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(sizeof(struct w1_therm_family_data),
977 GFP_KERNEL);
978 if (!sl->family_data)
979 return -ENOMEM;
980
981 atomic_set(THERM_REFCNT(sl->family_data), 1);
982
983 /* Get a pointer to the device specific function struct */
984 sl_family_conv = device_family(sl);
985 if (!sl_family_conv) {
986 kfree(sl->family_data);
987 return -ENODEV;
988 }
989 /* save this pointer to the device structure */
990 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
991
992 if (bulk_read_support(sl)) {
993 /*
994 * add the sys entry to trigger bulk_read
995 * at master level only the 1st time
996 */
997 if (!bulk_read_device_counter) {
998 int err = device_create_file(&sl->master->dev,
999 &dev_attr_therm_bulk_read);
1000
1001 if (err)
1002 dev_warn(&sl->dev,
1003 "%s: Device has been added, but bulk read is unavailable. err=%d\n",
1004 __func__, err);
1005 }
1006 /* Increment the counter */
1007 bulk_read_device_counter++;
1008 }
1009
1010 /* Getting the power mode of the device {external, parasite} */
1011 SLAVE_POWERMODE(sl) = read_powermode(sl);
1012
1013 if (SLAVE_POWERMODE(sl) < 0) {
1014 /* no error returned as device has been added */
1015 dev_warn(&sl->dev,
1016 "%s: Device has been added, but power_mode may be corrupted. err=%d\n",
1017 __func__, SLAVE_POWERMODE(sl));
1018 }
1019
1020 /* Getting the resolution of the device */
1021 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
1022 SLAVE_RESOLUTION(sl) =
1023 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1024 if (SLAVE_RESOLUTION(sl) < 0) {
1025 /* no error returned as device has been added */
1026 dev_warn(&sl->dev,
1027 "%s:Device has been added, but resolution may be corrupted. err=%d\n",
1028 __func__, SLAVE_RESOLUTION(sl));
1029 }
1030 }
1031
1032 /* Finally initialize convert_triggered flag */
1033 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1034
1035 return 0;
1036 }
1037
w1_therm_remove_slave(struct w1_slave * sl)1038 static void w1_therm_remove_slave(struct w1_slave *sl)
1039 {
1040 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
1041
1042 if (bulk_read_support(sl)) {
1043 bulk_read_device_counter--;
1044 /* Delete the entry if no more device support the feature */
1045 if (!bulk_read_device_counter)
1046 device_remove_file(&sl->master->dev,
1047 &dev_attr_therm_bulk_read);
1048 }
1049
1050 while (refcnt) {
1051 msleep(1000);
1052 refcnt = atomic_read(THERM_REFCNT(sl->family_data));
1053 }
1054 kfree(sl->family_data);
1055 sl->family_data = NULL;
1056 }
1057
1058 /* Hardware Functions */
1059
1060 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
reset_select_slave(struct w1_slave * sl)1061 static int reset_select_slave(struct w1_slave *sl)
1062 {
1063 u8 match[9] = { W1_MATCH_ROM, };
1064 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1065
1066 if (w1_reset_bus(sl->master))
1067 return -ENODEV;
1068
1069 memcpy(&match[1], &rn, 8);
1070 w1_write_block(sl->master, match, 9);
1071
1072 return 0;
1073 }
1074
1075 /**
1076 * w1_poll_completion - Poll for operation completion, with timeout
1077 * @dev_master: the device master of the bus
1078 * @tout_ms: timeout in milliseconds
1079 *
1080 * The device is answering 0's while an operation is in progress and 1's after it completes
1081 * Timeout may happen if the previous command was not recognised due to a line noise
1082 *
1083 * Return: 0 - OK, negative error - timeout
1084 */
w1_poll_completion(struct w1_master * dev_master,int tout_ms)1085 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1086 {
1087 int i;
1088
1089 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1090 /* Delay is before poll, for device to recognize a command */
1091 msleep(W1_POLL_PERIOD);
1092
1093 /* Compare all 8 bits to mitigate a noise on the bus */
1094 if (w1_read_8(dev_master) == 0xFF)
1095 break;
1096 }
1097 if (i == tout_ms/W1_POLL_PERIOD)
1098 return -EIO;
1099
1100 return 0;
1101 }
1102
convert_t(struct w1_slave * sl,struct therm_info * info)1103 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1104 {
1105 struct w1_master *dev_master = sl->master;
1106 int max_trying = W1_THERM_MAX_TRY;
1107 int t_conv;
1108 int ret = -ENODEV;
1109 bool strong_pullup;
1110
1111 if (!sl->family_data)
1112 goto error;
1113
1114 strong_pullup = (w1_strong_pullup == 2 ||
1115 (!SLAVE_POWERMODE(sl) &&
1116 w1_strong_pullup));
1117
1118 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1119 dev_warn(&sl->dev,
1120 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1121 __func__);
1122 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1123 }
1124
1125 /* get conversion duration device and id dependent */
1126 t_conv = conversion_time(sl);
1127
1128 memset(info->rom, 0, sizeof(info->rom));
1129
1130 /* prevent the slave from going away in sleep */
1131 atomic_inc(THERM_REFCNT(sl->family_data));
1132
1133 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1134 ret = -EAGAIN; /* Didn't acquire the mutex */
1135 goto dec_refcnt;
1136 }
1137
1138 while (max_trying-- && ret) { /* ret should be 0 */
1139
1140 info->verdict = 0;
1141 info->crc = 0;
1142 /* safe version to select slave */
1143 if (!reset_select_slave(sl)) {
1144 unsigned long sleep_rem;
1145
1146 /* 750ms strong pullup (or delay) after the convert */
1147 if (strong_pullup)
1148 w1_next_pullup(dev_master, t_conv);
1149
1150 w1_write_8(dev_master, W1_CONVERT_TEMP);
1151
1152 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1153 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1154 if (ret) {
1155 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1156 goto mt_unlock;
1157 }
1158 mutex_unlock(&dev_master->bus_mutex);
1159 } else if (!strong_pullup) { /*no device need pullup */
1160 sleep_rem = msleep_interruptible(t_conv);
1161 if (sleep_rem != 0) {
1162 ret = -EINTR;
1163 goto mt_unlock;
1164 }
1165 mutex_unlock(&dev_master->bus_mutex);
1166 } else { /*some device need pullup */
1167 mutex_unlock(&dev_master->bus_mutex);
1168 sleep_rem = msleep_interruptible(t_conv);
1169 if (sleep_rem != 0) {
1170 ret = -EINTR;
1171 goto dec_refcnt;
1172 }
1173 }
1174 ret = read_scratchpad(sl, info);
1175
1176 /* If enabled, check for conversion success */
1177 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1178 (info->rom[6] == 0xC) &&
1179 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1180 (info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1181 ) {
1182 /* Invalid reading (scratchpad byte 6 = 0xC)
1183 * due to insufficient conversion time
1184 * or power failure.
1185 */
1186 ret = -EIO;
1187 }
1188
1189 goto dec_refcnt;
1190 }
1191
1192 }
1193
1194 mt_unlock:
1195 mutex_unlock(&dev_master->bus_mutex);
1196 dec_refcnt:
1197 atomic_dec(THERM_REFCNT(sl->family_data));
1198 error:
1199 return ret;
1200 }
1201
conv_time_measure(struct w1_slave * sl,int * conv_time)1202 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1203 {
1204 struct therm_info inf,
1205 *info = &inf;
1206 struct w1_master *dev_master = sl->master;
1207 int max_trying = W1_THERM_MAX_TRY;
1208 int ret = -ENODEV;
1209 bool strong_pullup;
1210
1211 if (!sl->family_data)
1212 goto error;
1213
1214 strong_pullup = (w1_strong_pullup == 2 ||
1215 (!SLAVE_POWERMODE(sl) &&
1216 w1_strong_pullup));
1217
1218 if (strong_pullup) {
1219 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1220 return -EINVAL;
1221 }
1222
1223 memset(info->rom, 0, sizeof(info->rom));
1224
1225 /* prevent the slave from going away in sleep */
1226 atomic_inc(THERM_REFCNT(sl->family_data));
1227
1228 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1229 ret = -EAGAIN; /* Didn't acquire the mutex */
1230 goto dec_refcnt;
1231 }
1232
1233 while (max_trying-- && ret) { /* ret should be 0 */
1234 info->verdict = 0;
1235 info->crc = 0;
1236 /* safe version to select slave */
1237 if (!reset_select_slave(sl)) {
1238 int j_start, j_end;
1239
1240 /*no device need pullup */
1241 w1_write_8(dev_master, W1_CONVERT_TEMP);
1242
1243 j_start = jiffies;
1244 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1245 if (ret) {
1246 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1247 goto mt_unlock;
1248 }
1249 j_end = jiffies;
1250 /* 1.2x increase for variation and changes over temperature range */
1251 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1252 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1253 *conv_time, HZ);
1254 if (*conv_time <= CONV_TIME_MEASURE) {
1255 ret = -EIO;
1256 goto mt_unlock;
1257 }
1258 mutex_unlock(&dev_master->bus_mutex);
1259 ret = read_scratchpad(sl, info);
1260 goto dec_refcnt;
1261 }
1262
1263 }
1264 mt_unlock:
1265 mutex_unlock(&dev_master->bus_mutex);
1266 dec_refcnt:
1267 atomic_dec(THERM_REFCNT(sl->family_data));
1268 error:
1269 return ret;
1270 }
1271
read_scratchpad(struct w1_slave * sl,struct therm_info * info)1272 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1273 {
1274 struct w1_master *dev_master = sl->master;
1275 int max_trying = W1_THERM_MAX_TRY;
1276 int ret = -ENODEV;
1277
1278 info->verdict = 0;
1279
1280 if (!sl->family_data)
1281 goto error;
1282
1283 memset(info->rom, 0, sizeof(info->rom));
1284
1285 /* prevent the slave from going away in sleep */
1286 atomic_inc(THERM_REFCNT(sl->family_data));
1287
1288 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1289 ret = -EAGAIN; /* Didn't acquire the mutex */
1290 goto dec_refcnt;
1291 }
1292
1293 while (max_trying-- && ret) { /* ret should be 0 */
1294 /* safe version to select slave */
1295 if (!reset_select_slave(sl)) {
1296 u8 nb_bytes_read;
1297
1298 w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1299
1300 nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1301 if (nb_bytes_read != 9) {
1302 dev_warn(&sl->dev,
1303 "w1_read_block(): returned %u instead of 9.\n",
1304 nb_bytes_read);
1305 ret = -EIO;
1306 }
1307
1308 info->crc = w1_calc_crc8(info->rom, 8);
1309
1310 if (info->rom[8] == info->crc) {
1311 info->verdict = 1;
1312 ret = 0;
1313 } else
1314 ret = -EIO; /* CRC not checked */
1315 }
1316
1317 }
1318 mutex_unlock(&dev_master->bus_mutex);
1319
1320 dec_refcnt:
1321 atomic_dec(THERM_REFCNT(sl->family_data));
1322 error:
1323 return ret;
1324 }
1325
write_scratchpad(struct w1_slave * sl,const u8 * data,u8 nb_bytes)1326 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1327 {
1328 struct w1_master *dev_master = sl->master;
1329 int max_trying = W1_THERM_MAX_TRY;
1330 int ret = -ENODEV;
1331
1332 if (!sl->family_data)
1333 goto error;
1334
1335 /* prevent the slave from going away in sleep */
1336 atomic_inc(THERM_REFCNT(sl->family_data));
1337
1338 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1339 ret = -EAGAIN; /* Didn't acquire the mutex */
1340 goto dec_refcnt;
1341 }
1342
1343 while (max_trying-- && ret) { /* ret should be 0 */
1344 /* safe version to select slave */
1345 if (!reset_select_slave(sl)) {
1346 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1347 w1_write_block(dev_master, data, nb_bytes);
1348 ret = 0;
1349 }
1350 }
1351 mutex_unlock(&dev_master->bus_mutex);
1352
1353 dec_refcnt:
1354 atomic_dec(THERM_REFCNT(sl->family_data));
1355 error:
1356 return ret;
1357 }
1358
copy_scratchpad(struct w1_slave * sl)1359 static int copy_scratchpad(struct w1_slave *sl)
1360 {
1361 struct w1_master *dev_master = sl->master;
1362 int max_trying = W1_THERM_MAX_TRY;
1363 int t_write, ret = -ENODEV;
1364 bool strong_pullup;
1365
1366 if (!sl->family_data)
1367 goto error;
1368
1369 t_write = W1_THERM_EEPROM_WRITE_DELAY;
1370 strong_pullup = (w1_strong_pullup == 2 ||
1371 (!SLAVE_POWERMODE(sl) &&
1372 w1_strong_pullup));
1373
1374 /* prevent the slave from going away in sleep */
1375 atomic_inc(THERM_REFCNT(sl->family_data));
1376
1377 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1378 ret = -EAGAIN; /* Didn't acquire the mutex */
1379 goto dec_refcnt;
1380 }
1381
1382 while (max_trying-- && ret) { /* ret should be 0 */
1383 /* safe version to select slave */
1384 if (!reset_select_slave(sl)) {
1385 unsigned long sleep_rem;
1386
1387 /* 10ms strong pullup (or delay) after the convert */
1388 if (strong_pullup)
1389 w1_next_pullup(dev_master, t_write);
1390
1391 w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1392
1393 if (strong_pullup) {
1394 sleep_rem = msleep_interruptible(t_write);
1395 if (sleep_rem != 0) {
1396 ret = -EINTR;
1397 goto mt_unlock;
1398 }
1399 }
1400 ret = 0;
1401 }
1402
1403 }
1404
1405 mt_unlock:
1406 mutex_unlock(&dev_master->bus_mutex);
1407 dec_refcnt:
1408 atomic_dec(THERM_REFCNT(sl->family_data));
1409 error:
1410 return ret;
1411 }
1412
recall_eeprom(struct w1_slave * sl)1413 static int recall_eeprom(struct w1_slave *sl)
1414 {
1415 struct w1_master *dev_master = sl->master;
1416 int max_trying = W1_THERM_MAX_TRY;
1417 int ret = -ENODEV;
1418
1419 if (!sl->family_data)
1420 goto error;
1421
1422 /* prevent the slave from going away in sleep */
1423 atomic_inc(THERM_REFCNT(sl->family_data));
1424
1425 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1426 ret = -EAGAIN; /* Didn't acquire the mutex */
1427 goto dec_refcnt;
1428 }
1429
1430 while (max_trying-- && ret) { /* ret should be 0 */
1431 /* safe version to select slave */
1432 if (!reset_select_slave(sl)) {
1433
1434 w1_write_8(dev_master, W1_RECALL_EEPROM);
1435 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1436 }
1437
1438 }
1439
1440 mutex_unlock(&dev_master->bus_mutex);
1441
1442 dec_refcnt:
1443 atomic_dec(THERM_REFCNT(sl->family_data));
1444 error:
1445 return ret;
1446 }
1447
read_powermode(struct w1_slave * sl)1448 static int read_powermode(struct w1_slave *sl)
1449 {
1450 struct w1_master *dev_master = sl->master;
1451 int max_trying = W1_THERM_MAX_TRY;
1452 int ret = -ENODEV;
1453
1454 if (!sl->family_data)
1455 goto error;
1456
1457 /* prevent the slave from going away in sleep */
1458 atomic_inc(THERM_REFCNT(sl->family_data));
1459
1460 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1461 ret = -EAGAIN; /* Didn't acquire the mutex */
1462 goto dec_refcnt;
1463 }
1464
1465 while ((max_trying--) && (ret < 0)) {
1466 /* safe version to select slave */
1467 if (!reset_select_slave(sl)) {
1468 w1_write_8(dev_master, W1_READ_PSUPPLY);
1469 /*
1470 * Emit a read time slot and read only one bit,
1471 * 1 is externally powered,
1472 * 0 is parasite powered
1473 */
1474 ret = w1_touch_bit(dev_master, 1);
1475 /* ret should be either 1 either 0 */
1476 }
1477 }
1478 mutex_unlock(&dev_master->bus_mutex);
1479
1480 dec_refcnt:
1481 atomic_dec(THERM_REFCNT(sl->family_data));
1482 error:
1483 return ret;
1484 }
1485
trigger_bulk_read(struct w1_master * dev_master)1486 static int trigger_bulk_read(struct w1_master *dev_master)
1487 {
1488 struct w1_slave *sl = NULL; /* used to iterate through slaves */
1489 int max_trying = W1_THERM_MAX_TRY;
1490 int t_conv = 0;
1491 int ret = -ENODEV;
1492 bool strong_pullup = false;
1493
1494 /*
1495 * Check whether there are parasite powered device on the bus,
1496 * and compute duration of conversion for these devices
1497 * so we can apply a strong pullup if required
1498 */
1499 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1500 if (!sl->family_data)
1501 goto error;
1502 if (bulk_read_support(sl)) {
1503 int t_cur = conversion_time(sl);
1504
1505 t_conv = max(t_cur, t_conv);
1506 strong_pullup = strong_pullup ||
1507 (w1_strong_pullup == 2 ||
1508 (!SLAVE_POWERMODE(sl) &&
1509 w1_strong_pullup));
1510 }
1511 }
1512
1513 /*
1514 * t_conv is the max conversion time required on the bus
1515 * If its 0, no device support the bulk read feature
1516 */
1517 if (!t_conv)
1518 goto error;
1519
1520 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1521 ret = -EAGAIN; /* Didn't acquire the mutex */
1522 goto error;
1523 }
1524
1525 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1526
1527 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */
1528 unsigned long sleep_rem;
1529
1530 w1_write_8(dev_master, W1_SKIP_ROM);
1531
1532 if (strong_pullup) /* Apply pullup if required */
1533 w1_next_pullup(dev_master, t_conv);
1534
1535 w1_write_8(dev_master, W1_CONVERT_TEMP);
1536
1537 /* set a flag to instruct that converT pending */
1538 list_for_each_entry(sl,
1539 &dev_master->slist, w1_slave_entry) {
1540 if (bulk_read_support(sl))
1541 SLAVE_CONVERT_TRIGGERED(sl) = -1;
1542 }
1543
1544 if (strong_pullup) { /* some device need pullup */
1545 sleep_rem = msleep_interruptible(t_conv);
1546 if (sleep_rem != 0) {
1547 ret = -EINTR;
1548 goto mt_unlock;
1549 }
1550 mutex_unlock(&dev_master->bus_mutex);
1551 } else {
1552 mutex_unlock(&dev_master->bus_mutex);
1553 sleep_rem = msleep_interruptible(t_conv);
1554 if (sleep_rem != 0) {
1555 ret = -EINTR;
1556 goto set_flag;
1557 }
1558 }
1559 ret = 0;
1560 goto set_flag;
1561 }
1562 }
1563
1564 mt_unlock:
1565 mutex_unlock(&dev_master->bus_mutex);
1566 set_flag:
1567 /* set a flag to register convsersion is done */
1568 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1569 if (bulk_read_support(sl))
1570 SLAVE_CONVERT_TRIGGERED(sl) = 1;
1571 }
1572 error:
1573 return ret;
1574 }
1575
1576 /* Sysfs Interface definition */
1577
w1_slave_show(struct device * device,struct device_attribute * attr,char * buf)1578 static ssize_t w1_slave_show(struct device *device,
1579 struct device_attribute *attr, char *buf)
1580 {
1581 struct w1_slave *sl = dev_to_w1_slave(device);
1582 struct therm_info info;
1583 u8 *family_data = sl->family_data;
1584 int ret, i;
1585 ssize_t c = PAGE_SIZE;
1586
1587 if (bulk_read_support(sl)) {
1588 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1589 dev_dbg(device,
1590 "%s: Conversion in progress, retry later\n",
1591 __func__);
1592 return 0;
1593 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1594 /* A bulk read has been issued, read the device RAM */
1595 ret = read_scratchpad(sl, &info);
1596 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1597 } else
1598 ret = convert_t(sl, &info);
1599 } else
1600 ret = convert_t(sl, &info);
1601
1602 if (ret < 0) {
1603 dev_dbg(device,
1604 "%s: Temperature data may be corrupted. err=%d\n",
1605 __func__, ret);
1606 return 0;
1607 }
1608
1609 for (i = 0; i < 9; ++i)
1610 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1611 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1612 info.crc, (info.verdict) ? "YES" : "NO");
1613
1614 if (info.verdict)
1615 memcpy(family_data, info.rom, sizeof(info.rom));
1616 else
1617 dev_warn(device, "%s:Read failed CRC check\n", __func__);
1618
1619 for (i = 0; i < 9; ++i)
1620 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1621 ((u8 *)family_data)[i]);
1622
1623 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1624 temperature_from_RAM(sl, info.rom));
1625
1626 ret = PAGE_SIZE - c;
1627 return ret;
1628 }
1629
w1_slave_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1630 static ssize_t w1_slave_store(struct device *device,
1631 struct device_attribute *attr, const char *buf,
1632 size_t size)
1633 {
1634 int val, ret = 0;
1635 struct w1_slave *sl = dev_to_w1_slave(device);
1636
1637 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1638
1639 if (ret) { /* conversion error */
1640 dev_info(device,
1641 "%s: conversion error. err= %d\n", __func__, ret);
1642 return size; /* return size to avoid call back again */
1643 }
1644
1645 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1646 dev_info(device,
1647 "%s: Device not supported by the driver\n", __func__);
1648 return size; /* No device family */
1649 }
1650
1651 if (val == 0) /* val=0 : trigger a EEPROM save */
1652 ret = copy_scratchpad(sl);
1653 else {
1654 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1655 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1656 }
1657
1658 if (ret) {
1659 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1660 /* Propagate error to userspace */
1661 return ret;
1662 }
1663 SLAVE_RESOLUTION(sl) = val;
1664 /* Reset the conversion time to default - it depends on resolution */
1665 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1666
1667 return size; /* always return size to avoid infinite calling */
1668 }
1669
temperature_show(struct device * device,struct device_attribute * attr,char * buf)1670 static ssize_t temperature_show(struct device *device,
1671 struct device_attribute *attr, char *buf)
1672 {
1673 struct w1_slave *sl = dev_to_w1_slave(device);
1674 struct therm_info info;
1675 int ret = 0;
1676
1677 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1678 dev_info(device,
1679 "%s: Device not supported by the driver\n", __func__);
1680 return 0; /* No device family */
1681 }
1682
1683 if (bulk_read_support(sl)) {
1684 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1685 dev_dbg(device,
1686 "%s: Conversion in progress, retry later\n",
1687 __func__);
1688 return 0;
1689 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1690 /* A bulk read has been issued, read the device RAM */
1691 ret = read_scratchpad(sl, &info);
1692 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1693 } else
1694 ret = convert_t(sl, &info);
1695 } else
1696 ret = convert_t(sl, &info);
1697
1698 if (ret < 0) {
1699 dev_dbg(device,
1700 "%s: Temperature data may be corrupted. err=%d\n",
1701 __func__, ret);
1702 return 0;
1703 }
1704
1705 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1706 }
1707
ext_power_show(struct device * device,struct device_attribute * attr,char * buf)1708 static ssize_t ext_power_show(struct device *device,
1709 struct device_attribute *attr, char *buf)
1710 {
1711 struct w1_slave *sl = dev_to_w1_slave(device);
1712
1713 if (!sl->family_data) {
1714 dev_info(device,
1715 "%s: Device not supported by the driver\n", __func__);
1716 return 0; /* No device family */
1717 }
1718
1719 /* Getting the power mode of the device {external, parasite} */
1720 SLAVE_POWERMODE(sl) = read_powermode(sl);
1721
1722 if (SLAVE_POWERMODE(sl) < 0) {
1723 dev_dbg(device,
1724 "%s: Power_mode may be corrupted. err=%d\n",
1725 __func__, SLAVE_POWERMODE(sl));
1726 }
1727 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1728 }
1729
resolution_show(struct device * device,struct device_attribute * attr,char * buf)1730 static ssize_t resolution_show(struct device *device,
1731 struct device_attribute *attr, char *buf)
1732 {
1733 struct w1_slave *sl = dev_to_w1_slave(device);
1734
1735 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1736 dev_info(device,
1737 "%s: Device not supported by the driver\n", __func__);
1738 return 0; /* No device family */
1739 }
1740
1741 /* get the correct function depending on the device */
1742 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1743 if (SLAVE_RESOLUTION(sl) < 0) {
1744 dev_dbg(device,
1745 "%s: Resolution may be corrupted. err=%d\n",
1746 __func__, SLAVE_RESOLUTION(sl));
1747 }
1748
1749 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1750 }
1751
resolution_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1752 static ssize_t resolution_store(struct device *device,
1753 struct device_attribute *attr, const char *buf, size_t size)
1754 {
1755 struct w1_slave *sl = dev_to_w1_slave(device);
1756 int val;
1757 int ret = 0;
1758
1759 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1760
1761 if (ret) { /* conversion error */
1762 dev_info(device,
1763 "%s: conversion error. err= %d\n", __func__, ret);
1764 return size; /* return size to avoid call back again */
1765 }
1766
1767 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1768 dev_info(device,
1769 "%s: Device not supported by the driver\n", __func__);
1770 return size; /* No device family */
1771 }
1772
1773 /*
1774 * Don't deal with the val enterd by user,
1775 * only device knows what is correct or not
1776 */
1777
1778 /* get the correct function depending on the device */
1779 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1780
1781 if (ret)
1782 return ret;
1783
1784 SLAVE_RESOLUTION(sl) = val;
1785 /* Reset the conversion time to default because it depends on resolution */
1786 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1787
1788 return size;
1789 }
1790
eeprom_cmd_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1791 static ssize_t eeprom_cmd_store(struct device *device,
1792 struct device_attribute *attr, const char *buf, size_t size)
1793 {
1794 struct w1_slave *sl = dev_to_w1_slave(device);
1795 int ret = -EINVAL; /* Invalid argument */
1796
1797 if (size == sizeof(EEPROM_CMD_WRITE)) {
1798 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1799 ret = copy_scratchpad(sl);
1800 } else if (size == sizeof(EEPROM_CMD_READ)) {
1801 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1802 ret = recall_eeprom(sl);
1803 }
1804
1805 if (ret)
1806 dev_info(device, "%s: error in process %d\n", __func__, ret);
1807
1808 return size;
1809 }
1810
alarms_show(struct device * device,struct device_attribute * attr,char * buf)1811 static ssize_t alarms_show(struct device *device,
1812 struct device_attribute *attr, char *buf)
1813 {
1814 struct w1_slave *sl = dev_to_w1_slave(device);
1815 int ret;
1816 s8 th = 0, tl = 0;
1817 struct therm_info scratchpad;
1818
1819 ret = read_scratchpad(sl, &scratchpad);
1820
1821 if (!ret) {
1822 th = scratchpad.rom[2]; /* TH is byte 2 */
1823 tl = scratchpad.rom[3]; /* TL is byte 3 */
1824 } else {
1825 dev_info(device,
1826 "%s: error reading alarms register %d\n",
1827 __func__, ret);
1828 }
1829
1830 return sprintf(buf, "%hd %hd\n", tl, th);
1831 }
1832
alarms_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1833 static ssize_t alarms_store(struct device *device,
1834 struct device_attribute *attr, const char *buf, size_t size)
1835 {
1836 struct w1_slave *sl = dev_to_w1_slave(device);
1837 struct therm_info info;
1838 u8 new_config_register[3]; /* array of data to be written */
1839 int temp, ret;
1840 char *token = NULL;
1841 s8 tl, th; /* 1 byte per value + temp ring order */
1842 char *p_args, *orig;
1843
1844 p_args = orig = kmalloc(size, GFP_KERNEL);
1845 /* Safe string copys as buf is const */
1846 if (!p_args) {
1847 dev_warn(device,
1848 "%s: error unable to allocate memory %d\n",
1849 __func__, -ENOMEM);
1850 return size;
1851 }
1852 strcpy(p_args, buf);
1853
1854 /* Split string using space char */
1855 token = strsep(&p_args, " ");
1856
1857 if (!token) {
1858 dev_info(device,
1859 "%s: error parsing args %d\n", __func__, -EINVAL);
1860 goto free_m;
1861 }
1862
1863 /* Convert 1st entry to int */
1864 ret = kstrtoint (token, 10, &temp);
1865 if (ret) {
1866 dev_info(device,
1867 "%s: error parsing args %d\n", __func__, ret);
1868 goto free_m;
1869 }
1870
1871 tl = int_to_short(temp);
1872
1873 /* Split string using space char */
1874 token = strsep(&p_args, " ");
1875 if (!token) {
1876 dev_info(device,
1877 "%s: error parsing args %d\n", __func__, -EINVAL);
1878 goto free_m;
1879 }
1880 /* Convert 2nd entry to int */
1881 ret = kstrtoint (token, 10, &temp);
1882 if (ret) {
1883 dev_info(device,
1884 "%s: error parsing args %d\n", __func__, ret);
1885 goto free_m;
1886 }
1887
1888 /* Prepare to cast to short by eliminating out of range values */
1889 th = int_to_short(temp);
1890
1891 /* Reorder if required th and tl */
1892 if (tl > th)
1893 swap(tl, th);
1894
1895 /*
1896 * Read the scratchpad to change only the required bits
1897 * (th : byte 2 - tl: byte 3)
1898 */
1899 ret = read_scratchpad(sl, &info);
1900 if (!ret) {
1901 new_config_register[0] = th; /* Byte 2 */
1902 new_config_register[1] = tl; /* Byte 3 */
1903 new_config_register[2] = info.rom[4];/* Byte 4 */
1904 } else {
1905 dev_info(device,
1906 "%s: error reading from the slave device %d\n",
1907 __func__, ret);
1908 goto free_m;
1909 }
1910
1911 /* Write data in the device RAM */
1912 if (!SLAVE_SPECIFIC_FUNC(sl)) {
1913 dev_info(device,
1914 "%s: Device not supported by the driver %d\n",
1915 __func__, -ENODEV);
1916 goto free_m;
1917 }
1918
1919 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1920 if (ret)
1921 dev_info(device,
1922 "%s: error writing to the slave device %d\n",
1923 __func__, ret);
1924
1925 free_m:
1926 /* free allocated memory */
1927 kfree(orig);
1928
1929 return size;
1930 }
1931
therm_bulk_read_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1932 static ssize_t therm_bulk_read_store(struct device *device,
1933 struct device_attribute *attr, const char *buf, size_t size)
1934 {
1935 struct w1_master *dev_master = dev_to_w1_master(device);
1936 int ret = -EINVAL; /* Invalid argument */
1937
1938 if (size == sizeof(BULK_TRIGGER_CMD))
1939 if (!strncmp(buf, BULK_TRIGGER_CMD,
1940 sizeof(BULK_TRIGGER_CMD)-1))
1941 ret = trigger_bulk_read(dev_master);
1942
1943 if (ret)
1944 dev_info(device,
1945 "%s: unable to trigger a bulk read on the bus. err=%d\n",
1946 __func__, ret);
1947
1948 return size;
1949 }
1950
therm_bulk_read_show(struct device * device,struct device_attribute * attr,char * buf)1951 static ssize_t therm_bulk_read_show(struct device *device,
1952 struct device_attribute *attr, char *buf)
1953 {
1954 struct w1_master *dev_master = dev_to_w1_master(device);
1955 struct w1_slave *sl = NULL;
1956 int ret = 0;
1957
1958 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1959 if (sl->family_data) {
1960 if (bulk_read_support(sl)) {
1961 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1962 ret = -1;
1963 goto show_result;
1964 }
1965 if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1966 /* continue to check other slaves */
1967 ret = 1;
1968 }
1969 }
1970 }
1971 show_result:
1972 return sprintf(buf, "%d\n", ret);
1973 }
1974
conv_time_show(struct device * device,struct device_attribute * attr,char * buf)1975 static ssize_t conv_time_show(struct device *device,
1976 struct device_attribute *attr, char *buf)
1977 {
1978 struct w1_slave *sl = dev_to_w1_slave(device);
1979
1980 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1981 dev_info(device,
1982 "%s: Device is not supported by the driver\n", __func__);
1983 return 0; /* No device family */
1984 }
1985 return sprintf(buf, "%d\n", conversion_time(sl));
1986 }
1987
conv_time_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1988 static ssize_t conv_time_store(struct device *device,
1989 struct device_attribute *attr, const char *buf, size_t size)
1990 {
1991 int val, ret = 0;
1992 struct w1_slave *sl = dev_to_w1_slave(device);
1993
1994 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
1995 return -EINVAL;
1996
1997 if (check_family_data(sl))
1998 return -ENODEV;
1999
2000 if (val != CONV_TIME_MEASURE) {
2001 if (val >= CONV_TIME_DEFAULT)
2002 SLAVE_CONV_TIME_OVERRIDE(sl) = val;
2003 else
2004 return -EINVAL;
2005
2006 } else {
2007 int conv_time;
2008
2009 ret = conv_time_measure(sl, &conv_time);
2010 if (ret)
2011 return -EIO;
2012 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
2013 }
2014 return size;
2015 }
2016
features_show(struct device * device,struct device_attribute * attr,char * buf)2017 static ssize_t features_show(struct device *device,
2018 struct device_attribute *attr, char *buf)
2019 {
2020 struct w1_slave *sl = dev_to_w1_slave(device);
2021
2022 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
2023 dev_info(device,
2024 "%s: Device not supported by the driver\n", __func__);
2025 return 0; /* No device family */
2026 }
2027 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
2028 }
2029
features_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)2030 static ssize_t features_store(struct device *device,
2031 struct device_attribute *attr, const char *buf, size_t size)
2032 {
2033 int val, ret = 0;
2034 bool strong_pullup;
2035 struct w1_slave *sl = dev_to_w1_slave(device);
2036
2037 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
2038 if (ret)
2039 return -EINVAL; /* invalid number */
2040
2041 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
2042 dev_info(device, "%s: Device not supported by the driver\n", __func__);
2043 return -ENODEV;
2044 }
2045
2046 if ((val & W1_THERM_FEATURES_MASK) != val)
2047 return -EINVAL;
2048
2049 SLAVE_FEATURES(sl) = val;
2050
2051 strong_pullup = (w1_strong_pullup == 2 ||
2052 (!SLAVE_POWERMODE(sl) &&
2053 w1_strong_pullup));
2054
2055 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2056 dev_warn(&sl->dev,
2057 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2058 __func__);
2059 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2060 }
2061
2062 return size;
2063 }
2064
2065 #if IS_REACHABLE(CONFIG_HWMON)
w1_read_temp(struct device * device,u32 attr,int channel,long * val)2066 static int w1_read_temp(struct device *device, u32 attr, int channel,
2067 long *val)
2068 {
2069 struct w1_slave *sl = dev_get_drvdata(device);
2070 struct therm_info info;
2071 int ret;
2072
2073 switch (attr) {
2074 case hwmon_temp_input:
2075 ret = convert_t(sl, &info);
2076 if (ret)
2077 return ret;
2078
2079 if (!info.verdict) {
2080 ret = -EIO;
2081 return ret;
2082 }
2083
2084 *val = temperature_from_RAM(sl, info.rom);
2085 ret = 0;
2086 break;
2087 default:
2088 ret = -EOPNOTSUPP;
2089 break;
2090 }
2091
2092 return ret;
2093 }
2094 #endif
2095
2096 #define W1_42_CHAIN 0x99
2097 #define W1_42_CHAIN_OFF 0x3C
2098 #define W1_42_CHAIN_OFF_INV 0xC3
2099 #define W1_42_CHAIN_ON 0x5A
2100 #define W1_42_CHAIN_ON_INV 0xA5
2101 #define W1_42_CHAIN_DONE 0x96
2102 #define W1_42_CHAIN_DONE_INV 0x69
2103 #define W1_42_COND_READ 0x0F
2104 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2105 #define W1_42_FINISHED_BYTE 0xFF
w1_seq_show(struct device * device,struct device_attribute * attr,char * buf)2106 static ssize_t w1_seq_show(struct device *device,
2107 struct device_attribute *attr, char *buf)
2108 {
2109 struct w1_slave *sl = dev_to_w1_slave(device);
2110 ssize_t c = PAGE_SIZE;
2111 int i;
2112 u8 ack;
2113 u64 rn;
2114 struct w1_reg_num *reg_num;
2115 int seq = 0;
2116
2117 mutex_lock(&sl->master->bus_mutex);
2118 /* Place all devices in CHAIN state */
2119 if (w1_reset_bus(sl->master))
2120 goto error;
2121 w1_write_8(sl->master, W1_SKIP_ROM);
2122 w1_write_8(sl->master, W1_42_CHAIN);
2123 w1_write_8(sl->master, W1_42_CHAIN_ON);
2124 w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2125 msleep(sl->master->pullup_duration);
2126
2127 /* check for acknowledgment */
2128 ack = w1_read_8(sl->master);
2129 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2130 goto error;
2131
2132 /* In case the bus fails to send 0xFF, limit */
2133 for (i = 0; i <= 64; i++) {
2134 if (w1_reset_bus(sl->master))
2135 goto error;
2136
2137 w1_write_8(sl->master, W1_42_COND_READ);
2138 w1_read_block(sl->master, (u8 *)&rn, 8);
2139 reg_num = (struct w1_reg_num *) &rn;
2140 if (reg_num->family == W1_42_FINISHED_BYTE)
2141 break;
2142 if (sl->reg_num.id == reg_num->id)
2143 seq = i;
2144
2145 if (w1_reset_bus(sl->master))
2146 goto error;
2147
2148 /* Put the device into chain DONE state */
2149 w1_write_8(sl->master, W1_MATCH_ROM);
2150 w1_write_block(sl->master, (u8 *)&rn, 8);
2151 w1_write_8(sl->master, W1_42_CHAIN);
2152 w1_write_8(sl->master, W1_42_CHAIN_DONE);
2153 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2154
2155 /* check for acknowledgment */
2156 ack = w1_read_8(sl->master);
2157 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2158 goto error;
2159 }
2160
2161 /* Exit from CHAIN state */
2162 if (w1_reset_bus(sl->master))
2163 goto error;
2164 w1_write_8(sl->master, W1_SKIP_ROM);
2165 w1_write_8(sl->master, W1_42_CHAIN);
2166 w1_write_8(sl->master, W1_42_CHAIN_OFF);
2167 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
2168
2169 /* check for acknowledgment */
2170 ack = w1_read_8(sl->master);
2171 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2172 goto error;
2173 mutex_unlock(&sl->master->bus_mutex);
2174
2175 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
2176 return PAGE_SIZE - c;
2177 error:
2178 mutex_unlock(&sl->master->bus_mutex);
2179 return -EIO;
2180 }
2181
w1_therm_init(void)2182 static int __init w1_therm_init(void)
2183 {
2184 int err, i;
2185
2186 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
2187 err = w1_register_family(w1_therm_families[i].f);
2188 if (err)
2189 w1_therm_families[i].broken = 1;
2190 }
2191
2192 return 0;
2193 }
2194
w1_therm_fini(void)2195 static void __exit w1_therm_fini(void)
2196 {
2197 int i;
2198
2199 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
2200 if (!w1_therm_families[i].broken)
2201 w1_unregister_family(w1_therm_families[i].f);
2202 }
2203
2204 module_init(w1_therm_init);
2205 module_exit(w1_therm_fini);
2206
2207 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
2208 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
2209 MODULE_LICENSE("GPL");
2210 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
2211 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
2212 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
2213 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
2214 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
2215