1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	ds2490.c  USB to one wire bridge
4 *
5 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
6 */
7
8#include <linux/module.h>
9#include <linux/kernel.h>
10#include <linux/mod_devicetable.h>
11#include <linux/usb.h>
12#include <linux/slab.h>
13
14#include <linux/w1.h>
15
16/* USB Standard */
17/* USB Control request vendor type */
18#define VENDOR				0x40
19
20/* COMMAND TYPE CODES */
21#define CONTROL_CMD			0x00
22#define COMM_CMD			0x01
23#define MODE_CMD			0x02
24
25/* CONTROL COMMAND CODES */
26#define CTL_RESET_DEVICE		0x0000
27#define CTL_START_EXE			0x0001
28#define CTL_RESUME_EXE			0x0002
29#define CTL_HALT_EXE_IDLE		0x0003
30#define CTL_HALT_EXE_DONE		0x0004
31#define CTL_FLUSH_COMM_CMDS		0x0007
32#define CTL_FLUSH_RCV_BUFFER		0x0008
33#define CTL_FLUSH_XMT_BUFFER		0x0009
34#define CTL_GET_COMM_CMDS		0x000A
35
36/* MODE COMMAND CODES */
37#define MOD_PULSE_EN			0x0000
38#define MOD_SPEED_CHANGE_EN		0x0001
39#define MOD_1WIRE_SPEED			0x0002
40#define MOD_STRONG_PU_DURATION		0x0003
41#define MOD_PULLDOWN_SLEWRATE		0x0004
42#define MOD_PROG_PULSE_DURATION		0x0005
43#define MOD_WRITE1_LOWTIME		0x0006
44#define MOD_DSOW0_TREC			0x0007
45
46/* COMMUNICATION COMMAND CODES */
47#define COMM_ERROR_ESCAPE		0x0601
48#define COMM_SET_DURATION		0x0012
49#define COMM_BIT_IO			0x0020
50#define COMM_PULSE			0x0030
51#define COMM_1_WIRE_RESET		0x0042
52#define COMM_BYTE_IO			0x0052
53#define COMM_MATCH_ACCESS		0x0064
54#define COMM_BLOCK_IO			0x0074
55#define COMM_READ_STRAIGHT		0x0080
56#define COMM_DO_RELEASE			0x6092
57#define COMM_SET_PATH			0x00A2
58#define COMM_WRITE_SRAM_PAGE		0x00B2
59#define COMM_WRITE_EPROM		0x00C4
60#define COMM_READ_CRC_PROT_PAGE		0x00D4
61#define COMM_READ_REDIRECT_PAGE_CRC	0x21E4
62#define COMM_SEARCH_ACCESS		0x00F4
63
64/* Communication command bits */
65#define COMM_TYPE			0x0008
66#define COMM_SE				0x0008
67#define COMM_D				0x0008
68#define COMM_Z				0x0008
69#define COMM_CH				0x0008
70#define COMM_SM				0x0008
71#define COMM_R				0x0008
72#define COMM_IM				0x0001
73
74#define COMM_PS				0x4000
75#define COMM_PST			0x4000
76#define COMM_CIB			0x4000
77#define COMM_RTS			0x4000
78#define COMM_DT				0x2000
79#define COMM_SPU			0x1000
80#define COMM_F				0x0800
81#define COMM_NTF			0x0400
82#define COMM_ICP			0x0200
83#define COMM_RST			0x0100
84
85#define PULSE_PROG			0x01
86#define PULSE_SPUE			0x02
87
88#define BRANCH_MAIN			0xCC
89#define BRANCH_AUX			0x33
90
91/* Status flags */
92#define ST_SPUA				0x01  /* Strong Pull-up is active */
93#define ST_PRGA				0x02  /* 12V programming pulse is being generated */
94#define ST_12VP				0x04  /* external 12V programming voltage is present */
95#define ST_PMOD				0x08  /* DS2490 powered from USB and external sources */
96#define ST_HALT				0x10  /* DS2490 is currently halted */
97#define ST_IDLE				0x20  /* DS2490 is currently idle */
98#define ST_EPOF				0x80
99/* Status transfer size, 16 bytes status, 16 byte result flags */
100#define ST_SIZE				0x20
101
102/* Result Register flags */
103#define RR_DETECT			0xA5 /* New device detected */
104#define RR_NRS				0x01 /* Reset no presence or ... */
105#define RR_SH				0x02 /* short on reset or set path */
106#define RR_APP				0x04 /* alarming presence on reset */
107#define RR_VPP				0x08 /* 12V expected not seen */
108#define RR_CMP				0x10 /* compare error */
109#define RR_CRC				0x20 /* CRC error detected */
110#define RR_RDP				0x40 /* redirected page */
111#define RR_EOS				0x80 /* end of search error */
112
113#define SPEED_NORMAL			0x00
114#define SPEED_FLEXIBLE			0x01
115#define SPEED_OVERDRIVE			0x02
116
117#define NUM_EP				4
118#define EP_CONTROL			0
119#define EP_STATUS			1
120#define EP_DATA_OUT			2
121#define EP_DATA_IN			3
122
123struct ds_device {
124	struct list_head	ds_entry;
125
126	struct usb_device	*udev;
127	struct usb_interface	*intf;
128
129	int			ep[NUM_EP];
130
131	/* Strong PullUp
132	 * 0: pullup not active, else duration in milliseconds
133	 */
134	int			spu_sleep;
135	/* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
136	 * should be active or not for writes.
137	 */
138	u16			spu_bit;
139
140	u8			st_buf[ST_SIZE];
141	u8			byte_buf;
142
143	struct w1_bus_master	master;
144};
145
146struct ds_status {
147	u8			enable;
148	u8			speed;
149	u8			pullup_dur;
150	u8			ppuls_dur;
151	u8			pulldown_slew;
152	u8			write1_time;
153	u8			write0_time;
154	u8			reserved0;
155	u8			status;
156	u8			command0;
157	u8			command1;
158	u8			command_buffer_status;
159	u8			data_out_buffer_status;
160	u8			data_in_buffer_status;
161	u8			reserved1;
162	u8			reserved2;
163};
164
165static LIST_HEAD(ds_devices);
166static DEFINE_MUTEX(ds_mutex);
167
168static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
169{
170	int err;
171
172	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
173			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
174	if (err < 0) {
175		dev_err(&dev->udev->dev,
176			"Failed to send command control message %x.%x: err=%d.\n",
177			value, index, err);
178		return err;
179	}
180
181	return err;
182}
183
184static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
185{
186	int err;
187
188	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
189			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
190	if (err < 0) {
191		dev_err(&dev->udev->dev,
192			"Failed to send mode control message %x.%x: err=%d.\n",
193			value, index, err);
194		return err;
195	}
196
197	return err;
198}
199
200static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
201{
202	int err;
203
204	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
205			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
206	if (err < 0) {
207		dev_err(&dev->udev->dev,
208			"Failed to send control message %x.%x: err=%d.\n",
209			value, index, err);
210		return err;
211	}
212
213	return err;
214}
215
216static void ds_dump_status(struct ds_device *ds_dev, unsigned char *buf, int count)
217{
218	struct device *dev = &ds_dev->udev->dev;
219	int i;
220
221	dev_info(dev, "ep_status=0x%x, count=%d, status=%*phC",
222		ds_dev->ep[EP_STATUS], count, count, buf);
223
224	if (count >= 16) {
225		dev_dbg(dev, "enable flag: 0x%02x", buf[0]);
226		dev_dbg(dev, "1-wire speed: 0x%02x", buf[1]);
227		dev_dbg(dev, "strong pullup duration: 0x%02x", buf[2]);
228		dev_dbg(dev, "programming pulse duration: 0x%02x", buf[3]);
229		dev_dbg(dev, "pulldown slew rate control: 0x%02x", buf[4]);
230		dev_dbg(dev, "write-1 low time: 0x%02x", buf[5]);
231		dev_dbg(dev, "data sample offset/write-0 recovery time: 0x%02x", buf[6]);
232		dev_dbg(dev, "reserved (test register): 0x%02x", buf[7]);
233		dev_dbg(dev, "device status flags: 0x%02x", buf[8]);
234		dev_dbg(dev, "communication command byte 1: 0x%02x", buf[9]);
235		dev_dbg(dev, "communication command byte 2: 0x%02x", buf[10]);
236		dev_dbg(dev, "communication command buffer status: 0x%02x", buf[11]);
237		dev_dbg(dev, "1-wire data output buffer status: 0x%02x", buf[12]);
238		dev_dbg(dev, "1-wire data input buffer status: 0x%02x", buf[13]);
239		dev_dbg(dev, "reserved: 0x%02x", buf[14]);
240		dev_dbg(dev, "reserved: 0x%02x", buf[15]);
241	}
242
243	for (i = 16; i < count; ++i) {
244		if (buf[i] == RR_DETECT) {
245			dev_dbg(dev, "New device detect.\n");
246			continue;
247		}
248		dev_dbg(dev, "Result Register Value: 0x%02x", buf[i]);
249		if (buf[i] & RR_NRS)
250			dev_dbg(dev, "NRS: Reset no presence or ...\n");
251		if (buf[i] & RR_SH)
252			dev_dbg(dev, "SH: short on reset or set path\n");
253		if (buf[i] & RR_APP)
254			dev_dbg(dev, "APP: alarming presence on reset\n");
255		if (buf[i] & RR_VPP)
256			dev_dbg(dev, "VPP: 12V expected not seen\n");
257		if (buf[i] & RR_CMP)
258			dev_dbg(dev, "CMP: compare error\n");
259		if (buf[i] & RR_CRC)
260			dev_dbg(dev, "CRC: CRC error detected\n");
261		if (buf[i] & RR_RDP)
262			dev_dbg(dev, "RDP: redirected page\n");
263		if (buf[i] & RR_EOS)
264			dev_dbg(dev, "EOS: end of search error\n");
265	}
266}
267
268static int ds_recv_status(struct ds_device *dev, struct ds_status *st)
269{
270	int count, err;
271
272	if (st)
273		memset(st, 0, sizeof(*st));
274
275	count = 0;
276	err = usb_interrupt_msg(dev->udev,
277				usb_rcvintpipe(dev->udev,
278					       dev->ep[EP_STATUS]),
279				dev->st_buf, sizeof(dev->st_buf),
280				&count, 1000);
281	if (err < 0) {
282		dev_err(&dev->udev->dev,
283			"Failed to read 1-wire data from 0x%x: err=%d.\n",
284			dev->ep[EP_STATUS], err);
285		return err;
286	}
287
288	if (st && count >= sizeof(*st))
289		memcpy(st, dev->st_buf, sizeof(*st));
290
291	return count;
292}
293
294static void ds_reset_device(struct ds_device *dev)
295{
296	ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
297	/* Always allow strong pullup which allow individual writes to use
298	 * the strong pullup.
299	 */
300	if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
301		dev_err(&dev->udev->dev,
302			"%s: Error allowing strong pullup\n", __func__);
303	/* Chip strong pullup time was cleared. */
304	if (dev->spu_sleep) {
305		/* lower 4 bits are 0, see ds_set_pullup */
306		u8 del = dev->spu_sleep>>4;
307
308		if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
309			dev_err(&dev->udev->dev,
310				"%s: Error setting duration\n", __func__);
311	}
312}
313
314static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
315{
316	int count, err;
317
318	/* Careful on size.  If size is less than what is available in
319	 * the input buffer, the device fails the bulk transfer and
320	 * clears the input buffer.  It could read the maximum size of
321	 * the data buffer, but then do you return the first, last, or
322	 * some set of the middle size bytes?  As long as the rest of
323	 * the code is correct there will be size bytes waiting.  A
324	 * call to ds_wait_status will wait until the device is idle
325	 * and any data to be received would have been available.
326	 */
327	count = 0;
328	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
329				buf, size, &count, 1000);
330	if (err < 0) {
331		int recv_len;
332
333		dev_info(&dev->udev->dev, "Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
334		usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
335
336		/* status might tell us why endpoint is stuck? */
337		recv_len = ds_recv_status(dev, NULL);
338		if (recv_len >= 0)
339			ds_dump_status(dev, dev->st_buf, recv_len);
340
341		return err;
342	}
343
344#if 0
345	{
346		int i;
347
348		printk("%s: count=%d: ", __func__, count);
349		for (i = 0; i < count; ++i)
350			printk("%02x ", buf[i]);
351		printk("\n");
352	}
353#endif
354	return count;
355}
356
357static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
358{
359	int count, err;
360
361	count = 0;
362	err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
363	if (err < 0) {
364		dev_err(&dev->udev->dev, "Failed to write 1-wire data to ep0x%x: "
365			"err=%d.\n", dev->ep[EP_DATA_OUT], err);
366		return err;
367	}
368
369	return err;
370}
371
372#if 0
373
374int ds_stop_pulse(struct ds_device *dev, int limit)
375{
376	struct ds_status st;
377	int count = 0, err = 0;
378
379	do {
380		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
381		if (err)
382			break;
383		err = ds_send_control(dev, CTL_RESUME_EXE, 0);
384		if (err)
385			break;
386		err = ds_recv_status(dev, &st);
387		if (err)
388			break;
389
390		if ((st.status & ST_SPUA) == 0) {
391			err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
392			if (err)
393				break;
394		}
395	} while (++count < limit);
396
397	return err;
398}
399
400int ds_detect(struct ds_device *dev, struct ds_status *st)
401{
402	int err;
403
404	err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
405	if (err)
406		return err;
407
408	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
409	if (err)
410		return err;
411
412	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
413	if (err)
414		return err;
415
416	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
417	if (err)
418		return err;
419
420	err = ds_dump_status(dev, st);
421
422	return err;
423}
424
425#endif  /*  0  */
426
427static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
428{
429	int err, count = 0;
430
431	do {
432		st->status = 0;
433		err = ds_recv_status(dev, st);
434#if 0
435		if (err >= 0) {
436			int i;
437			printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
438			for (i = 0; i < err; ++i)
439				printk("%02x ", dev->st_buf[i]);
440			printk("\n");
441		}
442#endif
443	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
444
445	if (err >= 16 && st->status & ST_EPOF) {
446		dev_info(&dev->udev->dev, "Resetting device after ST_EPOF.\n");
447		ds_reset_device(dev);
448		/* Always dump the device status. */
449		count = 101;
450	}
451
452	/* Dump the status for errors or if there is extended return data.
453	 * The extended status includes new device detection (maybe someone
454	 * can do something with it).
455	 */
456	if (err > 16 || count >= 100 || err < 0)
457		ds_dump_status(dev, dev->st_buf, err);
458
459	/* Extended data isn't an error.  Well, a short is, but the dump
460	 * would have already told the user that and we can't do anything
461	 * about it in software anyway.
462	 */
463	if (count >= 100 || err < 0)
464		return -1;
465	else
466		return 0;
467}
468
469static int ds_reset(struct ds_device *dev)
470{
471	int err;
472
473	/* Other potentionally interesting flags for reset.
474	 *
475	 * COMM_NTF: Return result register feedback.  This could be used to
476	 * detect some conditions such as short, alarming presence, or
477	 * detect if a new device was detected.
478	 *
479	 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
480	 * Select the data transfer rate.
481	 */
482	err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
483	if (err)
484		return err;
485
486	return 0;
487}
488
489#if 0
490static int ds_set_speed(struct ds_device *dev, int speed)
491{
492	int err;
493
494	if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
495		return -EINVAL;
496
497	if (speed != SPEED_OVERDRIVE)
498		speed = SPEED_FLEXIBLE;
499
500	speed &= 0xff;
501
502	err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
503	if (err)
504		return err;
505
506	return err;
507}
508#endif  /*  0  */
509
510static int ds_set_pullup(struct ds_device *dev, int delay)
511{
512	int err = 0;
513	u8 del = 1 + (u8)(delay >> 4);
514	/* Just storing delay would not get the trunication and roundup. */
515	int ms = del<<4;
516
517	/* Enable spu_bit if a delay is set. */
518	dev->spu_bit = delay ? COMM_SPU : 0;
519	/* If delay is zero, it has already been disabled, if the time is
520	 * the same as the hardware was last programmed to, there is also
521	 * nothing more to do.  Compare with the recalculated value ms
522	 * rather than del or delay which can have a different value.
523	 */
524	if (delay == 0 || ms == dev->spu_sleep)
525		return err;
526
527	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
528	if (err)
529		return err;
530
531	dev->spu_sleep = ms;
532
533	return err;
534}
535
536static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
537{
538	int err;
539	struct ds_status st;
540
541	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
542		0);
543	if (err)
544		return err;
545
546	ds_wait_status(dev, &st);
547
548	err = ds_recv_data(dev, tbit, sizeof(*tbit));
549	if (err < 0)
550		return err;
551
552	return 0;
553}
554
555#if 0
556static int ds_write_bit(struct ds_device *dev, u8 bit)
557{
558	int err;
559	struct ds_status st;
560
561	/* Set COMM_ICP to write without a readback.  Note, this will
562	 * produce one time slot, a down followed by an up with COMM_D
563	 * only determing the timing.
564	 */
565	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
566		(bit ? COMM_D : 0), 0);
567	if (err)
568		return err;
569
570	ds_wait_status(dev, &st);
571
572	return 0;
573}
574#endif
575
576static int ds_write_byte(struct ds_device *dev, u8 byte)
577{
578	int err;
579	struct ds_status st;
580
581	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
582	if (err)
583		return err;
584
585	if (dev->spu_bit)
586		msleep(dev->spu_sleep);
587
588	err = ds_wait_status(dev, &st);
589	if (err)
590		return err;
591
592	err = ds_recv_data(dev, &dev->byte_buf, 1);
593	if (err < 0)
594		return err;
595
596	return !(byte == dev->byte_buf);
597}
598
599static int ds_read_byte(struct ds_device *dev, u8 *byte)
600{
601	int err;
602	struct ds_status st;
603
604	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM, 0xff);
605	if (err)
606		return err;
607
608	ds_wait_status(dev, &st);
609
610	err = ds_recv_data(dev, byte, sizeof(*byte));
611	if (err < 0)
612		return err;
613
614	return 0;
615}
616
617static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
618{
619	struct ds_status st;
620	int err;
621
622	if (len > 64*1024)
623		return -E2BIG;
624
625	memset(buf, 0xFF, len);
626
627	err = ds_send_data(dev, buf, len);
628	if (err < 0)
629		return err;
630
631	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
632	if (err)
633		return err;
634
635	ds_wait_status(dev, &st);
636
637	memset(buf, 0x00, len);
638	err = ds_recv_data(dev, buf, len);
639
640	return err;
641}
642
643static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
644{
645	int err;
646	struct ds_status st;
647
648	err = ds_send_data(dev, buf, len);
649	if (err < 0)
650		return err;
651
652	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
653	if (err)
654		return err;
655
656	if (dev->spu_bit)
657		msleep(dev->spu_sleep);
658
659	ds_wait_status(dev, &st);
660
661	err = ds_recv_data(dev, buf, len);
662	if (err < 0)
663		return err;
664
665	return !(err == len);
666}
667
668static void ds9490r_search(void *data, struct w1_master *master,
669	u8 search_type, w1_slave_found_callback callback)
670{
671	/* When starting with an existing id, the first id returned will
672	 * be that device (if it is still on the bus most likely).
673	 *
674	 * If the number of devices found is less than or equal to the
675	 * search_limit, that number of IDs will be returned.  If there are
676	 * more, search_limit IDs will be returned followed by a non-zero
677	 * discrepency value.
678	 */
679	struct ds_device *dev = data;
680	int err;
681	u16 value, index;
682	struct ds_status st;
683	int search_limit;
684	int found = 0;
685	int i;
686
687	/* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
688	 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
689	 */
690	const unsigned long jtime = msecs_to_jiffies(1000*8/75);
691	/* FIFO 128 bytes, bulk packet size 64, read a multiple of the
692	 * packet size.
693	 */
694	const size_t bufsize = 2 * 64;
695	u64 *buf, *found_ids;
696
697	buf = kmalloc(bufsize, GFP_KERNEL);
698	if (!buf)
699		return;
700
701	/*
702	 * We are holding the bus mutex during the scan, but adding devices via the
703	 * callback needs the bus to be unlocked. So we queue up found ids here.
704	 */
705	found_ids = kmalloc_array(master->max_slave_count, sizeof(u64), GFP_KERNEL);
706	if (!found_ids) {
707		kfree(buf);
708		return;
709	}
710
711	mutex_lock(&master->bus_mutex);
712
713	/* address to start searching at */
714	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
715		goto search_out;
716	master->search_id = 0;
717
718	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
719		COMM_RTS;
720	search_limit = master->max_slave_count;
721	if (search_limit > 255)
722		search_limit = 0;
723	index = search_type | (search_limit << 8);
724	if (ds_send_control(dev, value, index) < 0)
725		goto search_out;
726
727	do {
728		schedule_timeout(jtime);
729
730		err = ds_recv_status(dev, &st);
731		if (err < 0 || err < sizeof(st))
732			break;
733
734		if (st.data_in_buffer_status) {
735			/*
736			 * Bulk in can receive partial ids, but when it does
737			 * they fail crc and will be discarded anyway.
738			 * That has only been seen when status in buffer
739			 * is 0 and bulk is read anyway, so don't read
740			 * bulk without first checking if status says there
741			 * is data to read.
742			 */
743			err = ds_recv_data(dev, (u8 *)buf, bufsize);
744			if (err < 0)
745				break;
746			for (i = 0; i < err/8; ++i) {
747				found_ids[found++] = buf[i];
748				/*
749				 * can't know if there will be a discrepancy
750				 * value after until the next id
751				 */
752				if (found == search_limit) {
753					master->search_id = buf[i];
754					break;
755				}
756			}
757		}
758
759		if (test_bit(W1_ABORT_SEARCH, &master->flags))
760			break;
761	} while (!(st.status & (ST_IDLE | ST_HALT)));
762
763	/* only continue the search if some weren't found */
764	if (found <= search_limit) {
765		master->search_id = 0;
766	} else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
767		/*
768		 * Only max_slave_count will be scanned in a search,
769		 * but it will start where it left off next search
770		 * until all ids are identified and then it will start
771		 * over.  A continued search will report the previous
772		 * last id as the first id (provided it is still on the
773		 * bus).
774		 */
775		dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
776			"will continue next search.\n", __func__,
777			master->max_slave_count);
778		set_bit(W1_WARN_MAX_COUNT, &master->flags);
779	}
780
781search_out:
782	mutex_unlock(&master->bus_mutex);
783	kfree(buf);
784
785	for (i = 0; i < found; i++) /* run callback for all queued up IDs */
786		callback(master, found_ids[i]);
787	kfree(found_ids);
788}
789
790#if 0
791/*
792 * FIXME: if this disabled code is ever used in the future all ds_send_data()
793 * calls must be changed to use a DMAable buffer.
794 */
795static int ds_match_access(struct ds_device *dev, u64 init)
796{
797	int err;
798	struct ds_status st;
799
800	err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
801	if (err)
802		return err;
803
804	ds_wait_status(dev, &st);
805
806	err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
807	if (err)
808		return err;
809
810	ds_wait_status(dev, &st);
811
812	return 0;
813}
814
815static int ds_set_path(struct ds_device *dev, u64 init)
816{
817	int err;
818	struct ds_status st;
819	u8 buf[9];
820
821	memcpy(buf, &init, 8);
822	buf[8] = BRANCH_MAIN;
823
824	err = ds_send_data(dev, buf, sizeof(buf));
825	if (err)
826		return err;
827
828	ds_wait_status(dev, &st);
829
830	err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
831	if (err)
832		return err;
833
834	ds_wait_status(dev, &st);
835
836	return 0;
837}
838
839#endif  /*  0  */
840
841static u8 ds9490r_touch_bit(void *data, u8 bit)
842{
843	struct ds_device *dev = data;
844
845	if (ds_touch_bit(dev, bit, &dev->byte_buf))
846		return 0;
847
848	return dev->byte_buf;
849}
850
851#if 0
852static void ds9490r_write_bit(void *data, u8 bit)
853{
854	struct ds_device *dev = data;
855
856	ds_write_bit(dev, bit);
857}
858
859static u8 ds9490r_read_bit(void *data)
860{
861	struct ds_device *dev = data;
862	int err;
863
864	err = ds_touch_bit(dev, 1, &dev->byte_buf);
865	if (err)
866		return 0;
867
868	return dev->byte_buf & 1;
869}
870#endif
871
872static void ds9490r_write_byte(void *data, u8 byte)
873{
874	struct ds_device *dev = data;
875
876	ds_write_byte(dev, byte);
877}
878
879static u8 ds9490r_read_byte(void *data)
880{
881	struct ds_device *dev = data;
882	int err;
883
884	err = ds_read_byte(dev, &dev->byte_buf);
885	if (err)
886		return 0;
887
888	return dev->byte_buf;
889}
890
891static void ds9490r_write_block(void *data, const u8 *buf, int len)
892{
893	struct ds_device *dev = data;
894	u8 *tbuf;
895
896	if (len <= 0)
897		return;
898
899	tbuf = kmemdup(buf, len, GFP_KERNEL);
900	if (!tbuf)
901		return;
902
903	ds_write_block(dev, tbuf, len);
904
905	kfree(tbuf);
906}
907
908static u8 ds9490r_read_block(void *data, u8 *buf, int len)
909{
910	struct ds_device *dev = data;
911	int err;
912	u8 *tbuf;
913
914	if (len <= 0)
915		return 0;
916
917	tbuf = kmalloc(len, GFP_KERNEL);
918	if (!tbuf)
919		return 0;
920
921	err = ds_read_block(dev, tbuf, len);
922	if (err >= 0)
923		memcpy(buf, tbuf, len);
924
925	kfree(tbuf);
926
927	return err >= 0 ? len : 0;
928}
929
930static u8 ds9490r_reset(void *data)
931{
932	struct ds_device *dev = data;
933	int err;
934
935	err = ds_reset(dev);
936	if (err)
937		return 1;
938
939	return 0;
940}
941
942static u8 ds9490r_set_pullup(void *data, int delay)
943{
944	struct ds_device *dev = data;
945
946	if (ds_set_pullup(dev, delay))
947		return 1;
948
949	return 0;
950}
951
952static int ds_w1_init(struct ds_device *dev)
953{
954	memset(&dev->master, 0, sizeof(struct w1_bus_master));
955
956	/* Reset the device as it can be in a bad state.
957	 * This is necessary because a block write will wait for data
958	 * to be placed in the output buffer and block any later
959	 * commands which will keep accumulating and the device will
960	 * not be idle.  Another case is removing the ds2490 module
961	 * while a bus search is in progress, somehow a few commands
962	 * get through, but the input transfers fail leaving data in
963	 * the input buffer.  This will cause the next read to fail
964	 * see the note in ds_recv_data.
965	 */
966	ds_reset_device(dev);
967
968	dev->master.data	= dev;
969	dev->master.touch_bit	= &ds9490r_touch_bit;
970	/* read_bit and write_bit in w1_bus_master are expected to set and
971	 * sample the line level.  For write_bit that means it is expected to
972	 * set it to that value and leave it there.  ds2490 only supports an
973	 * individual time slot at the lowest level.  The requirement from
974	 * pulling the bus state down to reading the state is 15us, something
975	 * that isn't realistic on the USB bus anyway.
976	dev->master.read_bit	= &ds9490r_read_bit;
977	dev->master.write_bit	= &ds9490r_write_bit;
978	*/
979	dev->master.read_byte	= &ds9490r_read_byte;
980	dev->master.write_byte	= &ds9490r_write_byte;
981	dev->master.read_block	= &ds9490r_read_block;
982	dev->master.write_block	= &ds9490r_write_block;
983	dev->master.reset_bus	= &ds9490r_reset;
984	dev->master.set_pullup	= &ds9490r_set_pullup;
985	dev->master.search	= &ds9490r_search;
986
987	return w1_add_master_device(&dev->master);
988}
989
990static void ds_w1_fini(struct ds_device *dev)
991{
992	w1_remove_master_device(&dev->master);
993}
994
995static int ds_probe(struct usb_interface *intf,
996		    const struct usb_device_id *udev_id)
997{
998	struct usb_device *udev = interface_to_usbdev(intf);
999	struct usb_endpoint_descriptor *endpoint;
1000	struct usb_host_interface *iface_desc;
1001	struct ds_device *dev;
1002	int i, err, alt;
1003
1004	dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
1005	if (!dev)
1006		return -ENOMEM;
1007
1008	dev->udev = usb_get_dev(udev);
1009	if (!dev->udev) {
1010		err = -ENOMEM;
1011		goto err_out_free;
1012	}
1013	memset(dev->ep, 0, sizeof(dev->ep));
1014
1015	usb_set_intfdata(intf, dev);
1016
1017	err = usb_reset_configuration(dev->udev);
1018	if (err) {
1019		dev_err(&dev->udev->dev,
1020			"Failed to reset configuration: err=%d.\n", err);
1021		goto err_out_clear;
1022	}
1023
1024	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1025	alt = 3;
1026	err = usb_set_interface(dev->udev,
1027		intf->cur_altsetting->desc.bInterfaceNumber, alt);
1028	if (err) {
1029		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1030			"for %d interface: err=%d.\n", alt,
1031			intf->cur_altsetting->desc.bInterfaceNumber, err);
1032		goto err_out_clear;
1033	}
1034
1035	iface_desc = intf->cur_altsetting;
1036	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1037		dev_err(&dev->udev->dev, "Num endpoints=%d. It is not DS9490R.\n",
1038			iface_desc->desc.bNumEndpoints);
1039		err = -EINVAL;
1040		goto err_out_clear;
1041	}
1042
1043	/*
1044	 * This loop doesn'd show control 0 endpoint,
1045	 * so we will fill only 1-3 endpoints entry.
1046	 */
1047	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1048		endpoint = &iface_desc->endpoint[i].desc;
1049
1050		dev->ep[i+1] = endpoint->bEndpointAddress;
1051#if 0
1052		printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1053			i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1054			(endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1055			endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1056#endif
1057	}
1058
1059	err = ds_w1_init(dev);
1060	if (err)
1061		goto err_out_clear;
1062
1063	mutex_lock(&ds_mutex);
1064	list_add_tail(&dev->ds_entry, &ds_devices);
1065	mutex_unlock(&ds_mutex);
1066
1067	return 0;
1068
1069err_out_clear:
1070	usb_set_intfdata(intf, NULL);
1071	usb_put_dev(dev->udev);
1072err_out_free:
1073	kfree(dev);
1074	return err;
1075}
1076
1077static void ds_disconnect(struct usb_interface *intf)
1078{
1079	struct ds_device *dev;
1080
1081	dev = usb_get_intfdata(intf);
1082	if (!dev)
1083		return;
1084
1085	mutex_lock(&ds_mutex);
1086	list_del(&dev->ds_entry);
1087	mutex_unlock(&ds_mutex);
1088
1089	ds_w1_fini(dev);
1090
1091	usb_set_intfdata(intf, NULL);
1092
1093	usb_put_dev(dev->udev);
1094	kfree(dev);
1095}
1096
1097static const struct usb_device_id ds_id_table[] = {
1098	{ USB_DEVICE(0x04fa, 0x2490) },
1099	{ },
1100};
1101MODULE_DEVICE_TABLE(usb, ds_id_table);
1102
1103static struct usb_driver ds_driver = {
1104	.name =		"DS9490R",
1105	.probe =	ds_probe,
1106	.disconnect =	ds_disconnect,
1107	.id_table =	ds_id_table,
1108};
1109module_usb_driver(ds_driver);
1110
1111MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1112MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1113MODULE_LICENSE("GPL");
1114