x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
[linux/fpc-iii.git] / drivers / rtc / rtc-pcf8563.c
bloba4b8b603c807da32671788d6d62edc860ccd6e39
1 /*
2 * An I2C driver for the Philips PCF8563 RTC
3 * Copyright 2005-06 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 * Maintainers: http://www.nslu2-linux.org/
8 * based on the other drivers in this same directory.
10 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
17 #include <linux/clk-provider.h>
18 #include <linux/i2c.h>
19 #include <linux/bcd.h>
20 #include <linux/rtc.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/err.h>
26 #define PCF8563_REG_ST1 0x00 /* status */
27 #define PCF8563_REG_ST2 0x01
28 #define PCF8563_BIT_AIE (1 << 1)
29 #define PCF8563_BIT_AF (1 << 3)
30 #define PCF8563_BITS_ST2_N (7 << 5)
32 #define PCF8563_REG_SC 0x02 /* datetime */
33 #define PCF8563_REG_MN 0x03
34 #define PCF8563_REG_HR 0x04
35 #define PCF8563_REG_DM 0x05
36 #define PCF8563_REG_DW 0x06
37 #define PCF8563_REG_MO 0x07
38 #define PCF8563_REG_YR 0x08
40 #define PCF8563_REG_AMN 0x09 /* alarm */
42 #define PCF8563_REG_CLKO 0x0D /* clock out */
43 #define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
44 #define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
45 #define PCF8563_REG_CLKO_F_32768HZ 0x00
46 #define PCF8563_REG_CLKO_F_1024HZ 0x01
47 #define PCF8563_REG_CLKO_F_32HZ 0x02
48 #define PCF8563_REG_CLKO_F_1HZ 0x03
50 #define PCF8563_REG_TMRC 0x0E /* timer control */
51 #define PCF8563_TMRC_ENABLE BIT(7)
52 #define PCF8563_TMRC_4096 0
53 #define PCF8563_TMRC_64 1
54 #define PCF8563_TMRC_1 2
55 #define PCF8563_TMRC_1_60 3
56 #define PCF8563_TMRC_MASK 3
58 #define PCF8563_REG_TMR 0x0F /* timer */
60 #define PCF8563_SC_LV 0x80 /* low voltage */
61 #define PCF8563_MO_C 0x80 /* century */
63 static struct i2c_driver pcf8563_driver;
65 struct pcf8563 {
66 struct rtc_device *rtc;
68 * The meaning of MO_C bit varies by the chip type.
69 * From PCF8563 datasheet: this bit is toggled when the years
70 * register overflows from 99 to 00
71 * 0 indicates the century is 20xx
72 * 1 indicates the century is 19xx
73 * From RTC8564 datasheet: this bit indicates change of
74 * century. When the year digit data overflows from 99 to 00,
75 * this bit is set. By presetting it to 0 while still in the
76 * 20th century, it will be set in year 2000, ...
77 * There seems no reliable way to know how the system use this
78 * bit. So let's do it heuristically, assuming we are live in
79 * 1970...2069.
81 int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
82 int voltage_low; /* incicates if a low_voltage was detected */
84 struct i2c_client *client;
85 #ifdef CONFIG_COMMON_CLK
86 struct clk_hw clkout_hw;
87 #endif
90 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
91 unsigned char length, unsigned char *buf)
93 struct i2c_msg msgs[] = {
94 {/* setup read ptr */
95 .addr = client->addr,
96 .len = 1,
97 .buf = &reg,
100 .addr = client->addr,
101 .flags = I2C_M_RD,
102 .len = length,
103 .buf = buf
107 if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
108 dev_err(&client->dev, "%s: read error\n", __func__);
109 return -EIO;
112 return 0;
115 static int pcf8563_write_block_data(struct i2c_client *client,
116 unsigned char reg, unsigned char length,
117 unsigned char *buf)
119 int i, err;
121 for (i = 0; i < length; i++) {
122 unsigned char data[2] = { reg + i, buf[i] };
124 err = i2c_master_send(client, data, sizeof(data));
125 if (err != sizeof(data)) {
126 dev_err(&client->dev,
127 "%s: err=%d addr=%02x, data=%02x\n",
128 __func__, err, data[0], data[1]);
129 return -EIO;
133 return 0;
136 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
138 unsigned char buf;
139 int err;
141 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
142 if (err < 0)
143 return err;
145 if (on)
146 buf |= PCF8563_BIT_AIE;
147 else
148 buf &= ~PCF8563_BIT_AIE;
150 buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
152 err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
153 if (err < 0) {
154 dev_err(&client->dev, "%s: write error\n", __func__);
155 return -EIO;
158 return 0;
161 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
162 unsigned char *pen)
164 unsigned char buf;
165 int err;
167 err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
168 if (err)
169 return err;
171 if (en)
172 *en = !!(buf & PCF8563_BIT_AIE);
173 if (pen)
174 *pen = !!(buf & PCF8563_BIT_AF);
176 return 0;
179 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
181 struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
182 int err;
183 char pending;
185 err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
186 if (err)
187 return IRQ_NONE;
189 if (pending) {
190 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
191 pcf8563_set_alarm_mode(pcf8563->client, 1);
192 return IRQ_HANDLED;
195 return IRQ_NONE;
199 * In the routines that deal directly with the pcf8563 hardware, we use
200 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
202 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
204 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
205 unsigned char buf[9];
206 int err;
208 err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
209 if (err)
210 return err;
212 if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
213 pcf8563->voltage_low = 1;
214 dev_err(&client->dev,
215 "low voltage detected, date/time is not reliable.\n");
216 return -EINVAL;
219 dev_dbg(&client->dev,
220 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
221 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
222 __func__,
223 buf[0], buf[1], buf[2], buf[3],
224 buf[4], buf[5], buf[6], buf[7],
225 buf[8]);
228 tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
229 tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
230 tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
231 tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
232 tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
233 tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
234 tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
235 if (tm->tm_year < 70)
236 tm->tm_year += 100; /* assume we are in 1970...2069 */
237 /* detect the polarity heuristically. see note above. */
238 pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
239 (tm->tm_year >= 100) : (tm->tm_year < 100);
241 dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
242 "mday=%d, mon=%d, year=%d, wday=%d\n",
243 __func__,
244 tm->tm_sec, tm->tm_min, tm->tm_hour,
245 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
247 return 0;
250 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
252 struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
253 unsigned char buf[9];
255 dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
256 "mday=%d, mon=%d, year=%d, wday=%d\n",
257 __func__,
258 tm->tm_sec, tm->tm_min, tm->tm_hour,
259 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
261 /* hours, minutes and seconds */
262 buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
263 buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
264 buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
266 buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
268 /* month, 1 - 12 */
269 buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
271 /* year and century */
272 buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
273 if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
274 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
276 buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
278 return pcf8563_write_block_data(client, PCF8563_REG_SC,
279 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
282 #ifdef CONFIG_RTC_INTF_DEV
283 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
285 struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
286 struct rtc_time tm;
288 switch (cmd) {
289 case RTC_VL_READ:
290 if (pcf8563->voltage_low)
291 dev_info(dev, "low voltage detected, date/time is not reliable.\n");
293 if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
294 sizeof(int)))
295 return -EFAULT;
296 return 0;
297 case RTC_VL_CLR:
299 * Clear the VL bit in the seconds register in case
300 * the time has not been set already (which would
301 * have cleared it). This does not really matter
302 * because of the cached voltage_low value but do it
303 * anyway for consistency.
305 if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
306 pcf8563_set_datetime(to_i2c_client(dev), &tm);
308 /* Clear the cached value. */
309 pcf8563->voltage_low = 0;
311 return 0;
312 default:
313 return -ENOIOCTLCMD;
316 #else
317 #define pcf8563_rtc_ioctl NULL
318 #endif
320 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
322 return pcf8563_get_datetime(to_i2c_client(dev), tm);
325 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
327 return pcf8563_set_datetime(to_i2c_client(dev), tm);
330 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
332 struct i2c_client *client = to_i2c_client(dev);
333 unsigned char buf[4];
334 int err;
336 err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
337 if (err)
338 return err;
340 dev_dbg(&client->dev,
341 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
342 __func__, buf[0], buf[1], buf[2], buf[3]);
344 tm->time.tm_sec = 0;
345 tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
346 tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
347 tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
348 tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
350 err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
351 if (err < 0)
352 return err;
354 dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
355 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
356 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
357 tm->enabled, tm->pending);
359 return 0;
362 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
364 struct i2c_client *client = to_i2c_client(dev);
365 unsigned char buf[4];
366 int err;
368 /* The alarm has no seconds, round up to nearest minute */
369 if (tm->time.tm_sec) {
370 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
372 alarm_time += 60 - tm->time.tm_sec;
373 rtc_time64_to_tm(alarm_time, &tm->time);
376 dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
377 "enabled=%d pending=%d\n", __func__,
378 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
379 tm->time.tm_mday, tm->enabled, tm->pending);
381 buf[0] = bin2bcd(tm->time.tm_min);
382 buf[1] = bin2bcd(tm->time.tm_hour);
383 buf[2] = bin2bcd(tm->time.tm_mday);
384 buf[3] = tm->time.tm_wday & 0x07;
386 err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
387 if (err)
388 return err;
390 return pcf8563_set_alarm_mode(client, 1);
393 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
395 dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
396 return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
399 #ifdef CONFIG_COMMON_CLK
401 * Handling of the clkout
404 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
406 static int clkout_rates[] = {
407 32768,
408 1024,
413 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
414 unsigned long parent_rate)
416 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
417 struct i2c_client *client = pcf8563->client;
418 unsigned char buf;
419 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
421 if (ret < 0)
422 return 0;
424 buf &= PCF8563_REG_CLKO_F_MASK;
425 return clkout_rates[buf];
428 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
429 unsigned long *prate)
431 int i;
433 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
434 if (clkout_rates[i] <= rate)
435 return clkout_rates[i];
437 return 0;
440 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
441 unsigned long parent_rate)
443 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
444 struct i2c_client *client = pcf8563->client;
445 unsigned char buf;
446 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
447 int i;
449 if (ret < 0)
450 return ret;
452 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
453 if (clkout_rates[i] == rate) {
454 buf &= ~PCF8563_REG_CLKO_F_MASK;
455 buf |= i;
456 ret = pcf8563_write_block_data(client,
457 PCF8563_REG_CLKO, 1,
458 &buf);
459 return ret;
462 return -EINVAL;
465 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
467 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
468 struct i2c_client *client = pcf8563->client;
469 unsigned char buf;
470 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
472 if (ret < 0)
473 return ret;
475 if (enable)
476 buf |= PCF8563_REG_CLKO_FE;
477 else
478 buf &= ~PCF8563_REG_CLKO_FE;
480 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
481 return ret;
484 static int pcf8563_clkout_prepare(struct clk_hw *hw)
486 return pcf8563_clkout_control(hw, 1);
489 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
491 pcf8563_clkout_control(hw, 0);
494 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
496 struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
497 struct i2c_client *client = pcf8563->client;
498 unsigned char buf;
499 int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
501 if (ret < 0)
502 return ret;
504 return !!(buf & PCF8563_REG_CLKO_FE);
507 static const struct clk_ops pcf8563_clkout_ops = {
508 .prepare = pcf8563_clkout_prepare,
509 .unprepare = pcf8563_clkout_unprepare,
510 .is_prepared = pcf8563_clkout_is_prepared,
511 .recalc_rate = pcf8563_clkout_recalc_rate,
512 .round_rate = pcf8563_clkout_round_rate,
513 .set_rate = pcf8563_clkout_set_rate,
516 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
518 struct i2c_client *client = pcf8563->client;
519 struct device_node *node = client->dev.of_node;
520 struct clk *clk;
521 struct clk_init_data init;
522 int ret;
523 unsigned char buf;
525 /* disable the clkout output */
526 buf = 0;
527 ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
528 if (ret < 0)
529 return ERR_PTR(ret);
531 init.name = "pcf8563-clkout";
532 init.ops = &pcf8563_clkout_ops;
533 init.flags = 0;
534 init.parent_names = NULL;
535 init.num_parents = 0;
536 pcf8563->clkout_hw.init = &init;
538 /* optional override of the clockname */
539 of_property_read_string(node, "clock-output-names", &init.name);
541 /* register the clock */
542 clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
544 if (!IS_ERR(clk))
545 of_clk_add_provider(node, of_clk_src_simple_get, clk);
547 return clk;
549 #endif
551 static const struct rtc_class_ops pcf8563_rtc_ops = {
552 .ioctl = pcf8563_rtc_ioctl,
553 .read_time = pcf8563_rtc_read_time,
554 .set_time = pcf8563_rtc_set_time,
555 .read_alarm = pcf8563_rtc_read_alarm,
556 .set_alarm = pcf8563_rtc_set_alarm,
557 .alarm_irq_enable = pcf8563_irq_enable,
560 static int pcf8563_probe(struct i2c_client *client,
561 const struct i2c_device_id *id)
563 struct pcf8563 *pcf8563;
564 int err;
565 unsigned char buf;
566 unsigned char alm_pending;
568 dev_dbg(&client->dev, "%s\n", __func__);
570 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
571 return -ENODEV;
573 pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
574 GFP_KERNEL);
575 if (!pcf8563)
576 return -ENOMEM;
578 i2c_set_clientdata(client, pcf8563);
579 pcf8563->client = client;
580 device_set_wakeup_capable(&client->dev, 1);
582 /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
583 buf = PCF8563_TMRC_1_60;
584 err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
585 if (err < 0) {
586 dev_err(&client->dev, "%s: write error\n", __func__);
587 return err;
590 err = pcf8563_get_alarm_mode(client, NULL, &alm_pending);
591 if (err) {
592 dev_err(&client->dev, "%s: read error\n", __func__);
593 return err;
595 if (alm_pending)
596 pcf8563_set_alarm_mode(client, 0);
598 pcf8563->rtc = devm_rtc_device_register(&client->dev,
599 pcf8563_driver.driver.name,
600 &pcf8563_rtc_ops, THIS_MODULE);
602 if (IS_ERR(pcf8563->rtc))
603 return PTR_ERR(pcf8563->rtc);
605 if (client->irq > 0) {
606 err = devm_request_threaded_irq(&client->dev, client->irq,
607 NULL, pcf8563_irq,
608 IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING,
609 pcf8563->rtc->name, client);
610 if (err) {
611 dev_err(&client->dev, "unable to request IRQ %d\n",
612 client->irq);
613 return err;
618 #ifdef CONFIG_COMMON_CLK
619 /* register clk in common clk framework */
620 pcf8563_clkout_register_clk(pcf8563);
621 #endif
623 /* the pcf8563 alarm only supports a minute accuracy */
624 pcf8563->rtc->uie_unsupported = 1;
626 return 0;
629 static const struct i2c_device_id pcf8563_id[] = {
630 { "pcf8563", 0 },
631 { "rtc8564", 0 },
634 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
636 #ifdef CONFIG_OF
637 static const struct of_device_id pcf8563_of_match[] = {
638 { .compatible = "nxp,pcf8563" },
641 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
642 #endif
644 static struct i2c_driver pcf8563_driver = {
645 .driver = {
646 .name = "rtc-pcf8563",
647 .of_match_table = of_match_ptr(pcf8563_of_match),
649 .probe = pcf8563_probe,
650 .id_table = pcf8563_id,
653 module_i2c_driver(pcf8563_driver);
655 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
656 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
657 MODULE_LICENSE("GPL");