1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *	w1_ds28e17.c - w1 family 19 (DS28E17) driver
4 *
5 * Copyright (c) 2016 Jan Kandziora <jjj@gmx.de>
6 */
7
8#include <linux/crc16.h>
9#include <linux/delay.h>
10#include <linux/device.h>
11#include <linux/i2c.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/slab.h>
16#include <linux/types.h>
17#include <linux/uaccess.h>
18
19#define CRC16_INIT 0
20
21#include <linux/w1.h>
22
23#define W1_FAMILY_DS28E17 0x19
24
25/* Module setup. */
26MODULE_LICENSE("GPL v2");
27MODULE_AUTHOR("Jan Kandziora <jjj@gmx.de>");
28MODULE_DESCRIPTION("w1 family 19 driver for DS28E17, 1-wire to I2C master bridge");
29MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS28E17));
30
31
32/* Default I2C speed to be set when a DS28E17 is detected. */
33static int i2c_speed = 100;
34module_param_named(speed, i2c_speed, int, 0600);
35MODULE_PARM_DESC(speed, "Default I2C speed to be set when a DS28E17 is detected");
36
37/* Default I2C stretch value to be set when a DS28E17 is detected. */
38static char i2c_stretch = 1;
39module_param_named(stretch, i2c_stretch, byte, 0600);
40MODULE_PARM_DESC(stretch, "Default I2C stretch value to be set when a DS28E17 is detected");
41
42/* DS28E17 device command codes. */
43#define W1_F19_WRITE_DATA_WITH_STOP      0x4B
44#define W1_F19_WRITE_DATA_NO_STOP        0x5A
45#define W1_F19_WRITE_DATA_ONLY           0x69
46#define W1_F19_WRITE_DATA_ONLY_WITH_STOP 0x78
47#define W1_F19_READ_DATA_WITH_STOP       0x87
48#define W1_F19_WRITE_READ_DATA_WITH_STOP 0x2D
49#define W1_F19_WRITE_CONFIGURATION       0xD2
50#define W1_F19_READ_CONFIGURATION        0xE1
51#define W1_F19_ENABLE_SLEEP_MODE         0x1E
52#define W1_F19_READ_DEVICE_REVISION      0xC4
53
54/* DS28E17 status bits */
55#define W1_F19_STATUS_CRC     0x01
56#define W1_F19_STATUS_ADDRESS 0x02
57#define W1_F19_STATUS_START   0x08
58
59/*
60 * Maximum number of I2C bytes to transfer within one CRC16 protected onewire
61 * command.
62 */
63#define W1_F19_WRITE_DATA_LIMIT 255
64
65/* Maximum number of I2C bytes to read with one onewire command. */
66#define W1_F19_READ_DATA_LIMIT 255
67
68/* Constants for calculating the busy sleep. */
69#define W1_F19_BUSY_TIMEBASES { 90, 23, 10 }
70#define W1_F19_BUSY_GRATUITY  1000
71
72/* Number of checks for the busy flag before timeout. */
73#define W1_F19_BUSY_CHECKS 1000
74
75
76/* Slave specific data. */
77struct w1_f19_data {
78	u8 speed;
79	u8 stretch;
80	struct i2c_adapter adapter;
81};
82
83
84/* Wait a while until the busy flag clears. */
85static int w1_f19_i2c_busy_wait(struct w1_slave *sl, size_t count)
86{
87	const unsigned long timebases[3] = W1_F19_BUSY_TIMEBASES;
88	struct w1_f19_data *data = sl->family_data;
89	unsigned int checks;
90
91	/* Check the busy flag first in any case.*/
92	if (w1_touch_bit(sl->master, 1) == 0)
93		return 0;
94
95	/*
96	 * Do a generously long sleep in the beginning,
97	 * as we have to wait at least this time for all
98	 * the I2C bytes at the given speed to be transferred.
99	 */
100	usleep_range(timebases[data->speed] * (data->stretch) * count,
101		timebases[data->speed] * (data->stretch) * count
102		+ W1_F19_BUSY_GRATUITY);
103
104	/* Now continusly check the busy flag sent by the DS28E17. */
105	checks = W1_F19_BUSY_CHECKS;
106	while ((checks--) > 0) {
107		/* Return success if the busy flag is cleared. */
108		if (w1_touch_bit(sl->master, 1) == 0)
109			return 0;
110
111		/* Wait one non-streched byte timeslot. */
112		udelay(timebases[data->speed]);
113	}
114
115	/* Timeout. */
116	dev_warn(&sl->dev, "busy timeout\n");
117	return -ETIMEDOUT;
118}
119
120
121/* Utility function: result. */
122static size_t w1_f19_error(struct w1_slave *sl, u8 w1_buf[])
123{
124	/* Warnings. */
125	if (w1_buf[0] & W1_F19_STATUS_CRC)
126		dev_warn(&sl->dev, "crc16 mismatch\n");
127	if (w1_buf[0] & W1_F19_STATUS_ADDRESS)
128		dev_warn(&sl->dev, "i2c device not responding\n");
129	if ((w1_buf[0] & (W1_F19_STATUS_CRC | W1_F19_STATUS_ADDRESS)) == 0
130			&& w1_buf[1] != 0) {
131		dev_warn(&sl->dev, "i2c short write, %d bytes not acknowledged\n",
132			w1_buf[1]);
133	}
134
135	/* Check error conditions. */
136	if (w1_buf[0] & W1_F19_STATUS_ADDRESS)
137		return -ENXIO;
138	if (w1_buf[0] & W1_F19_STATUS_START)
139		return -EAGAIN;
140	if (w1_buf[0] != 0 || w1_buf[1] != 0)
141		return -EIO;
142
143	/* All ok. */
144	return 0;
145}
146
147
148/* Utility function: write data to I2C slave, single chunk. */
149static int __w1_f19_i2c_write(struct w1_slave *sl,
150	const u8 *command, size_t command_count,
151	const u8 *buffer, size_t count)
152{
153	u16 crc;
154	int error;
155	u8 w1_buf[2];
156
157	/* Send command and I2C data to DS28E17. */
158	crc = crc16(CRC16_INIT, command, command_count);
159	w1_write_block(sl->master, command, command_count);
160
161	w1_buf[0] = count;
162	crc = crc16(crc, w1_buf, 1);
163	w1_write_8(sl->master, w1_buf[0]);
164
165	crc = crc16(crc, buffer, count);
166	w1_write_block(sl->master, buffer, count);
167
168	w1_buf[0] = ~(crc & 0xFF);
169	w1_buf[1] = ~((crc >> 8) & 0xFF);
170	w1_write_block(sl->master, w1_buf, 2);
171
172	/* Wait until busy flag clears (or timeout). */
173	if (w1_f19_i2c_busy_wait(sl, count + 1) < 0)
174		return -ETIMEDOUT;
175
176	/* Read status from DS28E17. */
177	w1_read_block(sl->master, w1_buf, 2);
178
179	/* Check error conditions. */
180	error = w1_f19_error(sl, w1_buf);
181	if (error < 0)
182		return error;
183
184	/* Return number of bytes written. */
185	return count;
186}
187
188
189/* Write data to I2C slave. */
190static int w1_f19_i2c_write(struct w1_slave *sl, u16 i2c_address,
191	const u8 *buffer, size_t count, bool stop)
192{
193	int result;
194	int remaining = count;
195	const u8 *p;
196	u8 command[2];
197
198	/* Check input. */
199	if (count == 0)
200		return -EOPNOTSUPP;
201
202	/* Check whether we need multiple commands. */
203	if (count <= W1_F19_WRITE_DATA_LIMIT) {
204		/*
205		 * Small data amount. Data can be sent with
206		 * a single onewire command.
207		 */
208
209		/* Send all data to DS28E17. */
210		command[0] = (stop ? W1_F19_WRITE_DATA_WITH_STOP
211			: W1_F19_WRITE_DATA_NO_STOP);
212		command[1] = i2c_address << 1;
213		result = __w1_f19_i2c_write(sl, command, 2, buffer, count);
214	} else {
215		/* Large data amount. Data has to be sent in multiple chunks. */
216
217		/* Send first chunk to DS28E17. */
218		p = buffer;
219		command[0] = W1_F19_WRITE_DATA_NO_STOP;
220		command[1] = i2c_address << 1;
221		result = __w1_f19_i2c_write(sl, command, 2, p,
222			W1_F19_WRITE_DATA_LIMIT);
223		if (result < 0)
224			return result;
225
226		/* Resume to same DS28E17. */
227		if (w1_reset_resume_command(sl->master))
228			return -EIO;
229
230		/* Next data chunk. */
231		p += W1_F19_WRITE_DATA_LIMIT;
232		remaining -= W1_F19_WRITE_DATA_LIMIT;
233
234		while (remaining > W1_F19_WRITE_DATA_LIMIT) {
235			/* Send intermediate chunk to DS28E17. */
236			command[0] = W1_F19_WRITE_DATA_ONLY;
237			result = __w1_f19_i2c_write(sl, command, 1, p,
238					W1_F19_WRITE_DATA_LIMIT);
239			if (result < 0)
240				return result;
241
242			/* Resume to same DS28E17. */
243			if (w1_reset_resume_command(sl->master))
244				return -EIO;
245
246			/* Next data chunk. */
247			p += W1_F19_WRITE_DATA_LIMIT;
248			remaining -= W1_F19_WRITE_DATA_LIMIT;
249		}
250
251		/* Send final chunk to DS28E17. */
252		command[0] = (stop ? W1_F19_WRITE_DATA_ONLY_WITH_STOP
253			: W1_F19_WRITE_DATA_ONLY);
254		result = __w1_f19_i2c_write(sl, command, 1, p, remaining);
255	}
256
257	return result;
258}
259
260
261/* Read data from I2C slave. */
262static int w1_f19_i2c_read(struct w1_slave *sl, u16 i2c_address,
263	u8 *buffer, size_t count)
264{
265	u16 crc;
266	int error;
267	u8 w1_buf[5];
268
269	/* Check input. */
270	if (count == 0)
271		return -EOPNOTSUPP;
272
273	/* Send command to DS28E17. */
274	w1_buf[0] = W1_F19_READ_DATA_WITH_STOP;
275	w1_buf[1] = i2c_address << 1 | 0x01;
276	w1_buf[2] = count;
277	crc = crc16(CRC16_INIT, w1_buf, 3);
278	w1_buf[3] = ~(crc & 0xFF);
279	w1_buf[4] = ~((crc >> 8) & 0xFF);
280	w1_write_block(sl->master, w1_buf, 5);
281
282	/* Wait until busy flag clears (or timeout). */
283	if (w1_f19_i2c_busy_wait(sl, count + 1) < 0)
284		return -ETIMEDOUT;
285
286	/* Read status from DS28E17. */
287	w1_buf[0] = w1_read_8(sl->master);
288	w1_buf[1] = 0;
289
290	/* Check error conditions. */
291	error = w1_f19_error(sl, w1_buf);
292	if (error < 0)
293		return error;
294
295	/* Read received I2C data from DS28E17. */
296	return w1_read_block(sl->master, buffer, count);
297}
298
299
300/* Write to, then read data from I2C slave. */
301static int w1_f19_i2c_write_read(struct w1_slave *sl, u16 i2c_address,
302	const u8 *wbuffer, size_t wcount, u8 *rbuffer, size_t rcount)
303{
304	u16 crc;
305	int error;
306	u8 w1_buf[3];
307
308	/* Check input. */
309	if (wcount == 0 || rcount == 0)
310		return -EOPNOTSUPP;
311
312	/* Send command and I2C data to DS28E17. */
313	w1_buf[0] = W1_F19_WRITE_READ_DATA_WITH_STOP;
314	w1_buf[1] = i2c_address << 1;
315	w1_buf[2] = wcount;
316	crc = crc16(CRC16_INIT, w1_buf, 3);
317	w1_write_block(sl->master, w1_buf, 3);
318
319	crc = crc16(crc, wbuffer, wcount);
320	w1_write_block(sl->master, wbuffer, wcount);
321
322	w1_buf[0] = rcount;
323	crc = crc16(crc, w1_buf, 1);
324	w1_buf[1] = ~(crc & 0xFF);
325	w1_buf[2] = ~((crc >> 8) & 0xFF);
326	w1_write_block(sl->master, w1_buf, 3);
327
328	/* Wait until busy flag clears (or timeout). */
329	if (w1_f19_i2c_busy_wait(sl, wcount + rcount + 2) < 0)
330		return -ETIMEDOUT;
331
332	/* Read status from DS28E17. */
333	w1_read_block(sl->master, w1_buf, 2);
334
335	/* Check error conditions. */
336	error = w1_f19_error(sl, w1_buf);
337	if (error < 0)
338		return error;
339
340	/* Read received I2C data from DS28E17. */
341	return w1_read_block(sl->master, rbuffer, rcount);
342}
343
344
345/* Do an I2C master transfer. */
346static int w1_f19_i2c_master_transfer(struct i2c_adapter *adapter,
347	struct i2c_msg *msgs, int num)
348{
349	struct w1_slave *sl = (struct w1_slave *) adapter->algo_data;
350	int i = 0;
351	int result = 0;
352
353	/* Start onewire transaction. */
354	mutex_lock(&sl->master->bus_mutex);
355
356	/* Select DS28E17. */
357	if (w1_reset_select_slave(sl)) {
358		i = -EIO;
359		goto error;
360	}
361
362	/* Loop while there are still messages to transfer. */
363	while (i < num) {
364		/*
365		 * Check for special case: Small write followed
366		 * by read to same I2C device.
367		 */
368		if (i < (num-1)
369			&& msgs[i].addr == msgs[i+1].addr
370			&& !(msgs[i].flags & I2C_M_RD)
371			&& (msgs[i+1].flags & I2C_M_RD)
372			&& (msgs[i].len <= W1_F19_WRITE_DATA_LIMIT)) {
373			/*
374			 * The DS28E17 has a combined transfer
375			 * for small write+read.
376			 */
377			result = w1_f19_i2c_write_read(sl, msgs[i].addr,
378				msgs[i].buf, msgs[i].len,
379				msgs[i+1].buf, msgs[i+1].len);
380			if (result < 0) {
381				i = result;
382				goto error;
383			}
384
385			/*
386			 * Check if we should interpret the read data
387			 * as a length byte. The DS28E17 unfortunately
388			 * has no read without stop, so we can just do
389			 * another simple read in that case.
390			 */
391			if (msgs[i+1].flags & I2C_M_RECV_LEN) {
392				result = w1_f19_i2c_read(sl, msgs[i+1].addr,
393					&(msgs[i+1].buf[1]), msgs[i+1].buf[0]);
394				if (result < 0) {
395					i = result;
396					goto error;
397				}
398			}
399
400			/* Eat up read message, too. */
401			i++;
402		} else if (msgs[i].flags & I2C_M_RD) {
403			/* Read transfer. */
404			result = w1_f19_i2c_read(sl, msgs[i].addr,
405				msgs[i].buf, msgs[i].len);
406			if (result < 0) {
407				i = result;
408				goto error;
409			}
410
411			/*
412			 * Check if we should interpret the read data
413			 * as a length byte. The DS28E17 unfortunately
414			 * has no read without stop, so we can just do
415			 * another simple read in that case.
416			 */
417			if (msgs[i].flags & I2C_M_RECV_LEN) {
418				result = w1_f19_i2c_read(sl,
419					msgs[i].addr,
420					&(msgs[i].buf[1]),
421					msgs[i].buf[0]);
422				if (result < 0) {
423					i = result;
424					goto error;
425				}
426			}
427		} else {
428			/*
429			 * Write transfer.
430			 * Stop condition only for last
431			 * transfer.
432			 */
433			result = w1_f19_i2c_write(sl,
434				msgs[i].addr,
435				msgs[i].buf,
436				msgs[i].len,
437				i == (num-1));
438			if (result < 0) {
439				i = result;
440				goto error;
441			}
442		}
443
444		/* Next message. */
445		i++;
446
447		/* Are there still messages to send/receive? */
448		if (i < num) {
449			/* Yes. Resume to same DS28E17. */
450			if (w1_reset_resume_command(sl->master)) {
451				i = -EIO;
452				goto error;
453			}
454		}
455	}
456
457error:
458	/* End onewire transaction. */
459	mutex_unlock(&sl->master->bus_mutex);
460
461	/* Return number of messages processed or error. */
462	return i;
463}
464
465
466/* Get I2C adapter functionality. */
467static u32 w1_f19_i2c_functionality(struct i2c_adapter *adapter)
468{
469	/*
470	 * Plain I2C functions only.
471	 * SMBus is emulated by the kernel's I2C layer.
472	 * No "I2C_FUNC_SMBUS_QUICK"
473	 * No "I2C_FUNC_SMBUS_READ_BLOCK_DATA"
474	 * No "I2C_FUNC_SMBUS_BLOCK_PROC_CALL"
475	 */
476	return I2C_FUNC_I2C |
477		I2C_FUNC_SMBUS_BYTE |
478		I2C_FUNC_SMBUS_BYTE_DATA |
479		I2C_FUNC_SMBUS_WORD_DATA |
480		I2C_FUNC_SMBUS_PROC_CALL |
481		I2C_FUNC_SMBUS_WRITE_BLOCK_DATA |
482		I2C_FUNC_SMBUS_I2C_BLOCK |
483		I2C_FUNC_SMBUS_PEC;
484}
485
486
487/* I2C adapter quirks. */
488static const struct i2c_adapter_quirks w1_f19_i2c_adapter_quirks = {
489	.max_read_len = W1_F19_READ_DATA_LIMIT,
490};
491
492/* I2C algorithm. */
493static const struct i2c_algorithm w1_f19_i2c_algorithm = {
494	.master_xfer    = w1_f19_i2c_master_transfer,
495	.functionality  = w1_f19_i2c_functionality,
496};
497
498
499/* Read I2C speed from DS28E17. */
500static int w1_f19_get_i2c_speed(struct w1_slave *sl)
501{
502	struct w1_f19_data *data = sl->family_data;
503	int result = -EIO;
504
505	/* Start onewire transaction. */
506	mutex_lock(&sl->master->bus_mutex);
507
508	/* Select slave. */
509	if (w1_reset_select_slave(sl))
510		goto error;
511
512	/* Read slave configuration byte. */
513	w1_write_8(sl->master, W1_F19_READ_CONFIGURATION);
514	result = w1_read_8(sl->master);
515	if (result < 0 || result > 2) {
516		result = -EIO;
517		goto error;
518	}
519
520	/* Update speed in slave specific data. */
521	data->speed = result;
522
523error:
524	/* End onewire transaction. */
525	mutex_unlock(&sl->master->bus_mutex);
526
527	return result;
528}
529
530
531/* Set I2C speed on DS28E17. */
532static int __w1_f19_set_i2c_speed(struct w1_slave *sl, u8 speed)
533{
534	struct w1_f19_data *data = sl->family_data;
535	const int i2c_speeds[3] = { 100, 400, 900 };
536	u8 w1_buf[2];
537
538	/* Select slave. */
539	if (w1_reset_select_slave(sl))
540		return -EIO;
541
542	w1_buf[0] = W1_F19_WRITE_CONFIGURATION;
543	w1_buf[1] = speed;
544	w1_write_block(sl->master, w1_buf, 2);
545
546	/* Update speed in slave specific data. */
547	data->speed = speed;
548
549	dev_info(&sl->dev, "i2c speed set to %d kBaud\n", i2c_speeds[speed]);
550
551	return 0;
552}
553
554static int w1_f19_set_i2c_speed(struct w1_slave *sl, u8 speed)
555{
556	int result;
557
558	/* Start onewire transaction. */
559	mutex_lock(&sl->master->bus_mutex);
560
561	/* Set I2C speed on DS28E17. */
562	result = __w1_f19_set_i2c_speed(sl, speed);
563
564	/* End onewire transaction. */
565	mutex_unlock(&sl->master->bus_mutex);
566
567	return result;
568}
569
570
571/* Sysfs attributes. */
572
573/* I2C speed attribute for a single chip. */
574static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
575			     char *buf)
576{
577	struct w1_slave *sl = dev_to_w1_slave(dev);
578	int result;
579
580	/* Read current speed from slave. Updates data->speed. */
581	result = w1_f19_get_i2c_speed(sl);
582	if (result < 0)
583		return result;
584
585	/* Return current speed value. */
586	return sprintf(buf, "%d\n", result);
587}
588
589static ssize_t speed_store(struct device *dev, struct device_attribute *attr,
590			      const char *buf, size_t count)
591{
592	struct w1_slave *sl = dev_to_w1_slave(dev);
593	int error;
594
595	/* Valid values are: "100", "400", "900" */
596	if (count < 3 || count > 4 || !buf)
597		return -EINVAL;
598	if (count == 4 && buf[3] != '\n')
599		return -EINVAL;
600	if (buf[1] != '0' || buf[2] != '0')
601		return -EINVAL;
602
603	/* Set speed on slave. */
604	switch (buf[0]) {
605	case '1':
606		error = w1_f19_set_i2c_speed(sl, 0);
607		break;
608	case '4':
609		error = w1_f19_set_i2c_speed(sl, 1);
610		break;
611	case '9':
612		error = w1_f19_set_i2c_speed(sl, 2);
613		break;
614	default:
615		return -EINVAL;
616	}
617
618	if (error < 0)
619		return error;
620
621	/* Return bytes written. */
622	return count;
623}
624
625static DEVICE_ATTR_RW(speed);
626
627
628/* Busy stretch attribute for a single chip. */
629static ssize_t stretch_show(struct device *dev, struct device_attribute *attr,
630			     char *buf)
631{
632	struct w1_slave *sl = dev_to_w1_slave(dev);
633	struct w1_f19_data *data = sl->family_data;
634
635	/* Return current stretch value. */
636	return sprintf(buf, "%d\n", data->stretch);
637}
638
639static ssize_t stretch_store(struct device *dev, struct device_attribute *attr,
640			      const char *buf, size_t count)
641{
642	struct w1_slave *sl = dev_to_w1_slave(dev);
643	struct w1_f19_data *data = sl->family_data;
644
645	/* Valid values are '1' to '9' */
646	if (count < 1 || count > 2 || !buf)
647		return -EINVAL;
648	if (count == 2 && buf[1] != '\n')
649		return -EINVAL;
650	if (buf[0] < '1' || buf[0] > '9')
651		return -EINVAL;
652
653	/* Set busy stretch value. */
654	data->stretch = buf[0] & 0x0F;
655
656	/* Return bytes written. */
657	return count;
658}
659
660static DEVICE_ATTR_RW(stretch);
661
662
663/* All attributes. */
664static struct attribute *w1_f19_attrs[] = {
665	&dev_attr_speed.attr,
666	&dev_attr_stretch.attr,
667	NULL,
668};
669
670static const struct attribute_group w1_f19_group = {
671	.attrs		= w1_f19_attrs,
672};
673
674static const struct attribute_group *w1_f19_groups[] = {
675	&w1_f19_group,
676	NULL,
677};
678
679
680/* Slave add and remove functions. */
681static int w1_f19_add_slave(struct w1_slave *sl)
682{
683	struct w1_f19_data *data = NULL;
684
685	/* Allocate memory for slave specific data. */
686	data = devm_kzalloc(&sl->dev, sizeof(*data), GFP_KERNEL);
687	if (!data)
688		return -ENOMEM;
689	sl->family_data = data;
690
691	/* Setup default I2C speed on slave. */
692	switch (i2c_speed) {
693	case 100:
694		__w1_f19_set_i2c_speed(sl, 0);
695		break;
696	case 400:
697		__w1_f19_set_i2c_speed(sl, 1);
698		break;
699	case 900:
700		__w1_f19_set_i2c_speed(sl, 2);
701		break;
702	default:
703		/*
704		 * A i2c_speed module parameter of anything else
705		 * than 100, 400, 900 means not to touch the
706		 * speed of the DS28E17.
707		 * We assume 400kBaud, the power-on value.
708		 */
709		data->speed = 1;
710	}
711
712	/*
713	 * Setup default busy stretch
714	 * configuration for the DS28E17.
715	 */
716	data->stretch = i2c_stretch;
717
718	/* Setup I2C adapter. */
719	data->adapter.owner      = THIS_MODULE;
720	data->adapter.algo       = &w1_f19_i2c_algorithm;
721	data->adapter.algo_data  = sl;
722	strcpy(data->adapter.name, "w1-");
723	strcat(data->adapter.name, sl->name);
724	data->adapter.dev.parent = &sl->dev;
725	data->adapter.quirks     = &w1_f19_i2c_adapter_quirks;
726
727	return i2c_add_adapter(&data->adapter);
728}
729
730static void w1_f19_remove_slave(struct w1_slave *sl)
731{
732	struct w1_f19_data *family_data = sl->family_data;
733
734	/* Delete I2C adapter. */
735	i2c_del_adapter(&family_data->adapter);
736
737	/* Free slave specific data. */
738	devm_kfree(&sl->dev, family_data);
739	sl->family_data = NULL;
740}
741
742
743/* Declarations within the w1 subsystem. */
744static const struct w1_family_ops w1_f19_fops = {
745	.add_slave = w1_f19_add_slave,
746	.remove_slave = w1_f19_remove_slave,
747	.groups = w1_f19_groups,
748};
749
750static struct w1_family w1_family_19 = {
751	.fid = W1_FAMILY_DS28E17,
752	.fops = &w1_f19_fops,
753};
754
755module_w1_family(w1_family_19);
756