1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * w1_therm.c
4 *
5 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
6 */
7
8 #include <asm/types.h>
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/sched.h>
14 #include <linux/device.h>
15 #include <linux/types.h>
16 #include <linux/slab.h>
17 #include <linux/delay.h>
18 #include <linux/hwmon.h>
19 #include <linux/string.h>
20 #include <linux/jiffies.h>
21
22 #include <linux/w1.h>
23
24 #define W1_THERM_DS18S20 0x10
25 #define W1_THERM_DS1822 0x22
26 #define W1_THERM_DS18B20 0x28
27 #define W1_THERM_DS1825 0x3B
28 #define W1_THERM_DS28EA00 0x42
29
30 /*
31 * Allow the strong pullup to be disabled, but default to enabled.
32 * If it was disabled a parasite powered device might not get the require
33 * current to do a temperature conversion. If it is enabled parasite powered
34 * devices have a better chance of getting the current required.
35 * In case the parasite power-detection is not working (seems to be the case
36 * for some DS18S20) the strong pullup can also be forced, regardless of the
37 * power state of the devices.
38 *
39 * Summary of options:
40 * - strong_pullup = 0 Disable strong pullup completely
41 * - strong_pullup = 1 Enable automatic strong pullup detection
42 * - strong_pullup = 2 Force strong pullup
43 */
44 static int w1_strong_pullup = 1;
45 module_param_named(strong_pullup, w1_strong_pullup, int, 0);
46
47 /* Counter for devices supporting bulk reading */
48 static u16 bulk_read_device_counter; /* =0 as per C standard */
49
50 /* This command should be in public header w1.h but is not */
51 #define W1_RECALL_EEPROM 0xB8
52
53 /* Nb of try for an operation */
54 #define W1_THERM_MAX_TRY 5
55
56 /* ms delay to retry bus mutex */
57 #define W1_THERM_RETRY_DELAY 20
58
59 /* delay in ms to write in EEPROM */
60 #define W1_THERM_EEPROM_WRITE_DELAY 10
61
62 #define EEPROM_CMD_WRITE "save" /* cmd for write eeprom sysfs */
63 #define EEPROM_CMD_READ "restore" /* cmd for read eeprom sysfs */
64 #define BULK_TRIGGER_CMD "trigger" /* cmd to trigger a bulk read */
65
66 #define MIN_TEMP -55 /* min temperature that can be measured */
67 #define MAX_TEMP 125 /* max temperature that can be measured */
68
69 /* Allowed values for sysfs conv_time attribute */
70 #define CONV_TIME_DEFAULT 0
71 #define CONV_TIME_MEASURE 1
72
73 /* Bits in sysfs "features" value */
74 #define W1_THERM_CHECK_RESULT 1 /* Enable conversion success check */
75 #define W1_THERM_POLL_COMPLETION 2 /* Poll for conversion completion */
76 #define W1_THERM_FEATURES_MASK 3 /* All values mask */
77
78 /* Poll period in milliseconds. Should be less then a shortest operation on the device */
79 #define W1_POLL_PERIOD 32
80 #define W1_POLL_CONVERT_TEMP 2000 /* Timeout for W1_CONVERT_TEMP, ms */
81 #define W1_POLL_RECALL_EEPROM 500 /* Timeout for W1_RECALL_EEPROM, ms*/
82
83 /* Masks for resolution functions, work with all devices */
84 /* Bit mask for config register for all devices, bits 7,6,5 */
85 #define W1_THERM_RESOLUTION_MASK 0xE0
86 /* Bit offset of resolution in config register for all devices */
87 #define W1_THERM_RESOLUTION_SHIFT 5
88 /* Bit offset of resolution in config register for all devices */
89 #define W1_THERM_RESOLUTION_SHIFT 5
90 /* Add this to bit value to get resolution */
91 #define W1_THERM_RESOLUTION_MIN 9
92 /* Maximum allowed value */
93 #define W1_THERM_RESOLUTION_MAX 14
94
95 /* Helpers Macros */
96
97 /*
98 * return a pointer on the slave w1_therm_family_converter struct:
99 * always test family data existence before using this macro
100 */
101 #define SLAVE_SPECIFIC_FUNC(sl) \
102 (((struct w1_therm_family_data *)(sl->family_data))->specific_functions)
103
104 /*
105 * return the power mode of the sl slave : 1-ext, 0-parasite, <0 unknown
106 * always test family data existence before using this macro
107 */
108 #define SLAVE_POWERMODE(sl) \
109 (((struct w1_therm_family_data *)(sl->family_data))->external_powered)
110
111 /*
112 * return the resolution in bit of the sl slave : <0 unknown
113 * always test family data existence before using this macro
114 */
115 #define SLAVE_RESOLUTION(sl) \
116 (((struct w1_therm_family_data *)(sl->family_data))->resolution)
117
118 /*
119 * return the conv_time_override of the sl slave
120 * always test family data existence before using this macro
121 */
122 #define SLAVE_CONV_TIME_OVERRIDE(sl) \
123 (((struct w1_therm_family_data *)(sl->family_data))->conv_time_override)
124
125 /*
126 * return the features of the sl slave
127 * always test family data existence before using this macro
128 */
129 #define SLAVE_FEATURES(sl) \
130 (((struct w1_therm_family_data *)(sl->family_data))->features)
131
132 /*
133 * return whether or not a converT command has been issued to the slave
134 * * 0: no bulk read is pending
135 * * -1: conversion is in progress
136 * * 1: conversion done, result to be read
137 */
138 #define SLAVE_CONVERT_TRIGGERED(sl) \
139 (((struct w1_therm_family_data *)(sl->family_data))->convert_triggered)
140
141 /* return the address of the refcnt in the family data */
142 #define THERM_REFCNT(family_data) \
143 (&((struct w1_therm_family_data *)family_data)->refcnt)
144
145 /* Structs definition */
146
147 /**
148 * struct w1_therm_family_converter - bind device specific functions
149 * @broken: flag for non-registred families
150 * @reserved: not used here
151 * @f: pointer to the device binding structure
152 * @convert: pointer to the device conversion function
153 * @get_conversion_time: pointer to the device conversion time function
154 * @set_resolution: pointer to the device set_resolution function
155 * @get_resolution: pointer to the device get_resolution function
156 * @write_data: pointer to the device writing function (2 or 3 bytes)
157 * @bulk_read: true if device family support bulk read, false otherwise
158 */
159 struct w1_therm_family_converter {
160 u8 broken;
161 u16 reserved;
162 struct w1_family *f;
163 int (*convert)(u8 rom[9]);
164 int (*get_conversion_time)(struct w1_slave *sl);
165 int (*set_resolution)(struct w1_slave *sl, int val);
166 int (*get_resolution)(struct w1_slave *sl);
167 int (*write_data)(struct w1_slave *sl, const u8 *data);
168 bool bulk_read;
169 };
170
171 /**
172 * struct w1_therm_family_data - device data
173 * @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte)
174 * @refcnt: ref count
175 * @external_powered: 1 device powered externally,
176 * 0 device parasite powered,
177 * -x error or undefined
178 * @resolution: current device resolution
179 * @convert_triggered: conversion state of the device
180 * @conv_time_override: user selected conversion time or CONV_TIME_DEFAULT
181 * @features: bit mask - enable temperature validity check, poll for completion
182 * @specific_functions: pointer to struct of device specific function
183 */
184 struct w1_therm_family_data {
185 uint8_t rom[9];
186 atomic_t refcnt;
187 int external_powered;
188 int resolution;
189 int convert_triggered;
190 int conv_time_override;
191 unsigned int features;
192 struct w1_therm_family_converter *specific_functions;
193 };
194
195 /**
196 * struct therm_info - store temperature reading
197 * @rom: read device data (8 data bytes + 1 CRC byte)
198 * @crc: computed crc from rom
199 * @verdict: 1 crc checked, 0 crc not matching
200 */
201 struct therm_info {
202 u8 rom[9];
203 u8 crc;
204 u8 verdict;
205 };
206
207 /* Hardware Functions declaration */
208
209 /**
210 * reset_select_slave() - reset and select a slave
211 * @sl: the slave to select
212 *
213 * Resets the bus and select the slave by sending a ROM MATCH cmd
214 * w1_reset_select_slave() from w1_io.c could not be used here because
215 * it sent a SKIP ROM command if only one device is on the line.
216 * At the beginning of the such process, sl->master->slave_count is 1 even if
217 * more devices are on the line, causing collision on the line.
218 *
219 * Context: The w1 master lock must be held.
220 *
221 * Return: 0 if success, negative kernel error code otherwise.
222 */
223 static int reset_select_slave(struct w1_slave *sl);
224
225 /**
226 * convert_t() - Query the device for temperature conversion and read
227 * @sl: pointer to the slave to read
228 * @info: pointer to a structure to store the read results
229 *
230 * Return: 0 if success, -kernel error code otherwise
231 */
232 static int convert_t(struct w1_slave *sl, struct therm_info *info);
233
234 /**
235 * read_scratchpad() - read the data in device RAM
236 * @sl: pointer to the slave to read
237 * @info: pointer to a structure to store the read results
238 *
239 * Return: 0 if success, -kernel error code otherwise
240 */
241 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info);
242
243 /**
244 * write_scratchpad() - write nb_bytes in the device RAM
245 * @sl: pointer to the slave to write in
246 * @data: pointer to an array of 3 bytes, as 3 bytes MUST be written
247 * @nb_bytes: number of bytes to be written (2 for DS18S20, 3 otherwise)
248 *
249 * Return: 0 if success, -kernel error code otherwise
250 */
251 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes);
252
253 /**
254 * copy_scratchpad() - Copy the content of scratchpad in device EEPROM
255 * @sl: slave involved
256 *
257 * Return: 0 if success, -kernel error code otherwise
258 */
259 static int copy_scratchpad(struct w1_slave *sl);
260
261 /**
262 * recall_eeprom() - Restore EEPROM data to device RAM
263 * @sl: slave involved
264 *
265 * Return: 0 if success, -kernel error code otherwise
266 */
267 static int recall_eeprom(struct w1_slave *sl);
268
269 /**
270 * read_powermode() - Query the power mode of the slave
271 * @sl: slave to retrieve the power mode
272 *
273 * Ask the device to get its power mode (external or parasite)
274 * and store the power status in the &struct w1_therm_family_data.
275 *
276 * Return:
277 * * 0 parasite powered device
278 * * 1 externally powered device
279 * * <0 kernel error code
280 */
281 static int read_powermode(struct w1_slave *sl);
282
283 /**
284 * trigger_bulk_read() - function to trigger a bulk read on the bus
285 * @dev_master: the device master of the bus
286 *
287 * Send a SKIP ROM follow by a CONVERT T 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_cmd_store(struct device *device,
319 struct device_attribute *attr, const char *buf, size_t size);
320
321 static ssize_t alarms_store(struct device *device,
322 struct device_attribute *attr, const char *buf, size_t size);
323
324 static ssize_t alarms_show(struct device *device,
325 struct device_attribute *attr, char *buf);
326
327 static ssize_t therm_bulk_read_store(struct device *device,
328 struct device_attribute *attr, const char *buf, size_t size);
329
330 static ssize_t therm_bulk_read_show(struct device *device,
331 struct device_attribute *attr, char *buf);
332
333 static ssize_t conv_time_show(struct device *device,
334 struct device_attribute *attr, char *buf);
335
336 static ssize_t conv_time_store(struct device *device,
337 struct device_attribute *attr, const char *buf,
338 size_t size);
339
340 static ssize_t features_show(struct device *device,
341 struct device_attribute *attr, char *buf);
342
343 static ssize_t features_store(struct device *device,
344 struct device_attribute *attr, const char *buf,
345 size_t size);
346 /* Attributes declarations */
347
348 static DEVICE_ATTR_RW(w1_slave);
349 static DEVICE_ATTR_RO(w1_seq);
350 static DEVICE_ATTR_RO(temperature);
351 static DEVICE_ATTR_RO(ext_power);
352 static DEVICE_ATTR_RW(resolution);
353 static DEVICE_ATTR_WO(eeprom_cmd);
354 static DEVICE_ATTR_RW(alarms);
355 static DEVICE_ATTR_RW(conv_time);
356 static DEVICE_ATTR_RW(features);
357
358 static DEVICE_ATTR_RW(therm_bulk_read); /* attribut at master level */
359
360 /* Interface Functions declaration */
361
362 /**
363 * w1_therm_add_slave() - Called when a new slave is discovered
364 * @sl: slave just discovered by the master.
365 *
366 * Called by the master when the slave is discovered on the bus. Used to
367 * initialize slave state before the beginning of any communication.
368 *
369 * Return: 0 - If success, negative kernel code otherwise
370 */
371 static int w1_therm_add_slave(struct w1_slave *sl);
372
373 /**
374 * w1_therm_remove_slave() - Called when a slave is removed
375 * @sl: slave to be removed.
376 *
377 * Called by the master when the slave is considered not to be on the bus
378 * anymore. Used to free memory.
379 */
380 static void w1_therm_remove_slave(struct w1_slave *sl);
381
382 /* Family attributes */
383
384 static struct attribute *w1_therm_attrs[] = {
385 &dev_attr_w1_slave.attr,
386 &dev_attr_temperature.attr,
387 &dev_attr_ext_power.attr,
388 &dev_attr_resolution.attr,
389 &dev_attr_eeprom_cmd.attr,
390 &dev_attr_alarms.attr,
391 &dev_attr_conv_time.attr,
392 &dev_attr_features.attr,
393 NULL,
394 };
395
396 static struct attribute *w1_ds18s20_attrs[] = {
397 &dev_attr_w1_slave.attr,
398 &dev_attr_temperature.attr,
399 &dev_attr_ext_power.attr,
400 &dev_attr_eeprom_cmd.attr,
401 &dev_attr_alarms.attr,
402 &dev_attr_conv_time.attr,
403 &dev_attr_features.attr,
404 NULL,
405 };
406
407 static struct attribute *w1_ds28ea00_attrs[] = {
408 &dev_attr_w1_slave.attr,
409 &dev_attr_w1_seq.attr,
410 &dev_attr_temperature.attr,
411 &dev_attr_ext_power.attr,
412 &dev_attr_resolution.attr,
413 &dev_attr_eeprom_cmd.attr,
414 &dev_attr_alarms.attr,
415 &dev_attr_conv_time.attr,
416 &dev_attr_features.attr,
417 NULL,
418 };
419
420 /* Attribute groups */
421
422 ATTRIBUTE_GROUPS(w1_therm);
423 ATTRIBUTE_GROUPS(w1_ds18s20);
424 ATTRIBUTE_GROUPS(w1_ds28ea00);
425
426 #if IS_REACHABLE(CONFIG_HWMON)
427 static int w1_read_temp(struct device *dev, u32 attr, int channel,
428 long *val);
429
w1_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)430 static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
431 u32 attr, int channel)
432 {
433 return attr == hwmon_temp_input ? 0444 : 0;
434 }
435
w1_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)436 static int w1_read(struct device *dev, enum hwmon_sensor_types type,
437 u32 attr, int channel, long *val)
438 {
439 switch (type) {
440 case hwmon_temp:
441 return w1_read_temp(dev, attr, channel, val);
442 default:
443 return -EOPNOTSUPP;
444 }
445 }
446
447 static const u32 w1_temp_config[] = {
448 HWMON_T_INPUT,
449 0
450 };
451
452 static const struct hwmon_channel_info w1_temp = {
453 .type = hwmon_temp,
454 .config = w1_temp_config,
455 };
456
457 static const struct hwmon_channel_info *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 * bulk_read_support() - 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 = clamp(i, MIN_TEMP, MAX_TEMP);
910 return (s8) i;
911 }
912
913 /* Interface Functions */
914
w1_therm_add_slave(struct w1_slave * sl)915 static int w1_therm_add_slave(struct w1_slave *sl)
916 {
917 struct w1_therm_family_converter *sl_family_conv;
918
919 /* Allocate memory */
920 sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
921 GFP_KERNEL);
922 if (!sl->family_data)
923 return -ENOMEM;
924
925 atomic_set(THERM_REFCNT(sl->family_data), 1);
926
927 /* Get a pointer to the device specific function struct */
928 sl_family_conv = device_family(sl);
929 if (!sl_family_conv) {
930 kfree(sl->family_data);
931 return -ENODEV;
932 }
933 /* save this pointer to the device structure */
934 SLAVE_SPECIFIC_FUNC(sl) = sl_family_conv;
935
936 if (bulk_read_support(sl)) {
937 /*
938 * add the sys entry to trigger bulk_read
939 * at master level only the 1st time
940 */
941 if (!bulk_read_device_counter) {
942 int err = device_create_file(&sl->master->dev,
943 &dev_attr_therm_bulk_read);
944
945 if (err)
946 dev_warn(&sl->dev,
947 "%s: Device has been added, but bulk read is unavailable. err=%d\n",
948 __func__, err);
949 }
950 /* Increment the counter */
951 bulk_read_device_counter++;
952 }
953
954 /* Getting the power mode of the device {external, parasite} */
955 SLAVE_POWERMODE(sl) = read_powermode(sl);
956
957 if (SLAVE_POWERMODE(sl) < 0) {
958 /* no error returned as device has been added */
959 dev_warn(&sl->dev,
960 "%s: Device has been added, but power_mode may be corrupted. err=%d\n",
961 __func__, SLAVE_POWERMODE(sl));
962 }
963
964 /* Getting the resolution of the device */
965 if (SLAVE_SPECIFIC_FUNC(sl)->get_resolution) {
966 SLAVE_RESOLUTION(sl) =
967 SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
968 if (SLAVE_RESOLUTION(sl) < 0) {
969 /* no error returned as device has been added */
970 dev_warn(&sl->dev,
971 "%s:Device has been added, but resolution may be corrupted. err=%d\n",
972 __func__, SLAVE_RESOLUTION(sl));
973 }
974 }
975
976 /* Finally initialize convert_triggered flag */
977 SLAVE_CONVERT_TRIGGERED(sl) = 0;
978
979 return 0;
980 }
981
w1_therm_remove_slave(struct w1_slave * sl)982 static void w1_therm_remove_slave(struct w1_slave *sl)
983 {
984 int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
985
986 if (bulk_read_support(sl)) {
987 bulk_read_device_counter--;
988 /* Delete the entry if no more device support the feature */
989 if (!bulk_read_device_counter)
990 device_remove_file(&sl->master->dev,
991 &dev_attr_therm_bulk_read);
992 }
993
994 while (refcnt) {
995 msleep(1000);
996 refcnt = atomic_read(THERM_REFCNT(sl->family_data));
997 }
998 kfree(sl->family_data);
999 sl->family_data = NULL;
1000 }
1001
1002 /* Hardware Functions */
1003
1004 /* Safe version of reset_select_slave - avoid using the one in w_io.c */
reset_select_slave(struct w1_slave * sl)1005 static int reset_select_slave(struct w1_slave *sl)
1006 {
1007 u8 match[9] = { W1_MATCH_ROM, };
1008 u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
1009
1010 if (w1_reset_bus(sl->master))
1011 return -ENODEV;
1012
1013 memcpy(&match[1], &rn, 8);
1014 w1_write_block(sl->master, match, 9);
1015
1016 return 0;
1017 }
1018
1019 /**
1020 * w1_poll_completion - Poll for operation completion, with timeout
1021 * @dev_master: the device master of the bus
1022 * @tout_ms: timeout in milliseconds
1023 *
1024 * The device is answering 0's while an operation is in progress and 1's after it completes
1025 * Timeout may happen if the previous command was not recognised due to a line noise
1026 *
1027 * Return: 0 - OK, negative error - timeout
1028 */
w1_poll_completion(struct w1_master * dev_master,int tout_ms)1029 static int w1_poll_completion(struct w1_master *dev_master, int tout_ms)
1030 {
1031 int i;
1032
1033 for (i = 0; i < tout_ms/W1_POLL_PERIOD; i++) {
1034 /* Delay is before poll, for device to recognize a command */
1035 msleep(W1_POLL_PERIOD);
1036
1037 /* Compare all 8 bits to mitigate a noise on the bus */
1038 if (w1_read_8(dev_master) == 0xFF)
1039 break;
1040 }
1041 if (i == tout_ms/W1_POLL_PERIOD)
1042 return -EIO;
1043
1044 return 0;
1045 }
1046
convert_t(struct w1_slave * sl,struct therm_info * info)1047 static int convert_t(struct w1_slave *sl, struct therm_info *info)
1048 {
1049 struct w1_master *dev_master = sl->master;
1050 int max_trying = W1_THERM_MAX_TRY;
1051 int t_conv;
1052 int ret = -ENODEV;
1053 bool strong_pullup;
1054
1055 if (!sl->family_data)
1056 goto error;
1057
1058 strong_pullup = (w1_strong_pullup == 2 ||
1059 (!SLAVE_POWERMODE(sl) &&
1060 w1_strong_pullup));
1061
1062 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1063 dev_warn(&sl->dev,
1064 "%s: Disabling W1_THERM_POLL_COMPLETION in parasite power mode.\n",
1065 __func__);
1066 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
1067 }
1068
1069 /* get conversion duration device and id dependent */
1070 t_conv = conversion_time(sl);
1071
1072 memset(info->rom, 0, sizeof(info->rom));
1073
1074 /* prevent the slave from going away in sleep */
1075 atomic_inc(THERM_REFCNT(sl->family_data));
1076
1077 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1078 ret = -EAGAIN; /* Didn't acquire the mutex */
1079 goto dec_refcnt;
1080 }
1081
1082 while (max_trying-- && ret) { /* ret should be 0 */
1083
1084 info->verdict = 0;
1085 info->crc = 0;
1086 /* safe version to select slave */
1087 if (!reset_select_slave(sl)) {
1088 unsigned long sleep_rem;
1089
1090 /* 750ms strong pullup (or delay) after the convert */
1091 if (strong_pullup)
1092 w1_next_pullup(dev_master, t_conv);
1093
1094 w1_write_8(dev_master, W1_CONVERT_TEMP);
1095
1096 if (SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
1097 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1098 if (ret) {
1099 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1100 goto mt_unlock;
1101 }
1102 mutex_unlock(&dev_master->bus_mutex);
1103 } else if (!strong_pullup) { /*no device need pullup */
1104 sleep_rem = msleep_interruptible(t_conv);
1105 if (sleep_rem != 0) {
1106 ret = -EINTR;
1107 goto mt_unlock;
1108 }
1109 mutex_unlock(&dev_master->bus_mutex);
1110 } else { /*some device need pullup */
1111 mutex_unlock(&dev_master->bus_mutex);
1112 sleep_rem = msleep_interruptible(t_conv);
1113 if (sleep_rem != 0) {
1114 ret = -EINTR;
1115 goto dec_refcnt;
1116 }
1117 }
1118 ret = read_scratchpad(sl, info);
1119
1120 /* If enabled, check for conversion success */
1121 if ((SLAVE_FEATURES(sl) & W1_THERM_CHECK_RESULT) &&
1122 (info->rom[6] == 0xC) &&
1123 ((info->rom[1] == 0x5 && info->rom[0] == 0x50) ||
1124 (info->rom[1] == 0x7 && info->rom[0] == 0xFF))
1125 ) {
1126 /* Invalid reading (scratchpad byte 6 = 0xC)
1127 * due to insufficient conversion time
1128 * or power failure.
1129 */
1130 ret = -EIO;
1131 }
1132
1133 goto dec_refcnt;
1134 }
1135
1136 }
1137
1138 mt_unlock:
1139 mutex_unlock(&dev_master->bus_mutex);
1140 dec_refcnt:
1141 atomic_dec(THERM_REFCNT(sl->family_data));
1142 error:
1143 return ret;
1144 }
1145
conv_time_measure(struct w1_slave * sl,int * conv_time)1146 static int conv_time_measure(struct w1_slave *sl, int *conv_time)
1147 {
1148 struct therm_info inf,
1149 *info = &inf;
1150 struct w1_master *dev_master = sl->master;
1151 int max_trying = W1_THERM_MAX_TRY;
1152 int ret = -ENODEV;
1153 bool strong_pullup;
1154
1155 if (!sl->family_data)
1156 goto error;
1157
1158 strong_pullup = (w1_strong_pullup == 2 ||
1159 (!SLAVE_POWERMODE(sl) &&
1160 w1_strong_pullup));
1161
1162 if (strong_pullup) {
1163 pr_info("%s: Measure with strong_pullup is not supported.\n", __func__);
1164 return -EINVAL;
1165 }
1166
1167 memset(info->rom, 0, sizeof(info->rom));
1168
1169 /* prevent the slave from going away in sleep */
1170 atomic_inc(THERM_REFCNT(sl->family_data));
1171
1172 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1173 ret = -EAGAIN; /* Didn't acquire the mutex */
1174 goto dec_refcnt;
1175 }
1176
1177 while (max_trying-- && ret) { /* ret should be 0 */
1178 info->verdict = 0;
1179 info->crc = 0;
1180 /* safe version to select slave */
1181 if (!reset_select_slave(sl)) {
1182 int j_start, j_end;
1183
1184 /*no device need pullup */
1185 w1_write_8(dev_master, W1_CONVERT_TEMP);
1186
1187 j_start = jiffies;
1188 ret = w1_poll_completion(dev_master, W1_POLL_CONVERT_TEMP);
1189 if (ret) {
1190 dev_dbg(&sl->dev, "%s: Timeout\n", __func__);
1191 goto mt_unlock;
1192 }
1193 j_end = jiffies;
1194 /* 1.2x increase for variation and changes over temperature range */
1195 *conv_time = jiffies_to_msecs(j_end-j_start)*12/10;
1196 pr_debug("W1 Measure complete, conv_time = %d, HZ=%d.\n",
1197 *conv_time, HZ);
1198 if (*conv_time <= CONV_TIME_MEASURE) {
1199 ret = -EIO;
1200 goto mt_unlock;
1201 }
1202 mutex_unlock(&dev_master->bus_mutex);
1203 ret = read_scratchpad(sl, info);
1204 goto dec_refcnt;
1205 }
1206
1207 }
1208 mt_unlock:
1209 mutex_unlock(&dev_master->bus_mutex);
1210 dec_refcnt:
1211 atomic_dec(THERM_REFCNT(sl->family_data));
1212 error:
1213 return ret;
1214 }
1215
read_scratchpad(struct w1_slave * sl,struct therm_info * info)1216 static int read_scratchpad(struct w1_slave *sl, struct therm_info *info)
1217 {
1218 struct w1_master *dev_master = sl->master;
1219 int max_trying = W1_THERM_MAX_TRY;
1220 int ret = -ENODEV;
1221
1222 info->verdict = 0;
1223
1224 if (!sl->family_data)
1225 goto error;
1226
1227 memset(info->rom, 0, sizeof(info->rom));
1228
1229 /* prevent the slave from going away in sleep */
1230 atomic_inc(THERM_REFCNT(sl->family_data));
1231
1232 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1233 ret = -EAGAIN; /* Didn't acquire the mutex */
1234 goto dec_refcnt;
1235 }
1236
1237 while (max_trying-- && ret) { /* ret should be 0 */
1238 /* safe version to select slave */
1239 if (!reset_select_slave(sl)) {
1240 u8 nb_bytes_read;
1241
1242 w1_write_8(dev_master, W1_READ_SCRATCHPAD);
1243
1244 nb_bytes_read = w1_read_block(dev_master, info->rom, 9);
1245 if (nb_bytes_read != 9) {
1246 dev_warn(&sl->dev,
1247 "w1_read_block(): returned %u instead of 9.\n",
1248 nb_bytes_read);
1249 ret = -EIO;
1250 }
1251
1252 info->crc = w1_calc_crc8(info->rom, 8);
1253
1254 if (info->rom[8] == info->crc) {
1255 info->verdict = 1;
1256 ret = 0;
1257 } else
1258 ret = -EIO; /* CRC not checked */
1259 }
1260
1261 }
1262 mutex_unlock(&dev_master->bus_mutex);
1263
1264 dec_refcnt:
1265 atomic_dec(THERM_REFCNT(sl->family_data));
1266 error:
1267 return ret;
1268 }
1269
write_scratchpad(struct w1_slave * sl,const u8 * data,u8 nb_bytes)1270 static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes)
1271 {
1272 struct w1_master *dev_master = sl->master;
1273 int max_trying = W1_THERM_MAX_TRY;
1274 int ret = -ENODEV;
1275
1276 if (!sl->family_data)
1277 goto error;
1278
1279 /* prevent the slave from going away in sleep */
1280 atomic_inc(THERM_REFCNT(sl->family_data));
1281
1282 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1283 ret = -EAGAIN; /* Didn't acquire the mutex */
1284 goto dec_refcnt;
1285 }
1286
1287 while (max_trying-- && ret) { /* ret should be 0 */
1288 /* safe version to select slave */
1289 if (!reset_select_slave(sl)) {
1290 w1_write_8(dev_master, W1_WRITE_SCRATCHPAD);
1291 w1_write_block(dev_master, data, nb_bytes);
1292 ret = 0;
1293 }
1294 }
1295 mutex_unlock(&dev_master->bus_mutex);
1296
1297 dec_refcnt:
1298 atomic_dec(THERM_REFCNT(sl->family_data));
1299 error:
1300 return ret;
1301 }
1302
copy_scratchpad(struct w1_slave * sl)1303 static int copy_scratchpad(struct w1_slave *sl)
1304 {
1305 struct w1_master *dev_master = sl->master;
1306 int max_trying = W1_THERM_MAX_TRY;
1307 int t_write, ret = -ENODEV;
1308 bool strong_pullup;
1309
1310 if (!sl->family_data)
1311 goto error;
1312
1313 t_write = W1_THERM_EEPROM_WRITE_DELAY;
1314 strong_pullup = (w1_strong_pullup == 2 ||
1315 (!SLAVE_POWERMODE(sl) &&
1316 w1_strong_pullup));
1317
1318 /* prevent the slave from going away in sleep */
1319 atomic_inc(THERM_REFCNT(sl->family_data));
1320
1321 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1322 ret = -EAGAIN; /* Didn't acquire the mutex */
1323 goto dec_refcnt;
1324 }
1325
1326 while (max_trying-- && ret) { /* ret should be 0 */
1327 /* safe version to select slave */
1328 if (!reset_select_slave(sl)) {
1329 unsigned long sleep_rem;
1330
1331 /* 10ms strong pullup (or delay) after the convert */
1332 if (strong_pullup)
1333 w1_next_pullup(dev_master, t_write);
1334
1335 w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
1336
1337 if (strong_pullup) {
1338 sleep_rem = msleep_interruptible(t_write);
1339 if (sleep_rem != 0) {
1340 ret = -EINTR;
1341 goto mt_unlock;
1342 }
1343 }
1344 ret = 0;
1345 }
1346
1347 }
1348
1349 mt_unlock:
1350 mutex_unlock(&dev_master->bus_mutex);
1351 dec_refcnt:
1352 atomic_dec(THERM_REFCNT(sl->family_data));
1353 error:
1354 return ret;
1355 }
1356
recall_eeprom(struct w1_slave * sl)1357 static int recall_eeprom(struct w1_slave *sl)
1358 {
1359 struct w1_master *dev_master = sl->master;
1360 int max_trying = W1_THERM_MAX_TRY;
1361 int ret = -ENODEV;
1362
1363 if (!sl->family_data)
1364 goto error;
1365
1366 /* prevent the slave from going away in sleep */
1367 atomic_inc(THERM_REFCNT(sl->family_data));
1368
1369 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1370 ret = -EAGAIN; /* Didn't acquire the mutex */
1371 goto dec_refcnt;
1372 }
1373
1374 while (max_trying-- && ret) { /* ret should be 0 */
1375 /* safe version to select slave */
1376 if (!reset_select_slave(sl)) {
1377
1378 w1_write_8(dev_master, W1_RECALL_EEPROM);
1379 ret = w1_poll_completion(dev_master, W1_POLL_RECALL_EEPROM);
1380 }
1381
1382 }
1383
1384 mutex_unlock(&dev_master->bus_mutex);
1385
1386 dec_refcnt:
1387 atomic_dec(THERM_REFCNT(sl->family_data));
1388 error:
1389 return ret;
1390 }
1391
read_powermode(struct w1_slave * sl)1392 static int read_powermode(struct w1_slave *sl)
1393 {
1394 struct w1_master *dev_master = sl->master;
1395 int max_trying = W1_THERM_MAX_TRY;
1396 int ret = -ENODEV;
1397
1398 if (!sl->family_data)
1399 goto error;
1400
1401 /* prevent the slave from going away in sleep */
1402 atomic_inc(THERM_REFCNT(sl->family_data));
1403
1404 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1405 ret = -EAGAIN; /* Didn't acquire the mutex */
1406 goto dec_refcnt;
1407 }
1408
1409 while ((max_trying--) && (ret < 0)) {
1410 /* safe version to select slave */
1411 if (!reset_select_slave(sl)) {
1412 w1_write_8(dev_master, W1_READ_PSUPPLY);
1413 /*
1414 * Emit a read time slot and read only one bit,
1415 * 1 is externally powered,
1416 * 0 is parasite powered
1417 */
1418 ret = w1_touch_bit(dev_master, 1);
1419 /* ret should be either 1 either 0 */
1420 }
1421 }
1422 mutex_unlock(&dev_master->bus_mutex);
1423
1424 dec_refcnt:
1425 atomic_dec(THERM_REFCNT(sl->family_data));
1426 error:
1427 return ret;
1428 }
1429
trigger_bulk_read(struct w1_master * dev_master)1430 static int trigger_bulk_read(struct w1_master *dev_master)
1431 {
1432 struct w1_slave *sl = NULL; /* used to iterate through slaves */
1433 int max_trying = W1_THERM_MAX_TRY;
1434 int t_conv = 0;
1435 int ret = -ENODEV;
1436 bool strong_pullup = false;
1437
1438 /*
1439 * Check whether there are parasite powered device on the bus,
1440 * and compute duration of conversion for these devices
1441 * so we can apply a strong pullup if required
1442 */
1443 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1444 if (!sl->family_data)
1445 goto error;
1446 if (bulk_read_support(sl)) {
1447 int t_cur = conversion_time(sl);
1448
1449 t_conv = t_cur > t_conv ? t_cur : t_conv;
1450 strong_pullup = strong_pullup ||
1451 (w1_strong_pullup == 2 ||
1452 (!SLAVE_POWERMODE(sl) &&
1453 w1_strong_pullup));
1454 }
1455 }
1456
1457 /*
1458 * t_conv is the max conversion time required on the bus
1459 * If its 0, no device support the bulk read feature
1460 */
1461 if (!t_conv)
1462 goto error;
1463
1464 if (!bus_mutex_lock(&dev_master->bus_mutex)) {
1465 ret = -EAGAIN; /* Didn't acquire the mutex */
1466 goto error;
1467 }
1468
1469 while ((max_trying--) && (ret < 0)) { /* ret should be either 0 */
1470
1471 if (!w1_reset_bus(dev_master)) { /* Just reset the bus */
1472 unsigned long sleep_rem;
1473
1474 w1_write_8(dev_master, W1_SKIP_ROM);
1475
1476 if (strong_pullup) /* Apply pullup if required */
1477 w1_next_pullup(dev_master, t_conv);
1478
1479 w1_write_8(dev_master, W1_CONVERT_TEMP);
1480
1481 /* set a flag to instruct that converT pending */
1482 list_for_each_entry(sl,
1483 &dev_master->slist, w1_slave_entry) {
1484 if (bulk_read_support(sl))
1485 SLAVE_CONVERT_TRIGGERED(sl) = -1;
1486 }
1487
1488 if (strong_pullup) { /* some device need pullup */
1489 sleep_rem = msleep_interruptible(t_conv);
1490 if (sleep_rem != 0) {
1491 ret = -EINTR;
1492 goto mt_unlock;
1493 }
1494 mutex_unlock(&dev_master->bus_mutex);
1495 } else {
1496 mutex_unlock(&dev_master->bus_mutex);
1497 sleep_rem = msleep_interruptible(t_conv);
1498 if (sleep_rem != 0) {
1499 ret = -EINTR;
1500 goto set_flag;
1501 }
1502 }
1503 ret = 0;
1504 goto set_flag;
1505 }
1506 }
1507
1508 mt_unlock:
1509 mutex_unlock(&dev_master->bus_mutex);
1510 set_flag:
1511 /* set a flag to register convsersion is done */
1512 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1513 if (bulk_read_support(sl))
1514 SLAVE_CONVERT_TRIGGERED(sl) = 1;
1515 }
1516 error:
1517 return ret;
1518 }
1519
1520 /* Sysfs Interface definition */
1521
w1_slave_show(struct device * device,struct device_attribute * attr,char * buf)1522 static ssize_t w1_slave_show(struct device *device,
1523 struct device_attribute *attr, char *buf)
1524 {
1525 struct w1_slave *sl = dev_to_w1_slave(device);
1526 struct therm_info info;
1527 u8 *family_data = sl->family_data;
1528 int ret, i;
1529 ssize_t c = PAGE_SIZE;
1530
1531 if (bulk_read_support(sl)) {
1532 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1533 dev_dbg(device,
1534 "%s: Conversion in progress, retry later\n",
1535 __func__);
1536 return 0;
1537 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1538 /* A bulk read has been issued, read the device RAM */
1539 ret = read_scratchpad(sl, &info);
1540 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1541 } else
1542 ret = convert_t(sl, &info);
1543 } else
1544 ret = convert_t(sl, &info);
1545
1546 if (ret < 0) {
1547 dev_dbg(device,
1548 "%s: Temperature data may be corrupted. err=%d\n",
1549 __func__, ret);
1550 return 0;
1551 }
1552
1553 for (i = 0; i < 9; ++i)
1554 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]);
1555 c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
1556 info.crc, (info.verdict) ? "YES" : "NO");
1557
1558 if (info.verdict)
1559 memcpy(family_data, info.rom, sizeof(info.rom));
1560 else
1561 dev_warn(device, "%s:Read failed CRC check\n", __func__);
1562
1563 for (i = 0; i < 9; ++i)
1564 c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
1565 ((u8 *)family_data)[i]);
1566
1567 c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
1568 temperature_from_RAM(sl, info.rom));
1569
1570 ret = PAGE_SIZE - c;
1571 return ret;
1572 }
1573
w1_slave_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1574 static ssize_t w1_slave_store(struct device *device,
1575 struct device_attribute *attr, const char *buf,
1576 size_t size)
1577 {
1578 int val, ret = 0;
1579 struct w1_slave *sl = dev_to_w1_slave(device);
1580
1581 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1582
1583 if (ret) { /* conversion error */
1584 dev_info(device,
1585 "%s: conversion error. err= %d\n", __func__, ret);
1586 return size; /* return size to avoid call back again */
1587 }
1588
1589 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1590 dev_info(device,
1591 "%s: Device not supported by the driver\n", __func__);
1592 return size; /* No device family */
1593 }
1594
1595 if (val == 0) /* val=0 : trigger a EEPROM save */
1596 ret = copy_scratchpad(sl);
1597 else {
1598 if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
1599 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1600 }
1601
1602 if (ret) {
1603 dev_warn(device, "%s: Set resolution - error %d\n", __func__, ret);
1604 /* Propagate error to userspace */
1605 return ret;
1606 }
1607 SLAVE_RESOLUTION(sl) = val;
1608 /* Reset the conversion time to default - it depends on resolution */
1609 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1610
1611 return size; /* always return size to avoid infinite calling */
1612 }
1613
temperature_show(struct device * device,struct device_attribute * attr,char * buf)1614 static ssize_t temperature_show(struct device *device,
1615 struct device_attribute *attr, char *buf)
1616 {
1617 struct w1_slave *sl = dev_to_w1_slave(device);
1618 struct therm_info info;
1619 int ret = 0;
1620
1621 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1622 dev_info(device,
1623 "%s: Device not supported by the driver\n", __func__);
1624 return 0; /* No device family */
1625 }
1626
1627 if (bulk_read_support(sl)) {
1628 if (SLAVE_CONVERT_TRIGGERED(sl) < 0) {
1629 dev_dbg(device,
1630 "%s: Conversion in progress, retry later\n",
1631 __func__);
1632 return 0;
1633 } else if (SLAVE_CONVERT_TRIGGERED(sl) > 0) {
1634 /* A bulk read has been issued, read the device RAM */
1635 ret = read_scratchpad(sl, &info);
1636 SLAVE_CONVERT_TRIGGERED(sl) = 0;
1637 } else
1638 ret = convert_t(sl, &info);
1639 } else
1640 ret = convert_t(sl, &info);
1641
1642 if (ret < 0) {
1643 dev_dbg(device,
1644 "%s: Temperature data may be corrupted. err=%d\n",
1645 __func__, ret);
1646 return 0;
1647 }
1648
1649 return sprintf(buf, "%d\n", temperature_from_RAM(sl, info.rom));
1650 }
1651
ext_power_show(struct device * device,struct device_attribute * attr,char * buf)1652 static ssize_t ext_power_show(struct device *device,
1653 struct device_attribute *attr, char *buf)
1654 {
1655 struct w1_slave *sl = dev_to_w1_slave(device);
1656
1657 if (!sl->family_data) {
1658 dev_info(device,
1659 "%s: Device not supported by the driver\n", __func__);
1660 return 0; /* No device family */
1661 }
1662
1663 /* Getting the power mode of the device {external, parasite} */
1664 SLAVE_POWERMODE(sl) = read_powermode(sl);
1665
1666 if (SLAVE_POWERMODE(sl) < 0) {
1667 dev_dbg(device,
1668 "%s: Power_mode may be corrupted. err=%d\n",
1669 __func__, SLAVE_POWERMODE(sl));
1670 }
1671 return sprintf(buf, "%d\n", SLAVE_POWERMODE(sl));
1672 }
1673
resolution_show(struct device * device,struct device_attribute * attr,char * buf)1674 static ssize_t resolution_show(struct device *device,
1675 struct device_attribute *attr, char *buf)
1676 {
1677 struct w1_slave *sl = dev_to_w1_slave(device);
1678
1679 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1680 dev_info(device,
1681 "%s: Device not supported by the driver\n", __func__);
1682 return 0; /* No device family */
1683 }
1684
1685 /* get the correct function depending on the device */
1686 SLAVE_RESOLUTION(sl) = SLAVE_SPECIFIC_FUNC(sl)->get_resolution(sl);
1687 if (SLAVE_RESOLUTION(sl) < 0) {
1688 dev_dbg(device,
1689 "%s: Resolution may be corrupted. err=%d\n",
1690 __func__, SLAVE_RESOLUTION(sl));
1691 }
1692
1693 return sprintf(buf, "%d\n", SLAVE_RESOLUTION(sl));
1694 }
1695
resolution_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1696 static ssize_t resolution_store(struct device *device,
1697 struct device_attribute *attr, const char *buf, size_t size)
1698 {
1699 struct w1_slave *sl = dev_to_w1_slave(device);
1700 int val;
1701 int ret = 0;
1702
1703 ret = kstrtoint(buf, 10, &val); /* converting user entry to int */
1704
1705 if (ret) { /* conversion error */
1706 dev_info(device,
1707 "%s: conversion error. err= %d\n", __func__, ret);
1708 return size; /* return size to avoid call back again */
1709 }
1710
1711 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1712 dev_info(device,
1713 "%s: Device not supported by the driver\n", __func__);
1714 return size; /* No device family */
1715 }
1716
1717 /*
1718 * Don't deal with the val enterd by user,
1719 * only device knows what is correct or not
1720 */
1721
1722 /* get the correct function depending on the device */
1723 ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
1724
1725 if (ret)
1726 return ret;
1727
1728 SLAVE_RESOLUTION(sl) = val;
1729 /* Reset the conversion time to default because it depends on resolution */
1730 SLAVE_CONV_TIME_OVERRIDE(sl) = CONV_TIME_DEFAULT;
1731
1732 return size;
1733 }
1734
eeprom_cmd_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1735 static ssize_t eeprom_cmd_store(struct device *device,
1736 struct device_attribute *attr, const char *buf, size_t size)
1737 {
1738 struct w1_slave *sl = dev_to_w1_slave(device);
1739 int ret = -EINVAL; /* Invalid argument */
1740
1741 if (size == sizeof(EEPROM_CMD_WRITE)) {
1742 if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
1743 ret = copy_scratchpad(sl);
1744 } else if (size == sizeof(EEPROM_CMD_READ)) {
1745 if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
1746 ret = recall_eeprom(sl);
1747 }
1748
1749 if (ret)
1750 dev_info(device, "%s: error in process %d\n", __func__, ret);
1751
1752 return size;
1753 }
1754
alarms_show(struct device * device,struct device_attribute * attr,char * buf)1755 static ssize_t alarms_show(struct device *device,
1756 struct device_attribute *attr, char *buf)
1757 {
1758 struct w1_slave *sl = dev_to_w1_slave(device);
1759 int ret;
1760 s8 th = 0, tl = 0;
1761 struct therm_info scratchpad;
1762
1763 ret = read_scratchpad(sl, &scratchpad);
1764
1765 if (!ret) {
1766 th = scratchpad.rom[2]; /* TH is byte 2 */
1767 tl = scratchpad.rom[3]; /* TL is byte 3 */
1768 } else {
1769 dev_info(device,
1770 "%s: error reading alarms register %d\n",
1771 __func__, ret);
1772 }
1773
1774 return sprintf(buf, "%hd %hd\n", tl, th);
1775 }
1776
alarms_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1777 static ssize_t alarms_store(struct device *device,
1778 struct device_attribute *attr, const char *buf, size_t size)
1779 {
1780 struct w1_slave *sl = dev_to_w1_slave(device);
1781 struct therm_info info;
1782 u8 new_config_register[3]; /* array of data to be written */
1783 int temp, ret;
1784 char *token = NULL;
1785 s8 tl, th, tt; /* 1 byte per value + temp ring order */
1786 char *p_args, *orig;
1787
1788 p_args = orig = kmalloc(size, GFP_KERNEL);
1789 /* Safe string copys as buf is const */
1790 if (!p_args) {
1791 dev_warn(device,
1792 "%s: error unable to allocate memory %d\n",
1793 __func__, -ENOMEM);
1794 return size;
1795 }
1796 strcpy(p_args, buf);
1797
1798 /* Split string using space char */
1799 token = strsep(&p_args, " ");
1800
1801 if (!token) {
1802 dev_info(device,
1803 "%s: error parsing args %d\n", __func__, -EINVAL);
1804 goto free_m;
1805 }
1806
1807 /* Convert 1st entry to int */
1808 ret = kstrtoint (token, 10, &temp);
1809 if (ret) {
1810 dev_info(device,
1811 "%s: error parsing args %d\n", __func__, ret);
1812 goto free_m;
1813 }
1814
1815 tl = int_to_short(temp);
1816
1817 /* Split string using space char */
1818 token = strsep(&p_args, " ");
1819 if (!token) {
1820 dev_info(device,
1821 "%s: error parsing args %d\n", __func__, -EINVAL);
1822 goto free_m;
1823 }
1824 /* Convert 2nd entry to int */
1825 ret = kstrtoint (token, 10, &temp);
1826 if (ret) {
1827 dev_info(device,
1828 "%s: error parsing args %d\n", __func__, ret);
1829 goto free_m;
1830 }
1831
1832 /* Prepare to cast to short by eliminating out of range values */
1833 th = int_to_short(temp);
1834
1835 /* Reorder if required th and tl */
1836 if (tl > th) {
1837 tt = tl; tl = th; th = tt;
1838 }
1839
1840 /*
1841 * Read the scratchpad to change only the required bits
1842 * (th : byte 2 - tl: byte 3)
1843 */
1844 ret = read_scratchpad(sl, &info);
1845 if (!ret) {
1846 new_config_register[0] = th; /* Byte 2 */
1847 new_config_register[1] = tl; /* Byte 3 */
1848 new_config_register[2] = info.rom[4];/* Byte 4 */
1849 } else {
1850 dev_info(device,
1851 "%s: error reading from the slave device %d\n",
1852 __func__, ret);
1853 goto free_m;
1854 }
1855
1856 /* Write data in the device RAM */
1857 if (!SLAVE_SPECIFIC_FUNC(sl)) {
1858 dev_info(device,
1859 "%s: Device not supported by the driver %d\n",
1860 __func__, -ENODEV);
1861 goto free_m;
1862 }
1863
1864 ret = SLAVE_SPECIFIC_FUNC(sl)->write_data(sl, new_config_register);
1865 if (ret)
1866 dev_info(device,
1867 "%s: error writing to the slave device %d\n",
1868 __func__, ret);
1869
1870 free_m:
1871 /* free allocated memory */
1872 kfree(orig);
1873
1874 return size;
1875 }
1876
therm_bulk_read_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1877 static ssize_t therm_bulk_read_store(struct device *device,
1878 struct device_attribute *attr, const char *buf, size_t size)
1879 {
1880 struct w1_master *dev_master = dev_to_w1_master(device);
1881 int ret = -EINVAL; /* Invalid argument */
1882
1883 if (size == sizeof(BULK_TRIGGER_CMD))
1884 if (!strncmp(buf, BULK_TRIGGER_CMD,
1885 sizeof(BULK_TRIGGER_CMD)-1))
1886 ret = trigger_bulk_read(dev_master);
1887
1888 if (ret)
1889 dev_info(device,
1890 "%s: unable to trigger a bulk read on the bus. err=%d\n",
1891 __func__, ret);
1892
1893 return size;
1894 }
1895
therm_bulk_read_show(struct device * device,struct device_attribute * attr,char * buf)1896 static ssize_t therm_bulk_read_show(struct device *device,
1897 struct device_attribute *attr, char *buf)
1898 {
1899 struct w1_master *dev_master = dev_to_w1_master(device);
1900 struct w1_slave *sl = NULL;
1901 int ret = 0;
1902
1903 list_for_each_entry(sl, &dev_master->slist, w1_slave_entry) {
1904 if (sl->family_data) {
1905 if (bulk_read_support(sl)) {
1906 if (SLAVE_CONVERT_TRIGGERED(sl) == -1) {
1907 ret = -1;
1908 goto show_result;
1909 }
1910 if (SLAVE_CONVERT_TRIGGERED(sl) == 1)
1911 /* continue to check other slaves */
1912 ret = 1;
1913 }
1914 }
1915 }
1916 show_result:
1917 return sprintf(buf, "%d\n", ret);
1918 }
1919
conv_time_show(struct device * device,struct device_attribute * attr,char * buf)1920 static ssize_t conv_time_show(struct device *device,
1921 struct device_attribute *attr, char *buf)
1922 {
1923 struct w1_slave *sl = dev_to_w1_slave(device);
1924
1925 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1926 dev_info(device,
1927 "%s: Device is not supported by the driver\n", __func__);
1928 return 0; /* No device family */
1929 }
1930 return sprintf(buf, "%d\n", conversion_time(sl));
1931 }
1932
conv_time_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1933 static ssize_t conv_time_store(struct device *device,
1934 struct device_attribute *attr, const char *buf, size_t size)
1935 {
1936 int val, ret = 0;
1937 struct w1_slave *sl = dev_to_w1_slave(device);
1938
1939 if (kstrtoint(buf, 10, &val)) /* converting user entry to int */
1940 return -EINVAL;
1941
1942 if (check_family_data(sl))
1943 return -ENODEV;
1944
1945 if (val != CONV_TIME_MEASURE) {
1946 if (val >= CONV_TIME_DEFAULT)
1947 SLAVE_CONV_TIME_OVERRIDE(sl) = val;
1948 else
1949 return -EINVAL;
1950
1951 } else {
1952 int conv_time;
1953
1954 ret = conv_time_measure(sl, &conv_time);
1955 if (ret)
1956 return -EIO;
1957 SLAVE_CONV_TIME_OVERRIDE(sl) = conv_time;
1958 }
1959 return size;
1960 }
1961
features_show(struct device * device,struct device_attribute * attr,char * buf)1962 static ssize_t features_show(struct device *device,
1963 struct device_attribute *attr, char *buf)
1964 {
1965 struct w1_slave *sl = dev_to_w1_slave(device);
1966
1967 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1968 dev_info(device,
1969 "%s: Device not supported by the driver\n", __func__);
1970 return 0; /* No device family */
1971 }
1972 return sprintf(buf, "%u\n", SLAVE_FEATURES(sl));
1973 }
1974
features_store(struct device * device,struct device_attribute * attr,const char * buf,size_t size)1975 static ssize_t features_store(struct device *device,
1976 struct device_attribute *attr, const char *buf, size_t size)
1977 {
1978 int val, ret = 0;
1979 bool strong_pullup;
1980 struct w1_slave *sl = dev_to_w1_slave(device);
1981
1982 ret = kstrtouint(buf, 10, &val); /* converting user entry to int */
1983 if (ret)
1984 return -EINVAL; /* invalid number */
1985
1986 if ((!sl->family_data) || (!SLAVE_SPECIFIC_FUNC(sl))) {
1987 dev_info(device, "%s: Device not supported by the driver\n", __func__);
1988 return -ENODEV;
1989 }
1990
1991 if ((val & W1_THERM_FEATURES_MASK) != val)
1992 return -EINVAL;
1993
1994 SLAVE_FEATURES(sl) = val;
1995
1996 strong_pullup = (w1_strong_pullup == 2 ||
1997 (!SLAVE_POWERMODE(sl) &&
1998 w1_strong_pullup));
1999
2000 if (strong_pullup && SLAVE_FEATURES(sl) & W1_THERM_POLL_COMPLETION) {
2001 dev_warn(&sl->dev,
2002 "%s: W1_THERM_POLL_COMPLETION disabled in parasite power mode.\n",
2003 __func__);
2004 SLAVE_FEATURES(sl) &= ~W1_THERM_POLL_COMPLETION;
2005 }
2006
2007 return size;
2008 }
2009
2010 #if IS_REACHABLE(CONFIG_HWMON)
w1_read_temp(struct device * device,u32 attr,int channel,long * val)2011 static int w1_read_temp(struct device *device, u32 attr, int channel,
2012 long *val)
2013 {
2014 struct w1_slave *sl = dev_get_drvdata(device);
2015 struct therm_info info;
2016 int ret;
2017
2018 switch (attr) {
2019 case hwmon_temp_input:
2020 ret = convert_t(sl, &info);
2021 if (ret)
2022 return ret;
2023
2024 if (!info.verdict) {
2025 ret = -EIO;
2026 return ret;
2027 }
2028
2029 *val = temperature_from_RAM(sl, info.rom);
2030 ret = 0;
2031 break;
2032 default:
2033 ret = -EOPNOTSUPP;
2034 break;
2035 }
2036
2037 return ret;
2038 }
2039 #endif
2040
2041 #define W1_42_CHAIN 0x99
2042 #define W1_42_CHAIN_OFF 0x3C
2043 #define W1_42_CHAIN_OFF_INV 0xC3
2044 #define W1_42_CHAIN_ON 0x5A
2045 #define W1_42_CHAIN_ON_INV 0xA5
2046 #define W1_42_CHAIN_DONE 0x96
2047 #define W1_42_CHAIN_DONE_INV 0x69
2048 #define W1_42_COND_READ 0x0F
2049 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
2050 #define W1_42_FINISHED_BYTE 0xFF
w1_seq_show(struct device * device,struct device_attribute * attr,char * buf)2051 static ssize_t w1_seq_show(struct device *device,
2052 struct device_attribute *attr, char *buf)
2053 {
2054 struct w1_slave *sl = dev_to_w1_slave(device);
2055 ssize_t c = PAGE_SIZE;
2056 int i;
2057 u8 ack;
2058 u64 rn;
2059 struct w1_reg_num *reg_num;
2060 int seq = 0;
2061
2062 mutex_lock(&sl->master->bus_mutex);
2063 /* Place all devices in CHAIN state */
2064 if (w1_reset_bus(sl->master))
2065 goto error;
2066 w1_write_8(sl->master, W1_SKIP_ROM);
2067 w1_write_8(sl->master, W1_42_CHAIN);
2068 w1_write_8(sl->master, W1_42_CHAIN_ON);
2069 w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
2070 msleep(sl->master->pullup_duration);
2071
2072 /* check for acknowledgment */
2073 ack = w1_read_8(sl->master);
2074 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2075 goto error;
2076
2077 /* In case the bus fails to send 0xFF, limit */
2078 for (i = 0; i <= 64; i++) {
2079 if (w1_reset_bus(sl->master))
2080 goto error;
2081
2082 w1_write_8(sl->master, W1_42_COND_READ);
2083 w1_read_block(sl->master, (u8 *)&rn, 8);
2084 reg_num = (struct w1_reg_num *) &rn;
2085 if (reg_num->family == W1_42_FINISHED_BYTE)
2086 break;
2087 if (sl->reg_num.id == reg_num->id)
2088 seq = i;
2089
2090 if (w1_reset_bus(sl->master))
2091 goto error;
2092
2093 /* Put the device into chain DONE state */
2094 w1_write_8(sl->master, W1_MATCH_ROM);
2095 w1_write_block(sl->master, (u8 *)&rn, 8);
2096 w1_write_8(sl->master, W1_42_CHAIN);
2097 w1_write_8(sl->master, W1_42_CHAIN_DONE);
2098 w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
2099
2100 /* check for acknowledgment */
2101 ack = w1_read_8(sl->master);
2102 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2103 goto error;
2104 }
2105
2106 /* Exit from CHAIN state */
2107 if (w1_reset_bus(sl->master))
2108 goto error;
2109 w1_write_8(sl->master, W1_SKIP_ROM);
2110 w1_write_8(sl->master, W1_42_CHAIN);
2111 w1_write_8(sl->master, W1_42_CHAIN_OFF);
2112 w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
2113
2114 /* check for acknowledgment */
2115 ack = w1_read_8(sl->master);
2116 if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
2117 goto error;
2118 mutex_unlock(&sl->master->bus_mutex);
2119
2120 c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
2121 return PAGE_SIZE - c;
2122 error:
2123 mutex_unlock(&sl->master->bus_mutex);
2124 return -EIO;
2125 }
2126
w1_therm_init(void)2127 static int __init w1_therm_init(void)
2128 {
2129 int err, i;
2130
2131 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
2132 err = w1_register_family(w1_therm_families[i].f);
2133 if (err)
2134 w1_therm_families[i].broken = 1;
2135 }
2136
2137 return 0;
2138 }
2139
w1_therm_fini(void)2140 static void __exit w1_therm_fini(void)
2141 {
2142 int i;
2143
2144 for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
2145 if (!w1_therm_families[i].broken)
2146 w1_unregister_family(w1_therm_families[i].f);
2147 }
2148
2149 module_init(w1_therm_init);
2150 module_exit(w1_therm_fini);
2151
2152 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
2153 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
2154 MODULE_LICENSE("GPL");
2155 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20));
2156 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822));
2157 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20));
2158 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825));
2159 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
2160