386,
72         rtc_rv5c387a,
73 };
74
75 static const struct i2c_device_id rs5c372_id[] = {
76         { "r2025sd", rtc_r2025sd },
77         { "rs5c372a", rtc_rs5c372a },
78         { "rs5c372b", rtc_rs5c372b },
79         { "rv5c386", rtc_rv5c386 },
80         { "rv5c387a", rtc_rv5c387a },
81         { }
82 };
83 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
84
85 /* REVISIT:  this assumes that:
86  *  - we're in the 21st century, so it's safe to ignore the century
87  *    bit for rv5c38[67] (REG_MONTH bit 7);
88  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
89  */
90 struct rs5c372 {
91         struct i2c_client       *client;
92         struct rtc_device       *rtc;
93         enum rtc_type           type;
94         unsigned                time24:1;
95         unsigned                has_irq:1;
96         unsigned                smbus:1;
97         char                    buf[17];
98         char                    *regs;
99 };
100
101 static int rs5c_get_regs(struct rs5c372 *rs5c)
102 {
103         struct i2c_client       *client = rs5c->client;
104         struct i2c_msg          msgs[] = {
105                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
106         };
107
108         /* This implements the third reading method from the datasheet, using
109          * an internal address that's reset after each transaction (by STOP)
110          * to 0x0f ... so we read extra registers, and skip the first one.
111          *
112          * The first method doesn't work with the iop3xx adapter driver, on at
113          * least 80219 chips; this works around that bug.
114          *
115          * The third method on the other hand doesn't work for the SMBus-only
116          * configurations, so we use the the first method there, stripping off
117          * the extra register in the process.
118          */
119         if (rs5c->smbus) {
120                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
121                 int size = sizeof(rs5c->buf) - 1;
122
123                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
124                                                   rs5c->buf + 1) != size) {
125                         dev_warn(&client->dev, "can't read registers\n");
126                         return -EIO;
127                 }
128         } else {
129                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
130                         dev_warn(&client->dev, "can't read registers\n");
131                         return -EIO;
132                 }
133         }
134
135         dev_dbg(&client->dev,
136                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
137                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
138                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
139                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
140                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
141                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
142
143         return 0;
144 }
145
146 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
147 {
148         unsigned        hour;
149
150         if (rs5c->time24)
151                 return BCD2BIN(reg & 0x3f);
152
153         hour = BCD2BIN(reg & 0x1f);
154         if (hour == 12)
155                 hour = 0;
156         if (reg & 0x20)
157                 hour += 12;
158         return hour;
159 }
160
161 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
162 {
163         if (rs5c->time24)
164                 return BIN2BCD(hour);
165
166         if (hour > 12)
167                 return 0x20 | BIN2BCD(hour - 12);
168         if (hour == 12)
169                 return 0x20 | BIN2BCD(12);
170         if (hour == 0)
171                 return BIN2BCD(12);
172         return BIN2BCD(hour);
173 }
174
175 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
176 {
177         struct rs5c372  *rs5c = i2c_get_clientdata(client);
178         int             status = rs5c_get_regs(rs5c);
179
180         if (status < 0)
181                 return status;
182
183         tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
184         tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
185         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
186
187         tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
188         tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
189
190         /* tm->tm_mon is zero-based */
191         tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
192
193         /* year is 1900 + tm->tm_year */
194         tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
195
196         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
197                 "mday=%d, mon=%d, year=%d, wday=%d\n",
198                 __func__,
199                 tm->tm_sec, tm->tm_min, tm->tm_hour,
200                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
201
202         /* rtc might need initialization */
203         return rtc_valid_tm(tm);
204 }
205
206 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
207 {
208         struct rs5c372  *rs5c = i2c_get_clientdata(client);
209         unsigned char   buf[8];
210         int             addr;
211
212         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
213                 "mday=%d, mon=%d, year=%d, wday=%d\n",
214                 __func__,
215                 tm->tm_sec, tm->tm_min, tm->tm_hour,
216                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
217
218         addr   = RS5C_ADDR(RS5C372_REG_SECS);
219         buf[0] = BIN2BCD(tm->tm_sec);
220         buf[1] = BIN2BCD(tm->tm_min);
221         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
222         buf[3] = BIN2BCD(tm->tm_wday);
223         buf[4] = BIN2BCD(tm->tm_mday);
224         buf[5] = BIN2BCD(tm->tm_mon + 1);
225         buf[6] = BIN2BCD(tm->tm_year - 100);
226
227         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
228                 dev_err(&client->dev, "%s: write error\n", __func__);
229                 return -EIO;
230         }
231
232         return 0;
233 }
234
235 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
236 #define NEED_TRIM
237 #endif
238
239 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
240 #define NEED_TRIM
241 #endif
242
243 #ifdef  NEED_TRIM
244 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
245 {
246         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
247         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
248
249         if (osc)
250                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
251
252         if (trim) {
253                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
254                 tmp &= RS5C372_TRIM_MASK;
255                 if (tmp & 0x3e) {
256                         int t = tmp & 0x3f;
257
258                         if (tmp & 0x40)
259                                 t = (~t | (s8)0xc0) + 1;
260                         else
261                                 t = t - 1;
262
263                         tmp = t * 2;
264                 } else
265                         tmp = 0;
266                 *trim = tmp;
267         }
268
269         return 0;
270 }
271 #endif
272
273 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
274 {
275         return rs5c372_get_datetime(to_i2c_client(dev), tm);
276 }
277
278 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
279 {
280         return rs5c372_set_datetime(to_i2c_client(dev), tm);
281 }
282
283 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
284
285 static int
286 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
287 {
288         struct i2c_client       *client = to_i2c_client(dev);
289         struct rs5c372          *rs5c = i2c_get_clientdata(client);
290         unsigned char           buf;
291         int                     status, addr;
292
293         buf = rs5c->regs[RS5C_REG_CTRL1];
294         switch (cmd) {
295         case RTC_UIE_OFF:
296         case RTC_UIE_ON:
297                 /* some 327a modes use a different IRQ pin for 1Hz irqs */
298                 if (rs5c->type == rtc_rs5c372a
299                                 && (buf & RS5C372A_CTRL1_SL1))
300                         return -ENOIOCTLCMD;
301         case RTC_AIE_OFF:
302         case RTC_AIE_ON:
303                 /* these irq management calls only make sense for chips
304                  * which are wired up to an IRQ.
305                  */
306                 if (!rs5c->has_irq)
307                         return -ENOIOCTLCMD;
308                 break;
309         default:
310                 return -ENOIOCTLCMD;
311         }
312
313         status = rs5c_get_regs(rs5c);
314         if (status < 0)
315                 return status;
316
317         addr = RS5C_ADDR(RS5C_REG_CTRL1);
318         switch (cmd) {
319         case RTC_AIE_OFF:       /* alarm off */
320                 buf &= ~RS5C_CTRL1_AALE;
321                 break;
322         case RTC_AIE_ON:        /* alarm on */
323                 buf |= RS5C_CTRL1_AALE;
324                 break;
325         case RTC_UIE_OFF:       /* update off */
326                 buf &= ~RS5C_CTRL1_CT_MASK;
327                 break;
328         case RTC_UIE_ON:        /* update on */
329                 buf &= ~RS5C_CTRL1_CT_MASK;
330                 buf |= RS5C_CTRL1_CT4;
331                 break;
332         }
333
334         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
335                 printk(KERN_WARNING "%s: can't update alarm\n",
336                         rs5c->rtc->name);
337                 status = -EIO;
338         } else
339                 rs5c->regs[RS5C_REG_CTRL1] = buf;
340
341         return status;
342 }
343
344 #else
345 #define rs5c_rtc_ioctl  NULL
346 #endif
347
348
349 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
350  * which only exposes a polled programming interface; and since
351  * these calls map directly to those EFI requests; we don't demand
352  * we have an IRQ for this chip when we go through this API.
353  *
354  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
355  * though, managed through RTC_AIE_{ON,OFF} requests.
356  */
357
358 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
359 {
360         struct i2c_client       *client = to_i2c_client(dev);
361         struct rs5c372          *rs5c = i2c_get_clientdata(client);
362         int                     status;
363
364         status = rs5c_get_regs(rs5c);
365         if (status < 0)
366                 return status;
367
368         /* report alarm time */
369         t->time.tm_sec = 0;
370         t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
371         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
372         t->time.tm_mday = -1;
373         t->time.tm_mon = -1;
374         t->time.tm_year = -1;
375         t->time.tm_wday = -1;
376         t->time.tm_yday = -1;
377         t->time.tm_isdst = -1;
378
379         /* ... and status */
380         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
381         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
382
383         return 0;
384 }
385
386 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
387 {
388         struct i2c_client       *client = to_i2c_client(dev);
389         struct rs5c372          *rs5c = i2c_get_clientdata(client);
390         int                     status, addr, i;
391         unsigned char           buf[3];
392
393         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
394         if (t->time.tm_mday != -1
395                         || t->time.tm_mon != -1
396                         || t->time.tm_year != -1)
397                 return -EINVAL;
398
399         /* REVISIT: round up tm_sec */
400
401         /* if needed, disable irq (clears pending status) */
402         status = rs5c_get_regs(rs5c);
403         if (status < 0)
404                 return status;
405         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
406                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
407                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
408                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
409                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
410                         return -EIO;
411                 }
412                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
413         }
414
415         /* set alarm */
416         buf[0] = BIN2BCD(t->time.tm_min);
417         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
418         buf[2] = 0x7f;  /* any/all days */
419
420         for (i = 0; i < sizeof(buf); i++) {
421                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
422                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
423                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
424                         return -EIO;
425                 }
426         }
427
428         /* ... and maybe enable its irq */
429         if (t->enabled) {
430                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
431                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
432                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
433                         printk(KERN_WARNING "%s: can't enable alarm\n",
434                                 rs5c->rtc->name);
435                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
436         }
437
438         return 0;
439 }
440
441 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
442
443 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
444 {
445         int err, osc, trim;
446
447         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
448         if (err == 0) {
449                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
450                                 osc / 1000, osc % 1000);
451                 seq_printf(seq, "trim\t\t: %d\n", trim);
452         }
453
454         return 0;
455 }
456
457 #else
458 #define rs5c372_rtc_proc        NULL
459 #endif
460
461 static const struct rtc_class_ops rs5c372_rtc_ops = {
462         .proc           = rs5c372_rtc_proc,
463         .ioctl          = rs5c_rtc_ioctl,
464         .read_time      = rs5c372_rtc_read_time,
465         .set_time       = rs5c372_rtc_set_time,
466         .read_alarm     = rs5c_read_alarm,
467         .set_alarm      = rs5c_set_alarm,
468 };
469
470 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
471
472 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
473                                 struct device_attribute *attr, char *buf)
474 {
475         int err, trim;
476
477         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
478         if (err)
479                 return err;
480
481         return sprintf(buf, "%d\n", trim);
482 }
483 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
484
485 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
486                                 struct device_attribute *attr, char *buf)
487 {
488         int err, osc;
489
490         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
491         if (err)
492                 return err;
493
494         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
495 }
496 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
497
498 static int rs5c_sysfs_register(struct device *dev)
499 {
500         int err;
501
502         err = device_create_file(dev, &dev_attr_trim);
503         if (err)
504                 return err;
505         err = device_create_file(dev, &dev_attr_osc);
506         if (err)
507                 device_remove_file(dev, &dev_attr_trim);
508
509         return err;
510 }
511
512 static void rs5c_sysfs_unregister(struct device *dev)
513 {
514         device_remove_file(dev, &dev_attr_trim);
515         device_remove_file(dev, &dev_attr_osc);
516 }
517
518 #else
519 static int rs5c_sysfs_register(struct device *dev)
520 {
521         return 0;
522 }
523
524 static void rs5c_sysfs_unregister(struct device *dev)
525 {
526         /* nothing */
527 }
528 #endif  /* SYSFS */
529
530 static struct i2c_driver rs5c372_driver;
531
532 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
533 {
534         unsigned char buf[2];
535         int addr, i, ret = 0;
536
537         if (rs5c372->type == rtc_r2025sd) {
538                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
539                         return ret;
540                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
541         } else {
542                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
543                         return ret;
544                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
545         }
546
547         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
548         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
549         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
550
551         /* use 24hr mode */
552         switch (rs5c372->type) {
553         case rtc_rs5c372a:
554         case rtc_rs5c372b:
555                 buf[1] |= RS5C372_CTRL2_24;
556                 rs5c372->time24 = 1;
557                 break;
558         case rtc_r2025sd:
559         case rtc_rv5c386:
560         case rtc_rv5c387a:
561                 buf[0] |= RV5C387_CTRL1_24;
562                 rs5c372->time24 = 1;
563                 break;
564         default:
565                 /* impossible */
566                 break;
567         }
568
569         for (i = 0; i < sizeof(buf); i++) {
570                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
571                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
572                 if (unlikely(ret < 0))
573                         return ret;
574         }
575
576         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
577         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
578
579         return 0;
580 }
581
582 static int rs5c372_probe(struct i2c_client *client,
583                          const struct i2c_device_id *id)
584 {
585         int err = 0;
586         int smbus_mode = 0;
587         struct rs5c372 *rs5c372;
588         struct rtc_time tm;
589
590         dev_dbg(&client->dev, "%s\n", __func__);
591
592         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
593                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
594                 /*
595                  * If we don't have any master mode adapter, try breaking
596                  * it down in to the barest of capabilities.
597                  */
598                 if (i2c_check_functionality(client->adapter,
599                                 I2C_FUNC_SMBUS_BYTE_DATA |
600                                 I2C_FUNC_SMBUS_I2C_BLOCK))
601                         smbus_mode = 1;
602                 else {
603                         /* Still no good, give up */
604                         err = -ENODEV;
605                         goto exit;
606                 }
607         }
608
609         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
610                 err = -ENOMEM;
611                 goto exit;
612         }
613
614         rs5c372->client = client;
615         i2c_set_clientdata(client, rs5c372);
616         rs5c372->type = id->driver_data;
617
618         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
619         rs5c372->regs = &rs5c372->buf[1];
620         rs5c372->smbus = smbus_mode;
621
622         err = rs5c_get_regs(rs5c372);
623         if (err < 0)
624                 goto exit_kfree;
625
626         /* clock may be set for am/pm or 24 hr time */
627         switch (rs5c372->type) {
628         case rtc_rs5c372a:
629         case rtc_rs5c372b:
630                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
631                  * so does periodic irq, except some 327a modes.
632                  */
633                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
634                         rs5c372->time24 = 1;
635                 break;
636         case rtc_r2025sd:
637         case rtc_rv5c386:
638         case rtc_rv5c387a:
639                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
640                         rs5c372->time24 = 1;
641                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
642                  * irq, on both 386 and 387
643                  */
644                 break;
645         default:
646                 dev_err(&client->dev, "unknown RTC type\n");
647                 goto exit_kfree;
648         }
649
650         /* if the oscillator lost power and no other software (like
651          * the bootloader) set it up, do it here.
652          *
653          * The R2025S/D does this a little differently than the other
654          * parts, so we special case that..
655          */
656         err = rs5c_oscillator_setup(rs5c372);
657         if (unlikely(err < 0)) {
658                 dev_err(&client->dev, "setup error\n");
659                 goto exit_kfree;
660         }
661
662         if (rs5c372_get_datetime(client, &tm) < 0)
663                 dev_warn(&client->dev, "clock needs to be set\n");
664
665         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
666                         ({ char *s; switch (rs5c372->type) {
667                         case rtc_r2025sd:       s = "r2025sd"; break;
668                         case rtc_rs5c372a:      s = "rs5c372a"; break;
669                         case rtc_rs5c372b:      s = "rs5c372b"; break;
670                         case rtc_rv5c386:       s = "rv5c386"; break;
671                         case rtc_rv5c387a:      s = "rv5c387a"; break;
672                         default:                s = "chip"; break;
673                         }; s;}),
674                         rs5c372->time24 ? "24hr" : "am/pm"
675                         );
676
677         /* REVISIT use client->irq to register alarm irq ... */
678
679         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
680                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
681
682         if (IS_ERR(rs5c372->rtc)) {
683                 err = PTR_ERR(rs5c372->rtc);
684                 goto exit_kfree;
685         }
686
687         err = rs5c_sysfs_register(&client->dev);
688         if (err)
689                 goto exit_devreg;
690
691         return 0;
692
693 exit_devreg:
694         rtc_device_unregister(rs5c372->rtc);
695
696 exit_kfree:
697         kfree(rs5c372);
698
699 exit:
700         return err;
701 }
702
703 static int rs5c372_remove(struct i2c_client *client)
704 {
705         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
706
707         rtc_device_unregister(rs5c372->rtc);
708         rs5c_sysfs_unregister(&client->dev);
709         kfree(rs5c372);
710         return 0;
711 }
712
713 static struct i2c_driver rs5c372_driver = {
714         .driver         = {
715                 .name   = "rtc-rs5c372",
716         },
717         .probe          = rs5c372_probe,
718         .remove         = rs5c372_remove,
719         .id_table       = rs5c372_id,
720 };
721
722 static __init int rs5c372_init(void)
723 {
724         return i2c_add_driver(&rs5c372_driver);
725 }
726
727 static __exit void rs5c372_exit(void)
728 {
729         i2c_del_driver(&rs5c372_driver);
730 }
731
732 module_init(rs5c372_init);
733 module_exit(rs5c372_exit);
734
735 MODULE_AUTHOR(
736                 "Pavel Mironchik <pmironchik@optifacio.net>, "
737                 "Alessandro Zummo <a.zummo@towertech.it>, "
738                 "Paul Mundt <lethal@linux-sh.org>");
739 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
740 MODULE_LICENSE("GPL");
741 MODULE_VERSION(DRV_VERSION);