xref: /openbmc/linux/drivers/w1/masters/ds2490.c (revision 6c870213d6f3a25981c10728f46294a3bed1703f)
1 /*
2  *	ds2490.c  USB to one wire bridge
3  *
4  * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
5  *
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms 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.
11  *
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.
16  *
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
20  */
21 
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/mod_devicetable.h>
25 #include <linux/usb.h>
26 #include <linux/slab.h>
27 
28 #include "../w1_int.h"
29 #include "../w1.h"
30 
31 /* USB Standard */
32 /* USB Control request vendor type */
33 #define VENDOR				0x40
34 
35 /* COMMAND TYPE CODES */
36 #define CONTROL_CMD			0x00
37 #define COMM_CMD			0x01
38 #define MODE_CMD			0x02
39 
40 /* CONTROL COMMAND CODES */
41 #define CTL_RESET_DEVICE		0x0000
42 #define CTL_START_EXE			0x0001
43 #define CTL_RESUME_EXE			0x0002
44 #define CTL_HALT_EXE_IDLE		0x0003
45 #define CTL_HALT_EXE_DONE		0x0004
46 #define CTL_FLUSH_COMM_CMDS		0x0007
47 #define CTL_FLUSH_RCV_BUFFER		0x0008
48 #define CTL_FLUSH_XMT_BUFFER		0x0009
49 #define CTL_GET_COMM_CMDS		0x000A
50 
51 /* MODE COMMAND CODES */
52 #define MOD_PULSE_EN			0x0000
53 #define MOD_SPEED_CHANGE_EN		0x0001
54 #define MOD_1WIRE_SPEED			0x0002
55 #define MOD_STRONG_PU_DURATION		0x0003
56 #define MOD_PULLDOWN_SLEWRATE		0x0004
57 #define MOD_PROG_PULSE_DURATION		0x0005
58 #define MOD_WRITE1_LOWTIME		0x0006
59 #define MOD_DSOW0_TREC			0x0007
60 
61 /* COMMUNICATION COMMAND CODES */
62 #define COMM_ERROR_ESCAPE		0x0601
63 #define COMM_SET_DURATION		0x0012
64 #define COMM_BIT_IO			0x0020
65 #define COMM_PULSE			0x0030
66 #define COMM_1_WIRE_RESET		0x0042
67 #define COMM_BYTE_IO			0x0052
68 #define COMM_MATCH_ACCESS		0x0064
69 #define COMM_BLOCK_IO			0x0074
70 #define COMM_READ_STRAIGHT		0x0080
71 #define COMM_DO_RELEASE			0x6092
72 #define COMM_SET_PATH			0x00A2
73 #define COMM_WRITE_SRAM_PAGE		0x00B2
74 #define COMM_WRITE_EPROM		0x00C4
75 #define COMM_READ_CRC_PROT_PAGE		0x00D4
76 #define COMM_READ_REDIRECT_PAGE_CRC	0x21E4
77 #define COMM_SEARCH_ACCESS		0x00F4
78 
79 /* Communication command bits */
80 #define COMM_TYPE			0x0008
81 #define COMM_SE				0x0008
82 #define COMM_D				0x0008
83 #define COMM_Z				0x0008
84 #define COMM_CH				0x0008
85 #define COMM_SM				0x0008
86 #define COMM_R				0x0008
87 #define COMM_IM				0x0001
88 
89 #define COMM_PS				0x4000
90 #define COMM_PST			0x4000
91 #define COMM_CIB			0x4000
92 #define COMM_RTS			0x4000
93 #define COMM_DT				0x2000
94 #define COMM_SPU			0x1000
95 #define COMM_F				0x0800
96 #define COMM_NTF			0x0400
97 #define COMM_ICP			0x0200
98 #define COMM_RST			0x0100
99 
100 #define PULSE_PROG			0x01
101 #define PULSE_SPUE			0x02
102 
103 #define BRANCH_MAIN			0xCC
104 #define BRANCH_AUX			0x33
105 
106 /* Status flags */
107 #define ST_SPUA				0x01  /* Strong Pull-up is active */
108 #define ST_PRGA				0x02  /* 12V programming pulse is being generated */
109 #define ST_12VP				0x04  /* external 12V programming voltage is present */
110 #define ST_PMOD				0x08  /* DS2490 powered from USB and external sources */
111 #define ST_HALT				0x10  /* DS2490 is currently halted */
112 #define ST_IDLE				0x20  /* DS2490 is currently idle */
113 #define ST_EPOF				0x80
114 /* Status transfer size, 16 bytes status, 16 byte result flags */
115 #define ST_SIZE				0x20
116 
117 /* Result Register flags */
118 #define RR_DETECT			0xA5 /* New device detected */
119 #define RR_NRS				0x01 /* Reset no presence or ... */
120 #define RR_SH				0x02 /* short on reset or set path */
121 #define RR_APP				0x04 /* alarming presence on reset */
122 #define RR_VPP				0x08 /* 12V expected not seen */
123 #define RR_CMP				0x10 /* compare error */
124 #define RR_CRC				0x20 /* CRC error detected */
125 #define RR_RDP				0x40 /* redirected page */
126 #define RR_EOS				0x80 /* end of search error */
127 
128 #define SPEED_NORMAL			0x00
129 #define SPEED_FLEXIBLE			0x01
130 #define SPEED_OVERDRIVE			0x02
131 
132 #define NUM_EP				4
133 #define EP_CONTROL			0
134 #define EP_STATUS			1
135 #define EP_DATA_OUT			2
136 #define EP_DATA_IN			3
137 
138 struct ds_device
139 {
140 	struct list_head	ds_entry;
141 
142 	struct usb_device	*udev;
143 	struct usb_interface	*intf;
144 
145 	int			ep[NUM_EP];
146 
147 	/* Strong PullUp
148 	 * 0: pullup not active, else duration in milliseconds
149 	 */
150 	int			spu_sleep;
151 	/* spu_bit contains COMM_SPU or 0 depending on if the strong pullup
152 	 * should be active or not for writes.
153 	 */
154 	u16			spu_bit;
155 
156 	struct w1_bus_master	master;
157 };
158 
159 struct ds_status
160 {
161 	u8			enable;
162 	u8			speed;
163 	u8			pullup_dur;
164 	u8			ppuls_dur;
165 	u8			pulldown_slew;
166 	u8			write1_time;
167 	u8			write0_time;
168 	u8			reserved0;
169 	u8			status;
170 	u8			command0;
171 	u8			command1;
172 	u8			command_buffer_status;
173 	u8			data_out_buffer_status;
174 	u8			data_in_buffer_status;
175 	u8			reserved1;
176 	u8			reserved2;
177 
178 };
179 
180 static struct usb_device_id ds_id_table [] = {
181 	{ USB_DEVICE(0x04fa, 0x2490) },
182 	{ },
183 };
184 MODULE_DEVICE_TABLE(usb, ds_id_table);
185 
186 static int ds_probe(struct usb_interface *, const struct usb_device_id *);
187 static void ds_disconnect(struct usb_interface *);
188 
189 static int ds_send_control(struct ds_device *, u16, u16);
190 static int ds_send_control_cmd(struct ds_device *, u16, u16);
191 
192 static LIST_HEAD(ds_devices);
193 static DEFINE_MUTEX(ds_mutex);
194 
195 static struct usb_driver ds_driver = {
196 	.name =		"DS9490R",
197 	.probe =	ds_probe,
198 	.disconnect =	ds_disconnect,
199 	.id_table =	ds_id_table,
200 };
201 
202 static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
203 {
204 	int err;
205 
206 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
207 			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
208 	if (err < 0) {
209 		printk(KERN_ERR "Failed to send command control message %x.%x: err=%d.\n",
210 				value, index, err);
211 		return err;
212 	}
213 
214 	return err;
215 }
216 
217 static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
218 {
219 	int err;
220 
221 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
222 			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
223 	if (err < 0) {
224 		printk(KERN_ERR "Failed to send mode control message %x.%x: err=%d.\n",
225 				value, index, err);
226 		return err;
227 	}
228 
229 	return err;
230 }
231 
232 static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
233 {
234 	int err;
235 
236 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
237 			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
238 	if (err < 0) {
239 		printk(KERN_ERR "Failed to send control message %x.%x: err=%d.\n",
240 				value, index, err);
241 		return err;
242 	}
243 
244 	return err;
245 }
246 
247 static int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
248 				 unsigned char *buf, int size)
249 {
250 	int count, err;
251 
252 	memset(st, 0, sizeof(*st));
253 
254 	count = 0;
255 	err = usb_interrupt_msg(dev->udev, usb_rcvintpipe(dev->udev,
256 		dev->ep[EP_STATUS]), buf, size, &count, 100);
257 	if (err < 0) {
258 		printk(KERN_ERR "Failed to read 1-wire data from 0x%x: err=%d.\n", dev->ep[EP_STATUS], err);
259 		return err;
260 	}
261 
262 	if (count >= sizeof(*st))
263 		memcpy(st, buf, sizeof(*st));
264 
265 	return count;
266 }
267 
268 static inline void ds_print_msg(unsigned char *buf, unsigned char *str, int off)
269 {
270 	printk(KERN_INFO "%45s: %8x\n", str, buf[off]);
271 }
272 
273 static void ds_dump_status(struct ds_device *dev, unsigned char *buf, int count)
274 {
275 	int i;
276 
277 	printk(KERN_INFO "0x%x: count=%d, status: ", dev->ep[EP_STATUS], count);
278 	for (i=0; i<count; ++i)
279 		printk("%02x ", buf[i]);
280 	printk(KERN_INFO "\n");
281 
282 	if (count >= 16) {
283 		ds_print_msg(buf, "enable flag", 0);
284 		ds_print_msg(buf, "1-wire speed", 1);
285 		ds_print_msg(buf, "strong pullup duration", 2);
286 		ds_print_msg(buf, "programming pulse duration", 3);
287 		ds_print_msg(buf, "pulldown slew rate control", 4);
288 		ds_print_msg(buf, "write-1 low time", 5);
289 		ds_print_msg(buf, "data sample offset/write-0 recovery time",
290 			6);
291 		ds_print_msg(buf, "reserved (test register)", 7);
292 		ds_print_msg(buf, "device status flags", 8);
293 		ds_print_msg(buf, "communication command byte 1", 9);
294 		ds_print_msg(buf, "communication command byte 2", 10);
295 		ds_print_msg(buf, "communication command buffer status", 11);
296 		ds_print_msg(buf, "1-wire data output buffer status", 12);
297 		ds_print_msg(buf, "1-wire data input buffer status", 13);
298 		ds_print_msg(buf, "reserved", 14);
299 		ds_print_msg(buf, "reserved", 15);
300 	}
301 	for (i = 16; i < count; ++i) {
302 		if (buf[i] == RR_DETECT) {
303 			ds_print_msg(buf, "new device detect", i);
304 			continue;
305 		}
306 		ds_print_msg(buf, "Result Register Value: ", i);
307 		if (buf[i] & RR_NRS)
308 			printk(KERN_INFO "NRS: Reset no presence or ...\n");
309 		if (buf[i] & RR_SH)
310 			printk(KERN_INFO "SH: short on reset or set path\n");
311 		if (buf[i] & RR_APP)
312 			printk(KERN_INFO "APP: alarming presence on reset\n");
313 		if (buf[i] & RR_VPP)
314 			printk(KERN_INFO "VPP: 12V expected not seen\n");
315 		if (buf[i] & RR_CMP)
316 			printk(KERN_INFO "CMP: compare error\n");
317 		if (buf[i] & RR_CRC)
318 			printk(KERN_INFO "CRC: CRC error detected\n");
319 		if (buf[i] & RR_RDP)
320 			printk(KERN_INFO "RDP: redirected page\n");
321 		if (buf[i] & RR_EOS)
322 			printk(KERN_INFO "EOS: end of search error\n");
323 	}
324 }
325 
326 static void ds_reset_device(struct ds_device *dev)
327 {
328 	ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
329 	/* Always allow strong pullup which allow individual writes to use
330 	 * the strong pullup.
331 	 */
332 	if (ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_SPUE))
333 		printk(KERN_ERR "ds_reset_device: "
334 			"Error allowing strong pullup\n");
335 	/* Chip strong pullup time was cleared. */
336 	if (dev->spu_sleep) {
337 		/* lower 4 bits are 0, see ds_set_pullup */
338 		u8 del = dev->spu_sleep>>4;
339 		if (ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del))
340 			printk(KERN_ERR "ds_reset_device: "
341 				"Error setting duration\n");
342 	}
343 }
344 
345 static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
346 {
347 	int count, err;
348 	struct ds_status st;
349 
350 	/* Careful on size.  If size is less than what is available in
351 	 * the input buffer, the device fails the bulk transfer and
352 	 * clears the input buffer.  It could read the maximum size of
353 	 * the data buffer, but then do you return the first, last, or
354 	 * some set of the middle size bytes?  As long as the rest of
355 	 * the code is correct there will be size bytes waiting.  A
356 	 * call to ds_wait_status will wait until the device is idle
357 	 * and any data to be received would have been available.
358 	 */
359 	count = 0;
360 	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
361 				buf, size, &count, 1000);
362 	if (err < 0) {
363 		u8 buf[ST_SIZE];
364 		int count;
365 
366 		printk(KERN_INFO "Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);
367 		usb_clear_halt(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]));
368 
369 		count = ds_recv_status_nodump(dev, &st, buf, sizeof(buf));
370 		ds_dump_status(dev, buf, count);
371 		return err;
372 	}
373 
374 #if 0
375 	{
376 		int i;
377 
378 		printk("%s: count=%d: ", __func__, count);
379 		for (i=0; i<count; ++i)
380 			printk("%02x ", buf[i]);
381 		printk("\n");
382 	}
383 #endif
384 	return count;
385 }
386 
387 static int ds_send_data(struct ds_device *dev, unsigned char *buf, int len)
388 {
389 	int count, err;
390 
391 	count = 0;
392 	err = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, dev->ep[EP_DATA_OUT]), buf, len, &count, 1000);
393 	if (err < 0) {
394 		printk(KERN_ERR "Failed to write 1-wire data to ep0x%x: "
395 			"err=%d.\n", dev->ep[EP_DATA_OUT], err);
396 		return err;
397 	}
398 
399 	return err;
400 }
401 
402 #if 0
403 
404 int ds_stop_pulse(struct ds_device *dev, int limit)
405 {
406 	struct ds_status st;
407 	int count = 0, err = 0;
408 	u8 buf[ST_SIZE];
409 
410 	do {
411 		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);
412 		if (err)
413 			break;
414 		err = ds_send_control(dev, CTL_RESUME_EXE, 0);
415 		if (err)
416 			break;
417 		err = ds_recv_status_nodump(dev, &st, buf, sizeof(buf));
418 		if (err)
419 			break;
420 
421 		if ((st.status & ST_SPUA) == 0) {
422 			err = ds_send_control_mode(dev, MOD_PULSE_EN, 0);
423 			if (err)
424 				break;
425 		}
426 	} while(++count < limit);
427 
428 	return err;
429 }
430 
431 int ds_detect(struct ds_device *dev, struct ds_status *st)
432 {
433 	int err;
434 
435 	err = ds_send_control_cmd(dev, CTL_RESET_DEVICE, 0);
436 	if (err)
437 		return err;
438 
439 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, 0);
440 	if (err)
441 		return err;
442 
443 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM | COMM_TYPE, 0x40);
444 	if (err)
445 		return err;
446 
447 	err = ds_send_control_mode(dev, MOD_PULSE_EN, PULSE_PROG);
448 	if (err)
449 		return err;
450 
451 	err = ds_dump_status(dev, st);
452 
453 	return err;
454 }
455 
456 #endif  /*  0  */
457 
458 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
459 {
460 	u8 buf[ST_SIZE];
461 	int err, count = 0;
462 
463 	do {
464 		st->status = 0;
465 		err = ds_recv_status_nodump(dev, st, buf, sizeof(buf));
466 #if 0
467 		if (err >= 0) {
468 			int i;
469 			printk("0x%x: count=%d, status: ", dev->ep[EP_STATUS], err);
470 			for (i=0; i<err; ++i)
471 				printk("%02x ", buf[i]);
472 			printk("\n");
473 		}
474 #endif
475 	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
476 
477 	if (err >= 16 && st->status & ST_EPOF) {
478 		printk(KERN_INFO "Resetting device after ST_EPOF.\n");
479 		ds_reset_device(dev);
480 		/* Always dump the device status. */
481 		count = 101;
482 	}
483 
484 	/* Dump the status for errors or if there is extended return data.
485 	 * The extended status includes new device detection (maybe someone
486 	 * can do something with it).
487 	 */
488 	if (err > 16 || count >= 100 || err < 0)
489 		ds_dump_status(dev, buf, err);
490 
491 	/* Extended data isn't an error.  Well, a short is, but the dump
492 	 * would have already told the user that and we can't do anything
493 	 * about it in software anyway.
494 	 */
495 	if (count >= 100 || err < 0)
496 		return -1;
497 	else
498 		return 0;
499 }
500 
501 static int ds_reset(struct ds_device *dev)
502 {
503 	int err;
504 
505 	/* Other potentionally interesting flags for reset.
506 	 *
507 	 * COMM_NTF: Return result register feedback.  This could be used to
508 	 * detect some conditions such as short, alarming presence, or
509 	 * detect if a new device was detected.
510 	 *
511 	 * COMM_SE which allows SPEED_NORMAL, SPEED_FLEXIBLE, SPEED_OVERDRIVE:
512 	 * Select the data transfer rate.
513 	 */
514 	err = ds_send_control(dev, COMM_1_WIRE_RESET | COMM_IM, SPEED_NORMAL);
515 	if (err)
516 		return err;
517 
518 	return 0;
519 }
520 
521 #if 0
522 static int ds_set_speed(struct ds_device *dev, int speed)
523 {
524 	int err;
525 
526 	if (speed != SPEED_NORMAL && speed != SPEED_FLEXIBLE && speed != SPEED_OVERDRIVE)
527 		return -EINVAL;
528 
529 	if (speed != SPEED_OVERDRIVE)
530 		speed = SPEED_FLEXIBLE;
531 
532 	speed &= 0xff;
533 
534 	err = ds_send_control_mode(dev, MOD_1WIRE_SPEED, speed);
535 	if (err)
536 		return err;
537 
538 	return err;
539 }
540 #endif  /*  0  */
541 
542 static int ds_set_pullup(struct ds_device *dev, int delay)
543 {
544 	int err = 0;
545 	u8 del = 1 + (u8)(delay >> 4);
546 	/* Just storing delay would not get the trunication and roundup. */
547 	int ms = del<<4;
548 
549 	/* Enable spu_bit if a delay is set. */
550 	dev->spu_bit = delay ? COMM_SPU : 0;
551 	/* If delay is zero, it has already been disabled, if the time is
552 	 * the same as the hardware was last programmed to, there is also
553 	 * nothing more to do.  Compare with the recalculated value ms
554 	 * rather than del or delay which can have a different value.
555 	 */
556 	if (delay == 0 || ms == dev->spu_sleep)
557 		return err;
558 
559 	err = ds_send_control(dev, COMM_SET_DURATION | COMM_IM, del);
560 	if (err)
561 		return err;
562 
563 	dev->spu_sleep = ms;
564 
565 	return err;
566 }
567 
568 static int ds_touch_bit(struct ds_device *dev, u8 bit, u8 *tbit)
569 {
570 	int err;
571 	struct ds_status st;
572 
573 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | (bit ? COMM_D : 0),
574 		0);
575 	if (err)
576 		return err;
577 
578 	ds_wait_status(dev, &st);
579 
580 	err = ds_recv_data(dev, tbit, sizeof(*tbit));
581 	if (err < 0)
582 		return err;
583 
584 	return 0;
585 }
586 
587 #if 0
588 static int ds_write_bit(struct ds_device *dev, u8 bit)
589 {
590 	int err;
591 	struct ds_status st;
592 
593 	/* Set COMM_ICP to write without a readback.  Note, this will
594 	 * produce one time slot, a down followed by an up with COMM_D
595 	 * only determing the timing.
596 	 */
597 	err = ds_send_control(dev, COMM_BIT_IO | COMM_IM | COMM_ICP |
598 		(bit ? COMM_D : 0), 0);
599 	if (err)
600 		return err;
601 
602 	ds_wait_status(dev, &st);
603 
604 	return 0;
605 }
606 #endif
607 
608 static int ds_write_byte(struct ds_device *dev, u8 byte)
609 {
610 	int err;
611 	struct ds_status st;
612 	u8 rbyte;
613 
614 	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM | dev->spu_bit, byte);
615 	if (err)
616 		return err;
617 
618 	if (dev->spu_bit)
619 		msleep(dev->spu_sleep);
620 
621 	err = ds_wait_status(dev, &st);
622 	if (err)
623 		return err;
624 
625 	err = ds_recv_data(dev, &rbyte, sizeof(rbyte));
626 	if (err < 0)
627 		return err;
628 
629 	return !(byte == rbyte);
630 }
631 
632 static int ds_read_byte(struct ds_device *dev, u8 *byte)
633 {
634 	int err;
635 	struct ds_status st;
636 
637 	err = ds_send_control(dev, COMM_BYTE_IO | COMM_IM , 0xff);
638 	if (err)
639 		return err;
640 
641 	ds_wait_status(dev, &st);
642 
643 	err = ds_recv_data(dev, byte, sizeof(*byte));
644 	if (err < 0)
645 		return err;
646 
647 	return 0;
648 }
649 
650 static int ds_read_block(struct ds_device *dev, u8 *buf, int len)
651 {
652 	struct ds_status st;
653 	int err;
654 
655 	if (len > 64*1024)
656 		return -E2BIG;
657 
658 	memset(buf, 0xFF, len);
659 
660 	err = ds_send_data(dev, buf, len);
661 	if (err < 0)
662 		return err;
663 
664 	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM, len);
665 	if (err)
666 		return err;
667 
668 	ds_wait_status(dev, &st);
669 
670 	memset(buf, 0x00, len);
671 	err = ds_recv_data(dev, buf, len);
672 
673 	return err;
674 }
675 
676 static int ds_write_block(struct ds_device *dev, u8 *buf, int len)
677 {
678 	int err;
679 	struct ds_status st;
680 
681 	err = ds_send_data(dev, buf, len);
682 	if (err < 0)
683 		return err;
684 
685 	err = ds_send_control(dev, COMM_BLOCK_IO | COMM_IM | dev->spu_bit, len);
686 	if (err)
687 		return err;
688 
689 	if (dev->spu_bit)
690 		msleep(dev->spu_sleep);
691 
692 	ds_wait_status(dev, &st);
693 
694 	err = ds_recv_data(dev, buf, len);
695 	if (err < 0)
696 		return err;
697 
698 	return !(err == len);
699 }
700 
701 static void ds9490r_search(void *data, struct w1_master *master,
702 	u8 search_type, w1_slave_found_callback callback)
703 {
704 	/* When starting with an existing id, the first id returned will
705 	 * be that device (if it is still on the bus most likely).
706 	 *
707 	 * If the number of devices found is less than or equal to the
708 	 * search_limit, that number of IDs will be returned.  If there are
709 	 * more, search_limit IDs will be returned followed by a non-zero
710 	 * discrepency value.
711 	 */
712 	struct ds_device *dev = data;
713 	int err;
714 	u16 value, index;
715 	struct ds_status st;
716 	u8 st_buf[ST_SIZE];
717 	int search_limit;
718 	int found = 0;
719 	int i;
720 
721 	/* DS18b20 spec, 13.16 ms per device, 75 per second, sleep for
722 	 * discovering 8 devices (1 bulk transfer and 1/2 FIFO size) at a time.
723 	 */
724 	const unsigned long jtime = msecs_to_jiffies(1000*8/75);
725 	/* FIFO 128 bytes, bulk packet size 64, read a multiple of the
726 	 * packet size.
727 	 */
728 	u64 buf[2*64/8];
729 
730 	mutex_lock(&master->bus_mutex);
731 
732 	/* address to start searching at */
733 	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
734 		goto search_out;
735 	master->search_id = 0;
736 
737 	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
738 		COMM_RTS;
739 	search_limit = master->max_slave_count;
740 	if (search_limit > 255)
741 		search_limit = 0;
742 	index = search_type | (search_limit << 8);
743 	if (ds_send_control(dev, value, index) < 0)
744 		goto search_out;
745 
746 	do {
747 		schedule_timeout(jtime);
748 
749 		if (ds_recv_status_nodump(dev, &st, st_buf, sizeof(st_buf)) <
750 			sizeof(st)) {
751 			break;
752 		}
753 
754 		if (st.data_in_buffer_status) {
755 			/* Bulk in can receive partial ids, but when it does
756 			 * they fail crc and will be discarded anyway.
757 			 * That has only been seen when status in buffer
758 			 * is 0 and bulk is read anyway, so don't read
759 			 * bulk without first checking if status says there
760 			 * is data to read.
761 			 */
762 			err = ds_recv_data(dev, (u8 *)buf, sizeof(buf));
763 			if (err < 0)
764 				break;
765 			for (i = 0; i < err/8; ++i) {
766 				++found;
767 				if (found <= search_limit)
768 					callback(master, buf[i]);
769 				/* can't know if there will be a discrepancy
770 				 * value after until the next id */
771 				if (found == search_limit)
772 					master->search_id = buf[i];
773 			}
774 		}
775 
776 		if (test_bit(W1_ABORT_SEARCH, &master->flags))
777 			break;
778 	} while (!(st.status & (ST_IDLE | ST_HALT)));
779 
780 	/* only continue the search if some weren't found */
781 	if (found <= search_limit) {
782 		master->search_id = 0;
783 	} else if (!test_bit(W1_WARN_MAX_COUNT, &master->flags)) {
784 		/* Only max_slave_count will be scanned in a search,
785 		 * but it will start where it left off next search
786 		 * until all ids are identified and then it will start
787 		 * over.  A continued search will report the previous
788 		 * last id as the first id (provided it is still on the
789 		 * bus).
790 		 */
791 		dev_info(&dev->udev->dev, "%s: max_slave_count %d reached, "
792 			"will continue next search.\n", __func__,
793 			master->max_slave_count);
794 		set_bit(W1_WARN_MAX_COUNT, &master->flags);
795 	}
796 search_out:
797 	mutex_unlock(&master->bus_mutex);
798 }
799 
800 #if 0
801 static int ds_match_access(struct ds_device *dev, u64 init)
802 {
803 	int err;
804 	struct ds_status st;
805 
806 	err = ds_send_data(dev, (unsigned char *)&init, sizeof(init));
807 	if (err)
808 		return err;
809 
810 	ds_wait_status(dev, &st);
811 
812 	err = ds_send_control(dev, COMM_MATCH_ACCESS | COMM_IM | COMM_RST, 0x0055);
813 	if (err)
814 		return err;
815 
816 	ds_wait_status(dev, &st);
817 
818 	return 0;
819 }
820 
821 static int ds_set_path(struct ds_device *dev, u64 init)
822 {
823 	int err;
824 	struct ds_status st;
825 	u8 buf[9];
826 
827 	memcpy(buf, &init, 8);
828 	buf[8] = BRANCH_MAIN;
829 
830 	err = ds_send_data(dev, buf, sizeof(buf));
831 	if (err)
832 		return err;
833 
834 	ds_wait_status(dev, &st);
835 
836 	err = ds_send_control(dev, COMM_SET_PATH | COMM_IM | COMM_RST, 0);
837 	if (err)
838 		return err;
839 
840 	ds_wait_status(dev, &st);
841 
842 	return 0;
843 }
844 
845 #endif  /*  0  */
846 
847 static u8 ds9490r_touch_bit(void *data, u8 bit)
848 {
849 	u8 ret;
850 	struct ds_device *dev = data;
851 
852 	if (ds_touch_bit(dev, bit, &ret))
853 		return 0;
854 
855 	return ret;
856 }
857 
858 #if 0
859 static void ds9490r_write_bit(void *data, u8 bit)
860 {
861 	struct ds_device *dev = data;
862 
863 	ds_write_bit(dev, bit);
864 }
865 
866 static u8 ds9490r_read_bit(void *data)
867 {
868 	struct ds_device *dev = data;
869 	int err;
870 	u8 bit = 0;
871 
872 	err = ds_touch_bit(dev, 1, &bit);
873 	if (err)
874 		return 0;
875 
876 	return bit & 1;
877 }
878 #endif
879 
880 static void ds9490r_write_byte(void *data, u8 byte)
881 {
882 	struct ds_device *dev = data;
883 
884 	ds_write_byte(dev, byte);
885 }
886 
887 static u8 ds9490r_read_byte(void *data)
888 {
889 	struct ds_device *dev = data;
890 	int err;
891 	u8 byte = 0;
892 
893 	err = ds_read_byte(dev, &byte);
894 	if (err)
895 		return 0;
896 
897 	return byte;
898 }
899 
900 static void ds9490r_write_block(void *data, const u8 *buf, int len)
901 {
902 	struct ds_device *dev = data;
903 
904 	ds_write_block(dev, (u8 *)buf, len);
905 }
906 
907 static u8 ds9490r_read_block(void *data, u8 *buf, int len)
908 {
909 	struct ds_device *dev = data;
910 	int err;
911 
912 	err = ds_read_block(dev, buf, len);
913 	if (err < 0)
914 		return 0;
915 
916 	return len;
917 }
918 
919 static u8 ds9490r_reset(void *data)
920 {
921 	struct ds_device *dev = data;
922 	int err;
923 
924 	err = ds_reset(dev);
925 	if (err)
926 		return 1;
927 
928 	return 0;
929 }
930 
931 static u8 ds9490r_set_pullup(void *data, int delay)
932 {
933 	struct ds_device *dev = data;
934 
935 	if (ds_set_pullup(dev, delay))
936 		return 1;
937 
938 	return 0;
939 }
940 
941 static int ds_w1_init(struct ds_device *dev)
942 {
943 	memset(&dev->master, 0, sizeof(struct w1_bus_master));
944 
945 	/* Reset the device as it can be in a bad state.
946 	 * This is necessary because a block write will wait for data
947 	 * to be placed in the output buffer and block any later
948 	 * commands which will keep accumulating and the device will
949 	 * not be idle.  Another case is removing the ds2490 module
950 	 * while a bus search is in progress, somehow a few commands
951 	 * get through, but the input transfers fail leaving data in
952 	 * the input buffer.  This will cause the next read to fail
953 	 * see the note in ds_recv_data.
954 	 */
955 	ds_reset_device(dev);
956 
957 	dev->master.data	= dev;
958 	dev->master.touch_bit	= &ds9490r_touch_bit;
959 	/* read_bit and write_bit in w1_bus_master are expected to set and
960 	 * sample the line level.  For write_bit that means it is expected to
961 	 * set it to that value and leave it there.  ds2490 only supports an
962 	 * individual time slot at the lowest level.  The requirement from
963 	 * pulling the bus state down to reading the state is 15us, something
964 	 * that isn't realistic on the USB bus anyway.
965 	dev->master.read_bit	= &ds9490r_read_bit;
966 	dev->master.write_bit	= &ds9490r_write_bit;
967 	*/
968 	dev->master.read_byte	= &ds9490r_read_byte;
969 	dev->master.write_byte	= &ds9490r_write_byte;
970 	dev->master.read_block	= &ds9490r_read_block;
971 	dev->master.write_block	= &ds9490r_write_block;
972 	dev->master.reset_bus	= &ds9490r_reset;
973 	dev->master.set_pullup	= &ds9490r_set_pullup;
974 	dev->master.search	= &ds9490r_search;
975 
976 	return w1_add_master_device(&dev->master);
977 }
978 
979 static void ds_w1_fini(struct ds_device *dev)
980 {
981 	w1_remove_master_device(&dev->master);
982 }
983 
984 static int ds_probe(struct usb_interface *intf,
985 		    const struct usb_device_id *udev_id)
986 {
987 	struct usb_device *udev = interface_to_usbdev(intf);
988 	struct usb_endpoint_descriptor *endpoint;
989 	struct usb_host_interface *iface_desc;
990 	struct ds_device *dev;
991 	int i, err, alt;
992 
993 	dev = kzalloc(sizeof(struct ds_device), GFP_KERNEL);
994 	if (!dev) {
995 		printk(KERN_INFO "Failed to allocate new DS9490R structure.\n");
996 		return -ENOMEM;
997 	}
998 	dev->udev = usb_get_dev(udev);
999 	if (!dev->udev) {
1000 		err = -ENOMEM;
1001 		goto err_out_free;
1002 	}
1003 	memset(dev->ep, 0, sizeof(dev->ep));
1004 
1005 	usb_set_intfdata(intf, dev);
1006 
1007 	err = usb_reset_configuration(dev->udev);
1008 	if (err) {
1009 		dev_err(&dev->udev->dev,
1010 			"Failed to reset configuration: err=%d.\n", err);
1011 		goto err_out_clear;
1012 	}
1013 
1014 	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
1015 	alt = 3;
1016 	err = usb_set_interface(dev->udev,
1017 		intf->altsetting[alt].desc.bInterfaceNumber, alt);
1018 	if (err) {
1019 		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
1020 			"for %d interface: err=%d.\n", alt,
1021 			intf->altsetting[alt].desc.bInterfaceNumber, err);
1022 		goto err_out_clear;
1023 	}
1024 
1025 	iface_desc = &intf->altsetting[alt];
1026 	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
1027 		printk(KERN_INFO "Num endpoints=%d. It is not DS9490R.\n", iface_desc->desc.bNumEndpoints);
1028 		err = -EINVAL;
1029 		goto err_out_clear;
1030 	}
1031 
1032 	/*
1033 	 * This loop doesn'd show control 0 endpoint,
1034 	 * so we will fill only 1-3 endpoints entry.
1035 	 */
1036 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
1037 		endpoint = &iface_desc->endpoint[i].desc;
1038 
1039 		dev->ep[i+1] = endpoint->bEndpointAddress;
1040 #if 0
1041 		printk("%d: addr=%x, size=%d, dir=%s, type=%x\n",
1042 			i, endpoint->bEndpointAddress, le16_to_cpu(endpoint->wMaxPacketSize),
1043 			(endpoint->bEndpointAddress & USB_DIR_IN)?"IN":"OUT",
1044 			endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
1045 #endif
1046 	}
1047 
1048 	err = ds_w1_init(dev);
1049 	if (err)
1050 		goto err_out_clear;
1051 
1052 	mutex_lock(&ds_mutex);
1053 	list_add_tail(&dev->ds_entry, &ds_devices);
1054 	mutex_unlock(&ds_mutex);
1055 
1056 	return 0;
1057 
1058 err_out_clear:
1059 	usb_set_intfdata(intf, NULL);
1060 	usb_put_dev(dev->udev);
1061 err_out_free:
1062 	kfree(dev);
1063 	return err;
1064 }
1065 
1066 static void ds_disconnect(struct usb_interface *intf)
1067 {
1068 	struct ds_device *dev;
1069 
1070 	dev = usb_get_intfdata(intf);
1071 	if (!dev)
1072 		return;
1073 
1074 	mutex_lock(&ds_mutex);
1075 	list_del(&dev->ds_entry);
1076 	mutex_unlock(&ds_mutex);
1077 
1078 	ds_w1_fini(dev);
1079 
1080 	usb_set_intfdata(intf, NULL);
1081 
1082 	usb_put_dev(dev->udev);
1083 	kfree(dev);
1084 }
1085 
1086 module_usb_driver(ds_driver);
1087 
1088 MODULE_LICENSE("GPL");
1089 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1090 MODULE_DESCRIPTION("DS2490 USB <-> W1 bus master driver (DS9490*)");
1091