xref: /openbmc/linux/drivers/w1/slaves/w1_therm.c (revision 0df2a5e9)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	w1_therm.c
4  *
5  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
6  */
7 
8 #include <asm/types.h>
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/sched.h>
14 #include <linux/device.h>
15 #include <linux/types.h>
16 #include <linux/slab.h>
17 #include <linux/delay.h>
18 #include <linux/hwmon.h>
19 #include <linux/string.h>
20 #include <linux/jiffies.h>
21 
22 #include <linux/w1.h>
23 
24 #define W1_THERM_DS18S20	0x10
25 #define W1_THERM_DS1822		0x22
26 #define W1_THERM_DS18B20	0x28
27 #define W1_THERM_DS1825		0x3B
28 #define W1_THERM_DS28EA00	0x42
29 
30 /*
31  * Allow the strong pullup to be disabled, but default to enabled.
32  * If it was disabled a parasite powered device might not get the require
33  * current to do a temperature conversion.  If it is enabled parasite powered
34  * devices have a better chance of getting the current required.
35  * In case the parasite power-detection is not working (seems to be the case
36  * for some DS18S20) the strong pullup can also be forced, regardless of the
37  * power state of the devices.
38  *
39  * Summary of options:
40  * - strong_pullup = 0	Disable strong pullup completely
41  * - strong_pullup = 1	Enable automatic strong pullup detection
42  * - strong_pullup = 2	Force strong pullup
43  */
44 static int w1_strong_pullup = 1;
45 module_param_named(strong_pullup, w1_strong_pullup, int, 0);
46 
47 /* Counter for devices supporting bulk reading */
48 static u16 bulk_read_device_counter; /* =0 as per C standard */
49 
50 /* This command should be in public header w1.h but is not */
51 #define W1_RECALL_EEPROM	0xB8
52 
53 /* Nb of try for an operation */
54 #define W1_THERM_MAX_TRY		5
55 
56 /* ms delay to retry bus mutex */
57 #define W1_THERM_RETRY_DELAY		20
58 
59 /* delay in ms to write in EEPROM */
60 #define W1_THERM_EEPROM_WRITE_DELAY	10
61 
62 #define EEPROM_CMD_WRITE    "save"	/* cmd for write eeprom sysfs */
63 #define EEPROM_CMD_READ     "restore"	/* cmd for read eeprom sysfs */
64 #define BULK_TRIGGER_CMD    "trigger"	/* cmd to trigger a bulk read */
65 
66 #define MIN_TEMP	-55	/* min temperature that can be measured */
67 #define MAX_TEMP	125	/* max temperature that can be measured */
68 
69 /* Allowed values for sysfs conv_time attribute */
70 #define CONV_TIME_DEFAULT 0
71 #define CONV_TIME_MEASURE 1
72 
73 /* Bits in sysfs "features" value */
74 #define W1_THERM_CHECK_RESULT 1	/* Enable conversion success check */
75 #define W1_THERM_POLL_COMPLETION 2	/* Poll for conversion completion */
76 #define W1_THERM_FEATURES_MASK 3		/* All values mask */
77 
78 /* Poll period in milliseconds. Should be less then a shortest operation on the device */
79 #define W1_POLL_PERIOD 32
80 #define W1_POLL_CONVERT_TEMP 2000	/* Timeout for W1_CONVERT_TEMP, ms */
81 #define W1_POLL_RECALL_EEPROM 500	/* Timeout for W1_RECALL_EEPROM, ms*/
82 
83 /* Masks for resolution functions, work with all devices */
84 /* Bit mask for config register for all devices, bits 7,6,5 */
85 #define W1_THERM_RESOLUTION_MASK 0xE0
86 /* Bit offset of resolution in config register for all devices */
87 #define W1_THERM_RESOLUTION_SHIFT 5
88 /* Bit offset of resolution in config register for all devices */
89 #define W1_THERM_RESOLUTION_SHIFT 5
90 /* Add this to bit value to get resolution */
91 #define W1_THERM_RESOLUTION_MIN 9
92 /* Maximum allowed value */
93 #define W1_THERM_RESOLUTION_MAX 14
94 
95 /* Helpers Macros */
96 
97 /*
98  * return a pointer on the slave w1_therm_family_converter struct:
99  * always test family data existence before using this macro
100  */
101 #define SLAVE_SPECIFIC_FUNC(sl) \
102 	(((struct w1_therm_family_data *)(sl->family_data))->specific_functions)
103 
104 /*
105  * return the power mode of the sl slave : 1-ext, 0-parasite, <0 unknown
106  * always test family data existence before using this macro
107  */
108 #define SLAVE_POWERMODE(sl) \
109 	(((struct w1_therm_family_data *)(sl->family_data))->external_powered)
110 
111 /*
112  * return the resolution in bit of the sl slave : <0 unknown
113  * always test family data existence before using this macro
114  */
115 #define SLAVE_RESOLUTION(sl) \
116 	(((struct w1_therm_family_data *)(sl->family_data))->resolution)
117 
118 /*
119  * return the conv_time_override of the sl slave
120  * always test family data existence before using this macro
121  */
122  #define SLAVE_CONV_TIME_OVERRIDE(sl) \
123 	(((struct w1_therm_family_data *)(sl->family_data))->conv_time_override)
124 
125 /*
126  * return the features of the sl slave
127  * always test family data existence before using this macro
128  */
129  #define SLAVE_FEATURES(sl) \
130 	(((struct w1_therm_family_data *)(sl->family_data))->features)
131 
132 /*
133  * return whether or not a converT command has been issued to the slave
134  * * 0: no bulk read is pending
135  * * -1: conversion is in progress
136  * * 1: conversion done, result to be read
137  */
138 #define SLAVE_CONVERT_TRIGGERED(sl) \
139 	(((struct w1_therm_family_data *)(sl->family_data))->convert_triggered)
140 
141 /* return the address of the refcnt in the family data */
142 #define THERM_REFCNT(family_data) \
143 	(&((struct w1_therm_family_data *)family_data)->refcnt)
144 
145 /* Structs definition */
146 
147 /**
148  * struct w1_therm_family_converter - bind device specific functions
149  * @broken: flag for non-registred families
150  * @reserved: not used here
151  * @f: pointer to the device binding structure
152  * @convert: pointer to the device conversion function
153  * @get_conversion_time: pointer to the device conversion time function
154  * @set_resolution: pointer to the device set_resolution function
155  * @get_resolution: pointer to the device get_resolution function
156  * @write_data: pointer to the device writing function (2 or 3 bytes)
157  * @bulk_read: true if device family support bulk read, false otherwise
158  */
159 struct w1_therm_family_converter {
160 	u8		broken;
161 	u16		reserved;
162 	struct w1_family	*f;
163 	int		(*convert)(u8 rom[9]);
164 	int		(*get_conversion_time)(struct w1_slave *sl);
165 	int		(*set_resolution)(struct w1_slave *sl, int val);
166 	int		(*get_resolution)(struct w1_slave *sl);
167 	int		(*write_data)(struct w1_slave *sl, const u8 *data);
168 	bool		bulk_read;
169 };
170 
171 /**
172  * struct w1_therm_family_data - device data
173  * @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte)
174  * @refcnt: ref count
175  * @external_powered:	1 device powered externally,
176  *				0 device parasite powered,
177  *				-x error or undefined
178  * @resolution: current device resolution
179  * @convert_triggered: conversion state of the device
180  * @conv_time_override: user selected conversion time or CONV_TIME_DEFAULT
181  * @features: bit mask - enable temperature validity check, poll for completion
182  * @specific_functions: pointer to struct of device specific function
183  */
184 struct w1_therm_family_data {
185 	uint8_t rom[9];
186 	atomic_t refcnt;
187 	int external_powered;
188 	int resolution;
189 	int convert_triggered;
190 	int conv_time_override;
191 	unsigned int features;
192 	struct w1_therm_family_converter *specific_functions;
193 };
194 
195 /**
196  * struct therm_info - store temperature reading
197  * @rom: read device data (8 data bytes + 1 CRC byte)
198  * @crc: computed crc from rom
199  * @verdict: 1 crc checked, 0 crc not matching
200  */
201 struct therm_info {
202 	u8 rom[9];
203 	u8 crc;
204 	u8 verdict;
205 };
206 
207 /* Hardware Functions declaration */
208 
209 /**
210  * reset_select_slave() - reset and select a slave
211  * @sl: the slave to select
212  *
213  * Resets the bus and select the slave by sending a ROM MATCH cmd
214  * w1_reset_select_slave() from w1_io.c could not be used here because
215  * it sent a SKIP ROM command if only one device is on the line.
216  * At the beginning of the such process, sl->master->slave_count is 1 even if
217  * more devices are on the line, causing collision on the line.
218  *
219  * Context: The w1 master lock must be held.
220  *
221  * Return: 0 if success, negative kernel error code otherwise.
222  */
223 static int reset_select_slave(struct w1_slave *sl);
224 
225 /**
226  * convert_t() - Query the device for temperature conversion and read
227  * @sl: pointer to the slave to read
228  * @info: pointer to a structure to store the read results
229  *
230  * Return: 0 if success, -kernel error code otherwise
231  */
232 static int convert_t(struct w1_slave *sl, struct therm_info *info);
233 
234 /**
235  * read_scratchpad() - read the data in device RAM
236  * @sl: pointer to the slave to read
237  * @info: pointer to a structure to store the read results
238  *
239  * Return: 0 if success, -kernel error code otherwise
240  */
241 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info);
242 
243 /**
244  * write_scratchpad() - write nb_bytes in the device RAM
245  * @sl: pointer to the slave to write in
246  * @data: pointer to an array of 3 bytes, as 3 bytes MUST be written
247  * @nb_bytes: number of bytes to be written (2 for DS18S20, 3 otherwise)
248  *
249  * Return: 0 if success, -kernel error code otherwise
250  */
251 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes);
252 
253 /**
254  * copy_scratchpad() - Copy the content of scratchpad in device EEPROM
255  * @sl: slave involved
256  *
257  * Return: 0 if success, -kernel error code otherwise
258  */
259 static int copy_scratchpad(struct w1_slave *sl);
260 
261 /**
262  * recall_eeprom() - Restore EEPROM data to device RAM
263  * @sl: slave involved
264  *
265  * Return: 0 if success, -kernel error code otherwise
266  */
267 static int recall_eeprom(struct w1_slave *sl);
268 
269 /**
270  * read_powermode() - Query the power mode of the slave
271  * @sl: slave to retrieve the power mode
272  *
273  * Ask the device to get its power mode (external or parasite)
274  * and store the power status in the &struct w1_therm_family_data.
275  *
276  * Return:
277  * * 0 parasite powered device
278  * * 1 externally powered device
279  * * <0 kernel error code
280  */
281 static int read_powermode(struct w1_slave *sl);
282 
283 /**
284  * trigger_bulk_read() - function to trigger a bulk read on the bus
285  * @dev_master: the device master of the bus
286  *
287  * Send a SKIP ROM follow by a CONVERT T command on the bus.
288  * It also set the status flag in each slave &struct w1_therm_family_data
289  * to signal that a conversion is in progress.
290  *
291  * Return: 0 if success, -kernel error code otherwise
292  */
293 static int trigger_bulk_read(struct w1_master *dev_master);
294 
295 /* Sysfs interface declaration */
296 
297 static ssize_t w1_slave_show(struct device *device,
298 	struct device_attribute *attr, char *buf);
299 
300 static ssize_t w1_slave_store(struct device *device,
301 	struct device_attribute *attr, const char *buf, size_t size);
302 
303 static ssize_t w1_seq_show(struct device *device,
304 	struct device_attribute *attr, char *buf);
305 
306 static ssize_t temperature_show(struct device *device,
307 	struct device_attribute *attr, char *buf);
308 
309 static ssize_t ext_power_show(struct device *device,
310 	struct device_attribute *attr, char *buf);
311 
312 static ssize_t resolution_show(struct device *device,
313 	struct device_attribute *attr, char *buf);
314 
315 static ssize_t resolution_store(struct device *device,
316 	struct device_attribute *attr, const char *buf, size_t size);
317 
318 static ssize_t eeprom_cmd_store(struct device *device,
319 	struct device_attribute *attr, const char *buf, size_t size);
320 
321 static ssize_t alarms_store(struct device *device,
322 	struct device_attribute *attr, const char *buf, size_t size);
323 
324 static ssize_t alarms_show(struct device *device,
325 	struct device_attribute *attr, char *buf);
326 
327 static ssize_t therm_bulk_read_store(struct device *device,
328 	struct device_attribute *attr, const char *buf, size_t size);
329 
330 static ssize_t therm_bulk_read_show(struct device *device,
331 	struct device_attribute *attr, char *buf);
332 
333 static ssize_t conv_time_show(struct device *device,
334 			      struct device_attribute *attr, char *buf);
335 
336 static ssize_t conv_time_store(struct device *device,
337 			       struct device_attribute *attr, const char *buf,
338 			       size_t size);
339 
340 static ssize_t features_show(struct device *device,
341 			      struct device_attribute *attr, char *buf);
342 
343 static ssize_t features_store(struct device *device,
344 			       struct device_attribute *attr, const char *buf,
345 			       size_t size);
346 /* Attributes declarations */
347 
348 static DEVICE_ATTR_RW(w1_slave);
349 static DEVICE_ATTR_RO(w1_seq);
350 static DEVICE_ATTR_RO(temperature);
351 static DEVICE_ATTR_RO(ext_power);
352 static DEVICE_ATTR_RW(resolution);
353 static DEVICE_ATTR_WO(eeprom_cmd);
354 static DEVICE_ATTR_RW(alarms);
355 static DEVICE_ATTR_RW(conv_time);
356 static DEVICE_ATTR_RW(features);
357 
358 static DEVICE_ATTR_RW(therm_bulk_read); /* attribut at master level */
359 
360 /* Interface Functions declaration */
361 
362 /**
363  * w1_therm_add_slave() - Called when a new slave is discovered
364  * @sl: slave just discovered by the master.
365  *
366  * Called by the master when the slave is discovered on the bus. Used to
367  * initialize slave state before the beginning of any communication.
368  *
369  * Return: 0 - If success, negative kernel code otherwise
370  */
371 static int w1_therm_add_slave(struct w1_slave *sl);
372 
373 /**
374  * w1_therm_remove_slave() - Called when a slave is removed
375  * @sl: slave to be removed.
376  *
377  * Called by the master when the slave is considered not to be on the bus
378  * anymore. Used to free memory.
379  */
380 static void w1_therm_remove_slave(struct w1_slave *sl);
381 
382 /* Family attributes */
383 
384 static struct attribute *w1_therm_attrs[] = {
385 	&dev_attr_w1_slave.attr,
386 	&dev_attr_temperature.attr,
387 	&dev_attr_ext_power.attr,
388 	&dev_attr_resolution.attr,
389 	&dev_attr_eeprom_cmd.attr,
390 	&dev_attr_alarms.attr,
391 	&dev_attr_conv_time.attr,
392 	&dev_attr_features.attr,
393 	NULL,
394 };
395 
396 static struct attribute *w1_ds18s20_attrs[] = {
397 	&dev_attr_w1_slave.attr,
398 	&dev_attr_temperature.attr,
399 	&dev_attr_ext_power.attr,
400 	&dev_attr_eeprom_cmd.attr,
401 	&dev_attr_alarms.attr,
402 	&dev_attr_conv_time.attr,
403 	&dev_attr_features.attr,
404 	NULL,
405 };
406 
407 static struct attribute *w1_ds28ea00_attrs[] = {
408 	&dev_attr_w1_slave.attr,
409 	&dev_attr_w1_seq.attr,
410 	&dev_attr_temperature.attr,
411 	&dev_attr_ext_power.attr,
412 	&dev_attr_resolution.attr,
413 	&dev_attr_eeprom_cmd.attr,
414 	&dev_attr_alarms.attr,
415 	&dev_attr_conv_time.attr,
416 	&dev_attr_features.attr,
417 	NULL,
418 };
419 
420 /* Attribute groups */
421 
422 ATTRIBUTE_GROUPS(w1_therm);
423 ATTRIBUTE_GROUPS(w1_ds18s20);
424 ATTRIBUTE_GROUPS(w1_ds28ea00);
425 
426 #if IS_REACHABLE(CONFIG_HWMON)
427 static int w1_read_temp(struct device *dev, u32 attr, int channel,
428 			long *val);
429 
w1_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)430 static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
431 			     u32 attr, int channel)
432 {
433 	return attr == hwmon_temp_input ? 0444 : 0;
434 }
435 
w1_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)436 static int w1_read(struct device *dev, enum hwmon_sensor_types type,
437 		   u32 attr, int channel, long *val)
438 {
439 	switch (type) {
440 	case hwmon_temp:
441 		return w1_read_temp(dev, attr, channel, val);
442 	default:
443 		return -EOPNOTSUPP;
444 	}
445 }
446 
447 static const u32 w1_temp_config[] = {
448 	HWMON_T_INPUT,
449 	0
450 };
451 
452 static const struct hwmon_channel_info w1_temp = {
453 	.type = hwmon_temp,
454 	.config = w1_temp_config,
455 };
456 
457 static const struct hwmon_channel_info * const w1_info[] = {
458 	&w1_temp,
459 	NULL
460 };
461 
462 static const struct hwmon_ops w1_hwmon_ops = {
463 	.is_visible = w1_is_visible,
464 	.read = w1_read,
465 };
466 
467 static const struct hwmon_chip_info w1_chip_info = {
468 	.ops = &w1_hwmon_ops,
469 	.info = w1_info,
470 };
471 #define W1_CHIPINFO	(&w1_chip_info)
472 #else
473 #define W1_CHIPINFO	NULL
474 #endif
475 
476 /* Family operations */
477 
478 static const struct w1_family_ops w1_therm_fops = {
479 	.add_slave	= w1_therm_add_slave,
480 	.remove_slave	= w1_therm_remove_slave,
481 	.groups		= w1_therm_groups,
482 	.chip_info	= W1_CHIPINFO,
483 };
484 
485 static const struct w1_family_ops w1_ds18s20_fops = {
486 	.add_slave	= w1_therm_add_slave,
487 	.remove_slave	= w1_therm_remove_slave,
488 	.groups		= w1_ds18s20_groups,
489 	.chip_info	= W1_CHIPINFO,
490 };
491 
492 static const struct w1_family_ops w1_ds28ea00_fops = {
493 	.add_slave	= w1_therm_add_slave,
494 	.remove_slave	= w1_therm_remove_slave,
495 	.groups		= w1_ds28ea00_groups,
496 	.chip_info	= W1_CHIPINFO,
497 };
498 
499 /* Family binding operations struct */
500 
501 static struct w1_family w1_therm_family_DS18S20 = {
502 	.fid = W1_THERM_DS18S20,
503 	.fops = &w1_ds18s20_fops,
504 };
505 
506 static struct w1_family w1_therm_family_DS18B20 = {
507 	.fid = W1_THERM_DS18B20,
508 	.fops = &w1_therm_fops,
509 };
510 
511 static struct w1_family w1_therm_family_DS1822 = {
512 	.fid = W1_THERM_DS1822,
513 	.fops = &w1_therm_fops,
514 };
515 
516 static struct w1_family w1_therm_family_DS28EA00 = {
517 	.fid = W1_THERM_DS28EA00,
518 	.fops = &w1_ds28ea00_fops,
519 };
520 
521 static struct w1_family w1_therm_family_DS1825 = {
522 	.fid = W1_THERM_DS1825,
523 	.fops = &w1_therm_fops,
524 };
525 
526 /* Device dependent func */
527 
w1_DS18B20_convert_time(struct w1_slave * sl)528 static inline int w1_DS18B20_convert_time(struct w1_slave *sl)
529 {
530 	int ret;
531 
532 	if (!sl->family_data)
533 		return -ENODEV;	/* device unknown */
534 
535 	if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT)
536 		return SLAVE_CONV_TIME_OVERRIDE(sl);
537 
538 	/* Return the conversion time, depending on resolution,
539 	 * select maximum conversion time among all compatible devices
540 	 */
541 	switch (SLAVE_RESOLUTION(sl)) {
542 	case 9:
543 		ret = 95;
544 		break;
545 	case 10:
546 		ret = 190;
547 		break;
548 	case 11:
549 		ret = 375;
550 		break;
551 	case 12:
552 		ret = 750;
553 		break;
554 	case 13:
555 		ret = 850;  /* GX20MH01 only. Datasheet says 500ms, but that's not enough. */
556 		break;
557 	case 14:
558 		ret = 1600; /* GX20MH01 only. Datasheet says 1000ms - not enough */
559 		break;
560 	default:
561 		ret = 750;
562 	}
563 	return ret;
564 }
565 
w1_DS18S20_convert_time(struct w1_slave * sl)566 static inline int w1_DS18S20_convert_time(struct w1_slave *sl)
567 {
568 	if (!sl->family_data)
569 		return -ENODEV;	/* device unknown */
570 
571 	if (SLAVE_CONV_TIME_OVERRIDE(sl) == CONV_TIME_DEFAULT)
572 		return 750; /* default for DS18S20 */
573 	else
574 		return SLAVE_CONV_TIME_OVERRIDE(sl);
575 }
576 
w1_DS1825_convert_time(struct w1_slave * sl)577 static inline int w1_DS1825_convert_time(struct w1_slave *sl)
578 {
579 	int ret;
580 
581 	if (!sl->family_data)
582 		return -ENODEV;	/* device unknown */
583 
584 	if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT)
585 		return SLAVE_CONV_TIME_OVERRIDE(sl);
586 
587 	/* Return the conversion time, depending on resolution,
588 	 * select maximum conversion time among all compatible devices
589 	 */
590 	switch (SLAVE_RESOLUTION(sl)) {
591 	case 9:
592 		ret = 95;
593 		break;
594 	case 10:
595 		ret = 190;
596 		break;
597 	case 11:
598 		ret = 375;
599 		break;
600 	case 12:
601 		ret = 750;
602 		break;
603 	case 14:
604 		ret = 100; /* MAX31850 only. Datasheet says 100ms  */
605 		break;
606 	default:
607 		ret = 750;
608 	}
609 	return ret;
610 }
611 
w1_DS18B20_write_data(struct w1_slave * sl,const u8 * data)612 static inline int w1_DS18B20_write_data(struct w1_slave *sl,
613 				const u8 *data)
614 {
615 	return write_scratchpad(sl, data, 3);
616 }
617 
w1_DS18S20_write_data(struct w1_slave * sl,const u8 * data)618 static inline int w1_DS18S20_write_data(struct w1_slave *sl,
619 				const u8 *data)
620 {
621 	/* No config register */
622 	return write_scratchpad(sl, data, 2);
623 }
624 
w1_DS18B20_set_resolution(struct w1_slave * sl,int val)625 static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val)
626 {
627 	int ret;
628 	struct therm_info info, info2;
629 
630 	/* DS18B20 resolution is 9 to 12 bits */
631 	/* GX20MH01 resolution is 9 to 14 bits */
632 	/* MAX31850 resolution is fixed 14 bits */
633 	if (val < W1_THERM_RESOLUTION_MIN || val > W1_THERM_RESOLUTION_MAX)
634 		return -EINVAL;
635 
636 	/* Calc bit value from resolution */
637 	val = (val - W1_THERM_RESOLUTION_MIN) << W1_THERM_RESOLUTION_SHIFT;
638 
639 	/*
640 	 * Read the scratchpad to change only the required bits
641 	 * (bit5 & bit 6 from byte 4)
642 	 */
643 	ret = read_scratchpad(sl, &info);
644 
645 	if (ret)
646 		return ret;
647 
648 
649 	info.rom[4] &= ~W1_THERM_RESOLUTION_MASK;
650 	info.rom[4] |= val;
651 
652 	/* Write data in the device RAM */
653 	ret = w1_DS18B20_write_data(sl, info.rom + 2);
654 	if (ret)
655 		return ret;
656 
657 	/* Have to read back the resolution to verify an actual value
658 	 * GX20MH01 and DS18B20 are indistinguishable by family number, but resolutions differ
659 	 * Some DS18B20 clones don't support resolution change
660 	 */
661 	ret = read_scratchpad(sl, &info2);
662 	if (ret)
663 		/* Scratchpad read fail */
664 		return ret;
665 
666 	if ((info2.rom[4] & W1_THERM_RESOLUTION_MASK) == (info.rom[4] & W1_THERM_RESOLUTION_MASK))
667 		return 0;
668 
669 	/* Resolution verify error */
670 	return -EIO;
671 }
672 
w1_DS18B20_get_resolution(struct w1_slave * sl)673 static inline int w1_DS18B20_get_resolution(struct w1_slave *sl)
674 {
675 	int ret;
676 	int resolution;
677 	struct therm_info info;
678 
679 	ret = read_scratchpad(sl, &info);
680 
681 	if (ret)
682 		return ret;
683 
684 	resolution = ((info.rom[4] & W1_THERM_RESOLUTION_MASK) >> W1_THERM_RESOLUTION_SHIFT)
685 		+ W1_THERM_RESOLUTION_MIN;
686 	/* GX20MH01 has one special case:
687 	 *   >=14 means 14 bits when getting resolution from bit value.
688 	 * MAX31850 delivers fixed 15 and has 14 bits.
689 	 * Other devices have no more then 12 bits.
690 	 */
691 	if (resolution > W1_THERM_RESOLUTION_MAX)
692 		resolution = W1_THERM_RESOLUTION_MAX;
693 
694 	return resolution;
695 }
696 
697 /**
698  * w1_DS18B20_convert_temp() - temperature computation for DS18B20
699  * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
700  *
701  * Can be called for any DS18B20 compliant device.
702  *
703  * Return: value in millidegrees Celsius.
704  */
w1_DS18B20_convert_temp(u8 rom[9])705 static inline int w1_DS18B20_convert_temp(u8 rom[9])
706 {
707 	u16 bv;
708 	s16 t;
709 
710 	/* Signed 16-bit value to unsigned, cpu order */
711 	bv = le16_to_cpup((__le16 *)rom);
712 
713 	/* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */
714 	if (rom[4] & 0x80) {
715 		/* Insert two temperature bits from config register */
716 		/* Avoid arithmetic shift of signed value */
717 		bv = (bv << 2) | (rom[4] & 3);
718 		t = (s16) bv;	/* Degrees, lowest bit is 2^-6 */
719 		return (int)t * 1000 / 64;	/* Sign-extend to int; millidegrees */
720 	}
721 	t = (s16)bv;	/* Degrees, lowest bit is 2^-4 */
722 	return (int)t * 1000 / 16;	/* Sign-extend to int; millidegrees */
723 }
724 
725 /**
726  * w1_DS18S20_convert_temp() - temperature computation for DS18S20
727  * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
728  *
729  * Can be called for any DS18S20 compliant device.
730  *
731  * Return: value in millidegrees Celsius.
732  */
w1_DS18S20_convert_temp(u8 rom[9])733 static inline int w1_DS18S20_convert_temp(u8 rom[9])
734 {
735 	int t, h;
736 
737 	if (!rom[7]) {
738 		pr_debug("%s: Invalid argument for conversion\n", __func__);
739 		return 0;
740 	}
741 
742 	if (rom[1] == 0)
743 		t = ((s32)rom[0] >> 1)*1000;
744 	else
745 		t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
746 
747 	t -= 250;
748 	h = 1000*((s32)rom[7] - (s32)rom[6]);
749 	h /= (s32)rom[7];
750 	t += h;
751 
752 	return t;
753 }
754 
755 /**
756  * w1_DS1825_convert_temp() - temperature computation for DS1825
757  * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
758  *
759  * Can be called for any DS1825 compliant device.
760  * Is used by MAX31850, too
761  *
762  * Return: value in millidegrees Celsius.
763  */
764 
w1_DS1825_convert_temp(u8 rom[9])765 static inline int w1_DS1825_convert_temp(u8 rom[9])
766 {
767 	u16 bv;
768 	s16 t;
769 
770 	/* Signed 16-bit value to unsigned, cpu order */
771 	bv = le16_to_cpup((__le16 *)rom);
772 
773 	/* Config register bit 7 = 1 - MA31850 found, 14 bit resolution */
774 	if (rom[4] & 0x80) {
775 		/* Mask out bits 0 (Fault) and 1 (Reserved) */
776 		/* Avoid arithmetic shift of signed value */
777 		bv = (bv & 0xFFFC); /* Degrees, lowest 4 bits are 2^-1, 2^-2 and 2 zero bits */
778 	}
779 	t = (s16)bv;	/* Degrees, lowest bit is 2^-4 */
780 	return (int)t * 1000 / 16;	/* Sign-extend to int; millidegrees */
781 }
782 
783 /* Device capability description */
784 /* GX20MH01 device shares family number and structure with DS18B20 */
785 
786 static struct w1_therm_family_converter w1_therm_families[] = {
787 	{
788 		.f				= &w1_therm_family_DS18S20,
789 		.convert			= w1_DS18S20_convert_temp,
790 		.get_conversion_time	= w1_DS18S20_convert_time,
791 		.set_resolution		= NULL,	/* no config register */
792 		.get_resolution		= NULL,	/* no config register */
793 		.write_data			= w1_DS18S20_write_data,
794 		.bulk_read			= true
795 	},
796 	{
797 		.f				= &w1_therm_family_DS1822,
798 		.convert			= w1_DS18B20_convert_temp,
799 		.get_conversion_time	= w1_DS18B20_convert_time,
800 		.set_resolution		= w1_DS18B20_set_resolution,
801 		.get_resolution		= w1_DS18B20_get_resolution,
802 		.write_data			= w1_DS18B20_write_data,
803 		.bulk_read			= true
804 	},
805 	{
806 		/* Also used for GX20MH01 */
807 		.f				= &w1_therm_family_DS18B20,
808 		.convert			= w1_DS18B20_convert_temp,
809 		.get_conversion_time	= w1_DS18B20_convert_time,
810 		.set_resolution		= w1_DS18B20_set_resolution,
811 		.get_resolution		= w1_DS18B20_get_resolution,
812 		.write_data			= w1_DS18B20_write_data,
813 		.bulk_read			= true
814 	},
815 	{
816 		.f				= &w1_therm_family_DS28EA00,
817 		.convert			= w1_DS18B20_convert_temp,
818 		.get_conversion_time	= w1_DS18B20_convert_time,
819 		.set_resolution		= w1_DS18B20_set_resolution,
820 		.get_resolution		= w1_DS18B20_get_resolution,
821 		.write_data			= w1_DS18B20_write_data,
822 		.bulk_read			= false
823 	},
824 	{
825 		/* Also used for MAX31850 */
826 		.f				= &w1_therm_family_DS1825,
827 		.convert			= w1_DS1825_convert_temp,
828 		.get_conversion_time	= w1_DS1825_convert_time,
829 		.set_resolution		= w1_DS18B20_set_resolution,
830 		.get_resolution		= w1_DS18B20_get_resolution,
831 		.write_data			= w1_DS18B20_write_data,
832 		.bulk_read			= true
833 	}
834 };
835 
836 /* Helpers Functions */
837 
838 /**
839  * device_family() - Retrieve a pointer on &struct w1_therm_family_converter
840  * @sl: slave to retrieve the device specific structure
841  *
842  * Return: pointer to the slaves's family converter, NULL if not known
843  */
device_family(struct w1_slave * sl)844 static struct w1_therm_family_converter *device_family(struct w1_slave *sl)
845 {
846 	struct w1_therm_family_converter *ret = NULL;
847 	int i;
848 
849 	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
850 		if (w1_therm_families[i].f->fid == sl->family->fid) {
851 			ret = &w1_therm_families[i];
852 			break;
853 		}
854 	}
855 	return ret;
856 }
857 
858 /**
859  * bus_mutex_lock() - Acquire the mutex
860  * @lock: w1 bus mutex to acquire
861  *
862  * It try to acquire the mutex W1_THERM_MAX_TRY times and wait
863  * W1_THERM_RETRY_DELAY between 2 attempts.
864  *
865  * Return: true is mutex is acquired and lock, false otherwise
866  */
bus_mutex_lock(struct mutex * lock)867 static inline bool bus_mutex_lock(struct mutex *lock)
868 {
869 	int max_trying = W1_THERM_MAX_TRY;
870 
871 	/* try to acquire the mutex, if not, sleep retry_delay before retry) */
872 	while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) {
873 		unsigned long sleep_rem;
874 
875 		sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY);
876 		if (!sleep_rem)
877 			max_trying--;
878 	}
879 
880 	if (!max_trying)
881 		return false;	/* Didn't acquire the bus mutex */
882 
883 	return true;
884 }
885 
886 /**
887  * check_family_data() - Check if family data and specific functions are present
888  * @sl: W1 device data
889  *
890  * Return: 0 - OK, negative value - error
891  */
check_family_data(struct w1_slave * sl)892 static int check_family_data(struct w1_slave *sl)
893 {
894 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
895 		dev_info(&sl->dev,
896 			 "%s: Device is not supported by the driver\n", __func__);
897 		return -EINVAL;  /* No device family */
898 	}
899 	return 0;
900 }
901 
902 /**
903  * bulk_read_support() - check if slave support bulk read
904  * @sl: device to check the ability
905  *
906  * Return: true if bulk read is supported, false if not or error
907  */
bulk_read_support(struct w1_slave * sl)908 static inline bool bulk_read_support(struct w1_slave *sl)
909 {
910 	if (SLAVE_SPECIFIC_FUNC(sl))
911 		return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
912 
913 	dev_info(&sl->dev,
914 		"%s: Device not supported by the driver\n", __func__);
915 
916 	return false;  /* No device family */
917 }
918 
919 /**
920  * conversion_time() - get the Tconv for the slave
921  * @sl: device to get the conversion time
922  *
923  * On device supporting resolution settings, conversion time depend
924  * on the resolution setting. This helper function get the slave timing,
925  * depending on its current setting.
926  *
927  * Return: conversion time in ms, negative values are kernel error code
928  */
conversion_time(struct w1_slave * sl)929 static inline int conversion_time(struct w1_slave *sl)
930 {
931 	if (SLAVE_SPECIFIC_FUNC(sl))
932 		return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
933 
934 	dev_info(&sl->dev,
935 		"%s: Device not supported by the driver\n", __func__);
936 
937 	return -ENODEV;  /* No device family */
938 }
939 
940 /**
941  * temperature_from_RAM() - Convert the read info to temperature
942  * @sl: device that sent the RAM data
943  * @rom: read value on the slave device RAM
944  *
945  * Device dependent, the function bind the correct computation method.
946  *
947  * Return: temperature in 1/1000degC, 0 on error.
948  */
temperature_from_RAM(struct w1_slave * sl,u8 rom[9])949 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
950 {
951 	if (SLAVE_SPECIFIC_FUNC(sl))
952 		return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
953 
954 	dev_info(&sl->dev,
955 		"%s: Device not supported by the driver\n", __func__);
956 
957 	return 0;  /* No device family */
958 }
959 
960 /**
961  * int_to_short() - Safe casting of int to short
962  *
963  * @i: integer to be converted to short
964  *
965  * Device register use 1 byte to store signed integer.
966  * This helper function convert the int in a signed short,
967  * using the min/max values that device can measure as limits.
968  * min/max values are defined by macro.
969  *
970  * Return: a short in the range of min/max value
971  */
int_to_short(int i)972 static inline s8 int_to_short(int i)
973 {
974 	/* Prepare to cast to short by eliminating out of range values */
975 	i = clamp(i, MIN_TEMP, MAX_TEMP);
976 	return (s8) i;
977 }
978 
979 /* Interface Functions */
980 
w1_therm_add_slave(struct w1_slave * sl)981 static int w1_therm_add_slave(struct w1_slave *sl)
982 {
983 	struct w1_therm_family_converter *sl_family_conv;
984 
985 	/* Allocate memory */
986 	sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
987 		GFP_KERNEL);
988 	if (!sl->family_data)
989 		return -ENOMEM;
990 
991 	atomic_set(THERM_REFCNT(sl->family_data), 1);
992 
993 	/* Get a pointer to the device specific function struct */
994 	sl_family_conv = device_family(sl);
995 	if (!sl_family_conv) {
996 		kfree(sl->family_data);
997 		return -ENODEV;
998 	}
999 	/* save this pointer to the device structure */
1000 	SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
1001 
1002 	if (bulk_read_support(sl)) {
1003 		/*
1004 		 * add the sys entry to trigger bulk_read
1005 		 * at master level only the 1st time
1006 		 */
1007 		if (!bulk_read_device_counter) {
1008 			int err = device_create_file(&sl->master->dev,
1009 				&dev_attr_therm_bulk_read);
1010 
1011 			if (err)
1012 				dev_warn(&sl->dev,
1013 				"%s: Device has been added, but bulk read is unavailable. err=%d\n",
1014 				__func__, err);
1015 		}
1016 		/* Increment the counter */
1017 		bulk_read_device_counter++;
1018 	}
1019 
1020 	/* Getting the power mode of the device {external, parasite} */
1021 	SLAVE_POWERMODE(sl) = read_powermode(sl);
1022 
1023 	if (SLAVE_POWERMODE(sl) < 0) {
1024 		/* no error returned as device has been added */
1025 		dev_warn(&sl->dev,
1026 			"%s: Device has been added, but power_mode may be corrupted. err=%d\n",
1027 			 __func__, SLAVE_POWERMODE(sl));
1028 	}
1029 
1030 	/* Getting the resolution of the device */
1031 	if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
1032 		SLAVE_RESOLUTION(sl) =
1033 			SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1034 		if (SLAVE_RESOLUTION(sl) < 0) {
1035 			/* no error returned as device has been added */
1036 			dev_warn(&sl->dev,
1037 				"%s:Device has been added, but resolution may be corrupted. err=%d\n",
1038 				__func__, SLAVE_RESOLUTION(sl));
1039 		}
1040 	}
1041 
1042 	/* Finally initialize convert_triggered flag */
1043 	SLAVE_CONVERT_TRIGGERED(sl) = 0;
1044 
1045 	return 0;
1046 }
1047 
w1_therm_remove_slave(struct w1_slave * sl)1048 static void w1_therm_remove_slave(struct w1_slave *sl)
1049 {
1050 	int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
1051 
1052 	if (bulk_read_support(sl)) {
1053 		bulk_read_device_counter--;
1054 		/* Delete the entry if no more device support the feature */
1055 		if (!bulk_read_device_counter)
1056 			device_remove_file(&sl->master->dev,
1057 				&dev_attr_therm_bulk_read);
1058 	}
1059 
1060 	while (refcnt) {
1061 		msleep(1000);
1062 		refcnt = atomic_read(THERM_REFCNT(sl->family_data));
1063 	}
1064 	kfree(sl->family_data);
1065 	sl->family_data = NULL;
1066 }
1067 
1068 /* Hardware Functions */
1069 
1070 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
reset_select_slave(struct w1_slave * sl)1071 static int reset_select_slave(struct w1_slave *sl)
1072 {
1073 	u8 match[9] = { W1_MATCH_ROM, };
1074 	u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1075 
1076 	if (w1_reset_bus(sl->master))
1077 		return -ENODEV;
1078 
1079 	memcpy(&match[1], &rn, 8);
1080 	w1_write_block(sl->master, match, 9);
1081 
1082 	return 0;
1083 }
1084 
1085 /**
1086  * w1_poll_completion - Poll for operation completion, with timeout
1087  * @dev_master: the device master of the bus
1088  * @tout_ms: timeout in milliseconds
1089  *
1090  * The device is answering 0's while an operation is in progress and 1's after it completes
1091  * Timeout may happen if the previous command was not recognised due to a line noise
1092  *
1093  * Return: 0 - OK, negative error - timeout
1094  */
w1_poll_completion(struct w1_master * dev_master,int tout_ms)1095 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1096 {
1097 	int i;
1098 
1099 	for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1100 		/* Delay is before poll, for device to recognize a command */
1101 		msleep(W1_POLL_PERIOD);
1102 
1103 		/* Compare all 8 bits to mitigate a noise on the bus */
1104 		if (w1_read_8(dev_master) == 0xFF)
1105 			break;
1106 	}
1107 	if (i == tout_ms/W1_POLL_PERIOD)
1108 		return -EIO;
1109 
1110 	return 0;
1111 }
1112 
convert_t(struct w1_slave * sl,struct therm_info * info)1113 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1114 {
1115 	struct w1_master *dev_master = sl->master;
1116 	int max_trying = W1_THERM_MAX_TRY;
1117 	int t_conv;
1118 	int ret = -ENODEV;
1119 	bool strong_pullup;
1120 
1121 	if (!sl->family_data)
1122 		goto error;
1123 
1124 	strong_pullup = (w1_strong_pullup == 2 ||
1125 					(!SLAVE_POWERMODE(sl) &&
1126 					w1_strong_pullup));
1127 
1128 	if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1129 		dev_warn(&sl->dev,
1130 			"%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1131 			__func__);
1132 		SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1133 	}
1134 
1135 	/* get conversion duration device and id dependent */
1136 	t_conv = conversion_time(sl);
1137 
1138 	memset(info->rom, 0, sizeof(info->rom));
1139 
1140 	/* prevent the slave from going away in sleep */
1141 	atomic_inc(THERM_REFCNT(sl->family_data));
1142 
1143 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1144 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1145 		goto dec_refcnt;
1146 	}
1147 
1148 	while (max_trying-- && ret) { /* ret should be 0 */
1149 
1150 		info->verdict = 0;
1151 		info->crc = 0;
1152 		/* safe version to select slave */
1153 		if (!reset_select_slave(sl)) {
1154 			unsigned long sleep_rem;
1155 
1156 			/* 750ms strong pullup (or delay) after the convert */
1157 			if (strong_pullup)
1158 				w1_next_pullup(dev_master, t_conv);
1159 
1160 			w1_write_8(dev_master, W1_CONVERT_TEMP);
1161 
1162 			if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1163 				ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1164 				if (ret) {
1165 					dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1166 					goto mt_unlock;
1167 				}
1168 				mutex_unlock(&dev_master->bus_mutex);
1169 			} else if (!strong_pullup) { /*no device need pullup */
1170 				sleep_rem = msleep_interruptible(t_conv);
1171 				if (sleep_rem != 0) {
1172 					ret = -EINTR;
1173 					goto mt_unlock;
1174 				}
1175 				mutex_unlock(&dev_master->bus_mutex);
1176 			} else { /*some device need pullup */
1177 				mutex_unlock(&dev_master->bus_mutex);
1178 				sleep_rem = msleep_interruptible(t_conv);
1179 				if (sleep_rem != 0) {
1180 					ret = -EINTR;
1181 					goto dec_refcnt;
1182 				}
1183 			}
1184 			ret = read_scratchpad(sl, info);
1185 
1186 			/* If enabled, check for conversion success */
1187 			if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1188 				(info->rom[6] == 0xC) &&
1189 				((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1190 				(info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1191 			) {
1192 				/* Invalid reading (scratchpad byte 6 = 0xC)
1193 				 * due to insufficient conversion time
1194 				 * or power failure.
1195 				 */
1196 				ret = -EIO;
1197 			}
1198 
1199 			goto dec_refcnt;
1200 		}
1201 
1202 	}
1203 
1204 mt_unlock:
1205 	mutex_unlock(&dev_master->bus_mutex);
1206 dec_refcnt:
1207 	atomic_dec(THERM_REFCNT(sl->family_data));
1208 error:
1209 	return ret;
1210 }
1211 
conv_time_measure(struct w1_slave * sl,int * conv_time)1212 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1213 {
1214 	struct therm_info inf,
1215 		*info = &inf;
1216 	struct w1_master *dev_master = sl->master;
1217 	int max_trying = W1_THERM_MAX_TRY;
1218 	int ret = -ENODEV;
1219 	bool strong_pullup;
1220 
1221 	if (!sl->family_data)
1222 		goto error;
1223 
1224 	strong_pullup = (w1_strong_pullup == 2 ||
1225 		(!SLAVE_POWERMODE(sl) &&
1226 		w1_strong_pullup));
1227 
1228 	if (strong_pullup) {
1229 		pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1230 		return -EINVAL;
1231 	}
1232 
1233 	memset(info->rom, 0, sizeof(info->rom));
1234 
1235 	/* prevent the slave from going away in sleep */
1236 	atomic_inc(THERM_REFCNT(sl->family_data));
1237 
1238 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1239 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1240 		goto dec_refcnt;
1241 	}
1242 
1243 	while (max_trying-- && ret) { /* ret should be 0 */
1244 		info->verdict = 0;
1245 		info->crc = 0;
1246 		/* safe version to select slave */
1247 		if (!reset_select_slave(sl)) {
1248 			int j_start, j_end;
1249 
1250 			/*no device need pullup */
1251 			w1_write_8(dev_master, W1_CONVERT_TEMP);
1252 
1253 			j_start = jiffies;
1254 			ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1255 			if (ret) {
1256 				dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1257 				goto mt_unlock;
1258 			}
1259 			j_end = jiffies;
1260 			/* 1.2x increase for variation and changes over temperature range */
1261 			*conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1262 			pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1263 				*conv_time, HZ);
1264 			if (*conv_time <= CONV_TIME_MEASURE) {
1265 				ret = -EIO;
1266 				goto mt_unlock;
1267 			}
1268 			mutex_unlock(&dev_master->bus_mutex);
1269 			ret = read_scratchpad(sl, info);
1270 			goto dec_refcnt;
1271 		}
1272 
1273 	}
1274 mt_unlock:
1275 	mutex_unlock(&dev_master->bus_mutex);
1276 dec_refcnt:
1277 	atomic_dec(THERM_REFCNT(sl->family_data));
1278 error:
1279 	return ret;
1280 }
1281 
read_scratchpad(struct w1_slave * sl,struct therm_info * info)1282 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1283 {
1284 	struct w1_master *dev_master = sl->master;
1285 	int max_trying = W1_THERM_MAX_TRY;
1286 	int ret = -ENODEV;
1287 
1288 	info->verdict = 0;
1289 
1290 	if (!sl->family_data)
1291 		goto error;
1292 
1293 	memset(info->rom, 0, sizeof(info->rom));
1294 
1295 	/* prevent the slave from going away in sleep */
1296 	atomic_inc(THERM_REFCNT(sl->family_data));
1297 
1298 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1299 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1300 		goto dec_refcnt;
1301 	}
1302 
1303 	while (max_trying-- && ret) { /* ret should be 0 */
1304 		/* safe version to select slave */
1305 		if (!reset_select_slave(sl)) {
1306 			u8 nb_bytes_read;
1307 
1308 			w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1309 
1310 			nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1311 			if (nb_bytes_read != 9) {
1312 				dev_warn(&sl->dev,
1313 					"w1_read_block(): returned %u instead of 9.\n",
1314 					nb_bytes_read);
1315 				ret = -EIO;
1316 			}
1317 
1318 			info->crc = w1_calc_crc8(info->rom, 8);
1319 
1320 			if (info->rom[8] == info->crc) {
1321 				info->verdict = 1;
1322 				ret = 0;
1323 			} else
1324 				ret = -EIO; /* CRC not checked */
1325 		}
1326 
1327 	}
1328 	mutex_unlock(&dev_master->bus_mutex);
1329 
1330 dec_refcnt:
1331 	atomic_dec(THERM_REFCNT(sl->family_data));
1332 error:
1333 	return ret;
1334 }
1335 
write_scratchpad(struct w1_slave * sl,const u8 * data,u8 nb_bytes)1336 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1337 {
1338 	struct w1_master *dev_master = sl->master;
1339 	int max_trying = W1_THERM_MAX_TRY;
1340 	int ret = -ENODEV;
1341 
1342 	if (!sl->family_data)
1343 		goto error;
1344 
1345 	/* prevent the slave from going away in sleep */
1346 	atomic_inc(THERM_REFCNT(sl->family_data));
1347 
1348 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1349 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1350 		goto dec_refcnt;
1351 	}
1352 
1353 	while (max_trying-- && ret) { /* ret should be 0 */
1354 		/* safe version to select slave */
1355 		if (!reset_select_slave(sl)) {
1356 			w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1357 			w1_write_block(dev_master, data, nb_bytes);
1358 			ret = 0;
1359 		}
1360 	}
1361 	mutex_unlock(&dev_master->bus_mutex);
1362 
1363 dec_refcnt:
1364 	atomic_dec(THERM_REFCNT(sl->family_data));
1365 error:
1366 	return ret;
1367 }
1368 
copy_scratchpad(struct w1_slave * sl)1369 static int copy_scratchpad(struct w1_slave *sl)
1370 {
1371 	struct w1_master *dev_master = sl->master;
1372 	int max_trying = W1_THERM_MAX_TRY;
1373 	int t_write, ret = -ENODEV;
1374 	bool strong_pullup;
1375 
1376 	if (!sl->family_data)
1377 		goto error;
1378 
1379 	t_write = W1_THERM_EEPROM_WRITE_DELAY;
1380 	strong_pullup = (w1_strong_pullup == 2 ||
1381 					(!SLAVE_POWERMODE(sl) &&
1382 					w1_strong_pullup));
1383 
1384 	/* prevent the slave from going away in sleep */
1385 	atomic_inc(THERM_REFCNT(sl->family_data));
1386 
1387 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1388 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1389 		goto dec_refcnt;
1390 	}
1391 
1392 	while (max_trying-- && ret) { /* ret should be 0 */
1393 		/* safe version to select slave */
1394 		if (!reset_select_slave(sl)) {
1395 			unsigned long sleep_rem;
1396 
1397 			/* 10ms strong pullup (or delay) after the convert */
1398 			if (strong_pullup)
1399 				w1_next_pullup(dev_master, t_write);
1400 
1401 			w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1402 
1403 			if (strong_pullup) {
1404 				sleep_rem = msleep_interruptible(t_write);
1405 				if (sleep_rem != 0) {
1406 					ret = -EINTR;
1407 					goto mt_unlock;
1408 				}
1409 			}
1410 			ret = 0;
1411 		}
1412 
1413 	}
1414 
1415 mt_unlock:
1416 	mutex_unlock(&dev_master->bus_mutex);
1417 dec_refcnt:
1418 	atomic_dec(THERM_REFCNT(sl->family_data));
1419 error:
1420 	return ret;
1421 }
1422 
recall_eeprom(struct w1_slave * sl)1423 static int recall_eeprom(struct w1_slave *sl)
1424 {
1425 	struct w1_master *dev_master = sl->master;
1426 	int max_trying = W1_THERM_MAX_TRY;
1427 	int ret = -ENODEV;
1428 
1429 	if (!sl->family_data)
1430 		goto error;
1431 
1432 	/* prevent the slave from going away in sleep */
1433 	atomic_inc(THERM_REFCNT(sl->family_data));
1434 
1435 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1436 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1437 		goto dec_refcnt;
1438 	}
1439 
1440 	while (max_trying-- && ret) { /* ret should be 0 */
1441 		/* safe version to select slave */
1442 		if (!reset_select_slave(sl)) {
1443 
1444 			w1_write_8(dev_master, W1_RECALL_EEPROM);
1445 			ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1446 		}
1447 
1448 	}
1449 
1450 	mutex_unlock(&dev_master->bus_mutex);
1451 
1452 dec_refcnt:
1453 	atomic_dec(THERM_REFCNT(sl->family_data));
1454 error:
1455 	return ret;
1456 }
1457 
read_powermode(struct w1_slave * sl)1458 static int read_powermode(struct w1_slave *sl)
1459 {
1460 	struct w1_master *dev_master = sl->master;
1461 	int max_trying = W1_THERM_MAX_TRY;
1462 	int  ret = -ENODEV;
1463 
1464 	if (!sl->family_data)
1465 		goto error;
1466 
1467 	/* prevent the slave from going away in sleep */
1468 	atomic_inc(THERM_REFCNT(sl->family_data));
1469 
1470 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1471 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1472 		goto dec_refcnt;
1473 	}
1474 
1475 	while ((max_trying--) && (ret < 0)) {
1476 		/* safe version to select slave */
1477 		if (!reset_select_slave(sl)) {
1478 			w1_write_8(dev_master, W1_READ_PSUPPLY);
1479 			/*
1480 			 * Emit a read time slot and read only one bit,
1481 			 * 1 is externally powered,
1482 			 * 0 is parasite powered
1483 			 */
1484 			ret = w1_touch_bit(dev_master, 1);
1485 			/* ret should be either 1 either 0 */
1486 		}
1487 	}
1488 	mutex_unlock(&dev_master->bus_mutex);
1489 
1490 dec_refcnt:
1491 	atomic_dec(THERM_REFCNT(sl->family_data));
1492 error:
1493 	return ret;
1494 }
1495 
trigger_bulk_read(struct w1_master * dev_master)1496 static int trigger_bulk_read(struct w1_master *dev_master)
1497 {
1498 	struct w1_slave *sl = NULL; /* used to iterate through slaves */
1499 	int max_trying = W1_THERM_MAX_TRY;
1500 	int t_conv = 0;
1501 	int ret = -ENODEV;
1502 	bool strong_pullup = false;
1503 
1504 	/*
1505 	 * Check whether there are parasite powered device on the bus,
1506 	 * and compute duration of conversion for these devices
1507 	 * so we can apply a strong pullup if required
1508 	 */
1509 	list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1510 		if (!sl->family_data)
1511 			goto error;
1512 		if (bulk_read_support(sl)) {
1513 			int t_cur = conversion_time(sl);
1514 
1515 			t_conv = max(t_cur, t_conv);
1516 			strong_pullup = strong_pullup ||
1517 					(w1_strong_pullup == 2 ||
1518 					(!SLAVE_POWERMODE(sl) &&
1519 					w1_strong_pullup));
1520 		}
1521 	}
1522 
1523 	/*
1524 	 * t_conv is the max conversion time required on the bus
1525 	 * If its 0, no device support the bulk read feature
1526 	 */
1527 	if (!t_conv)
1528 		goto error;
1529 
1530 	if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1531 		ret = -EAGAIN;	/* Didn't acquire the mutex */
1532 		goto error;
1533 	}
1534 
1535 	while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1536 
1537 		if (!w1_reset_bus(dev_master)) {	/* Just reset the bus */
1538 			unsigned long sleep_rem;
1539 
1540 			w1_write_8(dev_master, W1_SKIP_ROM);
1541 
1542 			if (strong_pullup)	/* Apply pullup if required */
1543 				w1_next_pullup(dev_master, t_conv);
1544 
1545 			w1_write_8(dev_master, W1_CONVERT_TEMP);
1546 
1547 			/* set a flag to instruct that converT pending */
1548 			list_for_each_entry(sl,
1549 				&dev_master->slist, w1_slave_entry) {
1550 				if (bulk_read_support(sl))
1551 					SLAVE_CONVERT_TRIGGERED(sl) = -1;
1552 			}
1553 
1554 			if (strong_pullup) { /* some device need pullup */
1555 				sleep_rem = msleep_interruptible(t_conv);
1556 				if (sleep_rem != 0) {
1557 					ret = -EINTR;
1558 					goto mt_unlock;
1559 				}
1560 				mutex_unlock(&dev_master->bus_mutex);
1561 			} else {
1562 				mutex_unlock(&dev_master->bus_mutex);
1563 				sleep_rem = msleep_interruptible(t_conv);
1564 				if (sleep_rem != 0) {
1565 					ret = -EINTR;
1566 					goto set_flag;
1567 				}
1568 			}
1569 			ret = 0;
1570 			goto set_flag;
1571 		}
1572 	}
1573 
1574 mt_unlock:
1575 	mutex_unlock(&dev_master->bus_mutex);
1576 set_flag:
1577 	/* set a flag to register convsersion is done */
1578 	list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1579 		if (bulk_read_support(sl))
1580 			SLAVE_CONVERT_TRIGGERED(sl) = 1;
1581 	}
1582 error:
1583 	return ret;
1584 }
1585 
1586 /* Sysfs Interface definition */
1587 
w1_slave_show(struct device * device,struct device_attribute * attr,char * buf)1588 static ssize_t w1_slave_show(struct device *device,
1589 			     struct device_attribute *attr, char *buf)
1590 {
1591 	struct w1_slave *sl = dev_to_w1_slave(device);
1592 	struct therm_info info;
1593 	u8 *family_data = sl->family_data;
1594 	int ret, i;
1595 	ssize_t c = PAGE_SIZE;
1596 
1597 	if (bulk_read_support(sl)) {
1598 		if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1599 			dev_dbg(device,
1600 				"%s: Conversion in progress, retry later\n",
1601 				__func__);
1602 			return 0;
1603 		} else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1604 			/* A bulk read has been issued, read the device RAM */
1605 			ret = read_scratchpad(sl, &info);
1606 			SLAVE_CONVERT_TRIGGERED(sl) = 0;
1607 		} else
1608 			ret = convert_t(sl, &info);
1609 	} else
1610 		ret = convert_t(sl, &info);
1611 
1612 	if (ret < 0) {
1613 		dev_dbg(device,
1614 			"%s: Temperature data may be corrupted. err=%d\n",
1615 			__func__, ret);
1616 		return 0;
1617 	}
1618 
1619 	for (i = 0; i < 9; ++i)
1620 		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1621 	c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1622 		      info.crc, (info.verdict) ? "YES" : "NO");
1623 
1624 	if (info.verdict)
1625 		memcpy(family_data, info.rom, sizeof(info.rom));
1626 	else
1627 		dev_warn(device, "%s:Read failed CRC check\n", __func__);
1628 
1629 	for (i = 0; i < 9; ++i)
1630 		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1631 			      ((u8 *)family_data)[i]);
1632 
1633 	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1634 			temperature_from_RAM(sl, info.rom));
1635 
1636 	ret = PAGE_SIZE - c;
1637 	return ret;
1638 }
1639 
w1_slave_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1640 static ssize_t w1_slave_store(struct device *device,
1641 			      struct device_attribute *attr, const char *buf,
1642 			      size_t size)
1643 {
1644 	int val, ret = 0;
1645 	struct w1_slave *sl = dev_to_w1_slave(device);
1646 
1647 	ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1648 
1649 	if (ret) {	/* conversion error */
1650 		dev_info(device,
1651 			"%s: conversion error. err= %d\n", __func__, ret);
1652 		return size;	/* return size to avoid call back again */
1653 	}
1654 
1655 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1656 		dev_info(device,
1657 			"%s: Device not supported by the driver\n", __func__);
1658 		return size;  /* No device family */
1659 	}
1660 
1661 	if (val == 0)	/* val=0 : trigger a EEPROM save */
1662 		ret = copy_scratchpad(sl);
1663 	else {
1664 		if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1665 			ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1666 	}
1667 
1668 	if (ret) {
1669 		dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1670 		/* Propagate error to userspace */
1671 		return ret;
1672 	}
1673 	SLAVE_RESOLUTION(sl) = val;
1674 	/* Reset the conversion time to default - it depends on resolution */
1675 	SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1676 
1677 	return size; /* always return size to avoid infinite calling */
1678 }
1679 
temperature_show(struct device * device,struct device_attribute * attr,char * buf)1680 static ssize_t temperature_show(struct device *device,
1681 	struct device_attribute *attr, char *buf)
1682 {
1683 	struct w1_slave *sl = dev_to_w1_slave(device);
1684 	struct therm_info info;
1685 	int ret = 0;
1686 
1687 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1688 		dev_info(device,
1689 			"%s: Device not supported by the driver\n", __func__);
1690 		return 0;  /* No device family */
1691 	}
1692 
1693 	if (bulk_read_support(sl)) {
1694 		if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1695 			dev_dbg(device,
1696 				"%s: Conversion in progress, retry later\n",
1697 				__func__);
1698 			return 0;
1699 		} else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1700 			/* A bulk read has been issued, read the device RAM */
1701 			ret = read_scratchpad(sl, &info);
1702 			SLAVE_CONVERT_TRIGGERED(sl) = 0;
1703 		} else
1704 			ret = convert_t(sl, &info);
1705 	} else
1706 		ret = convert_t(sl, &info);
1707 
1708 	if (ret < 0) {
1709 		dev_dbg(device,
1710 			"%s: Temperature data may be corrupted. err=%d\n",
1711 			__func__, ret);
1712 		return 0;
1713 	}
1714 
1715 	return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1716 }
1717 
ext_power_show(struct device * device,struct device_attribute * attr,char * buf)1718 static ssize_t ext_power_show(struct device *device,
1719 	struct device_attribute *attr, char *buf)
1720 {
1721 	struct w1_slave *sl = dev_to_w1_slave(device);
1722 
1723 	if (!sl->family_data) {
1724 		dev_info(device,
1725 			"%s: Device not supported by the driver\n", __func__);
1726 		return 0;  /* No device family */
1727 	}
1728 
1729 	/* Getting the power mode of the device {external, parasite} */
1730 	SLAVE_POWERMODE(sl) = read_powermode(sl);
1731 
1732 	if (SLAVE_POWERMODE(sl) < 0) {
1733 		dev_dbg(device,
1734 			"%s: Power_mode may be corrupted. err=%d\n",
1735 			__func__, SLAVE_POWERMODE(sl));
1736 	}
1737 	return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1738 }
1739 
resolution_show(struct device * device,struct device_attribute * attr,char * buf)1740 static ssize_t resolution_show(struct device *device,
1741 	struct device_attribute *attr, char *buf)
1742 {
1743 	struct w1_slave *sl = dev_to_w1_slave(device);
1744 
1745 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1746 		dev_info(device,
1747 			"%s: Device not supported by the driver\n", __func__);
1748 		return 0;  /* No device family */
1749 	}
1750 
1751 	/* get the correct function depending on the device */
1752 	SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1753 	if (SLAVE_RESOLUTION(sl) < 0) {
1754 		dev_dbg(device,
1755 			"%s: Resolution may be corrupted. err=%d\n",
1756 			__func__, SLAVE_RESOLUTION(sl));
1757 	}
1758 
1759 	return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1760 }
1761 
resolution_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1762 static ssize_t resolution_store(struct device *device,
1763 	struct device_attribute *attr, const char *buf, size_t size)
1764 {
1765 	struct w1_slave *sl = dev_to_w1_slave(device);
1766 	int val;
1767 	int ret = 0;
1768 
1769 	ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1770 
1771 	if (ret) {	/* conversion error */
1772 		dev_info(device,
1773 			"%s: conversion error. err= %d\n", __func__, ret);
1774 		return size;	/* return size to avoid call back again */
1775 	}
1776 
1777 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1778 		dev_info(device,
1779 			"%s: Device not supported by the driver\n", __func__);
1780 		return size;  /* No device family */
1781 	}
1782 
1783 	/*
1784 	 * Don't deal with the val enterd by user,
1785 	 * only device knows what is correct or not
1786 	 */
1787 
1788 	/* get the correct function depending on the device */
1789 	ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1790 
1791 	if (ret)
1792 		return ret;
1793 
1794 	SLAVE_RESOLUTION(sl) = val;
1795 	/* Reset the conversion time to default because it depends on resolution */
1796 	SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1797 
1798 	return size;
1799 }
1800 
eeprom_cmd_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1801 static ssize_t eeprom_cmd_store(struct device *device,
1802 	struct device_attribute *attr, const char *buf, size_t size)
1803 {
1804 	struct w1_slave *sl = dev_to_w1_slave(device);
1805 	int ret = -EINVAL; /* Invalid argument */
1806 
1807 	if (size == sizeof(EEPROM_CMD_WRITE)) {
1808 		if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1809 			ret = copy_scratchpad(sl);
1810 	} else if (size == sizeof(EEPROM_CMD_READ)) {
1811 		if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1812 			ret = recall_eeprom(sl);
1813 	}
1814 
1815 	if (ret)
1816 		dev_info(device, "%s: error in process %d\n", __func__, ret);
1817 
1818 	return size;
1819 }
1820 
alarms_show(struct device * device,struct device_attribute * attr,char * buf)1821 static ssize_t alarms_show(struct device *device,
1822 	struct device_attribute *attr, char *buf)
1823 {
1824 	struct w1_slave *sl = dev_to_w1_slave(device);
1825 	int ret;
1826 	s8 th = 0, tl = 0;
1827 	struct therm_info scratchpad;
1828 
1829 	ret = read_scratchpad(sl, &scratchpad);
1830 
1831 	if (!ret)	{
1832 		th = scratchpad.rom[2]; /* TH is byte 2 */
1833 		tl = scratchpad.rom[3]; /* TL is byte 3 */
1834 	} else {
1835 		dev_info(device,
1836 			"%s: error reading alarms register %d\n",
1837 			__func__, ret);
1838 	}
1839 
1840 	return sprintf(buf, "%hd %hd\n", tl, th);
1841 }
1842 
alarms_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1843 static ssize_t alarms_store(struct device *device,
1844 	struct device_attribute *attr, const char *buf, size_t size)
1845 {
1846 	struct w1_slave *sl = dev_to_w1_slave(device);
1847 	struct therm_info info;
1848 	u8 new_config_register[3];	/* array of data to be written */
1849 	int temp, ret;
1850 	char *token = NULL;
1851 	s8 tl, th;	/* 1 byte per value + temp ring order */
1852 	char *p_args, *orig;
1853 
1854 	p_args = orig = kmalloc(size, GFP_KERNEL);
1855 	/* Safe string copys as buf is const */
1856 	if (!p_args) {
1857 		dev_warn(device,
1858 			"%s: error unable to allocate memory %d\n",
1859 			__func__, -ENOMEM);
1860 		return size;
1861 	}
1862 	strcpy(p_args, buf);
1863 
1864 	/* Split string using space char */
1865 	token = strsep(&p_args, " ");
1866 
1867 	if (!token)	{
1868 		dev_info(device,
1869 			"%s: error parsing args %d\n", __func__, -EINVAL);
1870 		goto free_m;
1871 	}
1872 
1873 	/* Convert 1st entry to int */
1874 	ret = kstrtoint (token, 10, &temp);
1875 	if (ret) {
1876 		dev_info(device,
1877 			"%s: error parsing args %d\n", __func__, ret);
1878 		goto free_m;
1879 	}
1880 
1881 	tl = int_to_short(temp);
1882 
1883 	/* Split string using space char */
1884 	token = strsep(&p_args, " ");
1885 	if (!token)	{
1886 		dev_info(device,
1887 			"%s: error parsing args %d\n", __func__, -EINVAL);
1888 		goto free_m;
1889 	}
1890 	/* Convert 2nd entry to int */
1891 	ret = kstrtoint (token, 10, &temp);
1892 	if (ret) {
1893 		dev_info(device,
1894 			"%s: error parsing args %d\n", __func__, ret);
1895 		goto free_m;
1896 	}
1897 
1898 	/* Prepare to cast to short by eliminating out of range values */
1899 	th = int_to_short(temp);
1900 
1901 	/* Reorder if required th and tl */
1902 	if (tl > th)
1903 		swap(tl, th);
1904 
1905 	/*
1906 	 * Read the scratchpad to change only the required bits
1907 	 * (th : byte 2 - tl: byte 3)
1908 	 */
1909 	ret = read_scratchpad(sl, &info);
1910 	if (!ret) {
1911 		new_config_register[0] = th;	/* Byte 2 */
1912 		new_config_register[1] = tl;	/* Byte 3 */
1913 		new_config_register[2] = info.rom[4];/* Byte 4 */
1914 	} else {
1915 		dev_info(device,
1916 			"%s: error reading from the slave device %d\n",
1917 			__func__, ret);
1918 		goto free_m;
1919 	}
1920 
1921 	/* Write data in the device RAM */
1922 	if (!SLAVE_SPECIFIC_FUNC(sl)) {
1923 		dev_info(device,
1924 			"%s: Device not supported by the driver %d\n",
1925 			__func__, -ENODEV);
1926 		goto free_m;
1927 	}
1928 
1929 	ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1930 	if (ret)
1931 		dev_info(device,
1932 			"%s: error writing to the slave device %d\n",
1933 			__func__, ret);
1934 
1935 free_m:
1936 	/* free allocated memory */
1937 	kfree(orig);
1938 
1939 	return size;
1940 }
1941 
therm_bulk_read_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1942 static ssize_t therm_bulk_read_store(struct device *device,
1943 	struct device_attribute *attr, const char *buf, size_t size)
1944 {
1945 	struct w1_master *dev_master = dev_to_w1_master(device);
1946 	int ret = -EINVAL; /* Invalid argument */
1947 
1948 	if (size == sizeof(BULK_TRIGGER_CMD))
1949 		if (!strncmp(buf, BULK_TRIGGER_CMD,
1950 				sizeof(BULK_TRIGGER_CMD)-1))
1951 			ret = trigger_bulk_read(dev_master);
1952 
1953 	if (ret)
1954 		dev_info(device,
1955 			"%s: unable to trigger a bulk read on the bus. err=%d\n",
1956 			__func__, ret);
1957 
1958 	return size;
1959 }
1960 
therm_bulk_read_show(struct device * device,struct device_attribute * attr,char * buf)1961 static ssize_t therm_bulk_read_show(struct device *device,
1962 	struct device_attribute *attr, char *buf)
1963 {
1964 	struct w1_master *dev_master = dev_to_w1_master(device);
1965 	struct w1_slave *sl = NULL;
1966 	int ret = 0;
1967 
1968 	list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1969 		if (sl->family_data) {
1970 			if (bulk_read_support(sl)) {
1971 				if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1972 					ret = -1;
1973 					goto show_result;
1974 				}
1975 				if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1976 					/* continue to check other slaves */
1977 					ret = 1;
1978 			}
1979 		}
1980 	}
1981 show_result:
1982 	return sprintf(buf, "%d\n", ret);
1983 }
1984 
conv_time_show(struct device * device,struct device_attribute * attr,char * buf)1985 static ssize_t conv_time_show(struct device *device,
1986 	struct device_attribute *attr, char *buf)
1987 {
1988 	struct w1_slave *sl = dev_to_w1_slave(device);
1989 
1990 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1991 		dev_info(device,
1992 			"%s: Device is not supported by the driver\n", __func__);
1993 		return 0;  /* No device family */
1994 	}
1995 	return sprintf(buf, "%d\n", conversion_time(sl));
1996 }
1997 
conv_time_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1998 static ssize_t conv_time_store(struct device *device,
1999 	struct device_attribute *attr, const char *buf, size_t size)
2000 {
2001 	int val, ret = 0;
2002 	struct w1_slave *sl = dev_to_w1_slave(device);
2003 
2004 	if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
2005 		return -EINVAL;
2006 
2007 	if (check_family_data(sl))
2008 		return -ENODEV;
2009 
2010 	if (val != CONV_TIME_MEASURE) {
2011 		if (val >= CONV_TIME_DEFAULT)
2012 			SLAVE_CONV_TIME_OVERRIDE(sl) = val;
2013 		else
2014 			return -EINVAL;
2015 
2016 	} else {
2017 		int conv_time;
2018 
2019 		ret = conv_time_measure(sl, &conv_time);
2020 		if (ret)
2021 			return -EIO;
2022 		SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
2023 	}
2024 	return size;
2025 }
2026 
features_show(struct device * device,struct device_attribute * attr,char * buf)2027 static ssize_t features_show(struct device *device,
2028 			     struct device_attribute *attr, char *buf)
2029 {
2030 	struct w1_slave *sl = dev_to_w1_slave(device);
2031 
2032 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
2033 		dev_info(device,
2034 			 "%s: Device not supported by the driver\n", __func__);
2035 		return 0;  /* No device family */
2036 	}
2037 	return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
2038 }
2039 
features_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)2040 static ssize_t features_store(struct device *device,
2041 			      struct device_attribute *attr, const char *buf, size_t size)
2042 {
2043 	int val, ret = 0;
2044 	bool strong_pullup;
2045 	struct w1_slave *sl = dev_to_w1_slave(device);
2046 
2047 	ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
2048 	if (ret)
2049 		return -EINVAL;  /* invalid number */
2050 
2051 	if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
2052 		dev_info(device, "%s: Device not supported by the driver\n", __func__);
2053 		return -ENODEV;
2054 	}
2055 
2056 	if ((val & W1_THERM_FEATURES_MASK) != val)
2057 		return -EINVAL;
2058 
2059 	SLAVE_FEATURES(sl) = val;
2060 
2061 	strong_pullup = (w1_strong_pullup == 2 ||
2062 			 (!SLAVE_POWERMODE(sl) &&
2063 			  w1_strong_pullup));
2064 
2065 	if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2066 		dev_warn(&sl->dev,
2067 			 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2068 			 __func__);
2069 		SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2070 	}
2071 
2072 	return size;
2073 }
2074 
2075 #if IS_REACHABLE(CONFIG_HWMON)
w1_read_temp(struct device * device,u32 attr,int channel,long * val)2076 static int w1_read_temp(struct device *device, u32 attr, int channel,
2077 			long *val)
2078 {
2079 	struct w1_slave *sl = dev_get_drvdata(device);
2080 	struct therm_info info;
2081 	int ret;
2082 
2083 	switch (attr) {
2084 	case hwmon_temp_input:
2085 		ret = convert_t(sl, &info);
2086 		if (ret)
2087 			return ret;
2088 
2089 		if (!info.verdict) {
2090 			ret = -EIO;
2091 			return ret;
2092 		}
2093 
2094 		*val = temperature_from_RAM(sl, info.rom);
2095 		ret = 0;
2096 		break;
2097 	default:
2098 		ret = -EOPNOTSUPP;
2099 		break;
2100 	}
2101 
2102 	return ret;
2103 }
2104 #endif
2105 
2106 #define W1_42_CHAIN	0x99
2107 #define W1_42_CHAIN_OFF	0x3C
2108 #define W1_42_CHAIN_OFF_INV	0xC3
2109 #define W1_42_CHAIN_ON	0x5A
2110 #define W1_42_CHAIN_ON_INV	0xA5
2111 #define W1_42_CHAIN_DONE 0x96
2112 #define W1_42_CHAIN_DONE_INV 0x69
2113 #define W1_42_COND_READ	0x0F
2114 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2115 #define W1_42_FINISHED_BYTE 0xFF
w1_seq_show(struct device * device,struct device_attribute * attr,char * buf)2116 static ssize_t w1_seq_show(struct device *device,
2117 	struct device_attribute *attr, char *buf)
2118 {
2119 	struct w1_slave *sl = dev_to_w1_slave(device);
2120 	ssize_t c = PAGE_SIZE;
2121 	int i;
2122 	u8 ack;
2123 	u64 rn;
2124 	struct w1_reg_num *reg_num;
2125 	int seq = 0;
2126 
2127 	mutex_lock(&sl->master->bus_mutex);
2128 	/* Place all devices in CHAIN state */
2129 	if (w1_reset_bus(sl->master))
2130 		goto error;
2131 	w1_write_8(sl->master, W1_SKIP_ROM);
2132 	w1_write_8(sl->master, W1_42_CHAIN);
2133 	w1_write_8(sl->master, W1_42_CHAIN_ON);
2134 	w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2135 	msleep(sl->master->pullup_duration);
2136 
2137 	/* check for acknowledgment */
2138 	ack = w1_read_8(sl->master);
2139 	if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2140 		goto error;
2141 
2142 	/* In case the bus fails to send 0xFF, limit */
2143 	for (i = 0; i <= 64; i++) {
2144 		if (w1_reset_bus(sl->master))
2145 			goto error;
2146 
2147 		w1_write_8(sl->master, W1_42_COND_READ);
2148 		w1_read_block(sl->master, (u8 *)&rn, 8);
2149 		reg_num = (struct w1_reg_num *) &rn;
2150 		if (reg_num->family == W1_42_FINISHED_BYTE)
2151 			break;
2152 		if (sl->reg_num.id == reg_num->id)
2153 			seq = i;
2154 
2155 		if (w1_reset_bus(sl->master))
2156 			goto error;
2157 
2158 		/* Put the device into chain DONE state */
2159 		w1_write_8(sl->master, W1_MATCH_ROM);
2160 		w1_write_block(sl->master, (u8 *)&rn, 8);
2161 		w1_write_8(sl->master, W1_42_CHAIN);
2162 		w1_write_8(sl->master, W1_42_CHAIN_DONE);
2163 		w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2164 
2165 		/* check for acknowledgment */
2166 		ack = w1_read_8(sl->master);
2167 		if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2168 			goto error;
2169 	}
2170 
2171 	/* Exit from CHAIN state */
2172 	if (w1_reset_bus(sl->master))
2173 		goto error;
2174 	w1_write_8(sl->master, W1_SKIP_ROM);
2175 	w1_write_8(sl->master, W1_42_CHAIN);
2176 	w1_write_8(sl->master, W1_42_CHAIN_OFF);
2177 	w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
2178 
2179 	/* check for acknowledgment */
2180 	ack = w1_read_8(sl->master);
2181 	if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2182 		goto error;
2183 	mutex_unlock(&sl->master->bus_mutex);
2184 
2185 	c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
2186 	return PAGE_SIZE - c;
2187 error:
2188 	mutex_unlock(&sl->master->bus_mutex);
2189 	return -EIO;
2190 }
2191 
w1_therm_init(void)2192 static int __init w1_therm_init(void)
2193 {
2194 	int err, i;
2195 
2196 	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
2197 		err = w1_register_family(w1_therm_families[i].f);
2198 		if (err)
2199 			w1_therm_families[i].broken = 1;
2200 	}
2201 
2202 	return 0;
2203 }
2204 
w1_therm_fini(void)2205 static void __exit w1_therm_fini(void)
2206 {
2207 	int i;
2208 
2209 	for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
2210 		if (!w1_therm_families[i].broken)
2211 			w1_unregister_family(w1_therm_families[i].f);
2212 }
2213 
2214 module_init(w1_therm_init);
2215 module_exit(w1_therm_fini);
2216 
2217 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
2218 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
2219 MODULE_LICENSE("GPL");
2220 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
2221 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
2222 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
2223 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
2224 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
2225