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 mesured */
67 #define MAX_TEMP 125 /* max temperature that can be mesured */
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 commmand 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_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);
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.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.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.attr,
414 &dev_attr_alarms.attr,
415 &dev_attr_conv_time.attr,
416 &dev_attr_features.attr,
417 NULL,
418 };
419
420 /* Attribute groups */
421
422 ATTRIBUTE_GROUPS(w1_therm);
423 ATTRIBUTE_GROUPS(w1_ds18s20);
424 ATTRIBUTE_GROUPS(w1_ds28ea00);
425
426 #if IS_REACHABLE(CONFIG_HWMON)
427 static int w1_read_temp(struct device *dev, u32 attr, int channel,
428 long *val);
429
w1_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)430 static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
431 u32 attr, int channel)
432 {
433 return attr == hwmon_temp_input ? 0444 : 0;
434 }
435
w1_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)436 static int w1_read(struct device *dev, enum hwmon_sensor_types type,
437 u32 attr, int channel, long *val)
438 {
439 switch (type) {
440 case hwmon_temp:
441 return w1_read_temp(dev, attr, channel, val);
442 default:
443 return -EOPNOTSUPP;
444 }
445 }
446
447 static const u32 w1_temp_config[] = {
448 HWMON_T_INPUT,
449 0
450 };
451
452 static const struct hwmon_channel_info w1_temp = {
453 .type = hwmon_temp,
454 .config = w1_temp_config,
455 };
456
457 static const struct hwmon_channel_info *w1_info[] = {
458 &w1_temp,
459 NULL
460 };
461
462 static const struct hwmon_ops w1_hwmon_ops = {
463 .is_visible = w1_is_visible,
464 .read = w1_read,
465 };
466
467 static const struct hwmon_chip_info w1_chip_info = {
468 .ops = &w1_hwmon_ops,
469 .info = w1_info,
470 };
471 #define W1_CHIPINFO (&w1_chip_info)
472 #else
473 #define W1_CHIPINFO NULL
474 #endif
475
476 /* Family operations */
477
478 static const struct w1_family_ops w1_therm_fops = {
479 .add_slave = w1_therm_add_slave,
480 .remove_slave = w1_therm_remove_slave,
481 .groups = w1_therm_groups,
482 .chip_info = W1_CHIPINFO,
483 };
484
485 static const struct w1_family_ops w1_ds18s20_fops = {
486 .add_slave = w1_therm_add_slave,
487 .remove_slave = w1_therm_remove_slave,
488 .groups = w1_ds18s20_groups,
489 .chip_info = W1_CHIPINFO,
490 };
491
492 static const struct w1_family_ops w1_ds28ea00_fops = {
493 .add_slave = w1_therm_add_slave,
494 .remove_slave = w1_therm_remove_slave,
495 .groups = w1_ds28ea00_groups,
496 .chip_info = W1_CHIPINFO,
497 };
498
499 /* Family binding operations struct */
500
501 static struct w1_family w1_therm_family_DS18S20 = {
502 .fid = W1_THERM_DS18S20,
503 .fops = &w1_ds18s20_fops,
504 };
505
506 static struct w1_family w1_therm_family_DS18B20 = {
507 .fid = W1_THERM_DS18B20,
508 .fops = &w1_therm_fops,
509 };
510
511 static struct w1_family w1_therm_family_DS1822 = {
512 .fid = W1_THERM_DS1822,
513 .fops = &w1_therm_fops,
514 };
515
516 static struct w1_family w1_therm_family_DS28EA00 = {
517 .fid = W1_THERM_DS28EA00,
518 .fops = &w1_ds28ea00_fops,
519 };
520
521 static struct w1_family w1_therm_family_DS1825 = {
522 .fid = W1_THERM_DS1825,
523 .fops = &w1_therm_fops,
524 };
525
526 /* Device dependent func */
527
w1_DS18B20_convert_time(struct w1_slave * sl)528 static inline int w1_DS18B20_convert_time(struct w1_slave *sl)
529 {
530 int ret;
531
532 if (!sl->family_data)
533 return -ENODEV; /* device unknown */
534
535 if (SLAVE_CONV_TIME_OVERRIDE(sl) != CONV_TIME_DEFAULT)
536 return SLAVE_CONV_TIME_OVERRIDE(sl);
537
538 /* Return the conversion time, depending on resolution,
539 * select maximum conversion time among all compatible devices
540 */
541 switch (SLAVE_RESOLUTION(sl)) {
542 case 9:
543 ret = 95;
544 break;
545 case 10:
546 ret = 190;
547 break;
548 case 11:
549 ret = 375;
550 break;
551 case 12:
552 ret = 750;
553 break;
554 case 13:
555 ret = 850; /* GX20MH01 only. Datasheet says 500ms, but that's not enough. */
556 break;
557 case 14:
558 ret = 1600; /* GX20MH01 only. Datasheet says 1000ms - not enough */
559 break;
560 default:
561 ret = 750;
562 }
563 return ret;
564 }
565
w1_DS18S20_convert_time(struct w1_slave * sl)566 static inline int w1_DS18S20_convert_time(struct w1_slave *sl)
567 {
568 if (!sl->family_data)
569 return -ENODEV; /* device unknown */
570
571 if (SLAVE_CONV_TIME_OVERRIDE(sl) == CONV_TIME_DEFAULT)
572 return 750; /* default for DS18S20 */
573 else
574 return SLAVE_CONV_TIME_OVERRIDE(sl);
575 }
576
w1_DS18B20_write_data(struct w1_slave * sl,const u8 * data)577 static inline int w1_DS18B20_write_data(struct w1_slave *sl,
578 const u8 *data)
579 {
580 return write_scratchpad(sl, data, 3);
581 }
582
w1_DS18S20_write_data(struct w1_slave * sl,const u8 * data)583 static inline int w1_DS18S20_write_data(struct w1_slave *sl,
584 const u8 *data)
585 {
586 /* No config register */
587 return write_scratchpad(sl, data, 2);
588 }
589
w1_DS18B20_set_resolution(struct w1_slave * sl,int val)590 static inline int w1_DS18B20_set_resolution(struct w1_slave *sl, int val)
591 {
592 int ret;
593 struct therm_info info, info2;
594
595 /* DS18B20 resolution is 9 to 12 bits */
596 /* GX20MH01 resolution is 9 to 14 bits */
597 if (val < W1_THERM_RESOLUTION_MIN || val > W1_THERM_RESOLUTION_MAX)
598 return -EINVAL;
599
600 /* Calc bit value from resolution */
601 val = (val - W1_THERM_RESOLUTION_MIN) << W1_THERM_RESOLUTION_SHIFT;
602
603 /*
604 * Read the scratchpad to change only the required bits
605 * (bit5 & bit 6 from byte 4)
606 */
607 ret = read_scratchpad(sl, &info);
608
609 if (ret)
610 return ret;
611
612
613 info.rom[4] &= ~W1_THERM_RESOLUTION_MASK;
614 info.rom[4] |= val;
615
616 /* Write data in the device RAM */
617 ret = w1_DS18B20_write_data(sl, info.rom + 2);
618 if (ret)
619 return ret;
620
621 /* Have to read back the resolution to verify an actual value
622 * GX20MH01 and DS18B20 are indistinguishable by family number, but resolutions differ
623 * Some DS18B20 clones don't support resolution change
624 */
625 ret = read_scratchpad(sl, &info2);
626 if (ret)
627 /* Scratchpad read fail */
628 return ret;
629
630 if ((info2.rom[4] & W1_THERM_RESOLUTION_MASK) == (info.rom[4] & W1_THERM_RESOLUTION_MASK))
631 return 0;
632
633 /* Resolution verify error */
634 return -EIO;
635 }
636
w1_DS18B20_get_resolution(struct w1_slave * sl)637 static inline int w1_DS18B20_get_resolution(struct w1_slave *sl)
638 {
639 int ret;
640 int resolution;
641 struct therm_info info;
642
643 ret = read_scratchpad(sl, &info);
644
645 if (ret)
646 return ret;
647
648 resolution = ((info.rom[4] & W1_THERM_RESOLUTION_MASK) >> W1_THERM_RESOLUTION_SHIFT)
649 + W1_THERM_RESOLUTION_MIN;
650 /* GX20MH01 has one special case:
651 * >=14 means 14 bits when getting resolution from bit value.
652 * Other devices have no more then 12 bits.
653 */
654 if (resolution > W1_THERM_RESOLUTION_MAX)
655 resolution = W1_THERM_RESOLUTION_MAX;
656
657 return resolution;
658 }
659
660 /**
661 * w1_DS18B20_convert_temp() - temperature computation for DS18B20
662 * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
663 *
664 * Can be called for any DS18B20 compliant device.
665 *
666 * Return: value in millidegrees Celsius.
667 */
w1_DS18B20_convert_temp(u8 rom[9])668 static inline int w1_DS18B20_convert_temp(u8 rom[9])
669 {
670 u16 bv;
671 s16 t;
672
673 /* Signed 16-bit value to unsigned, cpu order */
674 bv = le16_to_cpup((__le16 *)rom);
675
676 /* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */
677 if (rom[4] & 0x80) {
678 /* Insert two temperature bits from config register */
679 /* Avoid arithmetic shift of signed value */
680 bv = (bv << 2) | (rom[4] & 3);
681 t = (s16) bv; /* Degrees, lowest bit is 2^-6 */
682 return (int)t * 1000 / 64; /* Sign-extend to int; millidegrees */
683 }
684 t = (s16)bv; /* Degrees, lowest bit is 2^-4 */
685 return (int)t * 1000 / 16; /* Sign-extend to int; millidegrees */
686 }
687
688 /**
689 * w1_DS18S20_convert_temp() - temperature computation for DS18S20
690 * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
691 *
692 * Can be called for any DS18S20 compliant device.
693 *
694 * Return: value in millidegrees Celsius.
695 */
w1_DS18S20_convert_temp(u8 rom[9])696 static inline int w1_DS18S20_convert_temp(u8 rom[9])
697 {
698 int t, h;
699
700 if (!rom[7]) {
701 pr_debug("%s: Invalid argument for conversion\n", __func__);
702 return 0;
703 }
704
705 if (rom[1] == 0)
706 t = ((s32)rom[0] >> 1)*1000;
707 else
708 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
709
710 t -= 250;
711 h = 1000*((s32)rom[7] - (s32)rom[6]);
712 h /= (s32)rom[7];
713 t += h;
714
715 return t;
716 }
717
718 /* Device capability description */
719 /* GX20MH01 device shares family number and structure with DS18B20 */
720
721 static struct w1_therm_family_converter w1_therm_families[] = {
722 {
723 .f = &w1_therm_family_DS18S20,
724 .convert = w1_DS18S20_convert_temp,
725 .get_conversion_time = w1_DS18S20_convert_time,
726 .set_resolution = NULL, /* no config register */
727 .get_resolution = NULL, /* no config register */
728 .write_data = w1_DS18S20_write_data,
729 .bulk_read = true
730 },
731 {
732 .f = &w1_therm_family_DS1822,
733 .convert = w1_DS18B20_convert_temp,
734 .get_conversion_time = w1_DS18B20_convert_time,
735 .set_resolution = w1_DS18B20_set_resolution,
736 .get_resolution = w1_DS18B20_get_resolution,
737 .write_data = w1_DS18B20_write_data,
738 .bulk_read = true
739 },
740 {
741 /* Also used for GX20MH01 */
742 .f = &w1_therm_family_DS18B20,
743 .convert = w1_DS18B20_convert_temp,
744 .get_conversion_time = w1_DS18B20_convert_time,
745 .set_resolution = w1_DS18B20_set_resolution,
746 .get_resolution = w1_DS18B20_get_resolution,
747 .write_data = w1_DS18B20_write_data,
748 .bulk_read = true
749 },
750 {
751 .f = &w1_therm_family_DS28EA00,
752 .convert = w1_DS18B20_convert_temp,
753 .get_conversion_time = w1_DS18B20_convert_time,
754 .set_resolution = w1_DS18B20_set_resolution,
755 .get_resolution = w1_DS18B20_get_resolution,
756 .write_data = w1_DS18B20_write_data,
757 .bulk_read = false
758 },
759 {
760 .f = &w1_therm_family_DS1825,
761 .convert = w1_DS18B20_convert_temp,
762 .get_conversion_time = w1_DS18B20_convert_time,
763 .set_resolution = w1_DS18B20_set_resolution,
764 .get_resolution = w1_DS18B20_get_resolution,
765 .write_data = w1_DS18B20_write_data,
766 .bulk_read = true
767 }
768 };
769
770 /* Helpers Functions */
771
772 /**
773 * device_family() - Retrieve a pointer on &struct w1_therm_family_converter
774 * @sl: slave to retrieve the device specific structure
775 *
776 * Return: pointer to the slaves's family converter, NULL if not known
777 */
device_family(struct w1_slave * sl)778 static struct w1_therm_family_converter *device_family(struct w1_slave *sl)
779 {
780 struct w1_therm_family_converter *ret = NULL;
781 int i;
782
783 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
784 if (w1_therm_families[i].f->fid == sl->family->fid) {
785 ret = &w1_therm_families[i];
786 break;
787 }
788 }
789 return ret;
790 }
791
792 /**
793 * bus_mutex_lock() - Acquire the mutex
794 * @lock: w1 bus mutex to acquire
795 *
796 * It try to acquire the mutex W1_THERM_MAX_TRY times and wait
797 * W1_THERM_RETRY_DELAY between 2 attempts.
798 *
799 * Return: true is mutex is acquired and lock, false otherwise
800 */
bus_mutex_lock(struct mutex * lock)801 static inline bool bus_mutex_lock(struct mutex *lock)
802 {
803 int max_trying = W1_THERM_MAX_TRY;
804
805 /* try to acquire the mutex, if not, sleep retry_delay before retry) */
806 while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) {
807 unsigned long sleep_rem;
808
809 sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY);
810 if (!sleep_rem)
811 max_trying--;
812 }
813
814 if (!max_trying)
815 return false; /* Didn't acquire the bus mutex */
816
817 return true;
818 }
819
820 /**
821 * check_family_data() - Check if family data and specific functions are present
822 * @sl: W1 device data
823 *
824 * Return: 0 - OK, negative value - error
825 */
check_family_data(struct w1_slave * sl)826 static int check_family_data(struct w1_slave *sl)
827 {
828 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
829 dev_info(&sl->dev,
830 "%s: Device is not supported by the driver\n", __func__);
831 return -EINVAL; /* No device family */
832 }
833 return 0;
834 }
835
836 /**
837 * support_bulk_read() - check if slave support bulk read
838 * @sl: device to check the ability
839 *
840 * Return: true if bulk read is supported, false if not or error
841 */
bulk_read_support(struct w1_slave * sl)842 static inline bool bulk_read_support(struct w1_slave *sl)
843 {
844 if (SLAVE_SPECIFIC_FUNC(sl))
845 return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
846
847 dev_info(&sl->dev,
848 "%s: Device not supported by the driver\n", __func__);
849
850 return false; /* No device family */
851 }
852
853 /**
854 * conversion_time() - get the Tconv for the slave
855 * @sl: device to get the conversion time
856 *
857 * On device supporting resolution settings, conversion time depend
858 * on the resolution setting. This helper function get the slave timing,
859 * depending on its current setting.
860 *
861 * Return: conversion time in ms, negative values are kernel error code
862 */
conversion_time(struct w1_slave * sl)863 static inline int conversion_time(struct w1_slave *sl)
864 {
865 if (SLAVE_SPECIFIC_FUNC(sl))
866 return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
867
868 dev_info(&sl->dev,
869 "%s: Device not supported by the driver\n", __func__);
870
871 return -ENODEV; /* No device family */
872 }
873
874 /**
875 * temperature_from_RAM() - Convert the read info to temperature
876 * @sl: device that sent the RAM data
877 * @rom: read value on the slave device RAM
878 *
879 * Device dependent, the function bind the correct computation method.
880 *
881 * Return: temperature in 1/1000degC, 0 on error.
882 */
temperature_from_RAM(struct w1_slave * sl,u8 rom[9])883 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
884 {
885 if (SLAVE_SPECIFIC_FUNC(sl))
886 return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
887
888 dev_info(&sl->dev,
889 "%s: Device not supported by the driver\n", __func__);
890
891 return 0; /* No device family */
892 }
893
894 /**
895 * int_to_short() - Safe casting of int to short
896 *
897 * @i: integer to be converted to short
898 *
899 * Device register use 1 byte to store signed integer.
900 * This helper function convert the int in a signed short,
901 * using the min/max values that device can measure as limits.
902 * min/max values are defined by macro.
903 *
904 * Return: a short in the range of min/max value
905 */
int_to_short(int i)906 static inline s8 int_to_short(int i)
907 {
908 /* Prepare to cast to short by eliminating out of range values */
909 i = i > MAX_TEMP ? MAX_TEMP : i;
910 i = i < MIN_TEMP ? MIN_TEMP : i;
911 return (s8) i;
912 }
913
914 /* Interface Functions */
915
w1_therm_add_slave(struct w1_slave * sl)916 static int w1_therm_add_slave(struct w1_slave *sl)
917 {
918 struct w1_therm_family_converter *sl_family_conv;
919
920 /* Allocate memory */
921 sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
922 GFP_KERNEL);
923 if (!sl->family_data)
924 return -ENOMEM;
925
926 atomic_set(THERM_REFCNT(sl->family_data), 1);
927
928 /* Get a pointer to the device specific function struct */
929 sl_family_conv = device_family(sl);
930 if (!sl_family_conv) {
931 kfree(sl->family_data);
932 return -ENODEV;
933 }
934 /* save this pointer to the device structure */
935 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
936
937 if (bulk_read_support(sl)) {
938 /*
939 * add the sys entry to trigger bulk_read
940 * at master level only the 1st time
941 */
942 if (!bulk_read_device_counter) {
943 int err = device_create_file(&sl->master->dev,
944 &dev_attr_therm_bulk_read);
945
946 if (err)
947 dev_warn(&sl->dev,
948 "%s: Device has been added, but bulk read is unavailable. err=%d\n",
949 __func__, err);
950 }
951 /* Increment the counter */
952 bulk_read_device_counter++;
953 }
954
955 /* Getting the power mode of the device {external, parasite} */
956 SLAVE_POWERMODE(sl) = read_powermode(sl);
957
958 if (SLAVE_POWERMODE(sl) < 0) {
959 /* no error returned as device has been added */
960 dev_warn(&sl->dev,
961 "%s: Device has been added, but power_mode may be corrupted. err=%d\n",
962 __func__, SLAVE_POWERMODE(sl));
963 }
964
965 /* Getting the resolution of the device */
966 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
967 SLAVE_RESOLUTION(sl) =
968 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
969 if (SLAVE_RESOLUTION(sl) < 0) {
970 /* no error returned as device has been added */
971 dev_warn(&sl->dev,
972 "%s:Device has been added, but resolution may be corrupted. err=%d\n",
973 __func__, SLAVE_RESOLUTION(sl));
974 }
975 }
976
977 /* Finally initialize convert_triggered flag */
978 SLAVE_CONVERT_TRIGGERED(sl) = 0;
979
980 return 0;
981 }
982
w1_therm_remove_slave(struct w1_slave * sl)983 static void w1_therm_remove_slave(struct w1_slave *sl)
984 {
985 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
986
987 if (bulk_read_support(sl)) {
988 bulk_read_device_counter--;
989 /* Delete the entry if no more device support the feature */
990 if (!bulk_read_device_counter)
991 device_remove_file(&sl->master->dev,
992 &dev_attr_therm_bulk_read);
993 }
994
995 while (refcnt) {
996 msleep(1000);
997 refcnt = atomic_read(THERM_REFCNT(sl->family_data));
998 }
999 kfree(sl->family_data);
1000 sl->family_data = NULL;
1001 }
1002
1003 /* Hardware Functions */
1004
1005 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
reset_select_slave(struct w1_slave * sl)1006 static int reset_select_slave(struct w1_slave *sl)
1007 {
1008 u8 match[9] = { W1_MATCH_ROM, };
1009 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1010
1011 if (w1_reset_bus(sl->master))
1012 return -ENODEV;
1013
1014 memcpy(&match[1], &rn, 8);
1015 w1_write_block(sl->master, match, 9);
1016
1017 return 0;
1018 }
1019
1020 /**
1021 * w1_poll_completion - Poll for operation completion, with timeout
1022 * @dev_master: the device master of the bus
1023 * @tout_ms: timeout in milliseconds
1024 *
1025 * The device is answering 0's while an operation is in progress and 1's after it completes
1026 * Timeout may happen if the previous command was not recognised due to a line noise
1027 *
1028 * Return: 0 - OK, negative error - timeout
1029 */
w1_poll_completion(struct w1_master * dev_master,int tout_ms)1030 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1031 {
1032 int i;
1033
1034 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1035 /* Delay is before poll, for device to recognize a command */
1036 msleep(W1_POLL_PERIOD);
1037
1038 /* Compare all 8 bits to mitigate a noise on the bus */
1039 if (w1_read_8(dev_master) == 0xFF)
1040 break;
1041 }
1042 if (i == tout_ms/W1_POLL_PERIOD)
1043 return -EIO;
1044
1045 return 0;
1046 }
1047
convert_t(struct w1_slave * sl,struct therm_info * info)1048 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1049 {
1050 struct w1_master *dev_master = sl->master;
1051 int max_trying = W1_THERM_MAX_TRY;
1052 int t_conv;
1053 int ret = -ENODEV;
1054 bool strong_pullup;
1055
1056 if (!sl->family_data)
1057 goto error;
1058
1059 strong_pullup = (w1_strong_pullup == 2 ||
1060 (!SLAVE_POWERMODE(sl) &&
1061 w1_strong_pullup));
1062
1063 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1064 dev_warn(&sl->dev,
1065 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1066 __func__);
1067 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1068 }
1069
1070 /* get conversion duration device and id dependent */
1071 t_conv = conversion_time(sl);
1072
1073 memset(info->rom, 0, sizeof(info->rom));
1074
1075 /* prevent the slave from going away in sleep */
1076 atomic_inc(THERM_REFCNT(sl->family_data));
1077
1078 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1079 ret = -EAGAIN; /* Didn't acquire the mutex */
1080 goto dec_refcnt;
1081 }
1082
1083 while (max_trying-- && ret) { /* ret should be 0 */
1084
1085 info->verdict = 0;
1086 info->crc = 0;
1087 /* safe version to select slave */
1088 if (!reset_select_slave(sl)) {
1089 unsigned long sleep_rem;
1090
1091 /* 750ms strong pullup (or delay) after the convert */
1092 if (strong_pullup)
1093 w1_next_pullup(dev_master, t_conv);
1094
1095 w1_write_8(dev_master, W1_CONVERT_TEMP);
1096
1097 if (strong_pullup) { /*some device need pullup */
1098 sleep_rem = msleep_interruptible(t_conv);
1099 if (sleep_rem != 0) {
1100 ret = -EINTR;
1101 goto mt_unlock;
1102 }
1103 mutex_unlock(&dev_master->bus_mutex);
1104 } else { /*no device need pullup */
1105 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1106 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1107 if (ret) {
1108 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1109 goto mt_unlock;
1110 }
1111 mutex_unlock(&dev_master->bus_mutex);
1112 } else {
1113 /* Fixed delay */
1114 mutex_unlock(&dev_master->bus_mutex);
1115 sleep_rem = msleep_interruptible(t_conv);
1116 if (sleep_rem != 0) {
1117 ret = -EINTR;
1118 goto dec_refcnt;
1119 }
1120 }
1121 }
1122 ret = read_scratchpad(sl, info);
1123
1124 /* If enabled, check for conversion success */
1125 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1126 (info->rom[6] == 0xC) &&
1127 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1128 (info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1129 ) {
1130 /* Invalid reading (scratchpad byte 6 = 0xC)
1131 * due to insufficient conversion time
1132 * or power failure.
1133 */
1134 ret = -EIO;
1135 }
1136
1137 goto dec_refcnt;
1138 }
1139
1140 }
1141
1142 mt_unlock:
1143 mutex_unlock(&dev_master->bus_mutex);
1144 dec_refcnt:
1145 atomic_dec(THERM_REFCNT(sl->family_data));
1146 error:
1147 return ret;
1148 }
1149
conv_time_measure(struct w1_slave * sl,int * conv_time)1150 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1151 {
1152 struct therm_info inf,
1153 *info = &inf;
1154 struct w1_master *dev_master = sl->master;
1155 int max_trying = W1_THERM_MAX_TRY;
1156 int ret = -ENODEV;
1157 bool strong_pullup;
1158
1159 if (!sl->family_data)
1160 goto error;
1161
1162 strong_pullup = (w1_strong_pullup == 2 ||
1163 (!SLAVE_POWERMODE(sl) &&
1164 w1_strong_pullup));
1165
1166 if (strong_pullup) {
1167 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1168 return -EINVAL;
1169 }
1170
1171 memset(info->rom, 0, sizeof(info->rom));
1172
1173 /* prevent the slave from going away in sleep */
1174 atomic_inc(THERM_REFCNT(sl->family_data));
1175
1176 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1177 ret = -EAGAIN; /* Didn't acquire the mutex */
1178 goto dec_refcnt;
1179 }
1180
1181 while (max_trying-- && ret) { /* ret should be 0 */
1182 info->verdict = 0;
1183 info->crc = 0;
1184 /* safe version to select slave */
1185 if (!reset_select_slave(sl)) {
1186 int j_start, j_end;
1187
1188 /*no device need pullup */
1189 w1_write_8(dev_master, W1_CONVERT_TEMP);
1190
1191 j_start = jiffies;
1192 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1193 if (ret) {
1194 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1195 goto mt_unlock;
1196 }
1197 j_end = jiffies;
1198 /* 1.2x increase for variation and changes over temperature range */
1199 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1200 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1201 *conv_time, HZ);
1202 if (*conv_time <= CONV_TIME_MEASURE) {
1203 ret = -EIO;
1204 goto mt_unlock;
1205 }
1206 mutex_unlock(&dev_master->bus_mutex);
1207 ret = read_scratchpad(sl, info);
1208 goto dec_refcnt;
1209 }
1210
1211 }
1212 mt_unlock:
1213 mutex_unlock(&dev_master->bus_mutex);
1214 dec_refcnt:
1215 atomic_dec(THERM_REFCNT(sl->family_data));
1216 error:
1217 return ret;
1218 }
1219
read_scratchpad(struct w1_slave * sl,struct therm_info * info)1220 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1221 {
1222 struct w1_master *dev_master = sl->master;
1223 int max_trying = W1_THERM_MAX_TRY;
1224 int ret = -ENODEV;
1225
1226 info->verdict = 0;
1227
1228 if (!sl->family_data)
1229 goto error;
1230
1231 memset(info->rom, 0, sizeof(info->rom));
1232
1233 /* prevent the slave from going away in sleep */
1234 atomic_inc(THERM_REFCNT(sl->family_data));
1235
1236 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1237 ret = -EAGAIN; /* Didn't acquire the mutex */
1238 goto dec_refcnt;
1239 }
1240
1241 while (max_trying-- && ret) { /* ret should be 0 */
1242 /* safe version to select slave */
1243 if (!reset_select_slave(sl)) {
1244 u8 nb_bytes_read;
1245
1246 w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1247
1248 nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1249 if (nb_bytes_read != 9) {
1250 dev_warn(&sl->dev,
1251 "w1_read_block(): returned %u instead of 9.\n",
1252 nb_bytes_read);
1253 ret = -EIO;
1254 }
1255
1256 info->crc = w1_calc_crc8(info->rom, 8);
1257
1258 if (info->rom[8] == info->crc) {
1259 info->verdict = 1;
1260 ret = 0;
1261 } else
1262 ret = -EIO; /* CRC not checked */
1263 }
1264
1265 }
1266 mutex_unlock(&dev_master->bus_mutex);
1267
1268 dec_refcnt:
1269 atomic_dec(THERM_REFCNT(sl->family_data));
1270 error:
1271 return ret;
1272 }
1273
write_scratchpad(struct w1_slave * sl,const u8 * data,u8 nb_bytes)1274 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1275 {
1276 struct w1_master *dev_master = sl->master;
1277 int max_trying = W1_THERM_MAX_TRY;
1278 int ret = -ENODEV;
1279
1280 if (!sl->family_data)
1281 goto error;
1282
1283 /* prevent the slave from going away in sleep */
1284 atomic_inc(THERM_REFCNT(sl->family_data));
1285
1286 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1287 ret = -EAGAIN; /* Didn't acquire the mutex */
1288 goto dec_refcnt;
1289 }
1290
1291 while (max_trying-- && ret) { /* ret should be 0 */
1292 /* safe version to select slave */
1293 if (!reset_select_slave(sl)) {
1294 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1295 w1_write_block(dev_master, data, nb_bytes);
1296 ret = 0;
1297 }
1298 }
1299 mutex_unlock(&dev_master->bus_mutex);
1300
1301 dec_refcnt:
1302 atomic_dec(THERM_REFCNT(sl->family_data));
1303 error:
1304 return ret;
1305 }
1306
copy_scratchpad(struct w1_slave * sl)1307 static int copy_scratchpad(struct w1_slave *sl)
1308 {
1309 struct w1_master *dev_master = sl->master;
1310 int max_trying = W1_THERM_MAX_TRY;
1311 int t_write, ret = -ENODEV;
1312 bool strong_pullup;
1313
1314 if (!sl->family_data)
1315 goto error;
1316
1317 t_write = W1_THERM_EEPROM_WRITE_DELAY;
1318 strong_pullup = (w1_strong_pullup == 2 ||
1319 (!SLAVE_POWERMODE(sl) &&
1320 w1_strong_pullup));
1321
1322 /* prevent the slave from going away in sleep */
1323 atomic_inc(THERM_REFCNT(sl->family_data));
1324
1325 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1326 ret = -EAGAIN; /* Didn't acquire the mutex */
1327 goto dec_refcnt;
1328 }
1329
1330 while (max_trying-- && ret) { /* ret should be 0 */
1331 /* safe version to select slave */
1332 if (!reset_select_slave(sl)) {
1333 unsigned long sleep_rem;
1334
1335 /* 10ms strong pullup (or delay) after the convert */
1336 if (strong_pullup)
1337 w1_next_pullup(dev_master, t_write);
1338
1339 w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1340
1341 if (strong_pullup) {
1342 sleep_rem = msleep_interruptible(t_write);
1343 if (sleep_rem != 0) {
1344 ret = -EINTR;
1345 goto mt_unlock;
1346 }
1347 }
1348 ret = 0;
1349 }
1350
1351 }
1352
1353 mt_unlock:
1354 mutex_unlock(&dev_master->bus_mutex);
1355 dec_refcnt:
1356 atomic_dec(THERM_REFCNT(sl->family_data));
1357 error:
1358 return ret;
1359 }
1360
recall_eeprom(struct w1_slave * sl)1361 static int recall_eeprom(struct w1_slave *sl)
1362 {
1363 struct w1_master *dev_master = sl->master;
1364 int max_trying = W1_THERM_MAX_TRY;
1365 int ret = -ENODEV;
1366
1367 if (!sl->family_data)
1368 goto error;
1369
1370 /* prevent the slave from going away in sleep */
1371 atomic_inc(THERM_REFCNT(sl->family_data));
1372
1373 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1374 ret = -EAGAIN; /* Didn't acquire the mutex */
1375 goto dec_refcnt;
1376 }
1377
1378 while (max_trying-- && ret) { /* ret should be 0 */
1379 /* safe version to select slave */
1380 if (!reset_select_slave(sl)) {
1381
1382 w1_write_8(dev_master, W1_RECALL_EEPROM);
1383 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1384 }
1385
1386 }
1387
1388 mutex_unlock(&dev_master->bus_mutex);
1389
1390 dec_refcnt:
1391 atomic_dec(THERM_REFCNT(sl->family_data));
1392 error:
1393 return ret;
1394 }
1395
read_powermode(struct w1_slave * sl)1396 static int read_powermode(struct w1_slave *sl)
1397 {
1398 struct w1_master *dev_master = sl->master;
1399 int max_trying = W1_THERM_MAX_TRY;
1400 int ret = -ENODEV;
1401
1402 if (!sl->family_data)
1403 goto error;
1404
1405 /* prevent the slave from going away in sleep */
1406 atomic_inc(THERM_REFCNT(sl->family_data));
1407
1408 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1409 ret = -EAGAIN; /* Didn't acquire the mutex */
1410 goto dec_refcnt;
1411 }
1412
1413 while ((max_trying--) && (ret < 0)) {
1414 /* safe version to select slave */
1415 if (!reset_select_slave(sl)) {
1416 w1_write_8(dev_master, W1_READ_PSUPPLY);
1417 /*
1418 * Emit a read time slot and read only one bit,
1419 * 1 is externally powered,
1420 * 0 is parasite powered
1421 */
1422 ret = w1_touch_bit(dev_master, 1);
1423 /* ret should be either 1 either 0 */
1424 }
1425 }
1426 mutex_unlock(&dev_master->bus_mutex);
1427
1428 dec_refcnt:
1429 atomic_dec(THERM_REFCNT(sl->family_data));
1430 error:
1431 return ret;
1432 }
1433
trigger_bulk_read(struct w1_master * dev_master)1434 static int trigger_bulk_read(struct w1_master *dev_master)
1435 {
1436 struct w1_slave *sl = NULL; /* used to iterate through slaves */
1437 int max_trying = W1_THERM_MAX_TRY;
1438 int t_conv = 0;
1439 int ret = -ENODEV;
1440 bool strong_pullup = false;
1441
1442 /*
1443 * Check whether there are parasite powered device on the bus,
1444 * and compute duration of conversion for these devices
1445 * so we can apply a strong pullup if required
1446 */
1447 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1448 if (!sl->family_data)
1449 goto error;
1450 if (bulk_read_support(sl)) {
1451 int t_cur = conversion_time(sl);
1452
1453 t_conv = t_cur > t_conv ? t_cur : t_conv;
1454 strong_pullup = strong_pullup ||
1455 (w1_strong_pullup == 2 ||
1456 (!SLAVE_POWERMODE(sl) &&
1457 w1_strong_pullup));
1458 }
1459 }
1460
1461 /*
1462 * t_conv is the max conversion time required on the bus
1463 * If its 0, no device support the bulk read feature
1464 */
1465 if (!t_conv)
1466 goto error;
1467
1468 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1469 ret = -EAGAIN; /* Didn't acquire the mutex */
1470 goto error;
1471 }
1472
1473 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1474
1475 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */
1476 unsigned long sleep_rem;
1477
1478 w1_write_8(dev_master, W1_SKIP_ROM);
1479
1480 if (strong_pullup) /* Apply pullup if required */
1481 w1_next_pullup(dev_master, t_conv);
1482
1483 w1_write_8(dev_master, W1_CONVERT_TEMP);
1484
1485 /* set a flag to instruct that converT pending */
1486 list_for_each_entry(sl,
1487 &dev_master->slist, w1_slave_entry) {
1488 if (bulk_read_support(sl))
1489 SLAVE_CONVERT_TRIGGERED(sl) = -1;
1490 }
1491
1492 if (strong_pullup) { /* some device need pullup */
1493 sleep_rem = msleep_interruptible(t_conv);
1494 if (sleep_rem != 0) {
1495 ret = -EINTR;
1496 goto mt_unlock;
1497 }
1498 mutex_unlock(&dev_master->bus_mutex);
1499 } else {
1500 mutex_unlock(&dev_master->bus_mutex);
1501 sleep_rem = msleep_interruptible(t_conv);
1502 if (sleep_rem != 0) {
1503 ret = -EINTR;
1504 goto set_flag;
1505 }
1506 }
1507 ret = 0;
1508 goto set_flag;
1509 }
1510 }
1511
1512 mt_unlock:
1513 mutex_unlock(&dev_master->bus_mutex);
1514 set_flag:
1515 /* set a flag to register convsersion is done */
1516 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1517 if (bulk_read_support(sl))
1518 SLAVE_CONVERT_TRIGGERED(sl) = 1;
1519 }
1520 error:
1521 return ret;
1522 }
1523
1524 /* Sysfs Interface definition */
1525
w1_slave_show(struct device * device,struct device_attribute * attr,char * buf)1526 static ssize_t w1_slave_show(struct device *device,
1527 struct device_attribute *attr, char *buf)
1528 {
1529 struct w1_slave *sl = dev_to_w1_slave(device);
1530 struct therm_info info;
1531 u8 *family_data = sl->family_data;
1532 int ret, i;
1533 ssize_t c = PAGE_SIZE;
1534
1535 if (bulk_read_support(sl)) {
1536 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1537 dev_dbg(device,
1538 "%s: Conversion in progress, retry later\n",
1539 __func__);
1540 return 0;
1541 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1542 /* A bulk read has been issued, read the device RAM */
1543 ret = read_scratchpad(sl, &info);
1544 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1545 } else
1546 ret = convert_t(sl, &info);
1547 } else
1548 ret = convert_t(sl, &info);
1549
1550 if (ret < 0) {
1551 dev_dbg(device,
1552 "%s: Temperature data may be corrupted. err=%d\n",
1553 __func__, ret);
1554 return 0;
1555 }
1556
1557 for (i = 0; i < 9; ++i)
1558 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1559 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1560 info.crc, (info.verdict) ? "YES" : "NO");
1561
1562 if (info.verdict)
1563 memcpy(family_data, info.rom, sizeof(info.rom));
1564 else
1565 dev_warn(device, "%s:Read failed CRC check\n", __func__);
1566
1567 for (i = 0; i < 9; ++i)
1568 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1569 ((u8 *)family_data)[i]);
1570
1571 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1572 temperature_from_RAM(sl, info.rom));
1573
1574 ret = PAGE_SIZE - c;
1575 return ret;
1576 }
1577
w1_slave_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1578 static ssize_t w1_slave_store(struct device *device,
1579 struct device_attribute *attr, const char *buf,
1580 size_t size)
1581 {
1582 int val, ret = 0;
1583 struct w1_slave *sl = dev_to_w1_slave(device);
1584
1585 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1586
1587 if (ret) { /* conversion error */
1588 dev_info(device,
1589 "%s: conversion error. err= %d\n", __func__, ret);
1590 return size; /* return size to avoid call back again */
1591 }
1592
1593 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1594 dev_info(device,
1595 "%s: Device not supported by the driver\n", __func__);
1596 return size; /* No device family */
1597 }
1598
1599 if (val == 0) /* val=0 : trigger a EEPROM save */
1600 ret = copy_scratchpad(sl);
1601 else {
1602 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1603 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1604 }
1605
1606 if (ret) {
1607 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1608 /* Propagate error to userspace */
1609 return ret;
1610 }
1611 SLAVE_RESOLUTION(sl) = val;
1612 /* Reset the conversion time to default - it depends on resolution */
1613 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1614
1615 return size; /* always return size to avoid infinite calling */
1616 }
1617
temperature_show(struct device * device,struct device_attribute * attr,char * buf)1618 static ssize_t temperature_show(struct device *device,
1619 struct device_attribute *attr, char *buf)
1620 {
1621 struct w1_slave *sl = dev_to_w1_slave(device);
1622 struct therm_info info;
1623 int ret = 0;
1624
1625 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1626 dev_info(device,
1627 "%s: Device not supported by the driver\n", __func__);
1628 return 0; /* No device family */
1629 }
1630
1631 if (bulk_read_support(sl)) {
1632 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1633 dev_dbg(device,
1634 "%s: Conversion in progress, retry later\n",
1635 __func__);
1636 return 0;
1637 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1638 /* A bulk read has been issued, read the device RAM */
1639 ret = read_scratchpad(sl, &info);
1640 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1641 } else
1642 ret = convert_t(sl, &info);
1643 } else
1644 ret = convert_t(sl, &info);
1645
1646 if (ret < 0) {
1647 dev_dbg(device,
1648 "%s: Temperature data may be corrupted. err=%d\n",
1649 __func__, ret);
1650 return 0;
1651 }
1652
1653 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1654 }
1655
ext_power_show(struct device * device,struct device_attribute * attr,char * buf)1656 static ssize_t ext_power_show(struct device *device,
1657 struct device_attribute *attr, char *buf)
1658 {
1659 struct w1_slave *sl = dev_to_w1_slave(device);
1660
1661 if (!sl->family_data) {
1662 dev_info(device,
1663 "%s: Device not supported by the driver\n", __func__);
1664 return 0; /* No device family */
1665 }
1666
1667 /* Getting the power mode of the device {external, parasite} */
1668 SLAVE_POWERMODE(sl) = read_powermode(sl);
1669
1670 if (SLAVE_POWERMODE(sl) < 0) {
1671 dev_dbg(device,
1672 "%s: Power_mode may be corrupted. err=%d\n",
1673 __func__, SLAVE_POWERMODE(sl));
1674 }
1675 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1676 }
1677
resolution_show(struct device * device,struct device_attribute * attr,char * buf)1678 static ssize_t resolution_show(struct device *device,
1679 struct device_attribute *attr, char *buf)
1680 {
1681 struct w1_slave *sl = dev_to_w1_slave(device);
1682
1683 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1684 dev_info(device,
1685 "%s: Device not supported by the driver\n", __func__);
1686 return 0; /* No device family */
1687 }
1688
1689 /* get the correct function depending on the device */
1690 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1691 if (SLAVE_RESOLUTION(sl) < 0) {
1692 dev_dbg(device,
1693 "%s: Resolution may be corrupted. err=%d\n",
1694 __func__, SLAVE_RESOLUTION(sl));
1695 }
1696
1697 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1698 }
1699
resolution_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1700 static ssize_t resolution_store(struct device *device,
1701 struct device_attribute *attr, const char *buf, size_t size)
1702 {
1703 struct w1_slave *sl = dev_to_w1_slave(device);
1704 int val;
1705 int ret = 0;
1706
1707 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1708
1709 if (ret) { /* conversion error */
1710 dev_info(device,
1711 "%s: conversion error. err= %d\n", __func__, ret);
1712 return size; /* return size to avoid call back again */
1713 }
1714
1715 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1716 dev_info(device,
1717 "%s: Device not supported by the driver\n", __func__);
1718 return size; /* No device family */
1719 }
1720
1721 /*
1722 * Don't deal with the val enterd by user,
1723 * only device knows what is correct or not
1724 */
1725
1726 /* get the correct function depending on the device */
1727 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1728
1729 if (ret)
1730 return ret;
1731
1732 SLAVE_RESOLUTION(sl) = val;
1733 /* Reset the conversion time to default because it depends on resolution */
1734 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1735
1736 return size;
1737 }
1738
eeprom_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1739 static ssize_t eeprom_store(struct device *device,
1740 struct device_attribute *attr, const char *buf, size_t size)
1741 {
1742 struct w1_slave *sl = dev_to_w1_slave(device);
1743 int ret = -EINVAL; /* Invalid argument */
1744
1745 if (size == sizeof(EEPROM_CMD_WRITE)) {
1746 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1747 ret = copy_scratchpad(sl);
1748 } else if (size == sizeof(EEPROM_CMD_READ)) {
1749 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1750 ret = recall_eeprom(sl);
1751 }
1752
1753 if (ret)
1754 dev_info(device, "%s: error in process %d\n", __func__, ret);
1755
1756 return size;
1757 }
1758
alarms_show(struct device * device,struct device_attribute * attr,char * buf)1759 static ssize_t alarms_show(struct device *device,
1760 struct device_attribute *attr, char *buf)
1761 {
1762 struct w1_slave *sl = dev_to_w1_slave(device);
1763 int ret;
1764 s8 th = 0, tl = 0;
1765 struct therm_info scratchpad;
1766
1767 ret = read_scratchpad(sl, &scratchpad);
1768
1769 if (!ret) {
1770 th = scratchpad.rom[2]; /* TH is byte 2 */
1771 tl = scratchpad.rom[3]; /* TL is byte 3 */
1772 } else {
1773 dev_info(device,
1774 "%s: error reading alarms register %d\n",
1775 __func__, ret);
1776 }
1777
1778 return sprintf(buf, "%hd %hd\n", tl, th);
1779 }
1780
alarms_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1781 static ssize_t alarms_store(struct device *device,
1782 struct device_attribute *attr, const char *buf, size_t size)
1783 {
1784 struct w1_slave *sl = dev_to_w1_slave(device);
1785 struct therm_info info;
1786 u8 new_config_register[3]; /* array of data to be written */
1787 int temp, ret;
1788 char *token = NULL;
1789 s8 tl, th, tt; /* 1 byte per value + temp ring order */
1790 char *p_args, *orig;
1791
1792 p_args = orig = kmalloc(size, GFP_KERNEL);
1793 /* Safe string copys as buf is const */
1794 if (!p_args) {
1795 dev_warn(device,
1796 "%s: error unable to allocate memory %d\n",
1797 __func__, -ENOMEM);
1798 return size;
1799 }
1800 strcpy(p_args, buf);
1801
1802 /* Split string using space char */
1803 token = strsep(&p_args, " ");
1804
1805 if (!token) {
1806 dev_info(device,
1807 "%s: error parsing args %d\n", __func__, -EINVAL);
1808 goto free_m;
1809 }
1810
1811 /* Convert 1st entry to int */
1812 ret = kstrtoint (token, 10, &temp);
1813 if (ret) {
1814 dev_info(device,
1815 "%s: error parsing args %d\n", __func__, ret);
1816 goto free_m;
1817 }
1818
1819 tl = int_to_short(temp);
1820
1821 /* Split string using space char */
1822 token = strsep(&p_args, " ");
1823 if (!token) {
1824 dev_info(device,
1825 "%s: error parsing args %d\n", __func__, -EINVAL);
1826 goto free_m;
1827 }
1828 /* Convert 2nd entry to int */
1829 ret = kstrtoint (token, 10, &temp);
1830 if (ret) {
1831 dev_info(device,
1832 "%s: error parsing args %d\n", __func__, ret);
1833 goto free_m;
1834 }
1835
1836 /* Prepare to cast to short by eliminating out of range values */
1837 th = int_to_short(temp);
1838
1839 /* Reorder if required th and tl */
1840 if (tl > th) {
1841 tt = tl; tl = th; th = tt;
1842 }
1843
1844 /*
1845 * Read the scratchpad to change only the required bits
1846 * (th : byte 2 - tl: byte 3)
1847 */
1848 ret = read_scratchpad(sl, &info);
1849 if (!ret) {
1850 new_config_register[0] = th; /* Byte 2 */
1851 new_config_register[1] = tl; /* Byte 3 */
1852 new_config_register[2] = info.rom[4];/* Byte 4 */
1853 } else {
1854 dev_info(device,
1855 "%s: error reading from the slave device %d\n",
1856 __func__, ret);
1857 goto free_m;
1858 }
1859
1860 /* Write data in the device RAM */
1861 if (!SLAVE_SPECIFIC_FUNC(sl)) {
1862 dev_info(device,
1863 "%s: Device not supported by the driver %d\n",
1864 __func__, -ENODEV);
1865 goto free_m;
1866 }
1867
1868 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1869 if (ret)
1870 dev_info(device,
1871 "%s: error writing to the slave device %d\n",
1872 __func__, ret);
1873
1874 free_m:
1875 /* free allocated memory */
1876 kfree(orig);
1877
1878 return size;
1879 }
1880
therm_bulk_read_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1881 static ssize_t therm_bulk_read_store(struct device *device,
1882 struct device_attribute *attr, const char *buf, size_t size)
1883 {
1884 struct w1_master *dev_master = dev_to_w1_master(device);
1885 int ret = -EINVAL; /* Invalid argument */
1886
1887 if (size == sizeof(BULK_TRIGGER_CMD))
1888 if (!strncmp(buf, BULK_TRIGGER_CMD,
1889 sizeof(BULK_TRIGGER_CMD)-1))
1890 ret = trigger_bulk_read(dev_master);
1891
1892 if (ret)
1893 dev_info(device,
1894 "%s: unable to trigger a bulk read on the bus. err=%d\n",
1895 __func__, ret);
1896
1897 return size;
1898 }
1899
therm_bulk_read_show(struct device * device,struct device_attribute * attr,char * buf)1900 static ssize_t therm_bulk_read_show(struct device *device,
1901 struct device_attribute *attr, char *buf)
1902 {
1903 struct w1_master *dev_master = dev_to_w1_master(device);
1904 struct w1_slave *sl = NULL;
1905 int ret = 0;
1906
1907 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1908 if (sl->family_data) {
1909 if (bulk_read_support(sl)) {
1910 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1911 ret = -1;
1912 goto show_result;
1913 }
1914 if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1915 /* continue to check other slaves */
1916 ret = 1;
1917 }
1918 }
1919 }
1920 show_result:
1921 return sprintf(buf, "%d\n", ret);
1922 }
1923
conv_time_show(struct device * device,struct device_attribute * attr,char * buf)1924 static ssize_t conv_time_show(struct device *device,
1925 struct device_attribute *attr, char *buf)
1926 {
1927 struct w1_slave *sl = dev_to_w1_slave(device);
1928
1929 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1930 dev_info(device,
1931 "%s: Device is not supported by the driver\n", __func__);
1932 return 0; /* No device family */
1933 }
1934 return sprintf(buf, "%d\n", conversion_time(sl));
1935 }
1936
conv_time_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1937 static ssize_t conv_time_store(struct device *device,
1938 struct device_attribute *attr, const char *buf, size_t size)
1939 {
1940 int val, ret = 0;
1941 struct w1_slave *sl = dev_to_w1_slave(device);
1942
1943 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
1944 return -EINVAL;
1945
1946 if (check_family_data(sl))
1947 return -ENODEV;
1948
1949 if (val != CONV_TIME_MEASURE) {
1950 if (val >= CONV_TIME_DEFAULT)
1951 SLAVE_CONV_TIME_OVERRIDE(sl) = val;
1952 else
1953 return -EINVAL;
1954
1955 } else {
1956 int conv_time;
1957
1958 ret = conv_time_measure(sl, &conv_time);
1959 if (ret)
1960 return -EIO;
1961 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
1962 }
1963 return size;
1964 }
1965
features_show(struct device * device,struct device_attribute * attr,char * buf)1966 static ssize_t features_show(struct device *device,
1967 struct device_attribute *attr, char *buf)
1968 {
1969 struct w1_slave *sl = dev_to_w1_slave(device);
1970
1971 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1972 dev_info(device,
1973 "%s: Device not supported by the driver\n", __func__);
1974 return 0; /* No device family */
1975 }
1976 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
1977 }
1978
features_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1979 static ssize_t features_store(struct device *device,
1980 struct device_attribute *attr, const char *buf, size_t size)
1981 {
1982 int val, ret = 0;
1983 bool strong_pullup;
1984 struct w1_slave *sl = dev_to_w1_slave(device);
1985
1986 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
1987 if (ret)
1988 return -EINVAL; /* invalid number */
1989
1990 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1991 dev_info(device, "%s: Device not supported by the driver\n", __func__);
1992 return -ENODEV;
1993 }
1994
1995 if ((val & W1_THERM_FEATURES_MASK) != val)
1996 return -EINVAL;
1997
1998 SLAVE_FEATURES(sl) = val;
1999
2000 strong_pullup = (w1_strong_pullup == 2 ||
2001 (!SLAVE_POWERMODE(sl) &&
2002 w1_strong_pullup));
2003
2004 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2005 dev_warn(&sl->dev,
2006 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2007 __func__);
2008 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2009 }
2010
2011 return size;
2012 }
2013
2014 #if IS_REACHABLE(CONFIG_HWMON)
w1_read_temp(struct device * device,u32 attr,int channel,long * val)2015 static int w1_read_temp(struct device *device, u32 attr, int channel,
2016 long *val)
2017 {
2018 struct w1_slave *sl = dev_get_drvdata(device);
2019 struct therm_info info;
2020 int ret;
2021
2022 switch (attr) {
2023 case hwmon_temp_input:
2024 ret = convert_t(sl, &info);
2025 if (ret)
2026 return ret;
2027
2028 if (!info.verdict) {
2029 ret = -EIO;
2030 return ret;
2031 }
2032
2033 *val = temperature_from_RAM(sl, info.rom);
2034 ret = 0;
2035 break;
2036 default:
2037 ret = -EOPNOTSUPP;
2038 break;
2039 }
2040
2041 return ret;
2042 }
2043 #endif
2044
2045 #define W1_42_CHAIN 0x99
2046 #define W1_42_CHAIN_OFF 0x3C
2047 #define W1_42_CHAIN_OFF_INV 0xC3
2048 #define W1_42_CHAIN_ON 0x5A
2049 #define W1_42_CHAIN_ON_INV 0xA5
2050 #define W1_42_CHAIN_DONE 0x96
2051 #define W1_42_CHAIN_DONE_INV 0x69
2052 #define W1_42_COND_READ 0x0F
2053 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2054 #define W1_42_FINISHED_BYTE 0xFF
w1_seq_show(struct device * device,struct device_attribute * attr,char * buf)2055 static ssize_t w1_seq_show(struct device *device,
2056 struct device_attribute *attr, char *buf)
2057 {
2058 struct w1_slave *sl = dev_to_w1_slave(device);
2059 ssize_t c = PAGE_SIZE;
2060 int rv;
2061 int i;
2062 u8 ack;
2063 u64 rn;
2064 struct w1_reg_num *reg_num;
2065 int seq = 0;
2066
2067 mutex_lock(&sl->master->bus_mutex);
2068 /* Place all devices in CHAIN state */
2069 if (w1_reset_bus(sl->master))
2070 goto error;
2071 w1_write_8(sl->master, W1_SKIP_ROM);
2072 w1_write_8(sl->master, W1_42_CHAIN);
2073 w1_write_8(sl->master, W1_42_CHAIN_ON);
2074 w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2075 msleep(sl->master->pullup_duration);
2076
2077 /* check for acknowledgment */
2078 ack = w1_read_8(sl->master);
2079 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2080 goto error;
2081
2082 /* In case the bus fails to send 0xFF, limit */
2083 for (i = 0; i <= 64; i++) {
2084 if (w1_reset_bus(sl->master))
2085 goto error;
2086
2087 w1_write_8(sl->master, W1_42_COND_READ);
2088 rv = w1_read_block(sl->master, (u8 *)&rn, 8);
2089 reg_num = (struct w1_reg_num *) &rn;
2090 if (reg_num->family == W1_42_FINISHED_BYTE)
2091 break;
2092 if (sl->reg_num.id == reg_num->id)
2093 seq = i;
2094
2095 if (w1_reset_bus(sl->master))
2096 goto error;
2097
2098 /* Put the device into chain DONE state */
2099 w1_write_8(sl->master, W1_MATCH_ROM);
2100 w1_write_block(sl->master, (u8 *)&rn, 8);
2101 w1_write_8(sl->master, W1_42_CHAIN);
2102 w1_write_8(sl->master, W1_42_CHAIN_DONE);
2103 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2104
2105 /* check for acknowledgment */
2106 ack = w1_read_8(sl->master);
2107 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2108 goto error;
2109 }
2110
2111 /* Exit from CHAIN state */
2112 if (w1_reset_bus(sl->master))
2113 goto error;
2114 w1_write_8(sl->master, W1_SKIP_ROM);
2115 w1_write_8(sl->master, W1_42_CHAIN);
2116 w1_write_8(sl->master, W1_42_CHAIN_OFF);
2117 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
2118
2119 /* check for acknowledgment */
2120 ack = w1_read_8(sl->master);
2121 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2122 goto error;
2123 mutex_unlock(&sl->master->bus_mutex);
2124
2125 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
2126 return PAGE_SIZE - c;
2127 error:
2128 mutex_unlock(&sl->master->bus_mutex);
2129 return -EIO;
2130 }
2131
w1_therm_init(void)2132 static int __init w1_therm_init(void)
2133 {
2134 int err, i;
2135
2136 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
2137 err = w1_register_family(w1_therm_families[i].f);
2138 if (err)
2139 w1_therm_families[i].broken = 1;
2140 }
2141
2142 return 0;
2143 }
2144
w1_therm_fini(void)2145 static void __exit w1_therm_fini(void)
2146 {
2147 int i;
2148
2149 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
2150 if (!w1_therm_families[i].broken)
2151 w1_unregister_family(w1_therm_families[i].f);
2152 }
2153
2154 module_init(w1_therm_init);
2155 module_exit(w1_therm_fini);
2156
2157 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
2158 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
2159 MODULE_LICENSE("GPL");
2160 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
2161 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
2162 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
2163 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
2164 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
2165