rtc: rtc-s35390a.c needs the bitreverse library
[linux-2.6.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_NAME "isl1208"
19 #define DRV_VERSION "0.2"
20
21 /* Register map */
22 /* rtc section */
23 #define ISL1208_REG_SC  0x00
24 #define ISL1208_REG_MN  0x01
25 #define ISL1208_REG_HR  0x02
26 #define ISL1208_REG_HR_MIL     (1<<7) /* 24h/12h mode */
27 #define ISL1208_REG_HR_PM      (1<<5) /* PM/AM bit in 12h mode */
28 #define ISL1208_REG_DT  0x03
29 #define ISL1208_REG_MO  0x04
30 #define ISL1208_REG_YR  0x05
31 #define ISL1208_REG_DW  0x06
32 #define ISL1208_RTC_SECTION_LEN 7
33
34 /* control/status section */
35 #define ISL1208_REG_SR  0x07
36 #define ISL1208_REG_SR_ARST    (1<<7) /* auto reset */
37 #define ISL1208_REG_SR_XTOSCB  (1<<6) /* crystal oscillator */
38 #define ISL1208_REG_SR_WRTC    (1<<4) /* write rtc */
39 #define ISL1208_REG_SR_ALM     (1<<2) /* alarm */
40 #define ISL1208_REG_SR_BAT     (1<<1) /* battery */
41 #define ISL1208_REG_SR_RTCF    (1<<0) /* rtc fail */
42 #define ISL1208_REG_INT 0x08
43 #define ISL1208_REG_09  0x09 /* reserved */
44 #define ISL1208_REG_ATR 0x0a
45 #define ISL1208_REG_DTR 0x0b
46
47 /* alarm section */
48 #define ISL1208_REG_SCA 0x0c
49 #define ISL1208_REG_MNA 0x0d
50 #define ISL1208_REG_HRA 0x0e
51 #define ISL1208_REG_DTA 0x0f
52 #define ISL1208_REG_MOA 0x10
53 #define ISL1208_REG_DWA 0x11
54 #define ISL1208_ALARM_SECTION_LEN 6
55
56 /* user section */
57 #define ISL1208_REG_USR1 0x12
58 #define ISL1208_REG_USR2 0x13
59 #define ISL1208_USR_SECTION_LEN 2
60
61 /* i2c configuration */
62 #define ISL1208_I2C_ADDR 0xde
63
64 static const unsigned short normal_i2c[] = {
65         ISL1208_I2C_ADDR>>1, I2C_CLIENT_END
66 };
67 I2C_CLIENT_INSMOD; /* defines addr_data */
68
69 static int isl1208_attach_adapter(struct i2c_adapter *adapter);
70 static int isl1208_detach_client(struct i2c_client *client);
71
72 static struct i2c_driver isl1208_driver = {
73         .driver         = {
74                 .name   = DRV_NAME,
75         },
76         .id             = I2C_DRIVERID_ISL1208,
77         .attach_adapter = &isl1208_attach_adapter,
78         .detach_client  = &isl1208_detach_client,
79 };
80
81 /* block read */
82 static int
83 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
84                        unsigned len)
85 {
86         u8 reg_addr[1] = { reg };
87         struct i2c_msg msgs[2] = {
88                 { client->addr, client->flags, sizeof(reg_addr), reg_addr },
89                 { client->addr, client->flags | I2C_M_RD, len, buf }
90         };
91         int ret;
92
93         BUG_ON(len == 0);
94         BUG_ON(reg > ISL1208_REG_USR2);
95         BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
96
97         ret = i2c_transfer(client->adapter, msgs, 2);
98         if (ret > 0)
99                 ret = 0;
100         return ret;
101 }
102
103 /* block write */
104 static int
105 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
106                        unsigned len)
107 {
108         u8 i2c_buf[ISL1208_REG_USR2 + 2];
109         struct i2c_msg msgs[1] = {
110                 { client->addr, client->flags, len + 1, i2c_buf }
111         };
112         int ret;
113
114         BUG_ON(len == 0);
115         BUG_ON(reg > ISL1208_REG_USR2);
116         BUG_ON(reg + len > ISL1208_REG_USR2 + 1);
117
118         i2c_buf[0] = reg;
119         memcpy(&i2c_buf[1], &buf[0], len);
120
121         ret = i2c_transfer(client->adapter, msgs, 1);
122         if (ret > 0)
123                 ret = 0;
124         return ret;
125 }
126
127 /* simple check to see wether we have a isl1208 */
128 static int isl1208_i2c_validate_client(struct i2c_client *client)
129 {
130         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
131         u8 zero_mask[ISL1208_RTC_SECTION_LEN] = {
132                 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8
133         };
134         int i;
135         int ret;
136
137         ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
138         if (ret < 0)
139                 return ret;
140
141         for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) {
142                 if (regs[i] & zero_mask[i]) /* check if bits are cleared */
143                         return -ENODEV;
144         }
145
146         return 0;
147 }
148
149 static int isl1208_i2c_get_sr(struct i2c_client *client)
150 {
151         return i2c_smbus_read_byte_data(client, ISL1208_REG_SR) == -1 ? -EIO:0;
152 }
153
154 static int isl1208_i2c_get_atr(struct i2c_client *client)
155 {
156         int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR);
157
158         if (atr < 0)
159                 return -EIO;
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 isl1208_i2c_get_dtr(struct i2c_client *client)
180 {
181         int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR);
182
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 isl1208_i2c_get_usr(struct i2c_client *client)
193 {
194         u8 buf[ISL1208_USR_SECTION_LEN] = { 0, };
195         int ret;
196
197         ret = isl1208_i2c_read_regs (client, ISL1208_REG_USR1, buf,
198                                    ISL1208_USR_SECTION_LEN);
199         if (ret < 0)
200                 return ret;
201
202         return (buf[1] << 8) | buf[0];
203 }
204
205 static int isl1208_i2c_set_usr(struct i2c_client *client, u16 usr)
206 {
207         u8 buf[ISL1208_USR_SECTION_LEN];
208
209         buf[0] = usr & 0xff;
210         buf[1] = (usr >> 8) & 0xff;
211
212         return isl1208_i2c_set_regs (client, ISL1208_REG_USR1, buf,
213                                      ISL1208_USR_SECTION_LEN);
214 }
215
216 static int isl1208_rtc_proc(struct device *dev, struct seq_file *seq)
217 {
218         struct i2c_client *const client = to_i2c_client(dev);
219         int sr, dtr, atr, usr;
220
221         sr = isl1208_i2c_get_sr(client);
222         if (sr < 0) {
223                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
224                 return sr;
225         }
226
227         seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n",
228                    (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "",
229                    (sr & ISL1208_REG_SR_BAT) ? " BAT" : "",
230                    (sr & ISL1208_REG_SR_ALM) ? " ALM" : "",
231                    (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "",
232                    (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "",
233                    (sr & ISL1208_REG_SR_ARST) ? " ARST" : "",
234                    sr);
235
236         seq_printf(seq, "batt_status\t: %s\n",
237                    (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay");
238
239         dtr = isl1208_i2c_get_dtr(client);
240         if (dtr >= 0 -1)
241                 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr);
242
243         atr = isl1208_i2c_get_atr(client);
244         if (atr >= 0)
245                 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n",
246                            atr>>2, (atr&0x3)*25);
247
248         usr = isl1208_i2c_get_usr(client);
249         if (usr >= 0)
250                 seq_printf(seq, "user_data\t: 0x%.4x\n", usr);
251
252         return 0;
253 }
254
255
256 static int isl1208_i2c_read_time(struct i2c_client *client,
257                                  struct rtc_time *tm)
258 {
259         int sr;
260         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
261
262         sr = isl1208_i2c_get_sr(client);
263         if (sr < 0) {
264                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
265                 return -EIO;
266         }
267
268         sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
269         if (sr < 0) {
270                 dev_err(&client->dev, "%s: reading RTC section failed\n",
271                         __func__);
272                 return sr;
273         }
274
275         tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]);
276         tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]);
277         { /* HR field has a more complex interpretation */
278                 const u8 _hr = regs[ISL1208_REG_HR];
279                 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */
280                         tm->tm_hour = BCD2BIN(_hr & 0x3f);
281                 else { // 12h format
282                         tm->tm_hour = BCD2BIN(_hr & 0x1f);
283                         if (_hr & ISL1208_REG_HR_PM) /* PM flag set */
284                                 tm->tm_hour += 12;
285                 }
286         }
287
288         tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]);
289         tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */
290         tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100;
291         tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]);
292
293         return 0;
294 }
295
296 static int isl1208_i2c_read_alarm(struct i2c_client *client,
297                                   struct rtc_wkalrm *alarm)
298 {
299         struct rtc_time *const tm = &alarm->time;
300         u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, };
301         int sr;
302
303         sr = isl1208_i2c_get_sr(client);
304         if (sr < 0) {
305                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
306                 return sr;
307         }
308
309         sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs,
310                                   ISL1208_ALARM_SECTION_LEN);
311         if (sr < 0) {
312                 dev_err(&client->dev, "%s: reading alarm section failed\n",
313                         __func__);
314                 return sr;
315         }
316
317         /* MSB of each alarm register is an enable bit */
318         tm->tm_sec  = BCD2BIN(regs[ISL1208_REG_SCA-ISL1208_REG_SCA] & 0x7f);
319         tm->tm_min  = BCD2BIN(regs[ISL1208_REG_MNA-ISL1208_REG_SCA] & 0x7f);
320         tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA-ISL1208_REG_SCA] & 0x3f);
321         tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA-ISL1208_REG_SCA] & 0x3f);
322         tm->tm_mon  = BCD2BIN(regs[ISL1208_REG_MOA-ISL1208_REG_SCA] & 0x1f)-1;
323         tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA-ISL1208_REG_SCA] & 0x03);
324
325         return 0;
326 }
327
328 static int isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm)
329 {
330         return isl1208_i2c_read_time(to_i2c_client(dev), tm);
331 }
332
333 static int isl1208_i2c_set_time(struct i2c_client *client,
334                                 struct rtc_time const *tm)
335 {
336         int sr;
337         u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, };
338
339         regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec);
340         regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min);
341         regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL;
342
343         regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday);
344         regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1);
345         regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100);
346
347         regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7);
348
349         sr = isl1208_i2c_get_sr(client);
350         if (sr < 0) {
351                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
352                 return sr;
353         }
354
355         /* set WRTC */
356         sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR,
357                                        sr | ISL1208_REG_SR_WRTC);
358         if (sr < 0) {
359                 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
360                 return sr;
361         }
362
363         /* write RTC registers */
364         sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN);
365         if (sr < 0) {
366                 dev_err(&client->dev, "%s: writing RTC section failed\n",
367                         __func__);
368                 return sr;
369         }
370
371         /* clear WRTC again */
372         sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR,
373                                        sr & ~ISL1208_REG_SR_WRTC);
374         if (sr < 0) {
375                 dev_err(&client->dev, "%s: writing SR failed\n", __func__);
376                 return sr;
377         }
378
379         return 0;
380 }
381
382
383 static int isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm)
384 {
385         return isl1208_i2c_set_time(to_i2c_client(dev), tm);
386 }
387
388 static int isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
389 {
390         return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm);
391 }
392
393 static const struct rtc_class_ops isl1208_rtc_ops = {
394         .proc           = isl1208_rtc_proc,
395         .read_time      = isl1208_rtc_read_time,
396         .set_time       = isl1208_rtc_set_time,
397         .read_alarm     = isl1208_rtc_read_alarm,
398         //.set_alarm    = isl1208_rtc_set_alarm,
399 };
400
401 /* sysfs interface */
402
403 static ssize_t isl1208_sysfs_show_atrim(struct device *dev,
404                                         struct device_attribute *attr,
405                                         char *buf)
406 {
407         int atr;
408
409         atr = isl1208_i2c_get_atr(to_i2c_client(dev));
410         if (atr < 0)
411                 return atr;
412
413         return sprintf(buf, "%d.%.2d pF\n", atr>>2, (atr&0x3)*25);
414 }
415 static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL);
416
417 static ssize_t isl1208_sysfs_show_dtrim(struct device *dev,
418                                         struct device_attribute *attr,
419                                         char *buf)
420 {
421         int dtr;
422
423         dtr = isl1208_i2c_get_dtr(to_i2c_client(dev));
424         if (dtr < 0)
425                 return dtr;
426
427         return sprintf(buf, "%d ppm\n", dtr);
428 }
429 static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL);
430
431 static ssize_t isl1208_sysfs_show_usr(struct device *dev,
432                                        struct device_attribute *attr,
433                                        char *buf)
434 {
435         int usr;
436
437         usr = isl1208_i2c_get_usr(to_i2c_client(dev));
438         if (usr < 0)
439                 return usr;
440
441         return sprintf(buf, "0x%.4x\n", usr);
442 }
443
444 static ssize_t isl1208_sysfs_store_usr(struct device *dev,
445                                        struct device_attribute *attr,
446                                        const char *buf, size_t count)
447 {
448         int usr = -1;
449
450         if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) {
451                 if (sscanf(buf, "%x", &usr) != 1)
452                         return -EINVAL;
453         } else {
454                 if (sscanf(buf, "%d", &usr) != 1)
455                         return -EINVAL;
456         }
457
458         if (usr < 0 || usr > 0xffff)
459                 return -EINVAL;
460
461         return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count;
462 }
463 static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr,
464                    isl1208_sysfs_store_usr);
465
466 static int
467 isl1208_probe(struct i2c_adapter *adapter, int addr, int kind)
468 {
469         int rc = 0;
470         struct i2c_client *new_client = NULL;
471         struct rtc_device *rtc = NULL;
472
473         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
474                 rc = -ENODEV;
475                 goto failout;
476         }
477
478         new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
479         if (new_client == NULL) {
480                 rc = -ENOMEM;
481                 goto failout;
482         }
483
484         new_client->addr = addr;
485         new_client->adapter = adapter;
486         new_client->driver = &isl1208_driver;
487         new_client->flags = 0;
488         strcpy(new_client->name, DRV_NAME);
489
490         if (kind < 0) {
491                 rc = isl1208_i2c_validate_client(new_client);
492                 if (rc < 0)
493                         goto failout;
494         }
495
496         rc = i2c_attach_client(new_client);
497         if (rc < 0)
498                 goto failout;
499
500         dev_info(&new_client->dev,
501                  "chip found, driver version " DRV_VERSION "\n");
502
503         rtc = rtc_device_register(isl1208_driver.driver.name,
504                                   &new_client->dev,
505                                   &isl1208_rtc_ops, THIS_MODULE);
506
507         if (IS_ERR(rtc)) {
508                 rc = PTR_ERR(rtc);
509                 goto failout_detach;
510         }
511
512         i2c_set_clientdata(new_client, rtc);
513
514         rc = isl1208_i2c_get_sr(new_client);
515         if (rc < 0) {
516                 dev_err(&new_client->dev, "reading status failed\n");
517                 goto failout_unregister;
518         }
519
520         if (rc & ISL1208_REG_SR_RTCF)
521                 dev_warn(&new_client->dev, "rtc power failure detected, "
522                          "please set clock.\n");
523
524         rc = device_create_file(&new_client->dev, &dev_attr_atrim);
525         if (rc < 0)
526                 goto failout_unregister;
527         rc = device_create_file(&new_client->dev, &dev_attr_dtrim);
528         if (rc < 0)
529                 goto failout_atrim;
530         rc = device_create_file(&new_client->dev, &dev_attr_usr);
531         if (rc < 0)
532                 goto failout_dtrim;
533
534         return 0;
535
536  failout_dtrim:
537         device_remove_file(&new_client->dev, &dev_attr_dtrim);
538  failout_atrim:
539         device_remove_file(&new_client->dev, &dev_attr_atrim);
540  failout_unregister:
541         rtc_device_unregister(rtc);
542  failout_detach:
543         i2c_detach_client(new_client);
544  failout:
545         kfree(new_client);
546         return rc;
547 }
548
549 static int
550 isl1208_attach_adapter (struct i2c_adapter *adapter)
551 {
552         return i2c_probe(adapter, &addr_data, isl1208_probe);
553 }
554
555 static int
556 isl1208_detach_client(struct i2c_client *client)
557 {
558         int rc;
559         struct rtc_device *const rtc = i2c_get_clientdata(client);
560
561         if (rtc)
562                 rtc_device_unregister(rtc); /* do we need to kfree? */
563
564         rc = i2c_detach_client(client);
565         if (rc)
566                 return rc;
567
568         kfree(client);
569
570         return 0;
571 }
572
573 /* module management */
574
575 static int __init isl1208_init(void)
576 {
577         return i2c_add_driver(&isl1208_driver);
578 }
579
580 static void __exit isl1208_exit(void)
581 {
582         i2c_del_driver(&isl1208_driver);
583 }
584
585 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
586 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver");
587 MODULE_LICENSE("GPL");
588 MODULE_VERSION(DRV_VERSION);
589
590 module_init(isl1208_init);
591 module_exit(isl1208_exit);