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 struct hwmon_channel_info * const w1_info[] = {
448 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
449 NULL
450 };
451
452 static const struct hwmon_ops w1_hwmon_ops = {
453 .is_visible = w1_is_visible,
454 .read = w1_read,
455 };
456
457 static const struct hwmon_chip_info w1_chip_info = {
458 .ops = &w1_hwmon_ops,
459 .info = w1_info,
460 };
461 #define W1_CHIPINFO (&w1_chip_info)
462 #else
463 #define W1_CHIPINFO NULL
464 #endif
465
466 /* Family operations */
467
468 static const struct w1_family_ops w1_therm_fops = {
469 .add_slave = w1_therm_add_slave,
470 .remove_slave = w1_therm_remove_slave,
471 .groups = w1_therm_groups,
472 .chip_info = W1_CHIPINFO,
473 };
474
475 static const struct w1_family_ops w1_ds18s20_fops = {
476 .add_slave = w1_therm_add_slave,
477 .remove_slave = w1_therm_remove_slave,
478 .groups = w1_ds18s20_groups,
479 .chip_info = W1_CHIPINFO,
480 };
481
482 static const struct w1_family_ops w1_ds28ea00_fops = {
483 .add_slave = w1_therm_add_slave,
484 .remove_slave = w1_therm_remove_slave,
485 .groups = w1_ds28ea00_groups,
486 .chip_info = W1_CHIPINFO,
487 };
488
489 /* Family binding operations struct */
490
491 static struct w1_family w1_therm_family_DS18S20 = {
492 .fid = W1_THERM_DS18S20,
493 .fops = &w1_ds18s20_fops,
494 };
495
496 static struct w1_family w1_therm_family_DS18B20 = {
497 .fid = W1_THERM_DS18B20,
498 .fops = &w1_therm_fops,
499 };
500
501 static struct w1_family w1_therm_family_DS1822 = {
502 .fid = W1_THERM_DS1822,
503 .fops = &w1_therm_fops,
504 };
505
506 static struct w1_family w1_therm_family_DS28EA00 = {
507 .fid = W1_THERM_DS28EA00,
508 .fops = &w1_ds28ea00_fops,
509 };
510
511 static struct w1_family w1_therm_family_DS1825 = {
512 .fid = W1_THERM_DS1825,
513 .fops = &w1_therm_fops,
514 };
515
516 /* Device dependent func */
517
w1_DS18B20_convert_time(struct w1_slave * sl)518 static inline int w1_DS18B20_convert_time(struct w1_slave *sl)
519 {
520 int ret;
521
522 if (!sl->family_data)
523 return -ENODEV; /* device unknown */
524
525 if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT)
526 return SLAVE_CONV_TIME_OVERRIDE(sl);
527
528 /* Return the conversion time, depending on resolution,
529 * select maximum conversion time among all compatible devices
530 */
531 switch (SLAVE_RESOLUTION(sl)) {
532 case 9:
533 ret = 95;
534 break;
535 case 10:
536 ret = 190;
537 break;
538 case 11:
539 ret = 375;
540 break;
541 case 12:
542 ret = 750;
543 break;
544 case 13:
545 ret = 850; /* GX20MH01 only. Datasheet says 500ms, but that's not enough. */
546 break;
547 case 14:
548 ret = 1600; /* GX20MH01 only. Datasheet says 1000ms - not enough */
549 break;
550 default:
551 ret = 750;
552 }
553 return ret;
554 }
555
w1_DS18S20_convert_time(struct w1_slave * sl)556 static inline int w1_DS18S20_convert_time(struct w1_slave *sl)
557 {
558 if (!sl->family_data)
559 return -ENODEV; /* device unknown */
560
561 if (SLAVE_CONV_TIME_OVERRIDE(sl) == CONV_TIME_DEFAULT)
562 return 750; /* default for DS18S20 */
563 else
564 return SLAVE_CONV_TIME_OVERRIDE(sl);
565 }
566
w1_DS1825_convert_time(struct w1_slave * sl)567 static inline int w1_DS1825_convert_time(struct w1_slave *sl)
568 {
569 int ret;
570
571 if (!sl->family_data)
572 return -ENODEV; /* device unknown */
573
574 if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT)
575 return SLAVE_CONV_TIME_OVERRIDE(sl);
576
577 /* Return the conversion time, depending on resolution,
578 * select maximum conversion time among all compatible devices
579 */
580 switch (SLAVE_RESOLUTION(sl)) {
581 case 9:
582 ret = 95;
583 break;
584 case 10:
585 ret = 190;
586 break;
587 case 11:
588 ret = 375;
589 break;
590 case 12:
591 ret = 750;
592 break;
593 case 14:
594 ret = 100; /* MAX31850 only. Datasheet says 100ms */
595 break;
596 default:
597 ret = 750;
598 }
599 return ret;
600 }
601
w1_DS18B20_write_data(struct w1_slave * sl,const u8 * data)602 static inline int w1_DS18B20_write_data(struct w1_slave *sl,
603 const u8 *data)
604 {
605 return write_scratchpad(sl, data, 3);
606 }
607
w1_DS18S20_write_data(struct w1_slave * sl,const u8 * data)608 static inline int w1_DS18S20_write_data(struct w1_slave *sl,
609 const u8 *data)
610 {
611 /* No config register */
612 return write_scratchpad(sl, data, 2);
613 }
614
w1_DS18B20_set_resolution(struct w1_slave * sl,int val)615 static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val)
616 {
617 int ret;
618 struct therm_info info, info2;
619
620 /* DS18B20 resolution is 9 to 12 bits */
621 /* GX20MH01 resolution is 9 to 14 bits */
622 /* MAX31850 resolution is fixed 14 bits */
623 if (val < W1_THERM_RESOLUTION_MIN || val > W1_THERM_RESOLUTION_MAX)
624 return -EINVAL;
625
626 /* Calc bit value from resolution */
627 val = (val - W1_THERM_RESOLUTION_MIN) << W1_THERM_RESOLUTION_SHIFT;
628
629 /*
630 * Read the scratchpad to change only the required bits
631 * (bit5 & bit 6 from byte 4)
632 */
633 ret = read_scratchpad(sl, &info);
634
635 if (ret)
636 return ret;
637
638
639 info.rom[4] &= ~W1_THERM_RESOLUTION_MASK;
640 info.rom[4] |= val;
641
642 /* Write data in the device RAM */
643 ret = w1_DS18B20_write_data(sl, info.rom + 2);
644 if (ret)
645 return ret;
646
647 /* Have to read back the resolution to verify an actual value
648 * GX20MH01 and DS18B20 are indistinguishable by family number, but resolutions differ
649 * Some DS18B20 clones don't support resolution change
650 */
651 ret = read_scratchpad(sl, &info2);
652 if (ret)
653 /* Scratchpad read fail */
654 return ret;
655
656 if ((info2.rom[4] & W1_THERM_RESOLUTION_MASK) == (info.rom[4] & W1_THERM_RESOLUTION_MASK))
657 return 0;
658
659 /* Resolution verify error */
660 return -EIO;
661 }
662
w1_DS18B20_get_resolution(struct w1_slave * sl)663 static inline int w1_DS18B20_get_resolution(struct w1_slave *sl)
664 {
665 int ret;
666 int resolution;
667 struct therm_info info;
668
669 ret = read_scratchpad(sl, &info);
670
671 if (ret)
672 return ret;
673
674 resolution = ((info.rom[4] & W1_THERM_RESOLUTION_MASK) >> W1_THERM_RESOLUTION_SHIFT)
675 + W1_THERM_RESOLUTION_MIN;
676 /* GX20MH01 has one special case:
677 * >=14 means 14 bits when getting resolution from bit value.
678 * MAX31850 delivers fixed 15 and has 14 bits.
679 * Other devices have no more then 12 bits.
680 */
681 if (resolution > W1_THERM_RESOLUTION_MAX)
682 resolution = W1_THERM_RESOLUTION_MAX;
683
684 return resolution;
685 }
686
687 /**
688 * w1_DS18B20_convert_temp() - temperature computation for DS18B20
689 * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
690 *
691 * Can be called for any DS18B20 compliant device.
692 *
693 * Return: value in millidegrees Celsius.
694 */
w1_DS18B20_convert_temp(u8 rom[9])695 static inline int w1_DS18B20_convert_temp(u8 rom[9])
696 {
697 u16 bv;
698 s16 t;
699
700 /* Signed 16-bit value to unsigned, cpu order */
701 bv = le16_to_cpup((__le16 *)rom);
702
703 /* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */
704 if (rom[4] & 0x80) {
705 /* Insert two temperature bits from config register */
706 /* Avoid arithmetic shift of signed value */
707 bv = (bv << 2) | (rom[4] & 3);
708 t = (s16) bv; /* Degrees, lowest bit is 2^-6 */
709 return (int)t * 1000 / 64; /* Sign-extend to int; millidegrees */
710 }
711 t = (s16)bv; /* Degrees, lowest bit is 2^-4 */
712 return (int)t * 1000 / 16; /* Sign-extend to int; millidegrees */
713 }
714
715 /**
716 * w1_DS18S20_convert_temp() - temperature computation for DS18S20
717 * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
718 *
719 * Can be called for any DS18S20 compliant device.
720 *
721 * Return: value in millidegrees Celsius.
722 */
w1_DS18S20_convert_temp(u8 rom[9])723 static inline int w1_DS18S20_convert_temp(u8 rom[9])
724 {
725 int t, h;
726
727 if (!rom[7]) {
728 pr_debug("%s: Invalid argument for conversion\n", __func__);
729 return 0;
730 }
731
732 if (rom[1] == 0)
733 t = ((s32)rom[0] >> 1)*1000;
734 else
735 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
736
737 t -= 250;
738 h = 1000*((s32)rom[7] - (s32)rom[6]);
739 h /= (s32)rom[7];
740 t += h;
741
742 return t;
743 }
744
745 /**
746 * w1_DS1825_convert_temp() - temperature computation for DS1825
747 * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
748 *
749 * Can be called for any DS1825 compliant device.
750 * Is used by MAX31850, too
751 *
752 * Return: value in millidegrees Celsius.
753 */
754
w1_DS1825_convert_temp(u8 rom[9])755 static inline int w1_DS1825_convert_temp(u8 rom[9])
756 {
757 u16 bv;
758 s16 t;
759
760 /* Signed 16-bit value to unsigned, cpu order */
761 bv = le16_to_cpup((__le16 *)rom);
762
763 /* Config register bit 7 = 1 - MA31850 found, 14 bit resolution */
764 if (rom[4] & 0x80) {
765 /* Mask out bits 0 (Fault) and 1 (Reserved) */
766 /* Avoid arithmetic shift of signed value */
767 bv = (bv & 0xFFFC); /* Degrees, lowest 4 bits are 2^-1, 2^-2 and 2 zero bits */
768 }
769 t = (s16)bv; /* Degrees, lowest bit is 2^-4 */
770 return (int)t * 1000 / 16; /* Sign-extend to int; millidegrees */
771 }
772
773 /* Device capability description */
774 /* GX20MH01 device shares family number and structure with DS18B20 */
775
776 static struct w1_therm_family_converter w1_therm_families[] = {
777 {
778 .f = &w1_therm_family_DS18S20,
779 .convert = w1_DS18S20_convert_temp,
780 .get_conversion_time = w1_DS18S20_convert_time,
781 .set_resolution = NULL, /* no config register */
782 .get_resolution = NULL, /* no config register */
783 .write_data = w1_DS18S20_write_data,
784 .bulk_read = true
785 },
786 {
787 .f = &w1_therm_family_DS1822,
788 .convert = w1_DS18B20_convert_temp,
789 .get_conversion_time = w1_DS18B20_convert_time,
790 .set_resolution = w1_DS18B20_set_resolution,
791 .get_resolution = w1_DS18B20_get_resolution,
792 .write_data = w1_DS18B20_write_data,
793 .bulk_read = true
794 },
795 {
796 /* Also used for GX20MH01 */
797 .f = &w1_therm_family_DS18B20,
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 .f = &w1_therm_family_DS28EA00,
807 .convert = w1_DS18B20_convert_temp,
808 .get_conversion_time = w1_DS18B20_convert_time,
809 .set_resolution = w1_DS18B20_set_resolution,
810 .get_resolution = w1_DS18B20_get_resolution,
811 .write_data = w1_DS18B20_write_data,
812 .bulk_read = false
813 },
814 {
815 /* Also used for MAX31850 */
816 .f = &w1_therm_family_DS1825,
817 .convert = w1_DS1825_convert_temp,
818 .get_conversion_time = w1_DS1825_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 = true
823 }
824 };
825
826 /* Helpers Functions */
827
828 /**
829 * device_family() - Retrieve a pointer on &struct w1_therm_family_converter
830 * @sl: slave to retrieve the device specific structure
831 *
832 * Return: pointer to the slaves's family converter, NULL if not known
833 */
device_family(struct w1_slave * sl)834 static struct w1_therm_family_converter *device_family(struct w1_slave *sl)
835 {
836 struct w1_therm_family_converter *ret = NULL;
837 int i;
838
839 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
840 if (w1_therm_families[i].f->fid == sl->family->fid) {
841 ret = &w1_therm_families[i];
842 break;
843 }
844 }
845 return ret;
846 }
847
848 /**
849 * bus_mutex_lock() - Acquire the mutex
850 * @lock: w1 bus mutex to acquire
851 *
852 * It try to acquire the mutex W1_THERM_MAX_TRY times and wait
853 * W1_THERM_RETRY_DELAY between 2 attempts.
854 *
855 * Return: true is mutex is acquired and lock, false otherwise
856 */
bus_mutex_lock(struct mutex * lock)857 static inline bool bus_mutex_lock(struct mutex *lock)
858 {
859 int max_trying = W1_THERM_MAX_TRY;
860
861 /* try to acquire the mutex, if not, sleep retry_delay before retry) */
862 while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) {
863 unsigned long sleep_rem;
864
865 sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY);
866 if (!sleep_rem)
867 max_trying--;
868 }
869
870 if (!max_trying)
871 return false; /* Didn't acquire the bus mutex */
872
873 return true;
874 }
875
876 /**
877 * check_family_data() - Check if family data and specific functions are present
878 * @sl: W1 device data
879 *
880 * Return: 0 - OK, negative value - error
881 */
check_family_data(struct w1_slave * sl)882 static int check_family_data(struct w1_slave *sl)
883 {
884 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
885 dev_info(&sl->dev,
886 "%s: Device is not supported by the driver\n", __func__);
887 return -EINVAL; /* No device family */
888 }
889 return 0;
890 }
891
892 /**
893 * bulk_read_support() - check if slave support bulk read
894 * @sl: device to check the ability
895 *
896 * Return: true if bulk read is supported, false if not or error
897 */
bulk_read_support(struct w1_slave * sl)898 static inline bool bulk_read_support(struct w1_slave *sl)
899 {
900 if (SLAVE_SPECIFIC_FUNC(sl))
901 return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
902
903 dev_info(&sl->dev,
904 "%s: Device not supported by the driver\n", __func__);
905
906 return false; /* No device family */
907 }
908
909 /**
910 * conversion_time() - get the Tconv for the slave
911 * @sl: device to get the conversion time
912 *
913 * On device supporting resolution settings, conversion time depend
914 * on the resolution setting. This helper function get the slave timing,
915 * depending on its current setting.
916 *
917 * Return: conversion time in ms, negative values are kernel error code
918 */
conversion_time(struct w1_slave * sl)919 static inline int conversion_time(struct w1_slave *sl)
920 {
921 if (SLAVE_SPECIFIC_FUNC(sl))
922 return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
923
924 dev_info(&sl->dev,
925 "%s: Device not supported by the driver\n", __func__);
926
927 return -ENODEV; /* No device family */
928 }
929
930 /**
931 * temperature_from_RAM() - Convert the read info to temperature
932 * @sl: device that sent the RAM data
933 * @rom: read value on the slave device RAM
934 *
935 * Device dependent, the function bind the correct computation method.
936 *
937 * Return: temperature in 1/1000degC, 0 on error.
938 */
temperature_from_RAM(struct w1_slave * sl,u8 rom[9])939 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
940 {
941 if (SLAVE_SPECIFIC_FUNC(sl))
942 return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
943
944 dev_info(&sl->dev,
945 "%s: Device not supported by the driver\n", __func__);
946
947 return 0; /* No device family */
948 }
949
950 /**
951 * int_to_short() - Safe casting of int to short
952 *
953 * @i: integer to be converted to short
954 *
955 * Device register use 1 byte to store signed integer.
956 * This helper function convert the int in a signed short,
957 * using the min/max values that device can measure as limits.
958 * min/max values are defined by macro.
959 *
960 * Return: a short in the range of min/max value
961 */
int_to_short(int i)962 static inline s8 int_to_short(int i)
963 {
964 /* Prepare to cast to short by eliminating out of range values */
965 i = clamp(i, MIN_TEMP, MAX_TEMP);
966 return (s8) i;
967 }
968
969 /* Interface Functions */
970
w1_therm_add_slave(struct w1_slave * sl)971 static int w1_therm_add_slave(struct w1_slave *sl)
972 {
973 struct w1_therm_family_converter *sl_family_conv;
974
975 /* Allocate memory */
976 sl->family_data = kzalloc_obj(struct w1_therm_family_data);
977 if (!sl->family_data)
978 return -ENOMEM;
979
980 atomic_set(THERM_REFCNT(sl->family_data), 1);
981
982 /* Get a pointer to the device specific function struct */
983 sl_family_conv = device_family(sl);
984 if (!sl_family_conv) {
985 kfree(sl->family_data);
986 return -ENODEV;
987 }
988 /* save this pointer to the device structure */
989 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
990
991 if (bulk_read_support(sl)) {
992 /*
993 * add the sys entry to trigger bulk_read
994 * at master level only the 1st time
995 */
996 if (!bulk_read_device_counter) {
997 int err = device_create_file(&sl->master->dev,
998 &dev_attr_therm_bulk_read);
999
1000 if (err)
1001 dev_warn(&sl->dev,
1002 "%s: Device has been added, but bulk read is unavailable. err=%d\n",
1003 __func__, err);
1004 }
1005 /* Increment the counter */
1006 bulk_read_device_counter++;
1007 }
1008
1009 /* Getting the power mode of the device {external, parasite} */
1010 SLAVE_POWERMODE(sl) = read_powermode(sl);
1011
1012 if (SLAVE_POWERMODE(sl) < 0) {
1013 /* no error returned as device has been added */
1014 dev_warn(&sl->dev,
1015 "%s: Device has been added, but power_mode may be corrupted. err=%d\n",
1016 __func__, SLAVE_POWERMODE(sl));
1017 }
1018
1019 /* Getting the resolution of the device */
1020 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
1021 SLAVE_RESOLUTION(sl) =
1022 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1023 if (SLAVE_RESOLUTION(sl) < 0) {
1024 /* no error returned as device has been added */
1025 dev_warn(&sl->dev,
1026 "%s:Device has been added, but resolution may be corrupted. err=%d\n",
1027 __func__, SLAVE_RESOLUTION(sl));
1028 }
1029 }
1030
1031 /* Finally initialize convert_triggered flag */
1032 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1033
1034 return 0;
1035 }
1036
w1_therm_remove_slave(struct w1_slave * sl)1037 static void w1_therm_remove_slave(struct w1_slave *sl)
1038 {
1039 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
1040
1041 if (bulk_read_support(sl)) {
1042 bulk_read_device_counter--;
1043 /* Delete the entry if no more device support the feature */
1044 if (!bulk_read_device_counter)
1045 device_remove_file(&sl->master->dev,
1046 &dev_attr_therm_bulk_read);
1047 }
1048
1049 while (refcnt) {
1050 msleep(1000);
1051 refcnt = atomic_read(THERM_REFCNT(sl->family_data));
1052 }
1053 kfree(sl->family_data);
1054 sl->family_data = NULL;
1055 }
1056
1057 /* Hardware Functions */
1058
1059 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
reset_select_slave(struct w1_slave * sl)1060 static int reset_select_slave(struct w1_slave *sl)
1061 {
1062 u8 match[9] = { W1_MATCH_ROM, };
1063 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1064
1065 if (w1_reset_bus(sl->master))
1066 return -ENODEV;
1067
1068 memcpy(&match[1], &rn, 8);
1069 w1_write_block(sl->master, match, 9);
1070
1071 return 0;
1072 }
1073
1074 /**
1075 * w1_poll_completion - Poll for operation completion, with timeout
1076 * @dev_master: the device master of the bus
1077 * @tout_ms: timeout in milliseconds
1078 *
1079 * The device is answering 0's while an operation is in progress and 1's after it completes
1080 * Timeout may happen if the previous command was not recognised due to a line noise
1081 *
1082 * Return: 0 - OK, negative error - timeout
1083 */
w1_poll_completion(struct w1_master * dev_master,int tout_ms)1084 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1085 {
1086 int i;
1087
1088 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1089 /* Delay is before poll, for device to recognize a command */
1090 msleep(W1_POLL_PERIOD);
1091
1092 /* Compare all 8 bits to mitigate a noise on the bus */
1093 if (w1_read_8(dev_master) == 0xFF)
1094 break;
1095 }
1096 if (i == tout_ms/W1_POLL_PERIOD)
1097 return -EIO;
1098
1099 return 0;
1100 }
1101
convert_t(struct w1_slave * sl,struct therm_info * info)1102 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1103 {
1104 struct w1_master *dev_master = sl->master;
1105 int max_trying = W1_THERM_MAX_TRY;
1106 int t_conv;
1107 int ret = -ENODEV;
1108 bool strong_pullup;
1109
1110 if (!sl->family_data)
1111 goto error;
1112
1113 strong_pullup = (w1_strong_pullup == 2 ||
1114 (!SLAVE_POWERMODE(sl) &&
1115 w1_strong_pullup));
1116
1117 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1118 dev_warn(&sl->dev,
1119 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1120 __func__);
1121 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1122 }
1123
1124 /* get conversion duration device and id dependent */
1125 t_conv = conversion_time(sl);
1126
1127 memset(info->rom, 0, sizeof(info->rom));
1128
1129 /* prevent the slave from going away in sleep */
1130 atomic_inc(THERM_REFCNT(sl->family_data));
1131
1132 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1133 ret = -EAGAIN; /* Didn't acquire the mutex */
1134 goto dec_refcnt;
1135 }
1136
1137 while (max_trying-- && ret) { /* ret should be 0 */
1138
1139 info->verdict = 0;
1140 info->crc = 0;
1141 /* safe version to select slave */
1142 if (!reset_select_slave(sl)) {
1143 unsigned long sleep_rem;
1144
1145 /* 750ms strong pullup (or delay) after the convert */
1146 if (strong_pullup)
1147 w1_next_pullup(dev_master, t_conv);
1148
1149 w1_write_8(dev_master, W1_CONVERT_TEMP);
1150
1151 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1152 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1153 if (ret) {
1154 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1155 goto mt_unlock;
1156 }
1157 mutex_unlock(&dev_master->bus_mutex);
1158 } else if (!strong_pullup) { /*no device need pullup */
1159 sleep_rem = msleep_interruptible(t_conv);
1160 if (sleep_rem != 0) {
1161 ret = -EINTR;
1162 goto mt_unlock;
1163 }
1164 mutex_unlock(&dev_master->bus_mutex);
1165 } else { /*some device need pullup */
1166 mutex_unlock(&dev_master->bus_mutex);
1167 sleep_rem = msleep_interruptible(t_conv);
1168 if (sleep_rem != 0) {
1169 ret = -EINTR;
1170 goto dec_refcnt;
1171 }
1172 }
1173 ret = read_scratchpad(sl, info);
1174
1175 /* If enabled, check for conversion success */
1176 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1177 (info->rom[6] == 0xC) &&
1178 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1179 (info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1180 ) {
1181 /* Invalid reading (scratchpad byte 6 = 0xC)
1182 * due to insufficient conversion time
1183 * or power failure.
1184 */
1185 ret = -EIO;
1186 }
1187
1188 goto dec_refcnt;
1189 }
1190
1191 }
1192
1193 mt_unlock:
1194 mutex_unlock(&dev_master->bus_mutex);
1195 dec_refcnt:
1196 atomic_dec(THERM_REFCNT(sl->family_data));
1197 error:
1198 return ret;
1199 }
1200
conv_time_measure(struct w1_slave * sl,int * conv_time)1201 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1202 {
1203 struct therm_info inf,
1204 *info = &inf;
1205 struct w1_master *dev_master = sl->master;
1206 int max_trying = W1_THERM_MAX_TRY;
1207 int ret = -ENODEV;
1208 bool strong_pullup;
1209
1210 if (!sl->family_data)
1211 goto error;
1212
1213 strong_pullup = (w1_strong_pullup == 2 ||
1214 (!SLAVE_POWERMODE(sl) &&
1215 w1_strong_pullup));
1216
1217 if (strong_pullup) {
1218 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1219 return -EINVAL;
1220 }
1221
1222 memset(info->rom, 0, sizeof(info->rom));
1223
1224 /* prevent the slave from going away in sleep */
1225 atomic_inc(THERM_REFCNT(sl->family_data));
1226
1227 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1228 ret = -EAGAIN; /* Didn't acquire the mutex */
1229 goto dec_refcnt;
1230 }
1231
1232 while (max_trying-- && ret) { /* ret should be 0 */
1233 info->verdict = 0;
1234 info->crc = 0;
1235 /* safe version to select slave */
1236 if (!reset_select_slave(sl)) {
1237 int j_start, j_end;
1238
1239 /*no device need pullup */
1240 w1_write_8(dev_master, W1_CONVERT_TEMP);
1241
1242 j_start = jiffies;
1243 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1244 if (ret) {
1245 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1246 goto mt_unlock;
1247 }
1248 j_end = jiffies;
1249 /* 1.2x increase for variation and changes over temperature range */
1250 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1251 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1252 *conv_time, HZ);
1253 if (*conv_time <= CONV_TIME_MEASURE) {
1254 ret = -EIO;
1255 goto mt_unlock;
1256 }
1257 mutex_unlock(&dev_master->bus_mutex);
1258 ret = read_scratchpad(sl, info);
1259 goto dec_refcnt;
1260 }
1261
1262 }
1263 mt_unlock:
1264 mutex_unlock(&dev_master->bus_mutex);
1265 dec_refcnt:
1266 atomic_dec(THERM_REFCNT(sl->family_data));
1267 error:
1268 return ret;
1269 }
1270
read_scratchpad(struct w1_slave * sl,struct therm_info * info)1271 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1272 {
1273 struct w1_master *dev_master = sl->master;
1274 int max_trying = W1_THERM_MAX_TRY;
1275 int ret = -ENODEV;
1276
1277 info->verdict = 0;
1278
1279 if (!sl->family_data)
1280 goto error;
1281
1282 memset(info->rom, 0, sizeof(info->rom));
1283
1284 /* prevent the slave from going away in sleep */
1285 atomic_inc(THERM_REFCNT(sl->family_data));
1286
1287 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1288 ret = -EAGAIN; /* Didn't acquire the mutex */
1289 goto dec_refcnt;
1290 }
1291
1292 while (max_trying-- && ret) { /* ret should be 0 */
1293 /* safe version to select slave */
1294 if (!reset_select_slave(sl)) {
1295 u8 nb_bytes_read;
1296
1297 w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1298
1299 nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1300 if (nb_bytes_read != 9) {
1301 dev_warn(&sl->dev,
1302 "w1_read_block(): returned %u instead of 9.\n",
1303 nb_bytes_read);
1304 ret = -EIO;
1305 }
1306
1307 info->crc = w1_calc_crc8(info->rom, 8);
1308
1309 if (info->rom[8] == info->crc) {
1310 info->verdict = 1;
1311 ret = 0;
1312 } else
1313 ret = -EIO; /* CRC not checked */
1314 }
1315
1316 }
1317 mutex_unlock(&dev_master->bus_mutex);
1318
1319 dec_refcnt:
1320 atomic_dec(THERM_REFCNT(sl->family_data));
1321 error:
1322 return ret;
1323 }
1324
write_scratchpad(struct w1_slave * sl,const u8 * data,u8 nb_bytes)1325 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1326 {
1327 struct w1_master *dev_master = sl->master;
1328 int max_trying = W1_THERM_MAX_TRY;
1329 int ret = -ENODEV;
1330
1331 if (!sl->family_data)
1332 goto error;
1333
1334 /* prevent the slave from going away in sleep */
1335 atomic_inc(THERM_REFCNT(sl->family_data));
1336
1337 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1338 ret = -EAGAIN; /* Didn't acquire the mutex */
1339 goto dec_refcnt;
1340 }
1341
1342 while (max_trying-- && ret) { /* ret should be 0 */
1343 /* safe version to select slave */
1344 if (!reset_select_slave(sl)) {
1345 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1346 w1_write_block(dev_master, data, nb_bytes);
1347 ret = 0;
1348 }
1349 }
1350 mutex_unlock(&dev_master->bus_mutex);
1351
1352 dec_refcnt:
1353 atomic_dec(THERM_REFCNT(sl->family_data));
1354 error:
1355 return ret;
1356 }
1357
copy_scratchpad(struct w1_slave * sl)1358 static int copy_scratchpad(struct w1_slave *sl)
1359 {
1360 struct w1_master *dev_master = sl->master;
1361 int max_trying = W1_THERM_MAX_TRY;
1362 int t_write, ret = -ENODEV;
1363 bool strong_pullup;
1364
1365 if (!sl->family_data)
1366 goto error;
1367
1368 t_write = W1_THERM_EEPROM_WRITE_DELAY;
1369 strong_pullup = (w1_strong_pullup == 2 ||
1370 (!SLAVE_POWERMODE(sl) &&
1371 w1_strong_pullup));
1372
1373 /* prevent the slave from going away in sleep */
1374 atomic_inc(THERM_REFCNT(sl->family_data));
1375
1376 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1377 ret = -EAGAIN; /* Didn't acquire the mutex */
1378 goto dec_refcnt;
1379 }
1380
1381 while (max_trying-- && ret) { /* ret should be 0 */
1382 /* safe version to select slave */
1383 if (!reset_select_slave(sl)) {
1384 unsigned long sleep_rem;
1385
1386 /* 10ms strong pullup (or delay) after the convert */
1387 if (strong_pullup)
1388 w1_next_pullup(dev_master, t_write);
1389
1390 w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1391
1392 if (strong_pullup) {
1393 sleep_rem = msleep_interruptible(t_write);
1394 if (sleep_rem != 0) {
1395 ret = -EINTR;
1396 goto mt_unlock;
1397 }
1398 }
1399 ret = 0;
1400 }
1401
1402 }
1403
1404 mt_unlock:
1405 mutex_unlock(&dev_master->bus_mutex);
1406 dec_refcnt:
1407 atomic_dec(THERM_REFCNT(sl->family_data));
1408 error:
1409 return ret;
1410 }
1411
recall_eeprom(struct w1_slave * sl)1412 static int recall_eeprom(struct w1_slave *sl)
1413 {
1414 struct w1_master *dev_master = sl->master;
1415 int max_trying = W1_THERM_MAX_TRY;
1416 int ret = -ENODEV;
1417
1418 if (!sl->family_data)
1419 goto error;
1420
1421 /* prevent the slave from going away in sleep */
1422 atomic_inc(THERM_REFCNT(sl->family_data));
1423
1424 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1425 ret = -EAGAIN; /* Didn't acquire the mutex */
1426 goto dec_refcnt;
1427 }
1428
1429 while (max_trying-- && ret) { /* ret should be 0 */
1430 /* safe version to select slave */
1431 if (!reset_select_slave(sl)) {
1432
1433 w1_write_8(dev_master, W1_RECALL_EEPROM);
1434 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1435 }
1436
1437 }
1438
1439 mutex_unlock(&dev_master->bus_mutex);
1440
1441 dec_refcnt:
1442 atomic_dec(THERM_REFCNT(sl->family_data));
1443 error:
1444 return ret;
1445 }
1446
read_powermode(struct w1_slave * sl)1447 static int read_powermode(struct w1_slave *sl)
1448 {
1449 struct w1_master *dev_master = sl->master;
1450 int max_trying = W1_THERM_MAX_TRY;
1451 int ret = -ENODEV;
1452
1453 if (!sl->family_data)
1454 goto error;
1455
1456 /* prevent the slave from going away in sleep */
1457 atomic_inc(THERM_REFCNT(sl->family_data));
1458
1459 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1460 ret = -EAGAIN; /* Didn't acquire the mutex */
1461 goto dec_refcnt;
1462 }
1463
1464 while ((max_trying--) && (ret < 0)) {
1465 /* safe version to select slave */
1466 if (!reset_select_slave(sl)) {
1467 w1_write_8(dev_master, W1_READ_PSUPPLY);
1468 /*
1469 * Emit a read time slot and read only one bit,
1470 * 1 is externally powered,
1471 * 0 is parasite powered
1472 */
1473 ret = w1_touch_bit(dev_master, 1);
1474 /* ret should be either 1 either 0 */
1475 }
1476 }
1477 mutex_unlock(&dev_master->bus_mutex);
1478
1479 dec_refcnt:
1480 atomic_dec(THERM_REFCNT(sl->family_data));
1481 error:
1482 return ret;
1483 }
1484
trigger_bulk_read(struct w1_master * dev_master)1485 static int trigger_bulk_read(struct w1_master *dev_master)
1486 {
1487 struct w1_slave *sl = NULL; /* used to iterate through slaves */
1488 int max_trying = W1_THERM_MAX_TRY;
1489 int t_conv = 0;
1490 int ret = -ENODEV;
1491 bool strong_pullup = false;
1492
1493 /*
1494 * Check whether there are parasite powered device on the bus,
1495 * and compute duration of conversion for these devices
1496 * so we can apply a strong pullup if required
1497 */
1498 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1499 if (!sl->family_data)
1500 goto error;
1501 if (bulk_read_support(sl)) {
1502 int t_cur = conversion_time(sl);
1503
1504 t_conv = max(t_cur, t_conv);
1505 strong_pullup = strong_pullup ||
1506 (w1_strong_pullup == 2 ||
1507 (!SLAVE_POWERMODE(sl) &&
1508 w1_strong_pullup));
1509 }
1510 }
1511
1512 /*
1513 * t_conv is the max conversion time required on the bus
1514 * If its 0, no device support the bulk read feature
1515 */
1516 if (!t_conv)
1517 goto error;
1518
1519 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1520 ret = -EAGAIN; /* Didn't acquire the mutex */
1521 goto error;
1522 }
1523
1524 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1525
1526 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */
1527 unsigned long sleep_rem;
1528
1529 w1_write_8(dev_master, W1_SKIP_ROM);
1530
1531 if (strong_pullup) /* Apply pullup if required */
1532 w1_next_pullup(dev_master, t_conv);
1533
1534 w1_write_8(dev_master, W1_CONVERT_TEMP);
1535
1536 /* set a flag to instruct that converT pending */
1537 list_for_each_entry(sl,
1538 &dev_master->slist, w1_slave_entry) {
1539 if (bulk_read_support(sl))
1540 SLAVE_CONVERT_TRIGGERED(sl) = -1;
1541 }
1542
1543 if (strong_pullup) { /* some device need pullup */
1544 sleep_rem = msleep_interruptible(t_conv);
1545 if (sleep_rem != 0) {
1546 ret = -EINTR;
1547 goto mt_unlock;
1548 }
1549 mutex_unlock(&dev_master->bus_mutex);
1550 } else {
1551 mutex_unlock(&dev_master->bus_mutex);
1552 sleep_rem = msleep_interruptible(t_conv);
1553 if (sleep_rem != 0) {
1554 ret = -EINTR;
1555 goto set_flag;
1556 }
1557 }
1558 ret = 0;
1559 goto set_flag;
1560 }
1561 }
1562
1563 mt_unlock:
1564 mutex_unlock(&dev_master->bus_mutex);
1565 set_flag:
1566 /* set a flag to register convsersion is done */
1567 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1568 if (bulk_read_support(sl))
1569 SLAVE_CONVERT_TRIGGERED(sl) = 1;
1570 }
1571 error:
1572 return ret;
1573 }
1574
1575 /* Sysfs Interface definition */
1576
w1_slave_show(struct device * device,struct device_attribute * attr,char * buf)1577 static ssize_t w1_slave_show(struct device *device,
1578 struct device_attribute *attr, char *buf)
1579 {
1580 struct w1_slave *sl = dev_to_w1_slave(device);
1581 struct therm_info info;
1582 u8 *family_data = sl->family_data;
1583 int ret, i;
1584 ssize_t c = PAGE_SIZE;
1585
1586 if (bulk_read_support(sl)) {
1587 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1588 dev_dbg(device,
1589 "%s: Conversion in progress, retry later\n",
1590 __func__);
1591 return 0;
1592 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1593 /* A bulk read has been issued, read the device RAM */
1594 ret = read_scratchpad(sl, &info);
1595 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1596 } else
1597 ret = convert_t(sl, &info);
1598 } else
1599 ret = convert_t(sl, &info);
1600
1601 if (ret < 0) {
1602 dev_dbg(device,
1603 "%s: Temperature data may be corrupted. err=%d\n",
1604 __func__, ret);
1605 return 0;
1606 }
1607
1608 for (i = 0; i < 9; ++i)
1609 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1610 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1611 info.crc, (info.verdict) ? "YES" : "NO");
1612
1613 if (info.verdict)
1614 memcpy(family_data, info.rom, sizeof(info.rom));
1615 else
1616 dev_warn(device, "%s:Read failed CRC check\n", __func__);
1617
1618 for (i = 0; i < 9; ++i)
1619 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1620 ((u8 *)family_data)[i]);
1621
1622 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1623 temperature_from_RAM(sl, info.rom));
1624
1625 ret = PAGE_SIZE - c;
1626 return ret;
1627 }
1628
w1_slave_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1629 static ssize_t w1_slave_store(struct device *device,
1630 struct device_attribute *attr, const char *buf,
1631 size_t size)
1632 {
1633 int val, ret = 0;
1634 struct w1_slave *sl = dev_to_w1_slave(device);
1635
1636 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1637
1638 if (ret) { /* conversion error */
1639 dev_info(device,
1640 "%s: conversion error. err= %d\n", __func__, ret);
1641 return size; /* return size to avoid call back again */
1642 }
1643
1644 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1645 dev_info(device,
1646 "%s: Device not supported by the driver\n", __func__);
1647 return size; /* No device family */
1648 }
1649
1650 if (val == 0) /* val=0 : trigger a EEPROM save */
1651 ret = copy_scratchpad(sl);
1652 else {
1653 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1654 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1655 }
1656
1657 if (ret) {
1658 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1659 /* Propagate error to userspace */
1660 return ret;
1661 }
1662 SLAVE_RESOLUTION(sl) = val;
1663 /* Reset the conversion time to default - it depends on resolution */
1664 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1665
1666 return size; /* always return size to avoid infinite calling */
1667 }
1668
temperature_show(struct device * device,struct device_attribute * attr,char * buf)1669 static ssize_t temperature_show(struct device *device,
1670 struct device_attribute *attr, char *buf)
1671 {
1672 struct w1_slave *sl = dev_to_w1_slave(device);
1673 struct therm_info info;
1674 int ret = 0;
1675
1676 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1677 dev_info(device,
1678 "%s: Device not supported by the driver\n", __func__);
1679 return 0; /* No device family */
1680 }
1681
1682 if (bulk_read_support(sl)) {
1683 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1684 dev_dbg(device,
1685 "%s: Conversion in progress, retry later\n",
1686 __func__);
1687 return 0;
1688 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1689 /* A bulk read has been issued, read the device RAM */
1690 ret = read_scratchpad(sl, &info);
1691 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1692 } else
1693 ret = convert_t(sl, &info);
1694 } else
1695 ret = convert_t(sl, &info);
1696
1697 if (ret < 0) {
1698 dev_dbg(device,
1699 "%s: Temperature data may be corrupted. err=%d\n",
1700 __func__, ret);
1701 return 0;
1702 }
1703
1704 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1705 }
1706
ext_power_show(struct device * device,struct device_attribute * attr,char * buf)1707 static ssize_t ext_power_show(struct device *device,
1708 struct device_attribute *attr, char *buf)
1709 {
1710 struct w1_slave *sl = dev_to_w1_slave(device);
1711
1712 if (!sl->family_data) {
1713 dev_info(device,
1714 "%s: Device not supported by the driver\n", __func__);
1715 return 0; /* No device family */
1716 }
1717
1718 /* Getting the power mode of the device {external, parasite} */
1719 SLAVE_POWERMODE(sl) = read_powermode(sl);
1720
1721 if (SLAVE_POWERMODE(sl) < 0) {
1722 dev_dbg(device,
1723 "%s: Power_mode may be corrupted. err=%d\n",
1724 __func__, SLAVE_POWERMODE(sl));
1725 }
1726 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1727 }
1728
resolution_show(struct device * device,struct device_attribute * attr,char * buf)1729 static ssize_t resolution_show(struct device *device,
1730 struct device_attribute *attr, char *buf)
1731 {
1732 struct w1_slave *sl = dev_to_w1_slave(device);
1733
1734 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1735 dev_info(device,
1736 "%s: Device not supported by the driver\n", __func__);
1737 return 0; /* No device family */
1738 }
1739
1740 /* get the correct function depending on the device */
1741 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1742 if (SLAVE_RESOLUTION(sl) < 0) {
1743 dev_dbg(device,
1744 "%s: Resolution may be corrupted. err=%d\n",
1745 __func__, SLAVE_RESOLUTION(sl));
1746 }
1747
1748 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1749 }
1750
resolution_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1751 static ssize_t resolution_store(struct device *device,
1752 struct device_attribute *attr, const char *buf, size_t size)
1753 {
1754 struct w1_slave *sl = dev_to_w1_slave(device);
1755 int val;
1756 int ret = 0;
1757
1758 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1759
1760 if (ret) { /* conversion error */
1761 dev_info(device,
1762 "%s: conversion error. err= %d\n", __func__, ret);
1763 return size; /* return size to avoid call back again */
1764 }
1765
1766 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1767 dev_info(device,
1768 "%s: Device not supported by the driver\n", __func__);
1769 return size; /* No device family */
1770 }
1771
1772 /*
1773 * Don't deal with the val enterd by user,
1774 * only device knows what is correct or not
1775 */
1776
1777 /* get the correct function depending on the device */
1778 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1779
1780 if (ret)
1781 return ret;
1782
1783 SLAVE_RESOLUTION(sl) = val;
1784 /* Reset the conversion time to default because it depends on resolution */
1785 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1786
1787 return size;
1788 }
1789
eeprom_cmd_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1790 static ssize_t eeprom_cmd_store(struct device *device,
1791 struct device_attribute *attr, const char *buf, size_t size)
1792 {
1793 struct w1_slave *sl = dev_to_w1_slave(device);
1794 int ret = -EINVAL; /* Invalid argument */
1795
1796 if (size == sizeof(EEPROM_CMD_WRITE)) {
1797 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1798 ret = copy_scratchpad(sl);
1799 } else if (size == sizeof(EEPROM_CMD_READ)) {
1800 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1801 ret = recall_eeprom(sl);
1802 }
1803
1804 if (ret)
1805 dev_info(device, "%s: error in process %d\n", __func__, ret);
1806
1807 return size;
1808 }
1809
alarms_show(struct device * device,struct device_attribute * attr,char * buf)1810 static ssize_t alarms_show(struct device *device,
1811 struct device_attribute *attr, char *buf)
1812 {
1813 struct w1_slave *sl = dev_to_w1_slave(device);
1814 int ret;
1815 s8 th = 0, tl = 0;
1816 struct therm_info scratchpad;
1817
1818 ret = read_scratchpad(sl, &scratchpad);
1819
1820 if (!ret) {
1821 th = scratchpad.rom[2]; /* TH is byte 2 */
1822 tl = scratchpad.rom[3]; /* TL is byte 3 */
1823 } else {
1824 dev_info(device,
1825 "%s: error reading alarms register %d\n",
1826 __func__, ret);
1827 }
1828
1829 return sprintf(buf, "%hd %hd\n", tl, th);
1830 }
1831
alarms_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1832 static ssize_t alarms_store(struct device *device,
1833 struct device_attribute *attr, const char *buf, size_t size)
1834 {
1835 struct w1_slave *sl = dev_to_w1_slave(device);
1836 struct therm_info info;
1837 u8 new_config_register[3]; /* array of data to be written */
1838 long long temp;
1839 int ret = 0;
1840 s8 tl, th; /* 1 byte per value + temp ring order */
1841 const char *p = buf;
1842 char *endp;
1843
1844 temp = simple_strtoll(p, &endp, 10);
1845 if (p == endp || *endp != ' ')
1846 ret = -EINVAL;
1847 else if (temp < INT_MIN || temp > INT_MAX)
1848 ret = -ERANGE;
1849 if (ret) {
1850 dev_info(device,
1851 "%s: error parsing args %d\n", __func__, ret);
1852 return size;
1853 }
1854
1855 tl = int_to_short(temp);
1856
1857 p = endp + 1;
1858 temp = simple_strtoll(p, &endp, 10);
1859 if (p == endp)
1860 ret = -EINVAL;
1861 else if (temp < INT_MIN || temp > INT_MAX)
1862 ret = -ERANGE;
1863 if (ret) {
1864 dev_info(device,
1865 "%s: error parsing args %d\n", __func__, ret);
1866 return size;
1867 }
1868
1869 /* Prepare to cast to short by eliminating out of range values */
1870 th = int_to_short(temp);
1871
1872 /* Reorder if required th and tl */
1873 if (tl > th)
1874 swap(tl, th);
1875
1876 /*
1877 * Read the scratchpad to change only the required bits
1878 * (th : byte 2 - tl: byte 3)
1879 */
1880 ret = read_scratchpad(sl, &info);
1881 if (!ret) {
1882 new_config_register[0] = th; /* Byte 2 */
1883 new_config_register[1] = tl; /* Byte 3 */
1884 new_config_register[2] = info.rom[4];/* Byte 4 */
1885 } else {
1886 dev_info(device,
1887 "%s: error reading from the slave device %d\n",
1888 __func__, ret);
1889 return size;
1890 }
1891
1892 /* Write data in the device RAM */
1893 if (!SLAVE_SPECIFIC_FUNC(sl)) {
1894 dev_info(device,
1895 "%s: Device not supported by the driver %d\n",
1896 __func__, -ENODEV);
1897 return size;
1898 }
1899
1900 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1901 if (ret)
1902 dev_info(device,
1903 "%s: error writing to the slave device %d\n",
1904 __func__, ret);
1905
1906 return size;
1907 }
1908
therm_bulk_read_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1909 static ssize_t therm_bulk_read_store(struct device *device,
1910 struct device_attribute *attr, const char *buf, size_t size)
1911 {
1912 struct w1_master *dev_master = dev_to_w1_master(device);
1913 int ret = -EINVAL; /* Invalid argument */
1914
1915 if (size == sizeof(BULK_TRIGGER_CMD))
1916 if (!strncmp(buf, BULK_TRIGGER_CMD,
1917 sizeof(BULK_TRIGGER_CMD)-1))
1918 ret = trigger_bulk_read(dev_master);
1919
1920 if (ret)
1921 dev_info(device,
1922 "%s: unable to trigger a bulk read on the bus. err=%d\n",
1923 __func__, ret);
1924
1925 return size;
1926 }
1927
therm_bulk_read_show(struct device * device,struct device_attribute * attr,char * buf)1928 static ssize_t therm_bulk_read_show(struct device *device,
1929 struct device_attribute *attr, char *buf)
1930 {
1931 struct w1_master *dev_master = dev_to_w1_master(device);
1932 struct w1_slave *sl = NULL;
1933 int ret = 0;
1934
1935 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1936 if (sl->family_data) {
1937 if (bulk_read_support(sl)) {
1938 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1939 ret = -1;
1940 goto show_result;
1941 }
1942 if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1943 /* continue to check other slaves */
1944 ret = 1;
1945 }
1946 }
1947 }
1948 show_result:
1949 return sprintf(buf, "%d\n", ret);
1950 }
1951
conv_time_show(struct device * device,struct device_attribute * attr,char * buf)1952 static ssize_t conv_time_show(struct device *device,
1953 struct device_attribute *attr, char *buf)
1954 {
1955 struct w1_slave *sl = dev_to_w1_slave(device);
1956
1957 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1958 dev_info(device,
1959 "%s: Device is not supported by the driver\n", __func__);
1960 return 0; /* No device family */
1961 }
1962 return sprintf(buf, "%d\n", conversion_time(sl));
1963 }
1964
conv_time_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1965 static ssize_t conv_time_store(struct device *device,
1966 struct device_attribute *attr, const char *buf, size_t size)
1967 {
1968 int val, ret = 0;
1969 struct w1_slave *sl = dev_to_w1_slave(device);
1970
1971 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
1972 return -EINVAL;
1973
1974 if (check_family_data(sl))
1975 return -ENODEV;
1976
1977 if (val != CONV_TIME_MEASURE) {
1978 if (val >= CONV_TIME_DEFAULT)
1979 SLAVE_CONV_TIME_OVERRIDE(sl) = val;
1980 else
1981 return -EINVAL;
1982
1983 } else {
1984 int conv_time;
1985
1986 ret = conv_time_measure(sl, &conv_time);
1987 if (ret)
1988 return -EIO;
1989 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
1990 }
1991 return size;
1992 }
1993
features_show(struct device * device,struct device_attribute * attr,char * buf)1994 static ssize_t features_show(struct device *device,
1995 struct device_attribute *attr, char *buf)
1996 {
1997 struct w1_slave *sl = dev_to_w1_slave(device);
1998
1999 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
2000 dev_info(device,
2001 "%s: Device not supported by the driver\n", __func__);
2002 return 0; /* No device family */
2003 }
2004 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
2005 }
2006
features_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)2007 static ssize_t features_store(struct device *device,
2008 struct device_attribute *attr, const char *buf, size_t size)
2009 {
2010 int val, ret = 0;
2011 bool strong_pullup;
2012 struct w1_slave *sl = dev_to_w1_slave(device);
2013
2014 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
2015 if (ret)
2016 return -EINVAL; /* invalid number */
2017
2018 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
2019 dev_info(device, "%s: Device not supported by the driver\n", __func__);
2020 return -ENODEV;
2021 }
2022
2023 if ((val & W1_THERM_FEATURES_MASK) != val)
2024 return -EINVAL;
2025
2026 SLAVE_FEATURES(sl) = val;
2027
2028 strong_pullup = (w1_strong_pullup == 2 ||
2029 (!SLAVE_POWERMODE(sl) &&
2030 w1_strong_pullup));
2031
2032 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2033 dev_warn(&sl->dev,
2034 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2035 __func__);
2036 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2037 }
2038
2039 return size;
2040 }
2041
2042 #if IS_REACHABLE(CONFIG_HWMON)
w1_read_temp(struct device * device,u32 attr,int channel,long * val)2043 static int w1_read_temp(struct device *device, u32 attr, int channel,
2044 long *val)
2045 {
2046 struct w1_slave *sl = dev_get_drvdata(device);
2047 struct therm_info info;
2048 int ret;
2049
2050 switch (attr) {
2051 case hwmon_temp_input:
2052 ret = convert_t(sl, &info);
2053 if (ret)
2054 return ret;
2055
2056 if (!info.verdict) {
2057 ret = -EIO;
2058 return ret;
2059 }
2060
2061 *val = temperature_from_RAM(sl, info.rom);
2062 ret = 0;
2063 break;
2064 default:
2065 ret = -EOPNOTSUPP;
2066 break;
2067 }
2068
2069 return ret;
2070 }
2071 #endif
2072
2073 #define W1_42_CHAIN 0x99
2074 #define W1_42_CHAIN_OFF 0x3C
2075 #define W1_42_CHAIN_OFF_INV 0xC3
2076 #define W1_42_CHAIN_ON 0x5A
2077 #define W1_42_CHAIN_ON_INV 0xA5
2078 #define W1_42_CHAIN_DONE 0x96
2079 #define W1_42_CHAIN_DONE_INV 0x69
2080 #define W1_42_COND_READ 0x0F
2081 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2082 #define W1_42_FINISHED_BYTE 0xFF
w1_seq_show(struct device * device,struct device_attribute * attr,char * buf)2083 static ssize_t w1_seq_show(struct device *device,
2084 struct device_attribute *attr, char *buf)
2085 {
2086 struct w1_slave *sl = dev_to_w1_slave(device);
2087 ssize_t c = PAGE_SIZE;
2088 int i;
2089 u8 ack;
2090 u64 rn;
2091 struct w1_reg_num *reg_num;
2092 int seq = 0;
2093
2094 mutex_lock(&sl->master->bus_mutex);
2095 /* Place all devices in CHAIN state */
2096 if (w1_reset_bus(sl->master))
2097 goto error;
2098 w1_write_8(sl->master, W1_SKIP_ROM);
2099 w1_write_8(sl->master, W1_42_CHAIN);
2100 w1_write_8(sl->master, W1_42_CHAIN_ON);
2101 w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2102 msleep(sl->master->pullup_duration);
2103
2104 /* check for acknowledgment */
2105 ack = w1_read_8(sl->master);
2106 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2107 goto error;
2108
2109 /* In case the bus fails to send 0xFF, limit */
2110 for (i = 0; i <= 64; i++) {
2111 if (w1_reset_bus(sl->master))
2112 goto error;
2113
2114 w1_write_8(sl->master, W1_42_COND_READ);
2115 w1_read_block(sl->master, (u8 *)&rn, 8);
2116 reg_num = (struct w1_reg_num *) &rn;
2117 if (reg_num->family == W1_42_FINISHED_BYTE)
2118 break;
2119 if (sl->reg_num.id == reg_num->id)
2120 seq = i;
2121
2122 if (w1_reset_bus(sl->master))
2123 goto error;
2124
2125 /* Put the device into chain DONE state */
2126 w1_write_8(sl->master, W1_MATCH_ROM);
2127 w1_write_block(sl->master, (u8 *)&rn, 8);
2128 w1_write_8(sl->master, W1_42_CHAIN);
2129 w1_write_8(sl->master, W1_42_CHAIN_DONE);
2130 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2131
2132 /* check for acknowledgment */
2133 ack = w1_read_8(sl->master);
2134 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2135 goto error;
2136 }
2137
2138 /* Exit from CHAIN state */
2139 if (w1_reset_bus(sl->master))
2140 goto error;
2141 w1_write_8(sl->master, W1_SKIP_ROM);
2142 w1_write_8(sl->master, W1_42_CHAIN);
2143 w1_write_8(sl->master, W1_42_CHAIN_OFF);
2144 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
2145
2146 /* check for acknowledgment */
2147 ack = w1_read_8(sl->master);
2148 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2149 goto error;
2150 mutex_unlock(&sl->master->bus_mutex);
2151
2152 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
2153 return PAGE_SIZE - c;
2154 error:
2155 mutex_unlock(&sl->master->bus_mutex);
2156 return -EIO;
2157 }
2158
w1_therm_init(void)2159 static int __init w1_therm_init(void)
2160 {
2161 int err, i;
2162
2163 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
2164 err = w1_register_family(w1_therm_families[i].f);
2165 if (err)
2166 w1_therm_families[i].broken = 1;
2167 }
2168
2169 return 0;
2170 }
2171
w1_therm_fini(void)2172 static void __exit w1_therm_fini(void)
2173 {
2174 int i;
2175
2176 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
2177 if (!w1_therm_families[i].broken)
2178 w1_unregister_family(w1_therm_families[i].f);
2179 }
2180
2181 module_init(w1_therm_init);
2182 module_exit(w1_therm_fini);
2183
2184 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
2185 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
2186 MODULE_LICENSE("GPL");
2187 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
2188 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
2189 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
2190 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
2191 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
2192