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