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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
4  *
5  *  Copyright (C) 2005 James Chapman (ds1337 core)
6  *  Copyright (C) 2006 David Brownell
7  *  Copyright (C) 2009 Matthias Fuchs (rx8025 support)
8  *  Copyright (C) 2012 Bertrand Achard (nvram access fixes)
9  */
10 
11 #include <linux/acpi.h>
12 #include <linux/bcd.h>
13 #include <linux/i2c.h>
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/rtc/ds1307.h>
18 #include <linux/rtc.h>
19 #include <linux/slab.h>
20 #include <linux/string.h>
21 #include <linux/hwmon.h>
22 #include <linux/hwmon-sysfs.h>
23 #include <linux/clk-provider.h>
24 #include <linux/regmap.h>
25 #include <linux/watchdog.h>
26 
27 /*
28  * We can't determine type by probing, but if we expect pre-Linux code
29  * to have set the chip up as a clock (turning on the oscillator and
30  * setting the date and time), Linux can ignore the non-clock features.
31  * That's a natural job for a factory or repair bench.
32  */
33 enum ds_type {
34 	ds_1307,
35 	ds_1308,
36 	ds_1337,
37 	ds_1338,
38 	ds_1339,
39 	ds_1340,
40 	ds_1341,
41 	ds_1388,
42 	ds_3231,
43 	m41t0,
44 	m41t00,
45 	m41t11,
46 	mcp794xx,
47 	rx_8025,
48 	rx_8130,
49 	last_ds_type /* always last */
50 	/* rs5c372 too?  different address... */
51 };
52 
53 /* RTC registers don't differ much, except for the century flag */
54 #define DS1307_REG_SECS		0x00	/* 00-59 */
55 #	define DS1307_BIT_CH		0x80
56 #	define DS1340_BIT_nEOSC		0x80
57 #	define MCP794XX_BIT_ST		0x80
58 #define DS1307_REG_MIN		0x01	/* 00-59 */
59 #	define M41T0_BIT_OF		0x80
60 #define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */
61 #	define DS1307_BIT_12HR		0x40	/* in REG_HOUR */
62 #	define DS1307_BIT_PM		0x20	/* in REG_HOUR */
63 #	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
64 #	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
65 #define DS1307_REG_WDAY		0x03	/* 01-07 */
66 #	define MCP794XX_BIT_VBATEN	0x08
67 #define DS1307_REG_MDAY		0x04	/* 01-31 */
68 #define DS1307_REG_MONTH	0x05	/* 01-12 */
69 #	define DS1337_BIT_CENTURY	0x80	/* in REG_MONTH */
70 #define DS1307_REG_YEAR		0x06	/* 00-99 */
71 
72 /*
73  * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
74  * start at 7, and they differ a LOT. Only control and status matter for
75  * basic RTC date and time functionality; be careful using them.
76  */
77 #define DS1307_REG_CONTROL	0x07		/* or ds1338 */
78 #	define DS1307_BIT_OUT		0x80
79 #	define DS1338_BIT_OSF		0x20
80 #	define DS1307_BIT_SQWE		0x10
81 #	define DS1307_BIT_RS1		0x02
82 #	define DS1307_BIT_RS0		0x01
83 #define DS1337_REG_CONTROL	0x0e
84 #	define DS1337_BIT_nEOSC		0x80
85 #	define DS1339_BIT_BBSQI		0x20
86 #	define DS3231_BIT_BBSQW		0x40 /* same as BBSQI */
87 #	define DS1337_BIT_RS2		0x10
88 #	define DS1337_BIT_RS1		0x08
89 #	define DS1337_BIT_INTCN		0x04
90 #	define DS1337_BIT_A2IE		0x02
91 #	define DS1337_BIT_A1IE		0x01
92 #define DS1340_REG_CONTROL	0x07
93 #	define DS1340_BIT_OUT		0x80
94 #	define DS1340_BIT_FT		0x40
95 #	define DS1340_BIT_CALIB_SIGN	0x20
96 #	define DS1340_M_CALIBRATION	0x1f
97 #define DS1340_REG_FLAG		0x09
98 #	define DS1340_BIT_OSF		0x80
99 #define DS1337_REG_STATUS	0x0f
100 #	define DS1337_BIT_OSF		0x80
101 #	define DS3231_BIT_EN32KHZ	0x08
102 #	define DS1337_BIT_A2I		0x02
103 #	define DS1337_BIT_A1I		0x01
104 #define DS1339_REG_ALARM1_SECS	0x07
105 
106 #define DS13XX_TRICKLE_CHARGER_MAGIC	0xa0
107 
108 #define RX8025_REG_CTRL1	0x0e
109 #	define RX8025_BIT_2412		0x20
110 #define RX8025_REG_CTRL2	0x0f
111 #	define RX8025_BIT_PON		0x10
112 #	define RX8025_BIT_VDET		0x40
113 #	define RX8025_BIT_XST		0x20
114 
115 #define RX8130_REG_ALARM_MIN		0x17
116 #define RX8130_REG_ALARM_HOUR		0x18
117 #define RX8130_REG_ALARM_WEEK_OR_DAY	0x19
118 #define RX8130_REG_EXTENSION		0x1c
119 #define RX8130_REG_EXTENSION_WADA	BIT(3)
120 #define RX8130_REG_FLAG			0x1d
121 #define RX8130_REG_FLAG_VLF		BIT(1)
122 #define RX8130_REG_FLAG_AF		BIT(3)
123 #define RX8130_REG_CONTROL0		0x1e
124 #define RX8130_REG_CONTROL0_AIE		BIT(3)
125 #define RX8130_REG_CONTROL1		0x1f
126 #define RX8130_REG_CONTROL1_INIEN	BIT(4)
127 #define RX8130_REG_CONTROL1_CHGEN	BIT(5)
128 
129 #define MCP794XX_REG_CONTROL		0x07
130 #	define MCP794XX_BIT_ALM0_EN	0x10
131 #	define MCP794XX_BIT_ALM1_EN	0x20
132 #define MCP794XX_REG_ALARM0_BASE	0x0a
133 #define MCP794XX_REG_ALARM0_CTRL	0x0d
134 #define MCP794XX_REG_ALARM1_BASE	0x11
135 #define MCP794XX_REG_ALARM1_CTRL	0x14
136 #	define MCP794XX_BIT_ALMX_IF	BIT(3)
137 #	define MCP794XX_BIT_ALMX_C0	BIT(4)
138 #	define MCP794XX_BIT_ALMX_C1	BIT(5)
139 #	define MCP794XX_BIT_ALMX_C2	BIT(6)
140 #	define MCP794XX_BIT_ALMX_POL	BIT(7)
141 #	define MCP794XX_MSK_ALMX_MATCH	(MCP794XX_BIT_ALMX_C0 | \
142 					 MCP794XX_BIT_ALMX_C1 | \
143 					 MCP794XX_BIT_ALMX_C2)
144 
145 #define M41TXX_REG_CONTROL	0x07
146 #	define M41TXX_BIT_OUT		BIT(7)
147 #	define M41TXX_BIT_FT		BIT(6)
148 #	define M41TXX_BIT_CALIB_SIGN	BIT(5)
149 #	define M41TXX_M_CALIBRATION	GENMASK(4, 0)
150 
151 #define DS1388_REG_WDOG_HUN_SECS	0x08
152 #define DS1388_REG_WDOG_SECS		0x09
153 #define DS1388_REG_FLAG			0x0b
154 #	define DS1388_BIT_WF		BIT(6)
155 #	define DS1388_BIT_OSF		BIT(7)
156 #define DS1388_REG_CONTROL		0x0c
157 #	define DS1388_BIT_RST		BIT(0)
158 #	define DS1388_BIT_WDE		BIT(1)
159 #	define DS1388_BIT_nEOSC		BIT(7)
160 
161 /* negative offset step is -2.034ppm */
162 #define M41TXX_NEG_OFFSET_STEP_PPB	2034
163 /* positive offset step is +4.068ppm */
164 #define M41TXX_POS_OFFSET_STEP_PPB	4068
165 /* Min and max values supported with 'offset' interface by M41TXX */
166 #define M41TXX_MIN_OFFSET	((-31) * M41TXX_NEG_OFFSET_STEP_PPB)
167 #define M41TXX_MAX_OFFSET	((31) * M41TXX_POS_OFFSET_STEP_PPB)
168 
169 struct ds1307 {
170 	enum ds_type		type;
171 	unsigned long		flags;
172 #define HAS_NVRAM	0		/* bit 0 == sysfs file active */
173 #define HAS_ALARM	1		/* bit 1 == irq claimed */
174 	struct device		*dev;
175 	struct regmap		*regmap;
176 	const char		*name;
177 	struct rtc_device	*rtc;
178 #ifdef CONFIG_COMMON_CLK
179 	struct clk_hw		clks[2];
180 #endif
181 };
182 
183 struct chip_desc {
184 	unsigned		alarm:1;
185 	u16			nvram_offset;
186 	u16			nvram_size;
187 	u8			offset; /* register's offset */
188 	u8			century_reg;
189 	u8			century_enable_bit;
190 	u8			century_bit;
191 	u8			bbsqi_bit;
192 	irq_handler_t		irq_handler;
193 	const struct rtc_class_ops *rtc_ops;
194 	u16			trickle_charger_reg;
195 	u8			(*do_trickle_setup)(struct ds1307 *, u32,
196 						    bool);
197 	/* Does the RTC require trickle-resistor-ohms to select the value of
198 	 * the resistor between Vcc and Vbackup?
199 	 */
200 	bool			requires_trickle_resistor;
201 	/* Some RTC's batteries and supercaps were charged by default, others
202 	 * allow charging but were not configured previously to do so.
203 	 * Remember this behavior to stay backwards compatible.
204 	 */
205 	bool			charge_default;
206 };
207 
208 static const struct chip_desc chips[last_ds_type];
209 
ds1307_get_time(struct device * dev,struct rtc_time * t)210 static int ds1307_get_time(struct device *dev, struct rtc_time *t)
211 {
212 	struct ds1307	*ds1307 = dev_get_drvdata(dev);
213 	int		tmp, ret;
214 	const struct chip_desc *chip = &chips[ds1307->type];
215 	u8 regs[7];
216 
217 	if (ds1307->type == rx_8130) {
218 		unsigned int regflag;
219 		ret = regmap_read(ds1307->regmap, RX8130_REG_FLAG, &regflag);
220 		if (ret) {
221 			dev_err(dev, "%s error %d\n", "read", ret);
222 			return ret;
223 		}
224 
225 		if (regflag & RX8130_REG_FLAG_VLF) {
226 			dev_warn_once(dev, "oscillator failed, set time!\n");
227 			return -EINVAL;
228 		}
229 	}
230 
231 	/* read the RTC date and time registers all at once */
232 	ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
233 			       sizeof(regs));
234 	if (ret) {
235 		dev_err(dev, "%s error %d\n", "read", ret);
236 		return ret;
237 	}
238 
239 	dev_dbg(dev, "%s: %7ph\n", "read", regs);
240 
241 	/* if oscillator fail bit is set, no data can be trusted */
242 	if (ds1307->type == m41t0 &&
243 	    regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
244 		dev_warn_once(dev, "oscillator failed, set time!\n");
245 		return -EINVAL;
246 	}
247 
248 	tmp = regs[DS1307_REG_SECS];
249 	switch (ds1307->type) {
250 	case ds_1307:
251 	case m41t0:
252 	case m41t00:
253 	case m41t11:
254 		if (tmp & DS1307_BIT_CH)
255 			return -EINVAL;
256 		break;
257 	case ds_1308:
258 	case ds_1338:
259 		if (tmp & DS1307_BIT_CH)
260 			return -EINVAL;
261 
262 		ret = regmap_read(ds1307->regmap, DS1307_REG_CONTROL, &tmp);
263 		if (ret)
264 			return ret;
265 		if (tmp & DS1338_BIT_OSF)
266 			return -EINVAL;
267 		break;
268 	case ds_1340:
269 		if (tmp & DS1340_BIT_nEOSC)
270 			return -EINVAL;
271 
272 		ret = regmap_read(ds1307->regmap, DS1340_REG_FLAG, &tmp);
273 		if (ret)
274 			return ret;
275 		if (tmp & DS1340_BIT_OSF)
276 			return -EINVAL;
277 		break;
278 	case ds_1388:
279 		ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &tmp);
280 		if (ret)
281 			return ret;
282 		if (tmp & DS1388_BIT_OSF)
283 			return -EINVAL;
284 		break;
285 	case mcp794xx:
286 		if (!(tmp & MCP794XX_BIT_ST))
287 			return -EINVAL;
288 
289 		break;
290 	default:
291 		break;
292 	}
293 
294 	t->tm_sec = bcd2bin(regs[DS1307_REG_SECS] & 0x7f);
295 	t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f);
296 	tmp = regs[DS1307_REG_HOUR] & 0x3f;
297 	t->tm_hour = bcd2bin(tmp);
298 	/* rx8130 is bit position, not BCD */
299 	if (ds1307->type == rx_8130)
300 		t->tm_wday = fls(regs[DS1307_REG_WDAY] & 0x7f);
301 	else
302 		t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1;
303 	t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
304 	tmp = regs[DS1307_REG_MONTH] & 0x1f;
305 	t->tm_mon = bcd2bin(tmp) - 1;
306 	t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100;
307 
308 	if (regs[chip->century_reg] & chip->century_bit &&
309 	    IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
310 		t->tm_year += 100;
311 
312 	dev_dbg(dev, "%s secs=%d, mins=%d, "
313 		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
314 		"read", t->tm_sec, t->tm_min,
315 		t->tm_hour, t->tm_mday,
316 		t->tm_mon, t->tm_year, t->tm_wday);
317 
318 	return 0;
319 }
320 
ds1307_set_time(struct device * dev,struct rtc_time * t)321 static int ds1307_set_time(struct device *dev, struct rtc_time *t)
322 {
323 	struct ds1307	*ds1307 = dev_get_drvdata(dev);
324 	const struct chip_desc *chip = &chips[ds1307->type];
325 	int		result;
326 	int		tmp;
327 	u8		regs[7];
328 
329 	dev_dbg(dev, "%s secs=%d, mins=%d, "
330 		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
331 		"write", t->tm_sec, t->tm_min,
332 		t->tm_hour, t->tm_mday,
333 		t->tm_mon, t->tm_year, t->tm_wday);
334 
335 	if (t->tm_year < 100)
336 		return -EINVAL;
337 
338 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
339 	if (t->tm_year > (chip->century_bit ? 299 : 199))
340 		return -EINVAL;
341 #else
342 	if (t->tm_year > 199)
343 		return -EINVAL;
344 #endif
345 
346 	regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
347 	regs[DS1307_REG_MIN] = bin2bcd(t->tm_min);
348 	regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
349 	/* rx8130 is bit position, not BCD */
350 	if (ds1307->type == rx_8130)
351 		regs[DS1307_REG_WDAY] = 1 << t->tm_wday;
352 	else
353 		regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
354 	regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
355 	regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
356 
357 	/* assume 20YY not 19YY */
358 	tmp = t->tm_year - 100;
359 	regs[DS1307_REG_YEAR] = bin2bcd(tmp);
360 
361 	if (chip->century_enable_bit)
362 		regs[chip->century_reg] |= chip->century_enable_bit;
363 	if (t->tm_year > 199 && chip->century_bit)
364 		regs[chip->century_reg] |= chip->century_bit;
365 
366 	switch (ds1307->type) {
367 	case ds_1308:
368 	case ds_1338:
369 		regmap_update_bits(ds1307->regmap, DS1307_REG_CONTROL,
370 				   DS1338_BIT_OSF, 0);
371 		break;
372 	case ds_1340:
373 		regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG,
374 				   DS1340_BIT_OSF, 0);
375 		break;
376 	case ds_1388:
377 		regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
378 				   DS1388_BIT_OSF, 0);
379 		break;
380 	case mcp794xx:
381 		/*
382 		 * these bits were cleared when preparing the date/time
383 		 * values and need to be set again before writing the
384 		 * regsfer out to the device.
385 		 */
386 		regs[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
387 		regs[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
388 		break;
389 	default:
390 		break;
391 	}
392 
393 	dev_dbg(dev, "%s: %7ph\n", "write", regs);
394 
395 	result = regmap_bulk_write(ds1307->regmap, chip->offset, regs,
396 				   sizeof(regs));
397 	if (result) {
398 		dev_err(dev, "%s error %d\n", "write", result);
399 		return result;
400 	}
401 
402 	if (ds1307->type == rx_8130) {
403 		/* clear Voltage Loss Flag as data is available now */
404 		result = regmap_write(ds1307->regmap, RX8130_REG_FLAG,
405 				      ~(u8)RX8130_REG_FLAG_VLF);
406 		if (result) {
407 			dev_err(dev, "%s error %d\n", "write", result);
408 			return result;
409 		}
410 	}
411 
412 	return 0;
413 }
414 
ds1337_read_alarm(struct device * dev,struct rtc_wkalrm * t)415 static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
416 {
417 	struct ds1307		*ds1307 = dev_get_drvdata(dev);
418 	int			ret;
419 	u8			regs[9];
420 
421 	if (!test_bit(HAS_ALARM, &ds1307->flags))
422 		return -EINVAL;
423 
424 	/* read all ALARM1, ALARM2, and status registers at once */
425 	ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS,
426 			       regs, sizeof(regs));
427 	if (ret) {
428 		dev_err(dev, "%s error %d\n", "alarm read", ret);
429 		return ret;
430 	}
431 
432 	dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
433 		&regs[0], &regs[4], &regs[7]);
434 
435 	/*
436 	 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
437 	 * and that all four fields are checked matches
438 	 */
439 	t->time.tm_sec = bcd2bin(regs[0] & 0x7f);
440 	t->time.tm_min = bcd2bin(regs[1] & 0x7f);
441 	t->time.tm_hour = bcd2bin(regs[2] & 0x3f);
442 	t->time.tm_mday = bcd2bin(regs[3] & 0x3f);
443 
444 	/* ... and status */
445 	t->enabled = !!(regs[7] & DS1337_BIT_A1IE);
446 	t->pending = !!(regs[8] & DS1337_BIT_A1I);
447 
448 	dev_dbg(dev, "%s secs=%d, mins=%d, "
449 		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
450 		"alarm read", t->time.tm_sec, t->time.tm_min,
451 		t->time.tm_hour, t->time.tm_mday,
452 		t->enabled, t->pending);
453 
454 	return 0;
455 }
456 
ds1337_set_alarm(struct device * dev,struct rtc_wkalrm * t)457 static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
458 {
459 	struct ds1307		*ds1307 = dev_get_drvdata(dev);
460 	unsigned char		regs[9];
461 	u8			control, status;
462 	int			ret;
463 
464 	if (!test_bit(HAS_ALARM, &ds1307->flags))
465 		return -EINVAL;
466 
467 	dev_dbg(dev, "%s secs=%d, mins=%d, "
468 		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
469 		"alarm set", t->time.tm_sec, t->time.tm_min,
470 		t->time.tm_hour, t->time.tm_mday,
471 		t->enabled, t->pending);
472 
473 	/* read current status of both alarms and the chip */
474 	ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
475 			       sizeof(regs));
476 	if (ret) {
477 		dev_err(dev, "%s error %d\n", "alarm write", ret);
478 		return ret;
479 	}
480 	control = regs[7];
481 	status = regs[8];
482 
483 	dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
484 		&regs[0], &regs[4], control, status);
485 
486 	/* set ALARM1, using 24 hour and day-of-month modes */
487 	regs[0] = bin2bcd(t->time.tm_sec);
488 	regs[1] = bin2bcd(t->time.tm_min);
489 	regs[2] = bin2bcd(t->time.tm_hour);
490 	regs[3] = bin2bcd(t->time.tm_mday);
491 
492 	/* set ALARM2 to non-garbage */
493 	regs[4] = 0;
494 	regs[5] = 0;
495 	regs[6] = 0;
496 
497 	/* disable alarms */
498 	regs[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
499 	regs[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
500 
501 	ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs,
502 				sizeof(regs));
503 	if (ret) {
504 		dev_err(dev, "can't set alarm time\n");
505 		return ret;
506 	}
507 
508 	/* optionally enable ALARM1 */
509 	if (t->enabled) {
510 		dev_dbg(dev, "alarm IRQ armed\n");
511 		regs[7] |= DS1337_BIT_A1IE;	/* only ALARM1 is used */
512 		regmap_write(ds1307->regmap, DS1337_REG_CONTROL, regs[7]);
513 	}
514 
515 	return 0;
516 }
517 
ds1307_alarm_irq_enable(struct device * dev,unsigned int enabled)518 static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
519 {
520 	struct ds1307		*ds1307 = dev_get_drvdata(dev);
521 
522 	if (!test_bit(HAS_ALARM, &ds1307->flags))
523 		return -ENOTTY;
524 
525 	return regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
526 				  DS1337_BIT_A1IE,
527 				  enabled ? DS1337_BIT_A1IE : 0);
528 }
529 
do_trickle_setup_ds1339(struct ds1307 * ds1307,u32 ohms,bool diode)530 static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode)
531 {
532 	u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
533 		DS1307_TRICKLE_CHARGER_NO_DIODE;
534 
535 	setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
536 
537 	switch (ohms) {
538 	case 250:
539 		setup |= DS1307_TRICKLE_CHARGER_250_OHM;
540 		break;
541 	case 2000:
542 		setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
543 		break;
544 	case 4000:
545 		setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
546 		break;
547 	default:
548 		dev_warn(ds1307->dev,
549 			 "Unsupported ohm value %u in dt\n", ohms);
550 		return 0;
551 	}
552 	return setup;
553 }
554 
do_trickle_setup_rx8130(struct ds1307 * ds1307,u32 ohms,bool diode)555 static u8 do_trickle_setup_rx8130(struct ds1307 *ds1307, u32 ohms, bool diode)
556 {
557 	/* make sure that the backup battery is enabled */
558 	u8 setup = RX8130_REG_CONTROL1_INIEN;
559 	if (diode)
560 		setup |= RX8130_REG_CONTROL1_CHGEN;
561 
562 	return setup;
563 }
564 
rx8130_irq(int irq,void * dev_id)565 static irqreturn_t rx8130_irq(int irq, void *dev_id)
566 {
567 	struct ds1307           *ds1307 = dev_id;
568 	struct mutex            *lock = &ds1307->rtc->ops_lock;
569 	u8 ctl[3];
570 	int ret;
571 
572 	mutex_lock(lock);
573 
574 	/* Read control registers. */
575 	ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
576 			       sizeof(ctl));
577 	if (ret < 0)
578 		goto out;
579 	if (!(ctl[1] & RX8130_REG_FLAG_AF))
580 		goto out;
581 	ctl[1] &= ~RX8130_REG_FLAG_AF;
582 	ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
583 
584 	ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
585 				sizeof(ctl));
586 	if (ret < 0)
587 		goto out;
588 
589 	rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
590 
591 out:
592 	mutex_unlock(lock);
593 
594 	return IRQ_HANDLED;
595 }
596 
rx8130_read_alarm(struct device * dev,struct rtc_wkalrm * t)597 static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t)
598 {
599 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
600 	u8 ald[3], ctl[3];
601 	int ret;
602 
603 	if (!test_bit(HAS_ALARM, &ds1307->flags))
604 		return -EINVAL;
605 
606 	/* Read alarm registers. */
607 	ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
608 			       sizeof(ald));
609 	if (ret < 0)
610 		return ret;
611 
612 	/* Read control registers. */
613 	ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
614 			       sizeof(ctl));
615 	if (ret < 0)
616 		return ret;
617 
618 	t->enabled = !!(ctl[2] & RX8130_REG_CONTROL0_AIE);
619 	t->pending = !!(ctl[1] & RX8130_REG_FLAG_AF);
620 
621 	/* Report alarm 0 time assuming 24-hour and day-of-month modes. */
622 	t->time.tm_sec = -1;
623 	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
624 	t->time.tm_hour = bcd2bin(ald[1] & 0x7f);
625 	t->time.tm_wday = -1;
626 	t->time.tm_mday = bcd2bin(ald[2] & 0x7f);
627 	t->time.tm_mon = -1;
628 	t->time.tm_year = -1;
629 	t->time.tm_yday = -1;
630 	t->time.tm_isdst = -1;
631 
632 	dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n",
633 		__func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
634 		t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled);
635 
636 	return 0;
637 }
638 
rx8130_set_alarm(struct device * dev,struct rtc_wkalrm * t)639 static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t)
640 {
641 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
642 	u8 ald[3], ctl[3];
643 	int ret;
644 
645 	if (!test_bit(HAS_ALARM, &ds1307->flags))
646 		return -EINVAL;
647 
648 	dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
649 		"enabled=%d pending=%d\n", __func__,
650 		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
651 		t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
652 		t->enabled, t->pending);
653 
654 	/* Read control registers. */
655 	ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
656 			       sizeof(ctl));
657 	if (ret < 0)
658 		return ret;
659 
660 	ctl[0] &= RX8130_REG_EXTENSION_WADA;
661 	ctl[1] &= ~RX8130_REG_FLAG_AF;
662 	ctl[2] &= ~RX8130_REG_CONTROL0_AIE;
663 
664 	ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl,
665 				sizeof(ctl));
666 	if (ret < 0)
667 		return ret;
668 
669 	/* Hardware alarm precision is 1 minute! */
670 	ald[0] = bin2bcd(t->time.tm_min);
671 	ald[1] = bin2bcd(t->time.tm_hour);
672 	ald[2] = bin2bcd(t->time.tm_mday);
673 
674 	ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald,
675 				sizeof(ald));
676 	if (ret < 0)
677 		return ret;
678 
679 	if (!t->enabled)
680 		return 0;
681 
682 	ctl[2] |= RX8130_REG_CONTROL0_AIE;
683 
684 	return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, ctl[2]);
685 }
686 
rx8130_alarm_irq_enable(struct device * dev,unsigned int enabled)687 static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled)
688 {
689 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
690 	int ret, reg;
691 
692 	if (!test_bit(HAS_ALARM, &ds1307->flags))
693 		return -EINVAL;
694 
695 	ret = regmap_read(ds1307->regmap, RX8130_REG_CONTROL0, &reg);
696 	if (ret < 0)
697 		return ret;
698 
699 	if (enabled)
700 		reg |= RX8130_REG_CONTROL0_AIE;
701 	else
702 		reg &= ~RX8130_REG_CONTROL0_AIE;
703 
704 	return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, reg);
705 }
706 
mcp794xx_irq(int irq,void * dev_id)707 static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
708 {
709 	struct ds1307           *ds1307 = dev_id;
710 	struct mutex            *lock = &ds1307->rtc->ops_lock;
711 	int reg, ret;
712 
713 	mutex_lock(lock);
714 
715 	/* Check and clear alarm 0 interrupt flag. */
716 	ret = regmap_read(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, &reg);
717 	if (ret)
718 		goto out;
719 	if (!(reg & MCP794XX_BIT_ALMX_IF))
720 		goto out;
721 	reg &= ~MCP794XX_BIT_ALMX_IF;
722 	ret = regmap_write(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, reg);
723 	if (ret)
724 		goto out;
725 
726 	/* Disable alarm 0. */
727 	ret = regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
728 				 MCP794XX_BIT_ALM0_EN, 0);
729 	if (ret)
730 		goto out;
731 
732 	rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
733 
734 out:
735 	mutex_unlock(lock);
736 
737 	return IRQ_HANDLED;
738 }
739 
mcp794xx_read_alarm(struct device * dev,struct rtc_wkalrm * t)740 static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
741 {
742 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
743 	u8 regs[10];
744 	int ret;
745 
746 	if (!test_bit(HAS_ALARM, &ds1307->flags))
747 		return -EINVAL;
748 
749 	/* Read control and alarm 0 registers. */
750 	ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
751 			       sizeof(regs));
752 	if (ret)
753 		return ret;
754 
755 	t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
756 
757 	/* Report alarm 0 time assuming 24-hour and day-of-month modes. */
758 	t->time.tm_sec = bcd2bin(regs[3] & 0x7f);
759 	t->time.tm_min = bcd2bin(regs[4] & 0x7f);
760 	t->time.tm_hour = bcd2bin(regs[5] & 0x3f);
761 	t->time.tm_wday = bcd2bin(regs[6] & 0x7) - 1;
762 	t->time.tm_mday = bcd2bin(regs[7] & 0x3f);
763 	t->time.tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
764 	t->time.tm_year = -1;
765 	t->time.tm_yday = -1;
766 	t->time.tm_isdst = -1;
767 
768 	dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
769 		"enabled=%d polarity=%d irq=%d match=%lu\n", __func__,
770 		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
771 		t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
772 		!!(regs[6] & MCP794XX_BIT_ALMX_POL),
773 		!!(regs[6] & MCP794XX_BIT_ALMX_IF),
774 		(regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
775 
776 	return 0;
777 }
778 
779 /*
780  * We may have a random RTC weekday, therefore calculate alarm weekday based
781  * on current weekday we read from the RTC timekeeping regs
782  */
mcp794xx_alm_weekday(struct device * dev,struct rtc_time * tm_alarm)783 static int mcp794xx_alm_weekday(struct device *dev, struct rtc_time *tm_alarm)
784 {
785 	struct rtc_time tm_now;
786 	int days_now, days_alarm, ret;
787 
788 	ret = ds1307_get_time(dev, &tm_now);
789 	if (ret)
790 		return ret;
791 
792 	days_now = div_s64(rtc_tm_to_time64(&tm_now), 24 * 60 * 60);
793 	days_alarm = div_s64(rtc_tm_to_time64(tm_alarm), 24 * 60 * 60);
794 
795 	return (tm_now.tm_wday + days_alarm - days_now) % 7 + 1;
796 }
797 
mcp794xx_set_alarm(struct device * dev,struct rtc_wkalrm * t)798 static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
799 {
800 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
801 	unsigned char regs[10];
802 	int wday, ret;
803 
804 	if (!test_bit(HAS_ALARM, &ds1307->flags))
805 		return -EINVAL;
806 
807 	wday = mcp794xx_alm_weekday(dev, &t->time);
808 	if (wday < 0)
809 		return wday;
810 
811 	dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
812 		"enabled=%d pending=%d\n", __func__,
813 		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
814 		t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
815 		t->enabled, t->pending);
816 
817 	/* Read control and alarm 0 registers. */
818 	ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
819 			       sizeof(regs));
820 	if (ret)
821 		return ret;
822 
823 	/* Set alarm 0, using 24-hour and day-of-month modes. */
824 	regs[3] = bin2bcd(t->time.tm_sec);
825 	regs[4] = bin2bcd(t->time.tm_min);
826 	regs[5] = bin2bcd(t->time.tm_hour);
827 	regs[6] = wday;
828 	regs[7] = bin2bcd(t->time.tm_mday);
829 	regs[8] = bin2bcd(t->time.tm_mon + 1);
830 
831 	/* Clear the alarm 0 interrupt flag. */
832 	regs[6] &= ~MCP794XX_BIT_ALMX_IF;
833 	/* Set alarm match: second, minute, hour, day, date, month. */
834 	regs[6] |= MCP794XX_MSK_ALMX_MATCH;
835 	/* Disable interrupt. We will not enable until completely programmed */
836 	regs[0] &= ~MCP794XX_BIT_ALM0_EN;
837 
838 	ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs,
839 				sizeof(regs));
840 	if (ret)
841 		return ret;
842 
843 	if (!t->enabled)
844 		return 0;
845 	regs[0] |= MCP794XX_BIT_ALM0_EN;
846 	return regmap_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs[0]);
847 }
848 
mcp794xx_alarm_irq_enable(struct device * dev,unsigned int enabled)849 static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
850 {
851 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
852 
853 	if (!test_bit(HAS_ALARM, &ds1307->flags))
854 		return -EINVAL;
855 
856 	return regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL,
857 				  MCP794XX_BIT_ALM0_EN,
858 				  enabled ? MCP794XX_BIT_ALM0_EN : 0);
859 }
860 
m41txx_rtc_read_offset(struct device * dev,long * offset)861 static int m41txx_rtc_read_offset(struct device *dev, long *offset)
862 {
863 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
864 	unsigned int ctrl_reg;
865 	u8 val;
866 
867 	regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg);
868 
869 	val = ctrl_reg & M41TXX_M_CALIBRATION;
870 
871 	/* check if positive */
872 	if (ctrl_reg & M41TXX_BIT_CALIB_SIGN)
873 		*offset = (val * M41TXX_POS_OFFSET_STEP_PPB);
874 	else
875 		*offset = -(val * M41TXX_NEG_OFFSET_STEP_PPB);
876 
877 	return 0;
878 }
879 
m41txx_rtc_set_offset(struct device * dev,long offset)880 static int m41txx_rtc_set_offset(struct device *dev, long offset)
881 {
882 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
883 	unsigned int ctrl_reg;
884 
885 	if ((offset < M41TXX_MIN_OFFSET) || (offset > M41TXX_MAX_OFFSET))
886 		return -ERANGE;
887 
888 	if (offset >= 0) {
889 		ctrl_reg = DIV_ROUND_CLOSEST(offset,
890 					     M41TXX_POS_OFFSET_STEP_PPB);
891 		ctrl_reg |= M41TXX_BIT_CALIB_SIGN;
892 	} else {
893 		ctrl_reg = DIV_ROUND_CLOSEST(abs(offset),
894 					     M41TXX_NEG_OFFSET_STEP_PPB);
895 	}
896 
897 	return regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL,
898 				  M41TXX_M_CALIBRATION | M41TXX_BIT_CALIB_SIGN,
899 				  ctrl_reg);
900 }
901 
902 #ifdef CONFIG_WATCHDOG_CORE
ds1388_wdt_start(struct watchdog_device * wdt_dev)903 static int ds1388_wdt_start(struct watchdog_device *wdt_dev)
904 {
905 	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
906 	u8 regs[2];
907 	int ret;
908 
909 	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG,
910 				 DS1388_BIT_WF, 0);
911 	if (ret)
912 		return ret;
913 
914 	ret = regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
915 				 DS1388_BIT_WDE | DS1388_BIT_RST, 0);
916 	if (ret)
917 		return ret;
918 
919 	/*
920 	 * watchdog timeouts are measured in seconds. So ignore hundredths of
921 	 * seconds field.
922 	 */
923 	regs[0] = 0;
924 	regs[1] = bin2bcd(wdt_dev->timeout);
925 
926 	ret = regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
927 				sizeof(regs));
928 	if (ret)
929 		return ret;
930 
931 	return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
932 				  DS1388_BIT_WDE | DS1388_BIT_RST,
933 				  DS1388_BIT_WDE | DS1388_BIT_RST);
934 }
935 
ds1388_wdt_stop(struct watchdog_device * wdt_dev)936 static int ds1388_wdt_stop(struct watchdog_device *wdt_dev)
937 {
938 	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
939 
940 	return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL,
941 				  DS1388_BIT_WDE | DS1388_BIT_RST, 0);
942 }
943 
ds1388_wdt_ping(struct watchdog_device * wdt_dev)944 static int ds1388_wdt_ping(struct watchdog_device *wdt_dev)
945 {
946 	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
947 	u8 regs[2];
948 
949 	return regmap_bulk_read(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
950 				sizeof(regs));
951 }
952 
ds1388_wdt_set_timeout(struct watchdog_device * wdt_dev,unsigned int val)953 static int ds1388_wdt_set_timeout(struct watchdog_device *wdt_dev,
954 				  unsigned int val)
955 {
956 	struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev);
957 	u8 regs[2];
958 
959 	wdt_dev->timeout = val;
960 	regs[0] = 0;
961 	regs[1] = bin2bcd(wdt_dev->timeout);
962 
963 	return regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs,
964 				 sizeof(regs));
965 }
966 #endif
967 
968 static const struct rtc_class_ops rx8130_rtc_ops = {
969 	.read_time      = ds1307_get_time,
970 	.set_time       = ds1307_set_time,
971 	.read_alarm     = rx8130_read_alarm,
972 	.set_alarm      = rx8130_set_alarm,
973 	.alarm_irq_enable = rx8130_alarm_irq_enable,
974 };
975 
976 static const struct rtc_class_ops mcp794xx_rtc_ops = {
977 	.read_time      = ds1307_get_time,
978 	.set_time       = ds1307_set_time,
979 	.read_alarm     = mcp794xx_read_alarm,
980 	.set_alarm      = mcp794xx_set_alarm,
981 	.alarm_irq_enable = mcp794xx_alarm_irq_enable,
982 };
983 
984 static const struct rtc_class_ops m41txx_rtc_ops = {
985 	.read_time      = ds1307_get_time,
986 	.set_time       = ds1307_set_time,
987 	.read_alarm	= ds1337_read_alarm,
988 	.set_alarm	= ds1337_set_alarm,
989 	.alarm_irq_enable = ds1307_alarm_irq_enable,
990 	.read_offset	= m41txx_rtc_read_offset,
991 	.set_offset	= m41txx_rtc_set_offset,
992 };
993 
994 static const struct chip_desc chips[last_ds_type] = {
995 	[ds_1307] = {
996 		.nvram_offset	= 8,
997 		.nvram_size	= 56,
998 	},
999 	[ds_1308] = {
1000 		.nvram_offset	= 8,
1001 		.nvram_size	= 56,
1002 	},
1003 	[ds_1337] = {
1004 		.alarm		= 1,
1005 		.century_reg	= DS1307_REG_MONTH,
1006 		.century_bit	= DS1337_BIT_CENTURY,
1007 	},
1008 	[ds_1338] = {
1009 		.nvram_offset	= 8,
1010 		.nvram_size	= 56,
1011 	},
1012 	[ds_1339] = {
1013 		.alarm		= 1,
1014 		.century_reg	= DS1307_REG_MONTH,
1015 		.century_bit	= DS1337_BIT_CENTURY,
1016 		.bbsqi_bit	= DS1339_BIT_BBSQI,
1017 		.trickle_charger_reg = 0x10,
1018 		.do_trickle_setup = &do_trickle_setup_ds1339,
1019 		.requires_trickle_resistor = true,
1020 		.charge_default = true,
1021 	},
1022 	[ds_1340] = {
1023 		.century_reg	= DS1307_REG_HOUR,
1024 		.century_enable_bit = DS1340_BIT_CENTURY_EN,
1025 		.century_bit	= DS1340_BIT_CENTURY,
1026 		.do_trickle_setup = &do_trickle_setup_ds1339,
1027 		.trickle_charger_reg = 0x08,
1028 		.requires_trickle_resistor = true,
1029 		.charge_default = true,
1030 	},
1031 	[ds_1341] = {
1032 		.century_reg	= DS1307_REG_MONTH,
1033 		.century_bit	= DS1337_BIT_CENTURY,
1034 	},
1035 	[ds_1388] = {
1036 		.offset		= 1,
1037 		.trickle_charger_reg = 0x0a,
1038 	},
1039 	[ds_3231] = {
1040 		.alarm		= 1,
1041 		.century_reg	= DS1307_REG_MONTH,
1042 		.century_bit	= DS1337_BIT_CENTURY,
1043 		.bbsqi_bit	= DS3231_BIT_BBSQW,
1044 	},
1045 	[rx_8130] = {
1046 		.alarm		= 1,
1047 		/* this is battery backed SRAM */
1048 		.nvram_offset	= 0x20,
1049 		.nvram_size	= 4,	/* 32bit (4 word x 8 bit) */
1050 		.offset		= 0x10,
1051 		.irq_handler = rx8130_irq,
1052 		.rtc_ops = &rx8130_rtc_ops,
1053 		.trickle_charger_reg = RX8130_REG_CONTROL1,
1054 		.do_trickle_setup = &do_trickle_setup_rx8130,
1055 	},
1056 	[m41t0] = {
1057 		.rtc_ops	= &m41txx_rtc_ops,
1058 	},
1059 	[m41t00] = {
1060 		.rtc_ops	= &m41txx_rtc_ops,
1061 	},
1062 	[m41t11] = {
1063 		/* this is battery backed SRAM */
1064 		.nvram_offset	= 8,
1065 		.nvram_size	= 56,
1066 		.rtc_ops	= &m41txx_rtc_ops,
1067 	},
1068 	[mcp794xx] = {
1069 		.alarm		= 1,
1070 		/* this is battery backed SRAM */
1071 		.nvram_offset	= 0x20,
1072 		.nvram_size	= 0x40,
1073 		.irq_handler = mcp794xx_irq,
1074 		.rtc_ops = &mcp794xx_rtc_ops,
1075 	},
1076 };
1077 
1078 static const struct i2c_device_id ds1307_id[] = {
1079 	{ "ds1307", ds_1307 },
1080 	{ "ds1308", ds_1308 },
1081 	{ "ds1337", ds_1337 },
1082 	{ "ds1338", ds_1338 },
1083 	{ "ds1339", ds_1339 },
1084 	{ "ds1388", ds_1388 },
1085 	{ "ds1340", ds_1340 },
1086 	{ "ds1341", ds_1341 },
1087 	{ "ds3231", ds_3231 },
1088 	{ "m41t0", m41t0 },
1089 	{ "m41t00", m41t00 },
1090 	{ "m41t11", m41t11 },
1091 	{ "mcp7940x", mcp794xx },
1092 	{ "mcp7941x", mcp794xx },
1093 	{ "pt7c4338", ds_1307 },
1094 	{ "rx8025", rx_8025 },
1095 	{ "isl12057", ds_1337 },
1096 	{ "rx8130", rx_8130 },
1097 	{ }
1098 };
1099 MODULE_DEVICE_TABLE(i2c, ds1307_id);
1100 
1101 #ifdef CONFIG_OF
1102 static const struct of_device_id ds1307_of_match[] = {
1103 	{
1104 		.compatible = "dallas,ds1307",
1105 		.data = (void *)ds_1307
1106 	},
1107 	{
1108 		.compatible = "dallas,ds1308",
1109 		.data = (void *)ds_1308
1110 	},
1111 	{
1112 		.compatible = "dallas,ds1337",
1113 		.data = (void *)ds_1337
1114 	},
1115 	{
1116 		.compatible = "dallas,ds1338",
1117 		.data = (void *)ds_1338
1118 	},
1119 	{
1120 		.compatible = "dallas,ds1339",
1121 		.data = (void *)ds_1339
1122 	},
1123 	{
1124 		.compatible = "dallas,ds1388",
1125 		.data = (void *)ds_1388
1126 	},
1127 	{
1128 		.compatible = "dallas,ds1340",
1129 		.data = (void *)ds_1340
1130 	},
1131 	{
1132 		.compatible = "dallas,ds1341",
1133 		.data = (void *)ds_1341
1134 	},
1135 	{
1136 		.compatible = "maxim,ds3231",
1137 		.data = (void *)ds_3231
1138 	},
1139 	{
1140 		.compatible = "st,m41t0",
1141 		.data = (void *)m41t0
1142 	},
1143 	{
1144 		.compatible = "st,m41t00",
1145 		.data = (void *)m41t00
1146 	},
1147 	{
1148 		.compatible = "st,m41t11",
1149 		.data = (void *)m41t11
1150 	},
1151 	{
1152 		.compatible = "microchip,mcp7940x",
1153 		.data = (void *)mcp794xx
1154 	},
1155 	{
1156 		.compatible = "microchip,mcp7941x",
1157 		.data = (void *)mcp794xx
1158 	},
1159 	{
1160 		.compatible = "pericom,pt7c4338",
1161 		.data = (void *)ds_1307
1162 	},
1163 	{
1164 		.compatible = "epson,rx8025",
1165 		.data = (void *)rx_8025
1166 	},
1167 	{
1168 		.compatible = "isil,isl12057",
1169 		.data = (void *)ds_1337
1170 	},
1171 	{
1172 		.compatible = "epson,rx8130",
1173 		.data = (void *)rx_8130
1174 	},
1175 	{ }
1176 };
1177 MODULE_DEVICE_TABLE(of, ds1307_of_match);
1178 #endif
1179 
1180 #ifdef CONFIG_ACPI
1181 static const struct acpi_device_id ds1307_acpi_ids[] = {
1182 	{ .id = "DS1307", .driver_data = ds_1307 },
1183 	{ .id = "DS1308", .driver_data = ds_1308 },
1184 	{ .id = "DS1337", .driver_data = ds_1337 },
1185 	{ .id = "DS1338", .driver_data = ds_1338 },
1186 	{ .id = "DS1339", .driver_data = ds_1339 },
1187 	{ .id = "DS1388", .driver_data = ds_1388 },
1188 	{ .id = "DS1340", .driver_data = ds_1340 },
1189 	{ .id = "DS1341", .driver_data = ds_1341 },
1190 	{ .id = "DS3231", .driver_data = ds_3231 },
1191 	{ .id = "M41T0", .driver_data = m41t0 },
1192 	{ .id = "M41T00", .driver_data = m41t00 },
1193 	{ .id = "M41T11", .driver_data = m41t11 },
1194 	{ .id = "MCP7940X", .driver_data = mcp794xx },
1195 	{ .id = "MCP7941X", .driver_data = mcp794xx },
1196 	{ .id = "PT7C4338", .driver_data = ds_1307 },
1197 	{ .id = "RX8025", .driver_data = rx_8025 },
1198 	{ .id = "ISL12057", .driver_data = ds_1337 },
1199 	{ .id = "RX8130", .driver_data = rx_8130 },
1200 	{ }
1201 };
1202 MODULE_DEVICE_TABLE(acpi, ds1307_acpi_ids);
1203 #endif
1204 
1205 /*
1206  * The ds1337 and ds1339 both have two alarms, but we only use the first
1207  * one (with a "seconds" field).  For ds1337 we expect nINTA is our alarm
1208  * signal; ds1339 chips have only one alarm signal.
1209  */
ds1307_irq(int irq,void * dev_id)1210 static irqreturn_t ds1307_irq(int irq, void *dev_id)
1211 {
1212 	struct ds1307		*ds1307 = dev_id;
1213 	struct mutex		*lock = &ds1307->rtc->ops_lock;
1214 	int			stat, ret;
1215 
1216 	mutex_lock(lock);
1217 	ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &stat);
1218 	if (ret)
1219 		goto out;
1220 
1221 	if (stat & DS1337_BIT_A1I) {
1222 		stat &= ~DS1337_BIT_A1I;
1223 		regmap_write(ds1307->regmap, DS1337_REG_STATUS, stat);
1224 
1225 		ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1226 					 DS1337_BIT_A1IE, 0);
1227 		if (ret)
1228 			goto out;
1229 
1230 		rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
1231 	}
1232 
1233 out:
1234 	mutex_unlock(lock);
1235 
1236 	return IRQ_HANDLED;
1237 }
1238 
1239 /*----------------------------------------------------------------------*/
1240 
1241 static const struct rtc_class_ops ds13xx_rtc_ops = {
1242 	.read_time	= ds1307_get_time,
1243 	.set_time	= ds1307_set_time,
1244 	.read_alarm	= ds1337_read_alarm,
1245 	.set_alarm	= ds1337_set_alarm,
1246 	.alarm_irq_enable = ds1307_alarm_irq_enable,
1247 };
1248 
frequency_test_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1249 static ssize_t frequency_test_store(struct device *dev,
1250 				    struct device_attribute *attr,
1251 				    const char *buf, size_t count)
1252 {
1253 	struct ds1307 *ds1307 = dev_get_drvdata(dev->parent);
1254 	bool freq_test_en;
1255 	int ret;
1256 
1257 	ret = kstrtobool(buf, &freq_test_en);
1258 	if (ret) {
1259 		dev_err(dev, "Failed to store RTC Frequency Test attribute\n");
1260 		return ret;
1261 	}
1262 
1263 	regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL, M41TXX_BIT_FT,
1264 			   freq_test_en ? M41TXX_BIT_FT : 0);
1265 
1266 	return count;
1267 }
1268 
frequency_test_show(struct device * dev,struct device_attribute * attr,char * buf)1269 static ssize_t frequency_test_show(struct device *dev,
1270 				   struct device_attribute *attr,
1271 				   char *buf)
1272 {
1273 	struct ds1307 *ds1307 = dev_get_drvdata(dev->parent);
1274 	unsigned int ctrl_reg;
1275 
1276 	regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg);
1277 
1278 	return scnprintf(buf, PAGE_SIZE, (ctrl_reg & M41TXX_BIT_FT) ? "on\n" :
1279 			"off\n");
1280 }
1281 
1282 static DEVICE_ATTR_RW(frequency_test);
1283 
1284 static struct attribute *rtc_freq_test_attrs[] = {
1285 	&dev_attr_frequency_test.attr,
1286 	NULL,
1287 };
1288 
1289 static const struct attribute_group rtc_freq_test_attr_group = {
1290 	.attrs		= rtc_freq_test_attrs,
1291 };
1292 
ds1307_add_frequency_test(struct ds1307 * ds1307)1293 static int ds1307_add_frequency_test(struct ds1307 *ds1307)
1294 {
1295 	int err;
1296 
1297 	switch (ds1307->type) {
1298 	case m41t0:
1299 	case m41t00:
1300 	case m41t11:
1301 		err = rtc_add_group(ds1307->rtc, &rtc_freq_test_attr_group);
1302 		if (err)
1303 			return err;
1304 		break;
1305 	default:
1306 		break;
1307 	}
1308 
1309 	return 0;
1310 }
1311 
1312 /*----------------------------------------------------------------------*/
1313 
ds1307_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)1314 static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
1315 			     size_t bytes)
1316 {
1317 	struct ds1307 *ds1307 = priv;
1318 	const struct chip_desc *chip = &chips[ds1307->type];
1319 
1320 	return regmap_bulk_read(ds1307->regmap, chip->nvram_offset + offset,
1321 				val, bytes);
1322 }
1323 
ds1307_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)1324 static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
1325 			      size_t bytes)
1326 {
1327 	struct ds1307 *ds1307 = priv;
1328 	const struct chip_desc *chip = &chips[ds1307->type];
1329 
1330 	return regmap_bulk_write(ds1307->regmap, chip->nvram_offset + offset,
1331 				 val, bytes);
1332 }
1333 
1334 /*----------------------------------------------------------------------*/
1335 
ds1307_trickle_init(struct ds1307 * ds1307,const struct chip_desc * chip)1336 static u8 ds1307_trickle_init(struct ds1307 *ds1307,
1337 			      const struct chip_desc *chip)
1338 {
1339 	u32 ohms, chargeable;
1340 	bool diode = chip->charge_default;
1341 
1342 	if (!chip->do_trickle_setup)
1343 		return 0;
1344 
1345 	if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
1346 				     &ohms) && chip->requires_trickle_resistor)
1347 		return 0;
1348 
1349 	/* aux-voltage-chargeable takes precedence over the deprecated
1350 	 * trickle-diode-disable
1351 	 */
1352 	if (!device_property_read_u32(ds1307->dev, "aux-voltage-chargeable",
1353 				     &chargeable)) {
1354 		switch (chargeable) {
1355 		case 0:
1356 			diode = false;
1357 			break;
1358 		case 1:
1359 			diode = true;
1360 			break;
1361 		default:
1362 			dev_warn(ds1307->dev,
1363 				 "unsupported aux-voltage-chargeable value\n");
1364 			break;
1365 		}
1366 	} else if (device_property_read_bool(ds1307->dev,
1367 					     "trickle-diode-disable")) {
1368 		diode = false;
1369 	}
1370 
1371 	return chip->do_trickle_setup(ds1307, ohms, diode);
1372 }
1373 
1374 /*----------------------------------------------------------------------*/
1375 
1376 #if IS_REACHABLE(CONFIG_HWMON)
1377 
1378 /*
1379  * Temperature sensor support for ds3231 devices.
1380  */
1381 
1382 #define DS3231_REG_TEMPERATURE	0x11
1383 
1384 /*
1385  * A user-initiated temperature conversion is not started by this function,
1386  * so the temperature is updated once every 64 seconds.
1387  */
ds3231_hwmon_read_temp(struct device * dev,s32 * mC)1388 static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
1389 {
1390 	struct ds1307 *ds1307 = dev_get_drvdata(dev);
1391 	u8 temp_buf[2];
1392 	s16 temp;
1393 	int ret;
1394 
1395 	ret = regmap_bulk_read(ds1307->regmap, DS3231_REG_TEMPERATURE,
1396 			       temp_buf, sizeof(temp_buf));
1397 	if (ret)
1398 		return ret;
1399 	/*
1400 	 * Temperature is represented as a 10-bit code with a resolution of
1401 	 * 0.25 degree celsius and encoded in two's complement format.
1402 	 */
1403 	temp = (temp_buf[0] << 8) | temp_buf[1];
1404 	temp >>= 6;
1405 	*mC = temp * 250;
1406 
1407 	return 0;
1408 }
1409 
ds3231_hwmon_show_temp(struct device * dev,struct device_attribute * attr,char * buf)1410 static ssize_t ds3231_hwmon_show_temp(struct device *dev,
1411 				      struct device_attribute *attr, char *buf)
1412 {
1413 	int ret;
1414 	s32 temp;
1415 
1416 	ret = ds3231_hwmon_read_temp(dev, &temp);
1417 	if (ret)
1418 		return ret;
1419 
1420 	return sprintf(buf, "%d\n", temp);
1421 }
1422 static SENSOR_DEVICE_ATTR(temp1_input, 0444, ds3231_hwmon_show_temp,
1423 			  NULL, 0);
1424 
1425 static struct attribute *ds3231_hwmon_attrs[] = {
1426 	&sensor_dev_attr_temp1_input.dev_attr.attr,
1427 	NULL,
1428 };
1429 ATTRIBUTE_GROUPS(ds3231_hwmon);
1430 
ds1307_hwmon_register(struct ds1307 * ds1307)1431 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1432 {
1433 	struct device *dev;
1434 
1435 	if (ds1307->type != ds_3231)
1436 		return;
1437 
1438 	dev = devm_hwmon_device_register_with_groups(ds1307->dev, ds1307->name,
1439 						     ds1307,
1440 						     ds3231_hwmon_groups);
1441 	if (IS_ERR(dev)) {
1442 		dev_warn(ds1307->dev, "unable to register hwmon device %ld\n",
1443 			 PTR_ERR(dev));
1444 	}
1445 }
1446 
1447 #else
1448 
ds1307_hwmon_register(struct ds1307 * ds1307)1449 static void ds1307_hwmon_register(struct ds1307 *ds1307)
1450 {
1451 }
1452 
1453 #endif /* CONFIG_RTC_DRV_DS1307_HWMON */
1454 
1455 /*----------------------------------------------------------------------*/
1456 
1457 /*
1458  * Square-wave output support for DS3231
1459  * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1460  */
1461 #ifdef CONFIG_COMMON_CLK
1462 
1463 enum {
1464 	DS3231_CLK_SQW = 0,
1465 	DS3231_CLK_32KHZ,
1466 };
1467 
1468 #define clk_sqw_to_ds1307(clk)	\
1469 	container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1470 #define clk_32khz_to_ds1307(clk)	\
1471 	container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1472 
1473 static int ds3231_clk_sqw_rates[] = {
1474 	1,
1475 	1024,
1476 	4096,
1477 	8192,
1478 };
1479 
ds1337_write_control(struct ds1307 * ds1307,u8 mask,u8 value)1480 static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1481 {
1482 	struct mutex *lock = &ds1307->rtc->ops_lock;
1483 	int ret;
1484 
1485 	mutex_lock(lock);
1486 	ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL,
1487 				 mask, value);
1488 	mutex_unlock(lock);
1489 
1490 	return ret;
1491 }
1492 
ds3231_clk_sqw_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)1493 static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1494 						unsigned long parent_rate)
1495 {
1496 	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1497 	int control, ret;
1498 	int rate_sel = 0;
1499 
1500 	ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1501 	if (ret)
1502 		return ret;
1503 	if (control & DS1337_BIT_RS1)
1504 		rate_sel += 1;
1505 	if (control & DS1337_BIT_RS2)
1506 		rate_sel += 2;
1507 
1508 	return ds3231_clk_sqw_rates[rate_sel];
1509 }
1510 
ds3231_clk_sqw_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)1511 static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1512 				      unsigned long *prate)
1513 {
1514 	int i;
1515 
1516 	for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1517 		if (ds3231_clk_sqw_rates[i] <= rate)
1518 			return ds3231_clk_sqw_rates[i];
1519 	}
1520 
1521 	return 0;
1522 }
1523 
ds3231_clk_sqw_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)1524 static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1525 				   unsigned long parent_rate)
1526 {
1527 	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1528 	int control = 0;
1529 	int rate_sel;
1530 
1531 	for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1532 			rate_sel++) {
1533 		if (ds3231_clk_sqw_rates[rate_sel] == rate)
1534 			break;
1535 	}
1536 
1537 	if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1538 		return -EINVAL;
1539 
1540 	if (rate_sel & 1)
1541 		control |= DS1337_BIT_RS1;
1542 	if (rate_sel & 2)
1543 		control |= DS1337_BIT_RS2;
1544 
1545 	return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1546 				control);
1547 }
1548 
ds3231_clk_sqw_prepare(struct clk_hw * hw)1549 static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1550 {
1551 	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1552 
1553 	return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1554 }
1555 
ds3231_clk_sqw_unprepare(struct clk_hw * hw)1556 static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1557 {
1558 	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1559 
1560 	ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1561 }
1562 
ds3231_clk_sqw_is_prepared(struct clk_hw * hw)1563 static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1564 {
1565 	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1566 	int control, ret;
1567 
1568 	ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control);
1569 	if (ret)
1570 		return ret;
1571 
1572 	return !(control & DS1337_BIT_INTCN);
1573 }
1574 
1575 static const struct clk_ops ds3231_clk_sqw_ops = {
1576 	.prepare = ds3231_clk_sqw_prepare,
1577 	.unprepare = ds3231_clk_sqw_unprepare,
1578 	.is_prepared = ds3231_clk_sqw_is_prepared,
1579 	.recalc_rate = ds3231_clk_sqw_recalc_rate,
1580 	.round_rate = ds3231_clk_sqw_round_rate,
1581 	.set_rate = ds3231_clk_sqw_set_rate,
1582 };
1583 
ds3231_clk_32khz_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)1584 static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1585 						  unsigned long parent_rate)
1586 {
1587 	return 32768;
1588 }
1589 
ds3231_clk_32khz_control(struct ds1307 * ds1307,bool enable)1590 static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1591 {
1592 	struct mutex *lock = &ds1307->rtc->ops_lock;
1593 	int ret;
1594 
1595 	mutex_lock(lock);
1596 	ret = regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS,
1597 				 DS3231_BIT_EN32KHZ,
1598 				 enable ? DS3231_BIT_EN32KHZ : 0);
1599 	mutex_unlock(lock);
1600 
1601 	return ret;
1602 }
1603 
ds3231_clk_32khz_prepare(struct clk_hw * hw)1604 static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1605 {
1606 	struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1607 
1608 	return ds3231_clk_32khz_control(ds1307, true);
1609 }
1610 
ds3231_clk_32khz_unprepare(struct clk_hw * hw)1611 static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1612 {
1613 	struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1614 
1615 	ds3231_clk_32khz_control(ds1307, false);
1616 }
1617 
ds3231_clk_32khz_is_prepared(struct clk_hw * hw)1618 static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1619 {
1620 	struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1621 	int status, ret;
1622 
1623 	ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &status);
1624 	if (ret)
1625 		return ret;
1626 
1627 	return !!(status & DS3231_BIT_EN32KHZ);
1628 }
1629 
1630 static const struct clk_ops ds3231_clk_32khz_ops = {
1631 	.prepare = ds3231_clk_32khz_prepare,
1632 	.unprepare = ds3231_clk_32khz_unprepare,
1633 	.is_prepared = ds3231_clk_32khz_is_prepared,
1634 	.recalc_rate = ds3231_clk_32khz_recalc_rate,
1635 };
1636 
1637 static struct clk_init_data ds3231_clks_init[] = {
1638 	[DS3231_CLK_SQW] = {
1639 		.name = "ds3231_clk_sqw",
1640 		.ops = &ds3231_clk_sqw_ops,
1641 	},
1642 	[DS3231_CLK_32KHZ] = {
1643 		.name = "ds3231_clk_32khz",
1644 		.ops = &ds3231_clk_32khz_ops,
1645 	},
1646 };
1647 
ds3231_clks_register(struct ds1307 * ds1307)1648 static int ds3231_clks_register(struct ds1307 *ds1307)
1649 {
1650 	struct device_node *node = ds1307->dev->of_node;
1651 	struct clk_onecell_data	*onecell;
1652 	int i;
1653 
1654 	onecell = devm_kzalloc(ds1307->dev, sizeof(*onecell), GFP_KERNEL);
1655 	if (!onecell)
1656 		return -ENOMEM;
1657 
1658 	onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1659 	onecell->clks = devm_kcalloc(ds1307->dev, onecell->clk_num,
1660 				     sizeof(onecell->clks[0]), GFP_KERNEL);
1661 	if (!onecell->clks)
1662 		return -ENOMEM;
1663 
1664 	for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1665 		struct clk_init_data init = ds3231_clks_init[i];
1666 
1667 		/*
1668 		 * Interrupt signal due to alarm conditions and square-wave
1669 		 * output share same pin, so don't initialize both.
1670 		 */
1671 		if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1672 			continue;
1673 
1674 		/* optional override of the clockname */
1675 		of_property_read_string_index(node, "clock-output-names", i,
1676 					      &init.name);
1677 		ds1307->clks[i].init = &init;
1678 
1679 		onecell->clks[i] = devm_clk_register(ds1307->dev,
1680 						     &ds1307->clks[i]);
1681 		if (IS_ERR(onecell->clks[i]))
1682 			return PTR_ERR(onecell->clks[i]);
1683 	}
1684 
1685 	if (!node)
1686 		return 0;
1687 
1688 	of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1689 
1690 	return 0;
1691 }
1692 
ds1307_clks_register(struct ds1307 * ds1307)1693 static void ds1307_clks_register(struct ds1307 *ds1307)
1694 {
1695 	int ret;
1696 
1697 	if (ds1307->type != ds_3231)
1698 		return;
1699 
1700 	ret = ds3231_clks_register(ds1307);
1701 	if (ret) {
1702 		dev_warn(ds1307->dev, "unable to register clock device %d\n",
1703 			 ret);
1704 	}
1705 }
1706 
1707 #else
1708 
ds1307_clks_register(struct ds1307 * ds1307)1709 static void ds1307_clks_register(struct ds1307 *ds1307)
1710 {
1711 }
1712 
1713 #endif /* CONFIG_COMMON_CLK */
1714 
1715 #ifdef CONFIG_WATCHDOG_CORE
1716 static const struct watchdog_info ds1388_wdt_info = {
1717 	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
1718 	.identity = "DS1388 watchdog",
1719 };
1720 
1721 static const struct watchdog_ops ds1388_wdt_ops = {
1722 	.owner = THIS_MODULE,
1723 	.start = ds1388_wdt_start,
1724 	.stop = ds1388_wdt_stop,
1725 	.ping = ds1388_wdt_ping,
1726 	.set_timeout = ds1388_wdt_set_timeout,
1727 
1728 };
1729 
ds1307_wdt_register(struct ds1307 * ds1307)1730 static void ds1307_wdt_register(struct ds1307 *ds1307)
1731 {
1732 	struct watchdog_device	*wdt;
1733 	int err;
1734 	int val;
1735 
1736 	if (ds1307->type != ds_1388)
1737 		return;
1738 
1739 	wdt = devm_kzalloc(ds1307->dev, sizeof(*wdt), GFP_KERNEL);
1740 	if (!wdt)
1741 		return;
1742 
1743 	err = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &val);
1744 	if (!err && val & DS1388_BIT_WF)
1745 		wdt->bootstatus = WDIOF_CARDRESET;
1746 
1747 	wdt->info = &ds1388_wdt_info;
1748 	wdt->ops = &ds1388_wdt_ops;
1749 	wdt->timeout = 99;
1750 	wdt->max_timeout = 99;
1751 	wdt->min_timeout = 1;
1752 
1753 	watchdog_init_timeout(wdt, 0, ds1307->dev);
1754 	watchdog_set_drvdata(wdt, ds1307);
1755 	devm_watchdog_register_device(ds1307->dev, wdt);
1756 }
1757 #else
ds1307_wdt_register(struct ds1307 * ds1307)1758 static void ds1307_wdt_register(struct ds1307 *ds1307)
1759 {
1760 }
1761 #endif /* CONFIG_WATCHDOG_CORE */
1762 
1763 static const struct regmap_config regmap_config = {
1764 	.reg_bits = 8,
1765 	.val_bits = 8,
1766 };
1767 
ds1307_probe(struct i2c_client * client,const struct i2c_device_id * id)1768 static int ds1307_probe(struct i2c_client *client,
1769 			const struct i2c_device_id *id)
1770 {
1771 	struct ds1307		*ds1307;
1772 	int			err = -ENODEV;
1773 	int			tmp;
1774 	const struct chip_desc	*chip;
1775 	bool			want_irq;
1776 	bool			ds1307_can_wakeup_device = false;
1777 	unsigned char		regs[8];
1778 	struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1779 	u8			trickle_charger_setup = 0;
1780 
1781 	ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1782 	if (!ds1307)
1783 		return -ENOMEM;
1784 
1785 	dev_set_drvdata(&client->dev, ds1307);
1786 	ds1307->dev = &client->dev;
1787 	ds1307->name = client->name;
1788 
1789 	ds1307->regmap = devm_regmap_init_i2c(client, &regmap_config);
1790 	if (IS_ERR(ds1307->regmap)) {
1791 		dev_err(ds1307->dev, "regmap allocation failed\n");
1792 		return PTR_ERR(ds1307->regmap);
1793 	}
1794 
1795 	i2c_set_clientdata(client, ds1307);
1796 
1797 	if (client->dev.of_node) {
1798 		ds1307->type = (enum ds_type)
1799 			of_device_get_match_data(&client->dev);
1800 		chip = &chips[ds1307->type];
1801 	} else if (id) {
1802 		chip = &chips[id->driver_data];
1803 		ds1307->type = id->driver_data;
1804 	} else {
1805 		const struct acpi_device_id *acpi_id;
1806 
1807 		acpi_id = acpi_match_device(ACPI_PTR(ds1307_acpi_ids),
1808 					    ds1307->dev);
1809 		if (!acpi_id)
1810 			return -ENODEV;
1811 		chip = &chips[acpi_id->driver_data];
1812 		ds1307->type = acpi_id->driver_data;
1813 	}
1814 
1815 	want_irq = client->irq > 0 && chip->alarm;
1816 
1817 	if (!pdata)
1818 		trickle_charger_setup = ds1307_trickle_init(ds1307, chip);
1819 	else if (pdata->trickle_charger_setup)
1820 		trickle_charger_setup = pdata->trickle_charger_setup;
1821 
1822 	if (trickle_charger_setup && chip->trickle_charger_reg) {
1823 		dev_dbg(ds1307->dev,
1824 			"writing trickle charger info 0x%x to 0x%x\n",
1825 			trickle_charger_setup, chip->trickle_charger_reg);
1826 		regmap_write(ds1307->regmap, chip->trickle_charger_reg,
1827 			     trickle_charger_setup);
1828 	}
1829 
1830 #ifdef CONFIG_OF
1831 /*
1832  * For devices with no IRQ directly connected to the SoC, the RTC chip
1833  * can be forced as a wakeup source by stating that explicitly in
1834  * the device's .dts file using the "wakeup-source" boolean property.
1835  * If the "wakeup-source" property is set, don't request an IRQ.
1836  * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1837  * if supported by the RTC.
1838  */
1839 	if (chip->alarm && of_property_read_bool(client->dev.of_node,
1840 						 "wakeup-source"))
1841 		ds1307_can_wakeup_device = true;
1842 #endif
1843 
1844 	switch (ds1307->type) {
1845 	case ds_1337:
1846 	case ds_1339:
1847 	case ds_1341:
1848 	case ds_3231:
1849 		/* get registers that the "rtc" read below won't read... */
1850 		err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL,
1851 				       regs, 2);
1852 		if (err) {
1853 			dev_dbg(ds1307->dev, "read error %d\n", err);
1854 			goto exit;
1855 		}
1856 
1857 		/* oscillator off?  turn it on, so clock can tick. */
1858 		if (regs[0] & DS1337_BIT_nEOSC)
1859 			regs[0] &= ~DS1337_BIT_nEOSC;
1860 
1861 		/*
1862 		 * Using IRQ or defined as wakeup-source?
1863 		 * Disable the square wave and both alarms.
1864 		 * For some variants, be sure alarms can trigger when we're
1865 		 * running on Vbackup (BBSQI/BBSQW)
1866 		 */
1867 		if (want_irq || ds1307_can_wakeup_device) {
1868 			regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit;
1869 			regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1870 		}
1871 
1872 		regmap_write(ds1307->regmap, DS1337_REG_CONTROL,
1873 			     regs[0]);
1874 
1875 		/* oscillator fault?  clear flag, and warn */
1876 		if (regs[1] & DS1337_BIT_OSF) {
1877 			regmap_write(ds1307->regmap, DS1337_REG_STATUS,
1878 				     regs[1] & ~DS1337_BIT_OSF);
1879 			dev_warn(ds1307->dev, "SET TIME!\n");
1880 		}
1881 		break;
1882 
1883 	case rx_8025:
1884 		err = regmap_bulk_read(ds1307->regmap,
1885 				       RX8025_REG_CTRL1 << 4 | 0x08, regs, 2);
1886 		if (err) {
1887 			dev_dbg(ds1307->dev, "read error %d\n", err);
1888 			goto exit;
1889 		}
1890 
1891 		/* oscillator off?  turn it on, so clock can tick. */
1892 		if (!(regs[1] & RX8025_BIT_XST)) {
1893 			regs[1] |= RX8025_BIT_XST;
1894 			regmap_write(ds1307->regmap,
1895 				     RX8025_REG_CTRL2 << 4 | 0x08,
1896 				     regs[1]);
1897 			dev_warn(ds1307->dev,
1898 				 "oscillator stop detected - SET TIME!\n");
1899 		}
1900 
1901 		if (regs[1] & RX8025_BIT_PON) {
1902 			regs[1] &= ~RX8025_BIT_PON;
1903 			regmap_write(ds1307->regmap,
1904 				     RX8025_REG_CTRL2 << 4 | 0x08,
1905 				     regs[1]);
1906 			dev_warn(ds1307->dev, "power-on detected\n");
1907 		}
1908 
1909 		if (regs[1] & RX8025_BIT_VDET) {
1910 			regs[1] &= ~RX8025_BIT_VDET;
1911 			regmap_write(ds1307->regmap,
1912 				     RX8025_REG_CTRL2 << 4 | 0x08,
1913 				     regs[1]);
1914 			dev_warn(ds1307->dev, "voltage drop detected\n");
1915 		}
1916 
1917 		/* make sure we are running in 24hour mode */
1918 		if (!(regs[0] & RX8025_BIT_2412)) {
1919 			u8 hour;
1920 
1921 			/* switch to 24 hour mode */
1922 			regmap_write(ds1307->regmap,
1923 				     RX8025_REG_CTRL1 << 4 | 0x08,
1924 				     regs[0] | RX8025_BIT_2412);
1925 
1926 			err = regmap_bulk_read(ds1307->regmap,
1927 					       RX8025_REG_CTRL1 << 4 | 0x08,
1928 					       regs, 2);
1929 			if (err) {
1930 				dev_dbg(ds1307->dev, "read error %d\n", err);
1931 				goto exit;
1932 			}
1933 
1934 			/* correct hour */
1935 			hour = bcd2bin(regs[DS1307_REG_HOUR]);
1936 			if (hour == 12)
1937 				hour = 0;
1938 			if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1939 				hour += 12;
1940 
1941 			regmap_write(ds1307->regmap,
1942 				     DS1307_REG_HOUR << 4 | 0x08, hour);
1943 		}
1944 		break;
1945 	case ds_1388:
1946 		err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp);
1947 		if (err) {
1948 			dev_dbg(ds1307->dev, "read error %d\n", err);
1949 			goto exit;
1950 		}
1951 
1952 		/* oscillator off?  turn it on, so clock can tick. */
1953 		if (tmp & DS1388_BIT_nEOSC) {
1954 			tmp &= ~DS1388_BIT_nEOSC;
1955 			regmap_write(ds1307->regmap, DS1388_REG_CONTROL, tmp);
1956 		}
1957 		break;
1958 	default:
1959 		break;
1960 	}
1961 
1962 	/* read RTC registers */
1963 	err = regmap_bulk_read(ds1307->regmap, chip->offset, regs,
1964 			       sizeof(regs));
1965 	if (err) {
1966 		dev_dbg(ds1307->dev, "read error %d\n", err);
1967 		goto exit;
1968 	}
1969 
1970 	if (ds1307->type == mcp794xx &&
1971 	    !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1972 		regmap_write(ds1307->regmap, DS1307_REG_WDAY,
1973 			     regs[DS1307_REG_WDAY] |
1974 			     MCP794XX_BIT_VBATEN);
1975 	}
1976 
1977 	tmp = regs[DS1307_REG_HOUR];
1978 	switch (ds1307->type) {
1979 	case ds_1340:
1980 	case m41t0:
1981 	case m41t00:
1982 	case m41t11:
1983 		/*
1984 		 * NOTE: ignores century bits; fix before deploying
1985 		 * systems that will run through year 2100.
1986 		 */
1987 		break;
1988 	case rx_8025:
1989 		break;
1990 	default:
1991 		if (!(tmp & DS1307_BIT_12HR))
1992 			break;
1993 
1994 		/*
1995 		 * Be sure we're in 24 hour mode.  Multi-master systems
1996 		 * take note...
1997 		 */
1998 		tmp = bcd2bin(tmp & 0x1f);
1999 		if (tmp == 12)
2000 			tmp = 0;
2001 		if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
2002 			tmp += 12;
2003 		regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR,
2004 			     bin2bcd(tmp));
2005 	}
2006 
2007 	if (want_irq || ds1307_can_wakeup_device) {
2008 		device_set_wakeup_capable(ds1307->dev, true);
2009 		set_bit(HAS_ALARM, &ds1307->flags);
2010 	}
2011 
2012 	ds1307->rtc = devm_rtc_allocate_device(ds1307->dev);
2013 	if (IS_ERR(ds1307->rtc))
2014 		return PTR_ERR(ds1307->rtc);
2015 
2016 	if (ds1307_can_wakeup_device && !want_irq) {
2017 		dev_info(ds1307->dev,
2018 			 "'wakeup-source' is set, request for an IRQ is disabled!\n");
2019 		/* We cannot support UIE mode if we do not have an IRQ line */
2020 		ds1307->rtc->uie_unsupported = 1;
2021 	}
2022 
2023 	if (want_irq) {
2024 		err = devm_request_threaded_irq(ds1307->dev, client->irq, NULL,
2025 						chip->irq_handler ?: ds1307_irq,
2026 						IRQF_SHARED | IRQF_ONESHOT,
2027 						ds1307->name, ds1307);
2028 		if (err) {
2029 			client->irq = 0;
2030 			device_set_wakeup_capable(ds1307->dev, false);
2031 			clear_bit(HAS_ALARM, &ds1307->flags);
2032 			dev_err(ds1307->dev, "unable to request IRQ!\n");
2033 		} else {
2034 			dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq);
2035 		}
2036 	}
2037 
2038 	ds1307->rtc->ops = chip->rtc_ops ?: &ds13xx_rtc_ops;
2039 	err = ds1307_add_frequency_test(ds1307);
2040 	if (err)
2041 		return err;
2042 
2043 	err = rtc_register_device(ds1307->rtc);
2044 	if (err)
2045 		return err;
2046 
2047 	if (chip->nvram_size) {
2048 		struct nvmem_config nvmem_cfg = {
2049 			.name = "ds1307_nvram",
2050 			.word_size = 1,
2051 			.stride = 1,
2052 			.size = chip->nvram_size,
2053 			.reg_read = ds1307_nvram_read,
2054 			.reg_write = ds1307_nvram_write,
2055 			.priv = ds1307,
2056 		};
2057 
2058 		ds1307->rtc->nvram_old_abi = true;
2059 		rtc_nvmem_register(ds1307->rtc, &nvmem_cfg);
2060 	}
2061 
2062 	ds1307_hwmon_register(ds1307);
2063 	ds1307_clks_register(ds1307);
2064 	ds1307_wdt_register(ds1307);
2065 
2066 	return 0;
2067 
2068 exit:
2069 	return err;
2070 }
2071 
2072 static struct i2c_driver ds1307_driver = {
2073 	.driver = {
2074 		.name	= "rtc-ds1307",
2075 		.of_match_table = of_match_ptr(ds1307_of_match),
2076 		.acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
2077 	},
2078 	.probe		= ds1307_probe,
2079 	.id_table	= ds1307_id,
2080 };
2081 
2082 module_i2c_driver(ds1307_driver);
2083 
2084 MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
2085 MODULE_LICENSE("GPL");
2086