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 int t;
671 u32 bv;
672
673 /* Config register bit R2 = 1 - GX20MH01 in 13 or 14 bit resolution mode */
674 if (rom[4] & 0x80) {
675 /* Signed 16-bit value to unsigned, cpu order */
676 bv = le16_to_cpup((__le16 *)rom);
677
678 /* Insert two temperature bits from config register */
679 /* Avoid arithmetic shift of signed value */
680 bv = (bv << 2) | (rom[4] & 3);
681
682 t = (int) sign_extend32(bv, 17); /* Degrees, lowest bit is 2^-6 */
683 return (t*1000)/64; /* Millidegrees */
684 }
685
686 t = (int)le16_to_cpup((__le16 *)rom);
687 return t*1000/16;
688 }
689
690
691
692 /**
693 * w1_DS18S20_convert_temp() - temperature computation for DS18S20
694 * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
695 *
696 * Can be called for any DS18S20 compliant device.
697 *
698 * Return: value in millidegrees Celsius.
699 */
w1_DS18S20_convert_temp(u8 rom[9])700 static inline int w1_DS18S20_convert_temp(u8 rom[9])
701 {
702 int t, h;
703
704 if (!rom[7]) {
705 pr_debug("%s: Invalid argument for conversion\n", __func__);
706 return 0;
707 }
708
709 if (rom[1] == 0)
710 t = ((s32)rom[0] >> 1)*1000;
711 else
712 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
713
714 t -= 250;
715 h = 1000*((s32)rom[7] - (s32)rom[6]);
716 h /= (s32)rom[7];
717 t += h;
718
719 return t;
720 }
721
722 /* Device capability description */
723 /* GX20MH01 device shares family number and structure with DS18B20 */
724
725 static struct w1_therm_family_converter w1_therm_families[] = {
726 {
727 .f = &w1_therm_family_DS18S20,
728 .convert = w1_DS18S20_convert_temp,
729 .get_conversion_time = w1_DS18S20_convert_time,
730 .set_resolution = NULL, /* no config register */
731 .get_resolution = NULL, /* no config register */
732 .write_data = w1_DS18S20_write_data,
733 .bulk_read = true
734 },
735 {
736 .f = &w1_therm_family_DS1822,
737 .convert = w1_DS18B20_convert_temp,
738 .get_conversion_time = w1_DS18B20_convert_time,
739 .set_resolution = w1_DS18B20_set_resolution,
740 .get_resolution = w1_DS18B20_get_resolution,
741 .write_data = w1_DS18B20_write_data,
742 .bulk_read = true
743 },
744 {
745 /* Also used for GX20MH01 */
746 .f = &w1_therm_family_DS18B20,
747 .convert = w1_DS18B20_convert_temp,
748 .get_conversion_time = w1_DS18B20_convert_time,
749 .set_resolution = w1_DS18B20_set_resolution,
750 .get_resolution = w1_DS18B20_get_resolution,
751 .write_data = w1_DS18B20_write_data,
752 .bulk_read = true
753 },
754 {
755 .f = &w1_therm_family_DS28EA00,
756 .convert = w1_DS18B20_convert_temp,
757 .get_conversion_time = w1_DS18B20_convert_time,
758 .set_resolution = w1_DS18B20_set_resolution,
759 .get_resolution = w1_DS18B20_get_resolution,
760 .write_data = w1_DS18B20_write_data,
761 .bulk_read = false
762 },
763 {
764 .f = &w1_therm_family_DS1825,
765 .convert = w1_DS18B20_convert_temp,
766 .get_conversion_time = w1_DS18B20_convert_time,
767 .set_resolution = w1_DS18B20_set_resolution,
768 .get_resolution = w1_DS18B20_get_resolution,
769 .write_data = w1_DS18B20_write_data,
770 .bulk_read = true
771 }
772 };
773
774 /* Helpers Functions */
775
776 /**
777 * device_family() - Retrieve a pointer on &struct w1_therm_family_converter
778 * @sl: slave to retrieve the device specific structure
779 *
780 * Return: pointer to the slaves's family converter, NULL if not known
781 */
device_family(struct w1_slave * sl)782 static struct w1_therm_family_converter *device_family(struct w1_slave *sl)
783 {
784 struct w1_therm_family_converter *ret = NULL;
785 int i;
786
787 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
788 if (w1_therm_families[i].f->fid == sl->family->fid) {
789 ret = &w1_therm_families[i];
790 break;
791 }
792 }
793 return ret;
794 }
795
796 /**
797 * bus_mutex_lock() - Acquire the mutex
798 * @lock: w1 bus mutex to acquire
799 *
800 * It try to acquire the mutex W1_THERM_MAX_TRY times and wait
801 * W1_THERM_RETRY_DELAY between 2 attempts.
802 *
803 * Return: true is mutex is acquired and lock, false otherwise
804 */
bus_mutex_lock(struct mutex * lock)805 static inline bool bus_mutex_lock(struct mutex *lock)
806 {
807 int max_trying = W1_THERM_MAX_TRY;
808
809 /* try to acquire the mutex, if not, sleep retry_delay before retry) */
810 while (mutex_lock_interruptible(lock) != 0 && max_trying > 0) {
811 unsigned long sleep_rem;
812
813 sleep_rem = msleep_interruptible(W1_THERM_RETRY_DELAY);
814 if (!sleep_rem)
815 max_trying--;
816 }
817
818 if (!max_trying)
819 return false; /* Didn't acquire the bus mutex */
820
821 return true;
822 }
823
824 /**
825 * check_family_data() - Check if family data and specific functions are present
826 * @sl: W1 device data
827 *
828 * Return: 0 - OK, negative value - error
829 */
check_family_data(struct w1_slave * sl)830 static int check_family_data(struct w1_slave *sl)
831 {
832 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
833 dev_info(&sl->dev,
834 "%s: Device is not supported by the driver\n", __func__);
835 return -EINVAL; /* No device family */
836 }
837 return 0;
838 }
839
840 /**
841 * support_bulk_read() - check if slave support bulk read
842 * @sl: device to check the ability
843 *
844 * Return: true if bulk read is supported, false if not or error
845 */
bulk_read_support(struct w1_slave * sl)846 static inline bool bulk_read_support(struct w1_slave *sl)
847 {
848 if (SLAVE_SPECIFIC_FUNC(sl))
849 return SLAVE_SPECIFIC_FUNC(sl)->bulk_read;
850
851 dev_info(&sl->dev,
852 "%s: Device not supported by the driver\n", __func__);
853
854 return false; /* No device family */
855 }
856
857 /**
858 * conversion_time() - get the Tconv for the slave
859 * @sl: device to get the conversion time
860 *
861 * On device supporting resolution settings, conversion time depend
862 * on the resolution setting. This helper function get the slave timing,
863 * depending on its current setting.
864 *
865 * Return: conversion time in ms, negative values are kernel error code
866 */
conversion_time(struct w1_slave * sl)867 static inline int conversion_time(struct w1_slave *sl)
868 {
869 if (SLAVE_SPECIFIC_FUNC(sl))
870 return SLAVE_SPECIFIC_FUNC(sl)->get_conversion_time(sl);
871
872 dev_info(&sl->dev,
873 "%s: Device not supported by the driver\n", __func__);
874
875 return -ENODEV; /* No device family */
876 }
877
878 /**
879 * temperature_from_RAM() - Convert the read info to temperature
880 * @sl: device that sent the RAM data
881 * @rom: read value on the slave device RAM
882 *
883 * Device dependent, the function bind the correct computation method.
884 *
885 * Return: temperature in 1/1000degC, 0 on error.
886 */
temperature_from_RAM(struct w1_slave * sl,u8 rom[9])887 static inline int temperature_from_RAM(struct w1_slave *sl, u8 rom[9])
888 {
889 if (SLAVE_SPECIFIC_FUNC(sl))
890 return SLAVE_SPECIFIC_FUNC(sl)->convert(rom);
891
892 dev_info(&sl->dev,
893 "%s: Device not supported by the driver\n", __func__);
894
895 return 0; /* No device family */
896 }
897
898 /**
899 * int_to_short() - Safe casting of int to short
900 *
901 * @i: integer to be converted to short
902 *
903 * Device register use 1 byte to store signed integer.
904 * This helper function convert the int in a signed short,
905 * using the min/max values that device can measure as limits.
906 * min/max values are defined by macro.
907 *
908 * Return: a short in the range of min/max value
909 */
int_to_short(int i)910 static inline s8 int_to_short(int i)
911 {
912 /* Prepare to cast to short by eliminating out of range values */
913 i = i > MAX_TEMP ? MAX_TEMP : i;
914 i = i < MIN_TEMP ? MIN_TEMP : i;
915 return (s8) i;
916 }
917
918 /* Interface Functions */
919
w1_therm_add_slave(struct w1_slave * sl)920 static int w1_therm_add_slave(struct w1_slave *sl)
921 {
922 struct w1_therm_family_converter *sl_family_conv;
923
924 /* Allocate memory */
925 sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
926 GFP_KERNEL);
927 if (!sl->family_data)
928 return -ENOMEM;
929
930 atomic_set(THERM_REFCNT(sl->family_data), 1);
931
932 /* Get a pointer to the device specific function struct */
933 sl_family_conv = device_family(sl);
934 if (!sl_family_conv) {
935 kfree(sl->family_data);
936 return -ENODEV;
937 }
938 /* save this pointer to the device structure */
939 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
940
941 if (bulk_read_support(sl)) {
942 /*
943 * add the sys entry to trigger bulk_read
944 * at master level only the 1st time
945 */
946 if (!bulk_read_device_counter) {
947 int err = device_create_file(&sl->master->dev,
948 &dev_attr_therm_bulk_read);
949
950 if (err)
951 dev_warn(&sl->dev,
952 "%s: Device has been added, but bulk read is unavailable. err=%d\n",
953 __func__, err);
954 }
955 /* Increment the counter */
956 bulk_read_device_counter++;
957 }
958
959 /* Getting the power mode of the device {external, parasite} */
960 SLAVE_POWERMODE(sl) = read_powermode(sl);
961
962 if (SLAVE_POWERMODE(sl) < 0) {
963 /* no error returned as device has been added */
964 dev_warn(&sl->dev,
965 "%s: Device has been added, but power_mode may be corrupted. err=%d\n",
966 __func__, SLAVE_POWERMODE(sl));
967 }
968
969 /* Getting the resolution of the device */
970 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
971 SLAVE_RESOLUTION(sl) =
972 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
973 if (SLAVE_RESOLUTION(sl) < 0) {
974 /* no error returned as device has been added */
975 dev_warn(&sl->dev,
976 "%s:Device has been added, but resolution may be corrupted. err=%d\n",
977 __func__, SLAVE_RESOLUTION(sl));
978 }
979 }
980
981 /* Finally initialize convert_triggered flag */
982 SLAVE_CONVERT_TRIGGERED(sl) = 0;
983
984 return 0;
985 }
986
w1_therm_remove_slave(struct w1_slave * sl)987 static void w1_therm_remove_slave(struct w1_slave *sl)
988 {
989 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
990
991 if (bulk_read_support(sl)) {
992 bulk_read_device_counter--;
993 /* Delete the entry if no more device support the feature */
994 if (!bulk_read_device_counter)
995 device_remove_file(&sl->master->dev,
996 &dev_attr_therm_bulk_read);
997 }
998
999 while (refcnt) {
1000 msleep(1000);
1001 refcnt = atomic_read(THERM_REFCNT(sl->family_data));
1002 }
1003 kfree(sl->family_data);
1004 sl->family_data = NULL;
1005 }
1006
1007 /* Hardware Functions */
1008
1009 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
reset_select_slave(struct w1_slave * sl)1010 static int reset_select_slave(struct w1_slave *sl)
1011 {
1012 u8 match[9] = { W1_MATCH_ROM, };
1013 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1014
1015 if (w1_reset_bus(sl->master))
1016 return -ENODEV;
1017
1018 memcpy(&match[1], &rn, 8);
1019 w1_write_block(sl->master, match, 9);
1020
1021 return 0;
1022 }
1023
1024 /**
1025 * w1_poll_completion - Poll for operation completion, with timeout
1026 * @dev_master: the device master of the bus
1027 * @tout_ms: timeout in milliseconds
1028 *
1029 * The device is answering 0's while an operation is in progress and 1's after it completes
1030 * Timeout may happen if the previous command was not recognised due to a line noise
1031 *
1032 * Return: 0 - OK, negative error - timeout
1033 */
w1_poll_completion(struct w1_master * dev_master,int tout_ms)1034 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1035 {
1036 int i;
1037
1038 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1039 /* Delay is before poll, for device to recognize a command */
1040 msleep(W1_POLL_PERIOD);
1041
1042 /* Compare all 8 bits to mitigate a noise on the bus */
1043 if (w1_read_8(dev_master) == 0xFF)
1044 break;
1045 }
1046 if (i == tout_ms/W1_POLL_PERIOD)
1047 return -EIO;
1048
1049 return 0;
1050 }
1051
convert_t(struct w1_slave * sl,struct therm_info * info)1052 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1053 {
1054 struct w1_master *dev_master = sl->master;
1055 int max_trying = W1_THERM_MAX_TRY;
1056 int t_conv;
1057 int ret = -ENODEV;
1058 bool strong_pullup;
1059
1060 if (!sl->family_data)
1061 goto error;
1062
1063 strong_pullup = (w1_strong_pullup == 2 ||
1064 (!SLAVE_POWERMODE(sl) &&
1065 w1_strong_pullup));
1066
1067 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1068 dev_warn(&sl->dev,
1069 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1070 __func__);
1071 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1072 }
1073
1074 /* get conversion duration device and id dependent */
1075 t_conv = conversion_time(sl);
1076
1077 memset(info->rom, 0, sizeof(info->rom));
1078
1079 /* prevent the slave from going away in sleep */
1080 atomic_inc(THERM_REFCNT(sl->family_data));
1081
1082 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1083 ret = -EAGAIN; /* Didn't acquire the mutex */
1084 goto dec_refcnt;
1085 }
1086
1087 while (max_trying-- && ret) { /* ret should be 0 */
1088
1089 info->verdict = 0;
1090 info->crc = 0;
1091 /* safe version to select slave */
1092 if (!reset_select_slave(sl)) {
1093 unsigned long sleep_rem;
1094
1095 /* 750ms strong pullup (or delay) after the convert */
1096 if (strong_pullup)
1097 w1_next_pullup(dev_master, t_conv);
1098
1099 w1_write_8(dev_master, W1_CONVERT_TEMP);
1100
1101 if (strong_pullup) { /*some device need pullup */
1102 sleep_rem = msleep_interruptible(t_conv);
1103 if (sleep_rem != 0) {
1104 ret = -EINTR;
1105 goto mt_unlock;
1106 }
1107 mutex_unlock(&dev_master->bus_mutex);
1108 } else { /*no device need pullup */
1109 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1110 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1111 if (ret) {
1112 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1113 goto mt_unlock;
1114 }
1115 mutex_unlock(&dev_master->bus_mutex);
1116 } else {
1117 /* Fixed delay */
1118 mutex_unlock(&dev_master->bus_mutex);
1119 sleep_rem = msleep_interruptible(t_conv);
1120 if (sleep_rem != 0) {
1121 ret = -EINTR;
1122 goto dec_refcnt;
1123 }
1124 }
1125 }
1126 ret = read_scratchpad(sl, info);
1127
1128 /* If enabled, check for conversion success */
1129 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1130 (info->rom[6] == 0xC) &&
1131 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1132 (info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1133 ) {
1134 /* Invalid reading (scratchpad byte 6 = 0xC)
1135 * due to insufficient conversion time
1136 * or power failure.
1137 */
1138 ret = -EIO;
1139 }
1140
1141 goto dec_refcnt;
1142 }
1143
1144 }
1145
1146 mt_unlock:
1147 mutex_unlock(&dev_master->bus_mutex);
1148 dec_refcnt:
1149 atomic_dec(THERM_REFCNT(sl->family_data));
1150 error:
1151 return ret;
1152 }
1153
conv_time_measure(struct w1_slave * sl,int * conv_time)1154 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1155 {
1156 struct therm_info inf,
1157 *info = &inf;
1158 struct w1_master *dev_master = sl->master;
1159 int max_trying = W1_THERM_MAX_TRY;
1160 int ret = -ENODEV;
1161 bool strong_pullup;
1162
1163 if (!sl->family_data)
1164 goto error;
1165
1166 strong_pullup = (w1_strong_pullup == 2 ||
1167 (!SLAVE_POWERMODE(sl) &&
1168 w1_strong_pullup));
1169
1170 if (strong_pullup) {
1171 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1172 return -EINVAL;
1173 }
1174
1175 memset(info->rom, 0, sizeof(info->rom));
1176
1177 /* prevent the slave from going away in sleep */
1178 atomic_inc(THERM_REFCNT(sl->family_data));
1179
1180 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1181 ret = -EAGAIN; /* Didn't acquire the mutex */
1182 goto dec_refcnt;
1183 }
1184
1185 while (max_trying-- && ret) { /* ret should be 0 */
1186 info->verdict = 0;
1187 info->crc = 0;
1188 /* safe version to select slave */
1189 if (!reset_select_slave(sl)) {
1190 int j_start, j_end;
1191
1192 /*no device need pullup */
1193 w1_write_8(dev_master, W1_CONVERT_TEMP);
1194
1195 j_start = jiffies;
1196 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1197 if (ret) {
1198 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1199 goto mt_unlock;
1200 }
1201 j_end = jiffies;
1202 /* 1.2x increase for variation and changes over temperature range */
1203 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1204 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1205 *conv_time, HZ);
1206 if (*conv_time <= CONV_TIME_MEASURE) {
1207 ret = -EIO;
1208 goto mt_unlock;
1209 }
1210 mutex_unlock(&dev_master->bus_mutex);
1211 ret = read_scratchpad(sl, info);
1212 goto dec_refcnt;
1213 }
1214
1215 }
1216 mt_unlock:
1217 mutex_unlock(&dev_master->bus_mutex);
1218 dec_refcnt:
1219 atomic_dec(THERM_REFCNT(sl->family_data));
1220 error:
1221 return ret;
1222 }
1223
read_scratchpad(struct w1_slave * sl,struct therm_info * info)1224 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1225 {
1226 struct w1_master *dev_master = sl->master;
1227 int max_trying = W1_THERM_MAX_TRY;
1228 int ret = -ENODEV;
1229
1230 info->verdict = 0;
1231
1232 if (!sl->family_data)
1233 goto error;
1234
1235 memset(info->rom, 0, sizeof(info->rom));
1236
1237 /* prevent the slave from going away in sleep */
1238 atomic_inc(THERM_REFCNT(sl->family_data));
1239
1240 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1241 ret = -EAGAIN; /* Didn't acquire the mutex */
1242 goto dec_refcnt;
1243 }
1244
1245 while (max_trying-- && ret) { /* ret should be 0 */
1246 /* safe version to select slave */
1247 if (!reset_select_slave(sl)) {
1248 u8 nb_bytes_read;
1249
1250 w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1251
1252 nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1253 if (nb_bytes_read != 9) {
1254 dev_warn(&sl->dev,
1255 "w1_read_block(): returned %u instead of 9.\n",
1256 nb_bytes_read);
1257 ret = -EIO;
1258 }
1259
1260 info->crc = w1_calc_crc8(info->rom, 8);
1261
1262 if (info->rom[8] == info->crc) {
1263 info->verdict = 1;
1264 ret = 0;
1265 } else
1266 ret = -EIO; /* CRC not checked */
1267 }
1268
1269 }
1270 mutex_unlock(&dev_master->bus_mutex);
1271
1272 dec_refcnt:
1273 atomic_dec(THERM_REFCNT(sl->family_data));
1274 error:
1275 return ret;
1276 }
1277
write_scratchpad(struct w1_slave * sl,const u8 * data,u8 nb_bytes)1278 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1279 {
1280 struct w1_master *dev_master = sl->master;
1281 int max_trying = W1_THERM_MAX_TRY;
1282 int ret = -ENODEV;
1283
1284 if (!sl->family_data)
1285 goto error;
1286
1287 /* prevent the slave from going away in sleep */
1288 atomic_inc(THERM_REFCNT(sl->family_data));
1289
1290 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1291 ret = -EAGAIN; /* Didn't acquire the mutex */
1292 goto dec_refcnt;
1293 }
1294
1295 while (max_trying-- && ret) { /* ret should be 0 */
1296 /* safe version to select slave */
1297 if (!reset_select_slave(sl)) {
1298 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1299 w1_write_block(dev_master, data, nb_bytes);
1300 ret = 0;
1301 }
1302 }
1303 mutex_unlock(&dev_master->bus_mutex);
1304
1305 dec_refcnt:
1306 atomic_dec(THERM_REFCNT(sl->family_data));
1307 error:
1308 return ret;
1309 }
1310
copy_scratchpad(struct w1_slave * sl)1311 static int copy_scratchpad(struct w1_slave *sl)
1312 {
1313 struct w1_master *dev_master = sl->master;
1314 int max_trying = W1_THERM_MAX_TRY;
1315 int t_write, ret = -ENODEV;
1316 bool strong_pullup;
1317
1318 if (!sl->family_data)
1319 goto error;
1320
1321 t_write = W1_THERM_EEPROM_WRITE_DELAY;
1322 strong_pullup = (w1_strong_pullup == 2 ||
1323 (!SLAVE_POWERMODE(sl) &&
1324 w1_strong_pullup));
1325
1326 /* prevent the slave from going away in sleep */
1327 atomic_inc(THERM_REFCNT(sl->family_data));
1328
1329 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1330 ret = -EAGAIN; /* Didn't acquire the mutex */
1331 goto dec_refcnt;
1332 }
1333
1334 while (max_trying-- && ret) { /* ret should be 0 */
1335 /* safe version to select slave */
1336 if (!reset_select_slave(sl)) {
1337 unsigned long sleep_rem;
1338
1339 /* 10ms strong pullup (or delay) after the convert */
1340 if (strong_pullup)
1341 w1_next_pullup(dev_master, t_write);
1342
1343 w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1344
1345 if (strong_pullup) {
1346 sleep_rem = msleep_interruptible(t_write);
1347 if (sleep_rem != 0) {
1348 ret = -EINTR;
1349 goto mt_unlock;
1350 }
1351 }
1352 ret = 0;
1353 }
1354
1355 }
1356
1357 mt_unlock:
1358 mutex_unlock(&dev_master->bus_mutex);
1359 dec_refcnt:
1360 atomic_dec(THERM_REFCNT(sl->family_data));
1361 error:
1362 return ret;
1363 }
1364
recall_eeprom(struct w1_slave * sl)1365 static int recall_eeprom(struct w1_slave *sl)
1366 {
1367 struct w1_master *dev_master = sl->master;
1368 int max_trying = W1_THERM_MAX_TRY;
1369 int ret = -ENODEV;
1370
1371 if (!sl->family_data)
1372 goto error;
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
1386 w1_write_8(dev_master, W1_RECALL_EEPROM);
1387 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1388 }
1389
1390 }
1391
1392 mutex_unlock(&dev_master->bus_mutex);
1393
1394 dec_refcnt:
1395 atomic_dec(THERM_REFCNT(sl->family_data));
1396 error:
1397 return ret;
1398 }
1399
read_powermode(struct w1_slave * sl)1400 static int read_powermode(struct w1_slave *sl)
1401 {
1402 struct w1_master *dev_master = sl->master;
1403 int max_trying = W1_THERM_MAX_TRY;
1404 int ret = -ENODEV;
1405
1406 if (!sl->family_data)
1407 goto error;
1408
1409 /* prevent the slave from going away in sleep */
1410 atomic_inc(THERM_REFCNT(sl->family_data));
1411
1412 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1413 ret = -EAGAIN; /* Didn't acquire the mutex */
1414 goto dec_refcnt;
1415 }
1416
1417 while ((max_trying--) && (ret < 0)) {
1418 /* safe version to select slave */
1419 if (!reset_select_slave(sl)) {
1420 w1_write_8(dev_master, W1_READ_PSUPPLY);
1421 /*
1422 * Emit a read time slot and read only one bit,
1423 * 1 is externally powered,
1424 * 0 is parasite powered
1425 */
1426 ret = w1_touch_bit(dev_master, 1);
1427 /* ret should be either 1 either 0 */
1428 }
1429 }
1430 mutex_unlock(&dev_master->bus_mutex);
1431
1432 dec_refcnt:
1433 atomic_dec(THERM_REFCNT(sl->family_data));
1434 error:
1435 return ret;
1436 }
1437
trigger_bulk_read(struct w1_master * dev_master)1438 static int trigger_bulk_read(struct w1_master *dev_master)
1439 {
1440 struct w1_slave *sl = NULL; /* used to iterate through slaves */
1441 int max_trying = W1_THERM_MAX_TRY;
1442 int t_conv = 0;
1443 int ret = -ENODEV;
1444 bool strong_pullup = false;
1445
1446 /*
1447 * Check whether there are parasite powered device on the bus,
1448 * and compute duration of conversion for these devices
1449 * so we can apply a strong pullup if required
1450 */
1451 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1452 if (!sl->family_data)
1453 goto error;
1454 if (bulk_read_support(sl)) {
1455 int t_cur = conversion_time(sl);
1456
1457 t_conv = t_cur > t_conv ? t_cur : t_conv;
1458 strong_pullup = strong_pullup ||
1459 (w1_strong_pullup == 2 ||
1460 (!SLAVE_POWERMODE(sl) &&
1461 w1_strong_pullup));
1462 }
1463 }
1464
1465 /*
1466 * t_conv is the max conversion time required on the bus
1467 * If its 0, no device support the bulk read feature
1468 */
1469 if (!t_conv)
1470 goto error;
1471
1472 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1473 ret = -EAGAIN; /* Didn't acquire the mutex */
1474 goto error;
1475 }
1476
1477 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1478
1479 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */
1480 unsigned long sleep_rem;
1481
1482 w1_write_8(dev_master, W1_SKIP_ROM);
1483
1484 if (strong_pullup) /* Apply pullup if required */
1485 w1_next_pullup(dev_master, t_conv);
1486
1487 w1_write_8(dev_master, W1_CONVERT_TEMP);
1488
1489 /* set a flag to instruct that converT pending */
1490 list_for_each_entry(sl,
1491 &dev_master->slist, w1_slave_entry) {
1492 if (bulk_read_support(sl))
1493 SLAVE_CONVERT_TRIGGERED(sl) = -1;
1494 }
1495
1496 if (strong_pullup) { /* some device need pullup */
1497 sleep_rem = msleep_interruptible(t_conv);
1498 if (sleep_rem != 0) {
1499 ret = -EINTR;
1500 goto mt_unlock;
1501 }
1502 mutex_unlock(&dev_master->bus_mutex);
1503 } else {
1504 mutex_unlock(&dev_master->bus_mutex);
1505 sleep_rem = msleep_interruptible(t_conv);
1506 if (sleep_rem != 0) {
1507 ret = -EINTR;
1508 goto set_flag;
1509 }
1510 }
1511 ret = 0;
1512 goto set_flag;
1513 }
1514 }
1515
1516 mt_unlock:
1517 mutex_unlock(&dev_master->bus_mutex);
1518 set_flag:
1519 /* set a flag to register convsersion is done */
1520 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1521 if (bulk_read_support(sl))
1522 SLAVE_CONVERT_TRIGGERED(sl) = 1;
1523 }
1524 error:
1525 return ret;
1526 }
1527
1528 /* Sysfs Interface definition */
1529
w1_slave_show(struct device * device,struct device_attribute * attr,char * buf)1530 static ssize_t w1_slave_show(struct device *device,
1531 struct device_attribute *attr, char *buf)
1532 {
1533 struct w1_slave *sl = dev_to_w1_slave(device);
1534 struct therm_info info;
1535 u8 *family_data = sl->family_data;
1536 int ret, i;
1537 ssize_t c = PAGE_SIZE;
1538
1539 if (bulk_read_support(sl)) {
1540 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1541 dev_dbg(device,
1542 "%s: Conversion in progress, retry later\n",
1543 __func__);
1544 return 0;
1545 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1546 /* A bulk read has been issued, read the device RAM */
1547 ret = read_scratchpad(sl, &info);
1548 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1549 } else
1550 ret = convert_t(sl, &info);
1551 } else
1552 ret = convert_t(sl, &info);
1553
1554 if (ret < 0) {
1555 dev_dbg(device,
1556 "%s: Temperature data may be corrupted. err=%d\n",
1557 __func__, ret);
1558 return 0;
1559 }
1560
1561 for (i = 0; i < 9; ++i)
1562 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1563 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1564 info.crc, (info.verdict) ? "YES" : "NO");
1565
1566 if (info.verdict)
1567 memcpy(family_data, info.rom, sizeof(info.rom));
1568 else
1569 dev_warn(device, "%s:Read failed CRC check\n", __func__);
1570
1571 for (i = 0; i < 9; ++i)
1572 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1573 ((u8 *)family_data)[i]);
1574
1575 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1576 temperature_from_RAM(sl, info.rom));
1577
1578 ret = PAGE_SIZE - c;
1579 return ret;
1580 }
1581
w1_slave_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1582 static ssize_t w1_slave_store(struct device *device,
1583 struct device_attribute *attr, const char *buf,
1584 size_t size)
1585 {
1586 int val, ret = 0;
1587 struct w1_slave *sl = dev_to_w1_slave(device);
1588
1589 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1590
1591 if (ret) { /* conversion error */
1592 dev_info(device,
1593 "%s: conversion error. err= %d\n", __func__, ret);
1594 return size; /* return size to avoid call back again */
1595 }
1596
1597 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1598 dev_info(device,
1599 "%s: Device not supported by the driver\n", __func__);
1600 return size; /* No device family */
1601 }
1602
1603 if (val == 0) /* val=0 : trigger a EEPROM save */
1604 ret = copy_scratchpad(sl);
1605 else {
1606 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1607 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1608 }
1609
1610 if (ret) {
1611 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1612 /* Propagate error to userspace */
1613 return ret;
1614 }
1615 SLAVE_RESOLUTION(sl) = val;
1616 /* Reset the conversion time to default - it depends on resolution */
1617 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1618
1619 return size; /* always return size to avoid infinite calling */
1620 }
1621
temperature_show(struct device * device,struct device_attribute * attr,char * buf)1622 static ssize_t temperature_show(struct device *device,
1623 struct device_attribute *attr, char *buf)
1624 {
1625 struct w1_slave *sl = dev_to_w1_slave(device);
1626 struct therm_info info;
1627 int ret = 0;
1628
1629 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1630 dev_info(device,
1631 "%s: Device not supported by the driver\n", __func__);
1632 return 0; /* No device family */
1633 }
1634
1635 if (bulk_read_support(sl)) {
1636 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1637 dev_dbg(device,
1638 "%s: Conversion in progress, retry later\n",
1639 __func__);
1640 return 0;
1641 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1642 /* A bulk read has been issued, read the device RAM */
1643 ret = read_scratchpad(sl, &info);
1644 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1645 } else
1646 ret = convert_t(sl, &info);
1647 } else
1648 ret = convert_t(sl, &info);
1649
1650 if (ret < 0) {
1651 dev_dbg(device,
1652 "%s: Temperature data may be corrupted. err=%d\n",
1653 __func__, ret);
1654 return 0;
1655 }
1656
1657 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1658 }
1659
ext_power_show(struct device * device,struct device_attribute * attr,char * buf)1660 static ssize_t ext_power_show(struct device *device,
1661 struct device_attribute *attr, char *buf)
1662 {
1663 struct w1_slave *sl = dev_to_w1_slave(device);
1664
1665 if (!sl->family_data) {
1666 dev_info(device,
1667 "%s: Device not supported by the driver\n", __func__);
1668 return 0; /* No device family */
1669 }
1670
1671 /* Getting the power mode of the device {external, parasite} */
1672 SLAVE_POWERMODE(sl) = read_powermode(sl);
1673
1674 if (SLAVE_POWERMODE(sl) < 0) {
1675 dev_dbg(device,
1676 "%s: Power_mode may be corrupted. err=%d\n",
1677 __func__, SLAVE_POWERMODE(sl));
1678 }
1679 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1680 }
1681
resolution_show(struct device * device,struct device_attribute * attr,char * buf)1682 static ssize_t resolution_show(struct device *device,
1683 struct device_attribute *attr, char *buf)
1684 {
1685 struct w1_slave *sl = dev_to_w1_slave(device);
1686
1687 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1688 dev_info(device,
1689 "%s: Device not supported by the driver\n", __func__);
1690 return 0; /* No device family */
1691 }
1692
1693 /* get the correct function depending on the device */
1694 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1695 if (SLAVE_RESOLUTION(sl) < 0) {
1696 dev_dbg(device,
1697 "%s: Resolution may be corrupted. err=%d\n",
1698 __func__, SLAVE_RESOLUTION(sl));
1699 }
1700
1701 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1702 }
1703
resolution_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1704 static ssize_t resolution_store(struct device *device,
1705 struct device_attribute *attr, const char *buf, size_t size)
1706 {
1707 struct w1_slave *sl = dev_to_w1_slave(device);
1708 int val;
1709 int ret = 0;
1710
1711 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1712
1713 if (ret) { /* conversion error */
1714 dev_info(device,
1715 "%s: conversion error. err= %d\n", __func__, ret);
1716 return size; /* return size to avoid call back again */
1717 }
1718
1719 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1720 dev_info(device,
1721 "%s: Device not supported by the driver\n", __func__);
1722 return size; /* No device family */
1723 }
1724
1725 /*
1726 * Don't deal with the val enterd by user,
1727 * only device knows what is correct or not
1728 */
1729
1730 /* get the correct function depending on the device */
1731 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1732
1733 if (ret)
1734 return ret;
1735
1736 SLAVE_RESOLUTION(sl) = val;
1737 /* Reset the conversion time to default because it depends on resolution */
1738 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1739
1740 return size;
1741 }
1742
eeprom_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1743 static ssize_t eeprom_store(struct device *device,
1744 struct device_attribute *attr, const char *buf, size_t size)
1745 {
1746 struct w1_slave *sl = dev_to_w1_slave(device);
1747 int ret = -EINVAL; /* Invalid argument */
1748
1749 if (size == sizeof(EEPROM_CMD_WRITE)) {
1750 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1751 ret = copy_scratchpad(sl);
1752 } else if (size == sizeof(EEPROM_CMD_READ)) {
1753 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1754 ret = recall_eeprom(sl);
1755 }
1756
1757 if (ret)
1758 dev_info(device, "%s: error in process %d\n", __func__, ret);
1759
1760 return size;
1761 }
1762
alarms_show(struct device * device,struct device_attribute * attr,char * buf)1763 static ssize_t alarms_show(struct device *device,
1764 struct device_attribute *attr, char *buf)
1765 {
1766 struct w1_slave *sl = dev_to_w1_slave(device);
1767 int ret;
1768 s8 th = 0, tl = 0;
1769 struct therm_info scratchpad;
1770
1771 ret = read_scratchpad(sl, &scratchpad);
1772
1773 if (!ret) {
1774 th = scratchpad.rom[2]; /* TH is byte 2 */
1775 tl = scratchpad.rom[3]; /* TL is byte 3 */
1776 } else {
1777 dev_info(device,
1778 "%s: error reading alarms register %d\n",
1779 __func__, ret);
1780 }
1781
1782 return sprintf(buf, "%hd %hd\n", tl, th);
1783 }
1784
alarms_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1785 static ssize_t alarms_store(struct device *device,
1786 struct device_attribute *attr, const char *buf, size_t size)
1787 {
1788 struct w1_slave *sl = dev_to_w1_slave(device);
1789 struct therm_info info;
1790 u8 new_config_register[3]; /* array of data to be written */
1791 int temp, ret;
1792 char *token = NULL;
1793 s8 tl, th, tt; /* 1 byte per value + temp ring order */
1794 char *p_args, *orig;
1795
1796 p_args = orig = kmalloc(size, GFP_KERNEL);
1797 /* Safe string copys as buf is const */
1798 if (!p_args) {
1799 dev_warn(device,
1800 "%s: error unable to allocate memory %d\n",
1801 __func__, -ENOMEM);
1802 return size;
1803 }
1804 strcpy(p_args, buf);
1805
1806 /* Split string using space char */
1807 token = strsep(&p_args, " ");
1808
1809 if (!token) {
1810 dev_info(device,
1811 "%s: error parsing args %d\n", __func__, -EINVAL);
1812 goto free_m;
1813 }
1814
1815 /* Convert 1st entry to int */
1816 ret = kstrtoint (token, 10, &temp);
1817 if (ret) {
1818 dev_info(device,
1819 "%s: error parsing args %d\n", __func__, ret);
1820 goto free_m;
1821 }
1822
1823 tl = int_to_short(temp);
1824
1825 /* Split string using space char */
1826 token = strsep(&p_args, " ");
1827 if (!token) {
1828 dev_info(device,
1829 "%s: error parsing args %d\n", __func__, -EINVAL);
1830 goto free_m;
1831 }
1832 /* Convert 2nd entry to int */
1833 ret = kstrtoint (token, 10, &temp);
1834 if (ret) {
1835 dev_info(device,
1836 "%s: error parsing args %d\n", __func__, ret);
1837 goto free_m;
1838 }
1839
1840 /* Prepare to cast to short by eliminating out of range values */
1841 th = int_to_short(temp);
1842
1843 /* Reorder if required th and tl */
1844 if (tl > th) {
1845 tt = tl; tl = th; th = tt;
1846 }
1847
1848 /*
1849 * Read the scratchpad to change only the required bits
1850 * (th : byte 2 - tl: byte 3)
1851 */
1852 ret = read_scratchpad(sl, &info);
1853 if (!ret) {
1854 new_config_register[0] = th; /* Byte 2 */
1855 new_config_register[1] = tl; /* Byte 3 */
1856 new_config_register[2] = info.rom[4];/* Byte 4 */
1857 } else {
1858 dev_info(device,
1859 "%s: error reading from the slave device %d\n",
1860 __func__, ret);
1861 goto free_m;
1862 }
1863
1864 /* Write data in the device RAM */
1865 if (!SLAVE_SPECIFIC_FUNC(sl)) {
1866 dev_info(device,
1867 "%s: Device not supported by the driver %d\n",
1868 __func__, -ENODEV);
1869 goto free_m;
1870 }
1871
1872 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1873 if (ret)
1874 dev_info(device,
1875 "%s: error writing to the slave device %d\n",
1876 __func__, ret);
1877
1878 free_m:
1879 /* free allocated memory */
1880 kfree(orig);
1881
1882 return size;
1883 }
1884
therm_bulk_read_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1885 static ssize_t therm_bulk_read_store(struct device *device,
1886 struct device_attribute *attr, const char *buf, size_t size)
1887 {
1888 struct w1_master *dev_master = dev_to_w1_master(device);
1889 int ret = -EINVAL; /* Invalid argument */
1890
1891 if (size == sizeof(BULK_TRIGGER_CMD))
1892 if (!strncmp(buf, BULK_TRIGGER_CMD,
1893 sizeof(BULK_TRIGGER_CMD)-1))
1894 ret = trigger_bulk_read(dev_master);
1895
1896 if (ret)
1897 dev_info(device,
1898 "%s: unable to trigger a bulk read on the bus. err=%d\n",
1899 __func__, ret);
1900
1901 return size;
1902 }
1903
therm_bulk_read_show(struct device * device,struct device_attribute * attr,char * buf)1904 static ssize_t therm_bulk_read_show(struct device *device,
1905 struct device_attribute *attr, char *buf)
1906 {
1907 struct w1_master *dev_master = dev_to_w1_master(device);
1908 struct w1_slave *sl = NULL;
1909 int ret = 0;
1910
1911 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1912 if (sl->family_data) {
1913 if (bulk_read_support(sl)) {
1914 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1915 ret = -1;
1916 goto show_result;
1917 }
1918 if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1919 /* continue to check other slaves */
1920 ret = 1;
1921 }
1922 }
1923 }
1924 show_result:
1925 return sprintf(buf, "%d\n", ret);
1926 }
1927
conv_time_show(struct device * device,struct device_attribute * attr,char * buf)1928 static ssize_t conv_time_show(struct device *device,
1929 struct device_attribute *attr, char *buf)
1930 {
1931 struct w1_slave *sl = dev_to_w1_slave(device);
1932
1933 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1934 dev_info(device,
1935 "%s: Device is not supported by the driver\n", __func__);
1936 return 0; /* No device family */
1937 }
1938 return sprintf(buf, "%d\n", conversion_time(sl));
1939 }
1940
conv_time_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1941 static ssize_t conv_time_store(struct device *device,
1942 struct device_attribute *attr, const char *buf, size_t size)
1943 {
1944 int val, ret = 0;
1945 struct w1_slave *sl = dev_to_w1_slave(device);
1946
1947 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
1948 return -EINVAL;
1949
1950 if (check_family_data(sl))
1951 return -ENODEV;
1952
1953 if (val != CONV_TIME_MEASURE) {
1954 if (val >= CONV_TIME_DEFAULT)
1955 SLAVE_CONV_TIME_OVERRIDE(sl) = val;
1956 else
1957 return -EINVAL;
1958
1959 } else {
1960 int conv_time;
1961
1962 ret = conv_time_measure(sl, &conv_time);
1963 if (ret)
1964 return -EIO;
1965 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
1966 }
1967 return size;
1968 }
1969
features_show(struct device * device,struct device_attribute * attr,char * buf)1970 static ssize_t features_show(struct device *device,
1971 struct device_attribute *attr, char *buf)
1972 {
1973 struct w1_slave *sl = dev_to_w1_slave(device);
1974
1975 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1976 dev_info(device,
1977 "%s: Device not supported by the driver\n", __func__);
1978 return 0; /* No device family */
1979 }
1980 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
1981 }
1982
features_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1983 static ssize_t features_store(struct device *device,
1984 struct device_attribute *attr, const char *buf, size_t size)
1985 {
1986 int val, ret = 0;
1987 bool strong_pullup;
1988 struct w1_slave *sl = dev_to_w1_slave(device);
1989
1990 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
1991 if (ret)
1992 return -EINVAL; /* invalid number */
1993
1994 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1995 dev_info(device, "%s: Device not supported by the driver\n", __func__);
1996 return -ENODEV;
1997 }
1998
1999 if ((val & W1_THERM_FEATURES_MASK) != val)
2000 return -EINVAL;
2001
2002 SLAVE_FEATURES(sl) = val;
2003
2004 strong_pullup = (w1_strong_pullup == 2 ||
2005 (!SLAVE_POWERMODE(sl) &&
2006 w1_strong_pullup));
2007
2008 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2009 dev_warn(&sl->dev,
2010 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2011 __func__);
2012 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2013 }
2014
2015 return size;
2016 }
2017
2018 #if IS_REACHABLE(CONFIG_HWMON)
w1_read_temp(struct device * device,u32 attr,int channel,long * val)2019 static int w1_read_temp(struct device *device, u32 attr, int channel,
2020 long *val)
2021 {
2022 struct w1_slave *sl = dev_get_drvdata(device);
2023 struct therm_info info;
2024 int ret;
2025
2026 switch (attr) {
2027 case hwmon_temp_input:
2028 ret = convert_t(sl, &info);
2029 if (ret)
2030 return ret;
2031
2032 if (!info.verdict) {
2033 ret = -EIO;
2034 return ret;
2035 }
2036
2037 *val = temperature_from_RAM(sl, info.rom);
2038 ret = 0;
2039 break;
2040 default:
2041 ret = -EOPNOTSUPP;
2042 break;
2043 }
2044
2045 return ret;
2046 }
2047 #endif
2048
2049 #define W1_42_CHAIN 0x99
2050 #define W1_42_CHAIN_OFF 0x3C
2051 #define W1_42_CHAIN_OFF_INV 0xC3
2052 #define W1_42_CHAIN_ON 0x5A
2053 #define W1_42_CHAIN_ON_INV 0xA5
2054 #define W1_42_CHAIN_DONE 0x96
2055 #define W1_42_CHAIN_DONE_INV 0x69
2056 #define W1_42_COND_READ 0x0F
2057 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2058 #define W1_42_FINISHED_BYTE 0xFF
w1_seq_show(struct device * device,struct device_attribute * attr,char * buf)2059 static ssize_t w1_seq_show(struct device *device,
2060 struct device_attribute *attr, char *buf)
2061 {
2062 struct w1_slave *sl = dev_to_w1_slave(device);
2063 ssize_t c = PAGE_SIZE;
2064 int rv;
2065 int i;
2066 u8 ack;
2067 u64 rn;
2068 struct w1_reg_num *reg_num;
2069 int seq = 0;
2070
2071 mutex_lock(&sl->master->bus_mutex);
2072 /* Place all devices in CHAIN state */
2073 if (w1_reset_bus(sl->master))
2074 goto error;
2075 w1_write_8(sl->master, W1_SKIP_ROM);
2076 w1_write_8(sl->master, W1_42_CHAIN);
2077 w1_write_8(sl->master, W1_42_CHAIN_ON);
2078 w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2079 msleep(sl->master->pullup_duration);
2080
2081 /* check for acknowledgment */
2082 ack = w1_read_8(sl->master);
2083 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2084 goto error;
2085
2086 /* In case the bus fails to send 0xFF, limit */
2087 for (i = 0; i <= 64; i++) {
2088 if (w1_reset_bus(sl->master))
2089 goto error;
2090
2091 w1_write_8(sl->master, W1_42_COND_READ);
2092 rv = w1_read_block(sl->master, (u8 *)&rn, 8);
2093 reg_num = (struct w1_reg_num *) &rn;
2094 if (reg_num->family == W1_42_FINISHED_BYTE)
2095 break;
2096 if (sl->reg_num.id == reg_num->id)
2097 seq = i;
2098
2099 w1_write_8(sl->master, W1_42_CHAIN);
2100 w1_write_8(sl->master, W1_42_CHAIN_DONE);
2101 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2102 w1_read_block(sl->master, &ack, sizeof(ack));
2103
2104 /* check for acknowledgment */
2105 ack = w1_read_8(sl->master);
2106 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2107 goto error;
2108
2109 }
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