xref: /linux/drivers/usb/misc/usb-ljca.c (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel La Jolla Cove Adapter USB driver
4  *
5  * Copyright (c) 2023, Intel Corporation.
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/auxiliary_bus.h>
10 #include <linux/dev_printk.h>
11 #include <linux/kernel.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/types.h>
18 #include <linux/usb.h>
19 #include <linux/usb/ljca.h>
20 
21 #include <asm/unaligned.h>
22 
23 /* command flags */
24 #define LJCA_ACK_FLAG			BIT(0)
25 #define LJCA_RESP_FLAG			BIT(1)
26 #define LJCA_CMPL_FLAG			BIT(2)
27 
28 #define LJCA_MAX_PACKET_SIZE		64u
29 #define LJCA_MAX_PAYLOAD_SIZE		\
30 		(LJCA_MAX_PACKET_SIZE - sizeof(struct ljca_msg))
31 
32 #define LJCA_WRITE_TIMEOUT_MS		200
33 #define LJCA_WRITE_ACK_TIMEOUT_MS	500
34 #define LJCA_ENUM_CLIENT_TIMEOUT_MS	20
35 
36 /* ljca client type */
37 enum ljca_client_type {
38 	LJCA_CLIENT_MNG = 1,
39 	LJCA_CLIENT_GPIO = 3,
40 	LJCA_CLIENT_I2C = 4,
41 	LJCA_CLIENT_SPI = 5,
42 };
43 
44 /* MNG client commands */
45 enum ljca_mng_cmd {
46 	LJCA_MNG_RESET = 2,
47 	LJCA_MNG_ENUM_GPIO = 4,
48 	LJCA_MNG_ENUM_I2C = 5,
49 	LJCA_MNG_ENUM_SPI = 8,
50 };
51 
52 /* ljca client acpi _ADR */
53 enum ljca_client_acpi_adr {
54 	LJCA_GPIO_ACPI_ADR,
55 	LJCA_I2C1_ACPI_ADR,
56 	LJCA_I2C2_ACPI_ADR,
57 	LJCA_SPI1_ACPI_ADR,
58 	LJCA_SPI2_ACPI_ADR,
59 	LJCA_CLIENT_ACPI_ADR_MAX,
60 };
61 
62 /* ljca cmd message structure */
63 struct ljca_msg {
64 	u8 type;
65 	u8 cmd;
66 	u8 flags;
67 	u8 len;
68 	u8 data[] __counted_by(len);
69 } __packed;
70 
71 struct ljca_i2c_ctr_info {
72 	u8 id;
73 	u8 capacity;
74 	u8 intr_pin;
75 } __packed;
76 
77 struct ljca_i2c_descriptor {
78 	u8 num;
79 	struct ljca_i2c_ctr_info info[] __counted_by(num);
80 } __packed;
81 
82 struct ljca_spi_ctr_info {
83 	u8 id;
84 	u8 capacity;
85 	u8 intr_pin;
86 } __packed;
87 
88 struct ljca_spi_descriptor {
89 	u8 num;
90 	struct ljca_spi_ctr_info info[] __counted_by(num);
91 } __packed;
92 
93 struct ljca_bank_descriptor {
94 	u8 bank_id;
95 	u8 pin_num;
96 
97 	/* 1 bit for each gpio, 1 means valid */
98 	__le32 valid_pins;
99 } __packed;
100 
101 struct ljca_gpio_descriptor {
102 	u8 pins_per_bank;
103 	u8 bank_num;
104 	struct ljca_bank_descriptor bank_desc[] __counted_by(bank_num);
105 } __packed;
106 
107 /**
108  * struct ljca_adapter - represent a ljca adapter
109  *
110  * @intf: the usb interface for this ljca adapter
111  * @usb_dev: the usb device for this ljca adapter
112  * @dev: the specific device info of the usb interface
113  * @rx_pipe: bulk in pipe for receive data from firmware
114  * @tx_pipe: bulk out pipe for send data to firmware
115  * @rx_urb: urb used for the bulk in pipe
116  * @rx_buf: buffer used to receive command response and event
117  * @rx_len: length of rx buffer
118  * @ex_buf: external buffer to save command response
119  * @ex_buf_len: length of external buffer
120  * @actual_length: actual length of data copied to external buffer
121  * @tx_buf: buffer used to download command to firmware
122  * @tx_buf_len: length of tx buffer
123  * @lock: spinlock to protect tx_buf and ex_buf
124  * @cmd_completion: completion object as the command receives ack
125  * @mutex: mutex to avoid command download concurrently
126  * @client_list: client device list
127  * @disconnect: usb disconnect ongoing or not
128  * @reset_id: used to reset firmware
129  */
130 struct ljca_adapter {
131 	struct usb_interface *intf;
132 	struct usb_device *usb_dev;
133 	struct device *dev;
134 
135 	unsigned int rx_pipe;
136 	unsigned int tx_pipe;
137 
138 	struct urb *rx_urb;
139 	void *rx_buf;
140 	unsigned int rx_len;
141 
142 	u8 *ex_buf;
143 	u8 ex_buf_len;
144 	u8 actual_length;
145 
146 	void *tx_buf;
147 	u8 tx_buf_len;
148 
149 	spinlock_t lock;
150 
151 	struct completion cmd_completion;
152 	struct mutex mutex;
153 
154 	struct list_head client_list;
155 
156 	bool disconnect;
157 
158 	u32 reset_id;
159 };
160 
161 struct ljca_match_ids_walk_data {
162 	const struct acpi_device_id *ids;
163 	const char *uid;
164 	struct acpi_device *adev;
165 };
166 
167 static const struct acpi_device_id ljca_gpio_hids[] = {
168 	{ "INTC1074" },
169 	{ "INTC1096" },
170 	{ "INTC100B" },
171 	{ "INTC10D1" },
172 	{},
173 };
174 
175 static const struct acpi_device_id ljca_i2c_hids[] = {
176 	{ "INTC1075" },
177 	{ "INTC1097" },
178 	{ "INTC100C" },
179 	{ "INTC10D2" },
180 	{},
181 };
182 
183 static const struct acpi_device_id ljca_spi_hids[] = {
184 	{ "INTC1091" },
185 	{ "INTC1098" },
186 	{ "INTC100D" },
187 	{ "INTC10D3" },
188 	{},
189 };
190 
191 static void ljca_handle_event(struct ljca_adapter *adap,
192 			      struct ljca_msg *header)
193 {
194 	struct ljca_client *client;
195 
196 	list_for_each_entry(client, &adap->client_list, link) {
197 		/*
198 		 * Currently only GPIO register event callback, but
199 		 * firmware message structure should include id when
200 		 * multiple same type clients register event callback.
201 		 */
202 		if (client->type == header->type) {
203 			unsigned long flags;
204 
205 			spin_lock_irqsave(&client->event_cb_lock, flags);
206 			client->event_cb(client->context, header->cmd,
207 					 header->data, header->len);
208 			spin_unlock_irqrestore(&client->event_cb_lock, flags);
209 
210 			break;
211 		}
212 	}
213 }
214 
215 /* process command ack and received data if available */
216 static void ljca_handle_cmd_ack(struct ljca_adapter *adap, struct ljca_msg *header)
217 {
218 	struct ljca_msg *tx_header = adap->tx_buf;
219 	u8 ibuf_len, actual_len = 0;
220 	unsigned long flags;
221 	u8 *ibuf;
222 
223 	spin_lock_irqsave(&adap->lock, flags);
224 
225 	if (tx_header->type != header->type || tx_header->cmd != header->cmd) {
226 		spin_unlock_irqrestore(&adap->lock, flags);
227 		dev_err(adap->dev, "cmd ack mismatch error\n");
228 		return;
229 	}
230 
231 	ibuf_len = adap->ex_buf_len;
232 	ibuf = adap->ex_buf;
233 
234 	if (ibuf && ibuf_len) {
235 		actual_len = min(header->len, ibuf_len);
236 
237 		/* copy received data to external buffer */
238 		memcpy(ibuf, header->data, actual_len);
239 	}
240 	/* update copied data length */
241 	adap->actual_length = actual_len;
242 
243 	spin_unlock_irqrestore(&adap->lock, flags);
244 
245 	complete(&adap->cmd_completion);
246 }
247 
248 static void ljca_recv(struct urb *urb)
249 {
250 	struct ljca_msg *header = urb->transfer_buffer;
251 	struct ljca_adapter *adap = urb->context;
252 	int ret;
253 
254 	switch (urb->status) {
255 	case 0:
256 		/* success */
257 		break;
258 	case -ENOENT:
259 		/*
260 		 * directly complete the possible ongoing transfer
261 		 * during disconnect
262 		 */
263 		if (adap->disconnect)
264 			complete(&adap->cmd_completion);
265 		return;
266 	case -ECONNRESET:
267 	case -ESHUTDOWN:
268 	case -EPIPE:
269 		/* rx urb is terminated */
270 		dev_dbg(adap->dev, "rx urb terminated with status: %d\n",
271 			urb->status);
272 		return;
273 	default:
274 		dev_dbg(adap->dev, "rx urb error: %d\n", urb->status);
275 		goto resubmit;
276 	}
277 
278 	if (header->len + sizeof(*header) != urb->actual_length)
279 		goto resubmit;
280 
281 	if (header->flags & LJCA_ACK_FLAG)
282 		ljca_handle_cmd_ack(adap, header);
283 	else
284 		ljca_handle_event(adap, header);
285 
286 resubmit:
287 	ret = usb_submit_urb(urb, GFP_ATOMIC);
288 	if (ret && ret != -EPERM)
289 		dev_err(adap->dev, "resubmit rx urb error %d\n", ret);
290 }
291 
292 static int ljca_send(struct ljca_adapter *adap, u8 type, u8 cmd,
293 		     const u8 *obuf, u8 obuf_len, u8 *ibuf, u8 ibuf_len,
294 		     bool ack, unsigned long timeout)
295 {
296 	unsigned int msg_len = sizeof(struct ljca_msg) + obuf_len;
297 	struct ljca_msg *header = adap->tx_buf;
298 	unsigned int transferred;
299 	unsigned long flags;
300 	int ret;
301 
302 	if (adap->disconnect)
303 		return -ENODEV;
304 
305 	if (msg_len > adap->tx_buf_len)
306 		return -EINVAL;
307 
308 	mutex_lock(&adap->mutex);
309 
310 	spin_lock_irqsave(&adap->lock, flags);
311 
312 	header->type = type;
313 	header->cmd = cmd;
314 	header->len = obuf_len;
315 	if (obuf)
316 		memcpy(header->data, obuf, obuf_len);
317 
318 	header->flags = LJCA_CMPL_FLAG | (ack ? LJCA_ACK_FLAG : 0);
319 
320 	adap->ex_buf = ibuf;
321 	adap->ex_buf_len = ibuf_len;
322 	adap->actual_length = 0;
323 
324 	spin_unlock_irqrestore(&adap->lock, flags);
325 
326 	reinit_completion(&adap->cmd_completion);
327 
328 	ret = usb_autopm_get_interface(adap->intf);
329 	if (ret < 0)
330 		goto out;
331 
332 	ret = usb_bulk_msg(adap->usb_dev, adap->tx_pipe, header,
333 			   msg_len, &transferred, LJCA_WRITE_TIMEOUT_MS);
334 
335 	usb_autopm_put_interface(adap->intf);
336 
337 	if (ret < 0)
338 		goto out;
339 	if (transferred != msg_len) {
340 		ret = -EIO;
341 		goto out;
342 	}
343 
344 	if (ack) {
345 		ret = wait_for_completion_timeout(&adap->cmd_completion,
346 						  timeout);
347 		if (!ret) {
348 			ret = -ETIMEDOUT;
349 			goto out;
350 		}
351 	}
352 	ret = adap->actual_length;
353 
354 out:
355 	spin_lock_irqsave(&adap->lock, flags);
356 	adap->ex_buf = NULL;
357 	adap->ex_buf_len = 0;
358 
359 	memset(header, 0, sizeof(*header));
360 	spin_unlock_irqrestore(&adap->lock, flags);
361 
362 	mutex_unlock(&adap->mutex);
363 
364 	return ret;
365 }
366 
367 int ljca_transfer(struct ljca_client *client, u8 cmd, const u8 *obuf,
368 		  u8 obuf_len, u8 *ibuf, u8 ibuf_len)
369 {
370 	return ljca_send(client->adapter, client->type, cmd,
371 			 obuf, obuf_len, ibuf, ibuf_len, true,
372 			 LJCA_WRITE_ACK_TIMEOUT_MS);
373 }
374 EXPORT_SYMBOL_NS_GPL(ljca_transfer, LJCA);
375 
376 int ljca_transfer_noack(struct ljca_client *client, u8 cmd, const u8 *obuf,
377 			u8 obuf_len)
378 {
379 	return ljca_send(client->adapter, client->type, cmd, obuf,
380 			 obuf_len, NULL, 0, false, LJCA_WRITE_ACK_TIMEOUT_MS);
381 }
382 EXPORT_SYMBOL_NS_GPL(ljca_transfer_noack, LJCA);
383 
384 int ljca_register_event_cb(struct ljca_client *client, ljca_event_cb_t event_cb,
385 			   void *context)
386 {
387 	unsigned long flags;
388 
389 	if (!event_cb)
390 		return -EINVAL;
391 
392 	spin_lock_irqsave(&client->event_cb_lock, flags);
393 
394 	if (client->event_cb) {
395 		spin_unlock_irqrestore(&client->event_cb_lock, flags);
396 		return -EALREADY;
397 	}
398 
399 	client->event_cb = event_cb;
400 	client->context = context;
401 
402 	spin_unlock_irqrestore(&client->event_cb_lock, flags);
403 
404 	return 0;
405 }
406 EXPORT_SYMBOL_NS_GPL(ljca_register_event_cb, LJCA);
407 
408 void ljca_unregister_event_cb(struct ljca_client *client)
409 {
410 	unsigned long flags;
411 
412 	spin_lock_irqsave(&client->event_cb_lock, flags);
413 
414 	client->event_cb = NULL;
415 	client->context = NULL;
416 
417 	spin_unlock_irqrestore(&client->event_cb_lock, flags);
418 }
419 EXPORT_SYMBOL_NS_GPL(ljca_unregister_event_cb, LJCA);
420 
421 static int ljca_match_device_ids(struct acpi_device *adev, void *data)
422 {
423 	struct ljca_match_ids_walk_data *wd = data;
424 	const char *uid = acpi_device_uid(adev);
425 
426 	if (acpi_match_device_ids(adev, wd->ids))
427 		return 0;
428 
429 	if (!wd->uid)
430 		goto match;
431 
432 	if (!uid)
433 		/*
434 		 * Some DSDTs have only one ACPI companion for the two I2C
435 		 * controllers and they don't set a UID at all (e.g. Dell
436 		 * Latitude 9420). On these platforms only the first I2C
437 		 * controller is used, so if a HID match has no UID we use
438 		 * "0" as the UID and assign ACPI companion to the first
439 		 * I2C controller.
440 		 */
441 		uid = "0";
442 	else
443 		uid = strchr(uid, wd->uid[0]);
444 
445 	if (!uid || strcmp(uid, wd->uid))
446 		return 0;
447 
448 match:
449 	wd->adev = adev;
450 
451 	return 1;
452 }
453 
454 /* bind auxiliary device to acpi device */
455 static void ljca_auxdev_acpi_bind(struct ljca_adapter *adap,
456 				  struct auxiliary_device *auxdev,
457 				  u64 adr, u8 id)
458 {
459 	struct ljca_match_ids_walk_data wd = { 0 };
460 	struct acpi_device *parent, *adev;
461 	struct device *dev = adap->dev;
462 	char uid[4];
463 
464 	parent = ACPI_COMPANION(dev);
465 	if (!parent)
466 		return;
467 
468 	/*
469 	 * get auxdev ACPI handle from the ACPI device directly
470 	 * under the parent that matches _ADR.
471 	 */
472 	adev = acpi_find_child_device(parent, adr, false);
473 	if (adev) {
474 		ACPI_COMPANION_SET(&auxdev->dev, adev);
475 		return;
476 	}
477 
478 	/*
479 	 * _ADR is a grey area in the ACPI specification, some
480 	 * platforms use _HID to distinguish children devices.
481 	 */
482 	switch (adr) {
483 	case LJCA_GPIO_ACPI_ADR:
484 		wd.ids = ljca_gpio_hids;
485 		break;
486 	case LJCA_I2C1_ACPI_ADR:
487 	case LJCA_I2C2_ACPI_ADR:
488 		snprintf(uid, sizeof(uid), "%d", id);
489 		wd.uid = uid;
490 		wd.ids = ljca_i2c_hids;
491 		break;
492 	case LJCA_SPI1_ACPI_ADR:
493 	case LJCA_SPI2_ACPI_ADR:
494 		wd.ids = ljca_spi_hids;
495 		break;
496 	default:
497 		dev_warn(dev, "unsupported _ADR\n");
498 		return;
499 	}
500 
501 	acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
502 	if (wd.adev) {
503 		ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
504 		return;
505 	}
506 
507 	parent = ACPI_COMPANION(dev->parent->parent);
508 	if (!parent)
509 		return;
510 
511 	acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
512 	if (wd.adev)
513 		ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
514 }
515 
516 static void ljca_auxdev_release(struct device *dev)
517 {
518 	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
519 
520 	kfree(auxdev->dev.platform_data);
521 }
522 
523 static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
524 				  char *name, void *data, u64 adr)
525 {
526 	struct auxiliary_device *auxdev;
527 	struct ljca_client *client;
528 	int ret;
529 
530 	client = kzalloc(sizeof *client, GFP_KERNEL);
531 	if (!client)
532 		return -ENOMEM;
533 
534 	client->type = type;
535 	client->id = id;
536 	client->adapter = adap;
537 	spin_lock_init(&client->event_cb_lock);
538 
539 	auxdev = &client->auxdev;
540 	auxdev->name = name;
541 	auxdev->id = id;
542 
543 	auxdev->dev.parent = adap->dev;
544 	auxdev->dev.platform_data = data;
545 	auxdev->dev.release = ljca_auxdev_release;
546 
547 	ret = auxiliary_device_init(auxdev);
548 	if (ret)
549 		goto err_free;
550 
551 	ljca_auxdev_acpi_bind(adap, auxdev, adr, id);
552 
553 	ret = auxiliary_device_add(auxdev);
554 	if (ret)
555 		goto err_uninit;
556 
557 	list_add_tail(&client->link, &adap->client_list);
558 
559 	return 0;
560 
561 err_uninit:
562 	auxiliary_device_uninit(auxdev);
563 
564 err_free:
565 	kfree(client);
566 
567 	return ret;
568 }
569 
570 static int ljca_enumerate_gpio(struct ljca_adapter *adap)
571 {
572 	u32 valid_pin[LJCA_MAX_GPIO_NUM / BITS_PER_TYPE(u32)];
573 	struct ljca_gpio_descriptor *desc;
574 	struct ljca_gpio_info *gpio_info;
575 	u8 buf[LJCA_MAX_PAYLOAD_SIZE];
576 	int ret, gpio_num;
577 	unsigned int i;
578 
579 	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_GPIO, NULL, 0, buf,
580 			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);
581 	if (ret < 0)
582 		return ret;
583 
584 	/* check firmware response */
585 	desc = (struct ljca_gpio_descriptor *)buf;
586 	if (ret != struct_size(desc, bank_desc, desc->bank_num))
587 		return -EINVAL;
588 
589 	gpio_num = desc->pins_per_bank * desc->bank_num;
590 	if (gpio_num > LJCA_MAX_GPIO_NUM)
591 		return -EINVAL;
592 
593 	/* construct platform data */
594 	gpio_info = kzalloc(sizeof *gpio_info, GFP_KERNEL);
595 	if (!gpio_info)
596 		return -ENOMEM;
597 	gpio_info->num = gpio_num;
598 
599 	for (i = 0; i < desc->bank_num; i++)
600 		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
601 	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
602 
603 	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
604 				     gpio_info, LJCA_GPIO_ACPI_ADR);
605 	if (ret)
606 		kfree(gpio_info);
607 
608 	return ret;
609 }
610 
611 static int ljca_enumerate_i2c(struct ljca_adapter *adap)
612 {
613 	struct ljca_i2c_descriptor *desc;
614 	struct ljca_i2c_info *i2c_info;
615 	u8 buf[LJCA_MAX_PAYLOAD_SIZE];
616 	unsigned int i;
617 	int ret;
618 
619 	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_I2C, NULL, 0, buf,
620 			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);
621 	if (ret < 0)
622 		return ret;
623 
624 	/* check firmware response */
625 	desc = (struct ljca_i2c_descriptor *)buf;
626 	if (ret != struct_size(desc, info, desc->num))
627 		return -EINVAL;
628 
629 	for (i = 0; i < desc->num; i++) {
630 		/* construct platform data */
631 		i2c_info = kzalloc(sizeof *i2c_info, GFP_KERNEL);
632 		if (!i2c_info)
633 			return -ENOMEM;
634 
635 		i2c_info->id = desc->info[i].id;
636 		i2c_info->capacity = desc->info[i].capacity;
637 		i2c_info->intr_pin = desc->info[i].intr_pin;
638 
639 		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
640 					     "ljca-i2c", i2c_info,
641 					     LJCA_I2C1_ACPI_ADR + i);
642 		if (ret) {
643 			kfree(i2c_info);
644 			return ret;
645 		}
646 	}
647 
648 	return 0;
649 }
650 
651 static int ljca_enumerate_spi(struct ljca_adapter *adap)
652 {
653 	struct ljca_spi_descriptor *desc;
654 	struct ljca_spi_info *spi_info;
655 	u8 buf[LJCA_MAX_PAYLOAD_SIZE];
656 	unsigned int i;
657 	int ret;
658 
659 	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_SPI, NULL, 0, buf,
660 			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);
661 	if (ret < 0)
662 		return ret;
663 
664 	/* check firmware response */
665 	desc = (struct ljca_spi_descriptor *)buf;
666 	if (ret != struct_size(desc, info, desc->num))
667 		return -EINVAL;
668 
669 	for (i = 0; i < desc->num; i++) {
670 		/* construct platform data */
671 		spi_info = kzalloc(sizeof *spi_info, GFP_KERNEL);
672 		if (!spi_info)
673 			return -ENOMEM;
674 
675 		spi_info->id = desc->info[i].id;
676 		spi_info->capacity = desc->info[i].capacity;
677 
678 		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
679 					     "ljca-spi", spi_info,
680 					     LJCA_SPI1_ACPI_ADR + i);
681 		if (ret) {
682 			kfree(spi_info);
683 			return ret;
684 		}
685 	}
686 
687 	return 0;
688 }
689 
690 static int ljca_reset_handshake(struct ljca_adapter *adap)
691 {
692 	__le32 reset_id = cpu_to_le32(adap->reset_id);
693 	__le32 reset_id_ret = 0;
694 	int ret;
695 
696 	adap->reset_id++;
697 
698 	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_RESET, (u8 *)&reset_id,
699 			sizeof(__le32), (u8 *)&reset_id_ret, sizeof(__le32),
700 			true, LJCA_WRITE_ACK_TIMEOUT_MS);
701 	if (ret < 0)
702 		return ret;
703 
704 	if (reset_id_ret != reset_id)
705 		return -EINVAL;
706 
707 	return 0;
708 }
709 
710 static int ljca_enumerate_clients(struct ljca_adapter *adap)
711 {
712 	struct ljca_client *client, *next;
713 	int ret;
714 
715 	ret = ljca_reset_handshake(adap);
716 	if (ret)
717 		goto err_kill;
718 
719 	ret = ljca_enumerate_gpio(adap);
720 	if (ret) {
721 		dev_err(adap->dev, "enumerate GPIO error\n");
722 		goto err_kill;
723 	}
724 
725 	ret = ljca_enumerate_i2c(adap);
726 	if (ret) {
727 		dev_err(adap->dev, "enumerate I2C error\n");
728 		goto err_kill;
729 	}
730 
731 	ret = ljca_enumerate_spi(adap);
732 	if (ret) {
733 		dev_err(adap->dev, "enumerate SPI error\n");
734 		goto err_kill;
735 	}
736 
737 	return 0;
738 
739 err_kill:
740 	adap->disconnect = true;
741 
742 	usb_kill_urb(adap->rx_urb);
743 
744 	list_for_each_entry_safe_reverse(client, next, &adap->client_list, link) {
745 		auxiliary_device_delete(&client->auxdev);
746 		auxiliary_device_uninit(&client->auxdev);
747 
748 		list_del_init(&client->link);
749 		kfree(client);
750 	}
751 
752 	return ret;
753 }
754 
755 static int ljca_probe(struct usb_interface *interface,
756 		      const struct usb_device_id *id)
757 {
758 	struct usb_device *usb_dev = interface_to_usbdev(interface);
759 	struct usb_host_interface *alt = interface->cur_altsetting;
760 	struct usb_endpoint_descriptor *ep_in, *ep_out;
761 	struct device *dev = &interface->dev;
762 	struct ljca_adapter *adap;
763 	int ret;
764 
765 	adap = devm_kzalloc(dev, sizeof(*adap), GFP_KERNEL);
766 	if (!adap)
767 		return -ENOMEM;
768 
769 	/* separate tx buffer allocation for alignment */
770 	adap->tx_buf = devm_kzalloc(dev, LJCA_MAX_PACKET_SIZE, GFP_KERNEL);
771 	if (!adap->tx_buf)
772 		return -ENOMEM;
773 	adap->tx_buf_len = LJCA_MAX_PACKET_SIZE;
774 
775 	mutex_init(&adap->mutex);
776 	spin_lock_init(&adap->lock);
777 	init_completion(&adap->cmd_completion);
778 	INIT_LIST_HEAD(&adap->client_list);
779 
780 	adap->intf = usb_get_intf(interface);
781 	adap->usb_dev = usb_dev;
782 	adap->dev = dev;
783 
784 	/*
785 	 * find the first bulk in and out endpoints.
786 	 * ignore any others.
787 	 */
788 	ret = usb_find_common_endpoints(alt, &ep_in, &ep_out, NULL, NULL);
789 	if (ret) {
790 		dev_err(dev, "bulk endpoints not found\n");
791 		goto err_put;
792 	}
793 	adap->rx_pipe = usb_rcvbulkpipe(usb_dev, usb_endpoint_num(ep_in));
794 	adap->tx_pipe = usb_sndbulkpipe(usb_dev, usb_endpoint_num(ep_out));
795 
796 	/* setup rx buffer */
797 	adap->rx_len = usb_endpoint_maxp(ep_in);
798 	adap->rx_buf = devm_kzalloc(dev, adap->rx_len, GFP_KERNEL);
799 	if (!adap->rx_buf) {
800 		ret = -ENOMEM;
801 		goto err_put;
802 	}
803 
804 	/* alloc rx urb */
805 	adap->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
806 	if (!adap->rx_urb) {
807 		ret = -ENOMEM;
808 		goto err_put;
809 	}
810 	usb_fill_bulk_urb(adap->rx_urb, usb_dev, adap->rx_pipe,
811 			  adap->rx_buf, adap->rx_len, ljca_recv, adap);
812 
813 	usb_set_intfdata(interface, adap);
814 
815 	/* submit rx urb before enumerate clients */
816 	ret = usb_submit_urb(adap->rx_urb, GFP_KERNEL);
817 	if (ret) {
818 		dev_err(dev, "submit rx urb failed: %d\n", ret);
819 		goto err_free;
820 	}
821 
822 	ret = ljca_enumerate_clients(adap);
823 	if (ret)
824 		goto err_free;
825 
826 	usb_enable_autosuspend(usb_dev);
827 
828 	return 0;
829 
830 err_free:
831 	usb_free_urb(adap->rx_urb);
832 
833 err_put:
834 	usb_put_intf(adap->intf);
835 
836 	mutex_destroy(&adap->mutex);
837 
838 	return ret;
839 }
840 
841 static void ljca_disconnect(struct usb_interface *interface)
842 {
843 	struct ljca_adapter *adap = usb_get_intfdata(interface);
844 	struct ljca_client *client, *next;
845 
846 	adap->disconnect = true;
847 
848 	usb_kill_urb(adap->rx_urb);
849 
850 	list_for_each_entry_safe_reverse(client, next, &adap->client_list, link) {
851 		auxiliary_device_delete(&client->auxdev);
852 		auxiliary_device_uninit(&client->auxdev);
853 
854 		list_del_init(&client->link);
855 		kfree(client);
856 	}
857 
858 	usb_free_urb(adap->rx_urb);
859 
860 	usb_put_intf(adap->intf);
861 
862 	mutex_destroy(&adap->mutex);
863 }
864 
865 static int ljca_suspend(struct usb_interface *interface, pm_message_t message)
866 {
867 	struct ljca_adapter *adap = usb_get_intfdata(interface);
868 
869 	usb_kill_urb(adap->rx_urb);
870 
871 	return 0;
872 }
873 
874 static int ljca_resume(struct usb_interface *interface)
875 {
876 	struct ljca_adapter *adap = usb_get_intfdata(interface);
877 
878 	return usb_submit_urb(adap->rx_urb, GFP_KERNEL);
879 }
880 
881 static const struct usb_device_id ljca_table[] = {
882 	{ USB_DEVICE(0x8086, 0x0b63) },
883 	{ /* sentinel */ }
884 };
885 MODULE_DEVICE_TABLE(usb, ljca_table);
886 
887 static struct usb_driver ljca_driver = {
888 	.name = "ljca",
889 	.id_table = ljca_table,
890 	.probe = ljca_probe,
891 	.disconnect = ljca_disconnect,
892 	.suspend = ljca_suspend,
893 	.resume = ljca_resume,
894 	.supports_autosuspend = 1,
895 };
896 module_usb_driver(ljca_driver);
897 
898 MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
899 MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
900 MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
901 MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB driver");
902 MODULE_LICENSE("GPL");
903