4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the therms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <asm/types.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/sched.h>
28 #include <linux/device.h>
29 #include <linux/types.h>
30 #include <linux/slab.h>
31 #include <linux/delay.h>
32 #include <linux/hwmon.h>
36 #define W1_THERM_DS18S20 0x10
37 #define W1_THERM_DS1822 0x22
38 #define W1_THERM_DS18B20 0x28
39 #define W1_THERM_DS1825 0x3B
40 #define W1_THERM_DS28EA00 0x42
42 /* Allow the strong pullup to be disabled, but default to enabled.
43 * If it was disabled a parasite powered device might not get the require
44 * current to do a temperature conversion. If it is enabled parasite powered
45 * devices have a better chance of getting the current required.
46 * In case the parasite power-detection is not working (seems to be the case
47 * for some DS18S20) the strong pullup can also be forced, regardless of the
48 * power state of the devices.
51 * - strong_pullup = 0 Disable strong pullup completely
52 * - strong_pullup = 1 Enable automatic strong pullup detection
53 * - strong_pullup = 2 Force strong pullup
55 static int w1_strong_pullup
= 1;
56 module_param_named(strong_pullup
, w1_strong_pullup
, int, 0);
58 struct w1_therm_family_data
{
69 /* return the address of the refcnt in the family data */
70 #define THERM_REFCNT(family_data) \
71 (&((struct w1_therm_family_data *)family_data)->refcnt)
73 static int w1_therm_add_slave(struct w1_slave
*sl
)
75 sl
->family_data
= kzalloc(sizeof(struct w1_therm_family_data
),
79 atomic_set(THERM_REFCNT(sl
->family_data
), 1);
83 static void w1_therm_remove_slave(struct w1_slave
*sl
)
85 int refcnt
= atomic_sub_return(1, THERM_REFCNT(sl
->family_data
));
89 refcnt
= atomic_read(THERM_REFCNT(sl
->family_data
));
91 kfree(sl
->family_data
);
92 sl
->family_data
= NULL
;
95 static ssize_t
w1_slave_show(struct device
*device
,
96 struct device_attribute
*attr
, char *buf
);
98 static ssize_t
w1_slave_store(struct device
*device
,
99 struct device_attribute
*attr
, const char *buf
, size_t size
);
101 static ssize_t
w1_seq_show(struct device
*device
,
102 struct device_attribute
*attr
, char *buf
);
104 static DEVICE_ATTR_RW(w1_slave
);
105 static DEVICE_ATTR_RO(w1_seq
);
107 static struct attribute
*w1_therm_attrs
[] = {
108 &dev_attr_w1_slave
.attr
,
112 static struct attribute
*w1_ds28ea00_attrs
[] = {
113 &dev_attr_w1_slave
.attr
,
114 &dev_attr_w1_seq
.attr
,
118 ATTRIBUTE_GROUPS(w1_therm
);
119 ATTRIBUTE_GROUPS(w1_ds28ea00
);
121 #if IS_REACHABLE(CONFIG_HWMON)
122 static int w1_read_temp(struct device
*dev
, u32 attr
, int channel
,
125 static umode_t
w1_is_visible(const void *_data
, enum hwmon_sensor_types type
,
126 u32 attr
, int channel
)
128 return attr
== hwmon_temp_input
? 0444 : 0;
131 static int w1_read(struct device
*dev
, enum hwmon_sensor_types type
,
132 u32 attr
, int channel
, long *val
)
136 return w1_read_temp(dev
, attr
, channel
, val
);
142 static const u32 w1_temp_config
[] = {
147 static const struct hwmon_channel_info w1_temp
= {
149 .config
= w1_temp_config
,
152 static const struct hwmon_channel_info
*w1_info
[] = {
157 static const struct hwmon_ops w1_hwmon_ops
= {
158 .is_visible
= w1_is_visible
,
162 static const struct hwmon_chip_info w1_chip_info
= {
163 .ops
= &w1_hwmon_ops
,
166 #define W1_CHIPINFO (&w1_chip_info)
168 #define W1_CHIPINFO NULL
171 static struct w1_family_ops w1_therm_fops
= {
172 .add_slave
= w1_therm_add_slave
,
173 .remove_slave
= w1_therm_remove_slave
,
174 .groups
= w1_therm_groups
,
175 .chip_info
= W1_CHIPINFO
,
178 static struct w1_family_ops w1_ds28ea00_fops
= {
179 .add_slave
= w1_therm_add_slave
,
180 .remove_slave
= w1_therm_remove_slave
,
181 .groups
= w1_ds28ea00_groups
,
182 .chip_info
= W1_CHIPINFO
,
185 static struct w1_family w1_therm_family_DS18S20
= {
186 .fid
= W1_THERM_DS18S20
,
187 .fops
= &w1_therm_fops
,
190 static struct w1_family w1_therm_family_DS18B20
= {
191 .fid
= W1_THERM_DS18B20
,
192 .fops
= &w1_therm_fops
,
195 static struct w1_family w1_therm_family_DS1822
= {
196 .fid
= W1_THERM_DS1822
,
197 .fops
= &w1_therm_fops
,
200 static struct w1_family w1_therm_family_DS28EA00
= {
201 .fid
= W1_THERM_DS28EA00
,
202 .fops
= &w1_ds28ea00_fops
,
205 static struct w1_family w1_therm_family_DS1825
= {
206 .fid
= W1_THERM_DS1825
,
207 .fops
= &w1_therm_fops
,
210 struct w1_therm_family_converter
{
214 int (*convert
)(u8 rom
[9]);
215 int (*precision
)(struct device
*device
, int val
);
216 int (*eeprom
)(struct device
*device
);
219 /* write configuration to eeprom */
220 static inline int w1_therm_eeprom(struct device
*device
);
222 /* Set precision for conversion */
223 static inline int w1_DS18B20_precision(struct device
*device
, int val
);
224 static inline int w1_DS18S20_precision(struct device
*device
, int val
);
226 /* The return value is millidegrees Centigrade. */
227 static inline int w1_DS18B20_convert_temp(u8 rom
[9]);
228 static inline int w1_DS18S20_convert_temp(u8 rom
[9]);
230 static struct w1_therm_family_converter w1_therm_families
[] = {
232 .f
= &w1_therm_family_DS18S20
,
233 .convert
= w1_DS18S20_convert_temp
,
234 .precision
= w1_DS18S20_precision
,
235 .eeprom
= w1_therm_eeprom
238 .f
= &w1_therm_family_DS1822
,
239 .convert
= w1_DS18B20_convert_temp
,
240 .precision
= w1_DS18S20_precision
,
241 .eeprom
= w1_therm_eeprom
244 .f
= &w1_therm_family_DS18B20
,
245 .convert
= w1_DS18B20_convert_temp
,
246 .precision
= w1_DS18B20_precision
,
247 .eeprom
= w1_therm_eeprom
250 .f
= &w1_therm_family_DS28EA00
,
251 .convert
= w1_DS18B20_convert_temp
,
252 .precision
= w1_DS18S20_precision
,
253 .eeprom
= w1_therm_eeprom
256 .f
= &w1_therm_family_DS1825
,
257 .convert
= w1_DS18B20_convert_temp
,
258 .precision
= w1_DS18S20_precision
,
259 .eeprom
= w1_therm_eeprom
263 static inline int w1_therm_eeprom(struct device
*device
)
265 struct w1_slave
*sl
= dev_to_w1_slave(device
);
266 struct w1_master
*dev
= sl
->master
;
267 u8 rom
[9], external_power
;
268 int ret
, max_trying
= 10;
269 u8
*family_data
= sl
->family_data
;
271 if (!sl
->family_data
) {
276 /* prevent the slave from going away in sleep */
277 atomic_inc(THERM_REFCNT(family_data
));
279 ret
= mutex_lock_interruptible(&dev
->bus_mutex
);
283 memset(rom
, 0, sizeof(rom
));
285 while (max_trying
--) {
286 if (!w1_reset_select_slave(sl
)) {
287 unsigned int tm
= 10;
288 unsigned long sleep_rem
;
290 /* check if in parasite mode */
291 w1_write_8(dev
, W1_READ_PSUPPLY
);
292 external_power
= w1_read_8(dev
);
294 if (w1_reset_select_slave(sl
))
297 /* 10ms strong pullup/delay after the copy command */
298 if (w1_strong_pullup
== 2 ||
299 (!external_power
&& w1_strong_pullup
))
300 w1_next_pullup(dev
, tm
);
302 w1_write_8(dev
, W1_COPY_SCRATCHPAD
);
304 if (external_power
) {
305 mutex_unlock(&dev
->bus_mutex
);
307 sleep_rem
= msleep_interruptible(tm
);
308 if (sleep_rem
!= 0) {
313 ret
= mutex_lock_interruptible(&dev
->bus_mutex
);
316 } else if (!w1_strong_pullup
) {
317 sleep_rem
= msleep_interruptible(tm
);
318 if (sleep_rem
!= 0) {
329 mutex_unlock(&dev
->bus_mutex
);
331 atomic_dec(THERM_REFCNT(family_data
));
336 /* DS18S20 does not feature configuration register */
337 static inline int w1_DS18S20_precision(struct device
*device
, int val
)
342 static inline int w1_DS18B20_precision(struct device
*device
, int val
)
344 struct w1_slave
*sl
= dev_to_w1_slave(device
);
345 struct w1_master
*dev
= sl
->master
;
347 int ret
, max_trying
= 10;
348 u8
*family_data
= sl
->family_data
;
349 uint8_t precision_bits
;
352 if (val
> 12 || val
< 9) {
353 pr_warn("Unsupported precision\n");
358 if (!sl
->family_data
) {
363 /* prevent the slave from going away in sleep */
364 atomic_inc(THERM_REFCNT(family_data
));
366 ret
= mutex_lock_interruptible(&dev
->bus_mutex
);
370 memset(rom
, 0, sizeof(rom
));
372 /* translate precision to bitmask (see datasheet page 9) */
375 precision_bits
= 0x00;
378 precision_bits
= 0x20;
381 precision_bits
= 0x40;
385 precision_bits
= 0x60;
389 while (max_trying
--) {
392 if (!w1_reset_select_slave(sl
)) {
395 /* read values to only alter precision bits */
396 w1_write_8(dev
, W1_READ_SCRATCHPAD
);
397 count
= w1_read_block(dev
, rom
, 9);
399 dev_warn(device
, "w1_read_block() returned %u instead of 9.\n", count
);
401 crc
= w1_calc_crc8(rom
, 8);
403 rom
[4] = (rom
[4] & ~mask
) | (precision_bits
& mask
);
405 if (!w1_reset_select_slave(sl
)) {
406 w1_write_8(dev
, W1_WRITE_SCRATCHPAD
);
407 w1_write_8(dev
, rom
[2]);
408 w1_write_8(dev
, rom
[3]);
409 w1_write_8(dev
, rom
[4]);
417 mutex_unlock(&dev
->bus_mutex
);
419 atomic_dec(THERM_REFCNT(family_data
));
424 static inline int w1_DS18B20_convert_temp(u8 rom
[9])
426 s16 t
= le16_to_cpup((__le16
*)rom
);
431 static inline int w1_DS18S20_convert_temp(u8 rom
[9])
439 t
= ((s32
)rom
[0] >> 1)*1000;
441 t
= 1000*(-1*(s32
)(0x100-rom
[0]) >> 1);
444 h
= 1000*((s32
)rom
[7] - (s32
)rom
[6]);
451 static inline int w1_convert_temp(u8 rom
[9], u8 fid
)
455 for (i
= 0; i
< ARRAY_SIZE(w1_therm_families
); ++i
)
456 if (w1_therm_families
[i
].f
->fid
== fid
)
457 return w1_therm_families
[i
].convert(rom
);
462 static ssize_t
w1_slave_store(struct device
*device
,
463 struct device_attribute
*attr
, const char *buf
,
467 struct w1_slave
*sl
= dev_to_w1_slave(device
);
470 ret
= kstrtoint(buf
, 0, &val
);
474 for (i
= 0; i
< ARRAY_SIZE(w1_therm_families
); ++i
) {
475 if (w1_therm_families
[i
].f
->fid
== sl
->family
->fid
) {
476 /* zero value indicates to write current configuration to eeprom */
478 ret
= w1_therm_families
[i
].eeprom(device
);
480 ret
= w1_therm_families
[i
].precision(device
, val
);
487 static ssize_t
read_therm(struct device
*device
,
488 struct w1_slave
*sl
, struct therm_info
*info
)
490 struct w1_master
*dev
= sl
->master
;
492 int ret
, max_trying
= 10;
493 u8
*family_data
= sl
->family_data
;
500 /* prevent the slave from going away in sleep */
501 atomic_inc(THERM_REFCNT(family_data
));
503 ret
= mutex_lock_interruptible(&dev
->bus_mutex
);
507 memset(info
->rom
, 0, sizeof(info
->rom
));
509 while (max_trying
--) {
514 if (!w1_reset_select_slave(sl
)) {
516 unsigned int tm
= 750;
517 unsigned long sleep_rem
;
519 w1_write_8(dev
, W1_READ_PSUPPLY
);
520 external_power
= w1_read_8(dev
);
522 if (w1_reset_select_slave(sl
))
525 /* 750ms strong pullup (or delay) after the convert */
526 if (w1_strong_pullup
== 2 ||
527 (!external_power
&& w1_strong_pullup
))
528 w1_next_pullup(dev
, tm
);
530 w1_write_8(dev
, W1_CONVERT_TEMP
);
532 if (external_power
) {
533 mutex_unlock(&dev
->bus_mutex
);
535 sleep_rem
= msleep_interruptible(tm
);
536 if (sleep_rem
!= 0) {
541 ret
= mutex_lock_interruptible(&dev
->bus_mutex
);
544 } else if (!w1_strong_pullup
) {
545 sleep_rem
= msleep_interruptible(tm
);
546 if (sleep_rem
!= 0) {
552 if (!w1_reset_select_slave(sl
)) {
554 w1_write_8(dev
, W1_READ_SCRATCHPAD
);
555 count
= w1_read_block(dev
, info
->rom
, 9);
557 dev_warn(device
, "w1_read_block() "
558 "returned %u instead of 9.\n",
562 info
->crc
= w1_calc_crc8(info
->rom
, 8);
564 if (info
->rom
[8] == info
->crc
)
574 mutex_unlock(&dev
->bus_mutex
);
576 atomic_dec(THERM_REFCNT(family_data
));
581 static ssize_t
w1_slave_show(struct device
*device
,
582 struct device_attribute
*attr
, char *buf
)
584 struct w1_slave
*sl
= dev_to_w1_slave(device
);
585 struct therm_info info
;
586 u8
*family_data
= sl
->family_data
;
588 ssize_t c
= PAGE_SIZE
;
589 u8 fid
= sl
->family
->fid
;
591 ret
= read_therm(device
, sl
, &info
);
595 for (i
= 0; i
< 9; ++i
)
596 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%02x ", info
.rom
[i
]);
597 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, ": crc=%02x %s\n",
598 info
.crc
, (info
.verdict
) ? "YES" : "NO");
600 memcpy(family_data
, info
.rom
, sizeof(info
.rom
));
602 dev_warn(device
, "Read failed CRC check\n");
604 for (i
= 0; i
< 9; ++i
)
605 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%02x ",
606 ((u8
*)family_data
)[i
]);
608 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "t=%d\n",
609 w1_convert_temp(info
.rom
, fid
));
614 #if IS_REACHABLE(CONFIG_HWMON)
615 static int w1_read_temp(struct device
*device
, u32 attr
, int channel
,
618 struct w1_slave
*sl
= dev_get_drvdata(device
);
619 struct therm_info info
;
620 u8 fid
= sl
->family
->fid
;
624 case hwmon_temp_input
:
625 ret
= read_therm(device
, sl
, &info
);
634 *val
= w1_convert_temp(info
.rom
, fid
);
646 #define W1_42_CHAIN 0x99
647 #define W1_42_CHAIN_OFF 0x3C
648 #define W1_42_CHAIN_OFF_INV 0xC3
649 #define W1_42_CHAIN_ON 0x5A
650 #define W1_42_CHAIN_ON_INV 0xA5
651 #define W1_42_CHAIN_DONE 0x96
652 #define W1_42_CHAIN_DONE_INV 0x69
653 #define W1_42_COND_READ 0x0F
654 #define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
655 #define W1_42_FINISHED_BYTE 0xFF
656 static ssize_t
w1_seq_show(struct device
*device
,
657 struct device_attribute
*attr
, char *buf
)
659 struct w1_slave
*sl
= dev_to_w1_slave(device
);
660 ssize_t c
= PAGE_SIZE
;
665 struct w1_reg_num
*reg_num
;
668 mutex_lock(&sl
->master
->bus_mutex
);
669 /* Place all devices in CHAIN state */
670 if (w1_reset_bus(sl
->master
))
672 w1_write_8(sl
->master
, W1_SKIP_ROM
);
673 w1_write_8(sl
->master
, W1_42_CHAIN
);
674 w1_write_8(sl
->master
, W1_42_CHAIN_ON
);
675 w1_write_8(sl
->master
, W1_42_CHAIN_ON_INV
);
676 msleep(sl
->master
->pullup_duration
);
678 /* check for acknowledgment */
679 ack
= w1_read_8(sl
->master
);
680 if (ack
!= W1_42_SUCCESS_CONFIRM_BYTE
)
683 /* In case the bus fails to send 0xFF, limit*/
684 for (i
= 0; i
<= 64; i
++) {
685 if (w1_reset_bus(sl
->master
))
688 w1_write_8(sl
->master
, W1_42_COND_READ
);
689 rv
= w1_read_block(sl
->master
, (u8
*)&rn
, 8);
690 reg_num
= (struct w1_reg_num
*) &rn
;
691 if (reg_num
->family
== W1_42_FINISHED_BYTE
)
693 if (sl
->reg_num
.id
== reg_num
->id
)
696 w1_write_8(sl
->master
, W1_42_CHAIN
);
697 w1_write_8(sl
->master
, W1_42_CHAIN_DONE
);
698 w1_write_8(sl
->master
, W1_42_CHAIN_DONE_INV
);
699 w1_read_block(sl
->master
, &ack
, sizeof(ack
));
701 /* check for acknowledgment */
702 ack
= w1_read_8(sl
->master
);
703 if (ack
!= W1_42_SUCCESS_CONFIRM_BYTE
)
708 /* Exit from CHAIN state */
709 if (w1_reset_bus(sl
->master
))
711 w1_write_8(sl
->master
, W1_SKIP_ROM
);
712 w1_write_8(sl
->master
, W1_42_CHAIN
);
713 w1_write_8(sl
->master
, W1_42_CHAIN_OFF
);
714 w1_write_8(sl
->master
, W1_42_CHAIN_OFF_INV
);
716 /* check for acknowledgment */
717 ack
= w1_read_8(sl
->master
);
718 if (ack
!= W1_42_SUCCESS_CONFIRM_BYTE
)
720 mutex_unlock(&sl
->master
->bus_mutex
);
722 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%d\n", seq
);
723 return PAGE_SIZE
- c
;
725 mutex_unlock(&sl
->master
->bus_mutex
);
729 static int __init
w1_therm_init(void)
733 for (i
= 0; i
< ARRAY_SIZE(w1_therm_families
); ++i
) {
734 err
= w1_register_family(w1_therm_families
[i
].f
);
736 w1_therm_families
[i
].broken
= 1;
742 static void __exit
w1_therm_fini(void)
746 for (i
= 0; i
< ARRAY_SIZE(w1_therm_families
); ++i
)
747 if (!w1_therm_families
[i
].broken
)
748 w1_unregister_family(w1_therm_families
[i
].f
);
751 module_init(w1_therm_init
);
752 module_exit(w1_therm_fini
);
754 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
755 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
756 MODULE_LICENSE("GPL");
757 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18S20
));
758 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1822
));
759 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS18B20
));
760 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS1825
));
761 MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00
));