1/*
2 * Driver for the Diolan DLN-2 USB adapter
3 *
4 * Copyright (c) 2014 Intel Corporation
5 *
6 * Derived from:
7 *  i2c-diolan-u2c.c
8 *  Copyright (c) 2010-2011 Ericsson AB
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation, version 2.
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/types.h>
18#include <linux/slab.h>
19#include <linux/usb.h>
20#include <linux/i2c.h>
21#include <linux/mutex.h>
22#include <linux/platform_device.h>
23#include <linux/mfd/core.h>
24#include <linux/mfd/dln2.h>
25#include <linux/rculist.h>
26
27struct dln2_header {
28	__le16 size;
29	__le16 id;
30	__le16 echo;
31	__le16 handle;
32};
33
34struct dln2_response {
35	struct dln2_header hdr;
36	__le16 result;
37};
38
39#define DLN2_GENERIC_MODULE_ID		0x00
40#define DLN2_GENERIC_CMD(cmd)		DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID)
41#define CMD_GET_DEVICE_VER		DLN2_GENERIC_CMD(0x30)
42#define CMD_GET_DEVICE_SN		DLN2_GENERIC_CMD(0x31)
43
44#define DLN2_HW_ID			0x200
45#define DLN2_USB_TIMEOUT		200	/* in ms */
46#define DLN2_MAX_RX_SLOTS		16
47#define DLN2_MAX_URBS			16
48#define DLN2_RX_BUF_SIZE		512
49
50enum dln2_handle {
51	DLN2_HANDLE_EVENT = 0,		/* don't change, hardware defined */
52	DLN2_HANDLE_CTRL,
53	DLN2_HANDLE_GPIO,
54	DLN2_HANDLE_I2C,
55	DLN2_HANDLE_SPI,
56	DLN2_HANDLES
57};
58
59/*
60 * Receive context used between the receive demultiplexer and the transfer
61 * routine. While sending a request the transfer routine will look for a free
62 * receive context and use it to wait for a response and to receive the URB and
63 * thus the response data.
64 */
65struct dln2_rx_context {
66	/* completion used to wait for a response */
67	struct completion done;
68
69	/* if non-NULL the URB contains the response */
70	struct urb *urb;
71
72	/* if true then this context is used to wait for a response */
73	bool in_use;
74};
75
76/*
77 * Receive contexts for a particular DLN2 module (i2c, gpio, etc.). We use the
78 * handle header field to identify the module in dln2_dev.mod_rx_slots and then
79 * the echo header field to index the slots field and find the receive context
80 * for a particular request.
81 */
82struct dln2_mod_rx_slots {
83	/* RX slots bitmap */
84	DECLARE_BITMAP(bmap, DLN2_MAX_RX_SLOTS);
85
86	/* used to wait for a free RX slot */
87	wait_queue_head_t wq;
88
89	/* used to wait for an RX operation to complete */
90	struct dln2_rx_context slots[DLN2_MAX_RX_SLOTS];
91
92	/* avoid races between alloc/free_rx_slot and dln2_rx_transfer */
93	spinlock_t lock;
94};
95
96struct dln2_dev {
97	struct usb_device *usb_dev;
98	struct usb_interface *interface;
99	u8 ep_in;
100	u8 ep_out;
101
102	struct urb *rx_urb[DLN2_MAX_URBS];
103	void *rx_buf[DLN2_MAX_URBS];
104
105	struct dln2_mod_rx_slots mod_rx_slots[DLN2_HANDLES];
106
107	struct list_head event_cb_list;
108	spinlock_t event_cb_lock;
109
110	bool disconnect;
111	int active_transfers;
112	wait_queue_head_t disconnect_wq;
113	spinlock_t disconnect_lock;
114};
115
116struct dln2_event_cb_entry {
117	struct list_head list;
118	u16 id;
119	struct platform_device *pdev;
120	dln2_event_cb_t callback;
121};
122
123int dln2_register_event_cb(struct platform_device *pdev, u16 id,
124			   dln2_event_cb_t event_cb)
125{
126	struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
127	struct dln2_event_cb_entry *i, *entry;
128	unsigned long flags;
129	int ret = 0;
130
131	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
132	if (!entry)
133		return -ENOMEM;
134
135	entry->id = id;
136	entry->callback = event_cb;
137	entry->pdev = pdev;
138
139	spin_lock_irqsave(&dln2->event_cb_lock, flags);
140
141	list_for_each_entry(i, &dln2->event_cb_list, list) {
142		if (i->id == id) {
143			ret = -EBUSY;
144			break;
145		}
146	}
147
148	if (!ret)
149		list_add_rcu(&entry->list, &dln2->event_cb_list);
150
151	spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
152
153	if (ret)
154		kfree(entry);
155
156	return ret;
157}
158EXPORT_SYMBOL(dln2_register_event_cb);
159
160void dln2_unregister_event_cb(struct platform_device *pdev, u16 id)
161{
162	struct dln2_dev *dln2 = dev_get_drvdata(pdev->dev.parent);
163	struct dln2_event_cb_entry *i;
164	unsigned long flags;
165	bool found = false;
166
167	spin_lock_irqsave(&dln2->event_cb_lock, flags);
168
169	list_for_each_entry(i, &dln2->event_cb_list, list) {
170		if (i->id == id) {
171			list_del_rcu(&i->list);
172			found = true;
173			break;
174		}
175	}
176
177	spin_unlock_irqrestore(&dln2->event_cb_lock, flags);
178
179	if (found) {
180		synchronize_rcu();
181		kfree(i);
182	}
183}
184EXPORT_SYMBOL(dln2_unregister_event_cb);
185
186/*
187 * Returns true if a valid transfer slot is found. In this case the URB must not
188 * be resubmitted immediately in dln2_rx as we need the data when dln2_transfer
189 * is woke up. It will be resubmitted there.
190 */
191static bool dln2_transfer_complete(struct dln2_dev *dln2, struct urb *urb,
192				   u16 handle, u16 rx_slot)
193{
194	struct device *dev = &dln2->interface->dev;
195	struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
196	struct dln2_rx_context *rxc;
197	bool valid_slot = false;
198
199	if (rx_slot >= DLN2_MAX_RX_SLOTS)
200		goto out;
201
202	rxc = &rxs->slots[rx_slot];
203
204	/*
205	 * No need to disable interrupts as this lock is not taken in interrupt
206	 * context elsewhere in this driver. This function (or its callers) are
207	 * also not exported to other modules.
208	 */
209	spin_lock(&rxs->lock);
210	if (rxc->in_use && !rxc->urb) {
211		rxc->urb = urb;
212		complete(&rxc->done);
213		valid_slot = true;
214	}
215	spin_unlock(&rxs->lock);
216
217out:
218	if (!valid_slot)
219		dev_warn(dev, "bad/late response %d/%d\n", handle, rx_slot);
220
221	return valid_slot;
222}
223
224static void dln2_run_event_callbacks(struct dln2_dev *dln2, u16 id, u16 echo,
225				     void *data, int len)
226{
227	struct dln2_event_cb_entry *i;
228
229	rcu_read_lock();
230
231	list_for_each_entry_rcu(i, &dln2->event_cb_list, list) {
232		if (i->id == id) {
233			i->callback(i->pdev, echo, data, len);
234			break;
235		}
236	}
237
238	rcu_read_unlock();
239}
240
241static void dln2_rx(struct urb *urb)
242{
243	struct dln2_dev *dln2 = urb->context;
244	struct dln2_header *hdr = urb->transfer_buffer;
245	struct device *dev = &dln2->interface->dev;
246	u16 id, echo, handle, size;
247	u8 *data;
248	int len;
249	int err;
250
251	switch (urb->status) {
252	case 0:
253		/* success */
254		break;
255	case -ECONNRESET:
256	case -ENOENT:
257	case -ESHUTDOWN:
258	case -EPIPE:
259		/* this urb is terminated, clean up */
260		dev_dbg(dev, "urb shutting down with status %d\n", urb->status);
261		return;
262	default:
263		dev_dbg(dev, "nonzero urb status received %d\n", urb->status);
264		goto out;
265	}
266
267	if (urb->actual_length < sizeof(struct dln2_header)) {
268		dev_err(dev, "short response: %d\n", urb->actual_length);
269		goto out;
270	}
271
272	handle = le16_to_cpu(hdr->handle);
273	id = le16_to_cpu(hdr->id);
274	echo = le16_to_cpu(hdr->echo);
275	size = le16_to_cpu(hdr->size);
276
277	if (size != urb->actual_length) {
278		dev_err(dev, "size mismatch: handle %x cmd %x echo %x size %d actual %d\n",
279			handle, id, echo, size, urb->actual_length);
280		goto out;
281	}
282
283	if (handle >= DLN2_HANDLES) {
284		dev_warn(dev, "invalid handle %d\n", handle);
285		goto out;
286	}
287
288	data = urb->transfer_buffer + sizeof(struct dln2_header);
289	len = urb->actual_length - sizeof(struct dln2_header);
290
291	if (handle == DLN2_HANDLE_EVENT) {
292		dln2_run_event_callbacks(dln2, id, echo, data, len);
293	} else {
294		/* URB will be re-submitted in _dln2_transfer (free_rx_slot) */
295		if (dln2_transfer_complete(dln2, urb, handle, echo))
296			return;
297	}
298
299out:
300	err = usb_submit_urb(urb, GFP_ATOMIC);
301	if (err < 0)
302		dev_err(dev, "failed to resubmit RX URB: %d\n", err);
303}
304
305static void *dln2_prep_buf(u16 handle, u16 cmd, u16 echo, const void *obuf,
306			   int *obuf_len, gfp_t gfp)
307{
308	int len;
309	void *buf;
310	struct dln2_header *hdr;
311
312	len = *obuf_len + sizeof(*hdr);
313	buf = kmalloc(len, gfp);
314	if (!buf)
315		return NULL;
316
317	hdr = (struct dln2_header *)buf;
318	hdr->id = cpu_to_le16(cmd);
319	hdr->size = cpu_to_le16(len);
320	hdr->echo = cpu_to_le16(echo);
321	hdr->handle = cpu_to_le16(handle);
322
323	memcpy(buf + sizeof(*hdr), obuf, *obuf_len);
324
325	*obuf_len = len;
326
327	return buf;
328}
329
330static int dln2_send_wait(struct dln2_dev *dln2, u16 handle, u16 cmd, u16 echo,
331			  const void *obuf, int obuf_len)
332{
333	int ret = 0;
334	int len = obuf_len;
335	void *buf;
336	int actual;
337
338	buf = dln2_prep_buf(handle, cmd, echo, obuf, &len, GFP_KERNEL);
339	if (!buf)
340		return -ENOMEM;
341
342	ret = usb_bulk_msg(dln2->usb_dev,
343			   usb_sndbulkpipe(dln2->usb_dev, dln2->ep_out),
344			   buf, len, &actual, DLN2_USB_TIMEOUT);
345
346	kfree(buf);
347
348	return ret;
349}
350
351static bool find_free_slot(struct dln2_dev *dln2, u16 handle, int *slot)
352{
353	struct dln2_mod_rx_slots *rxs;
354	unsigned long flags;
355
356	if (dln2->disconnect) {
357		*slot = -ENODEV;
358		return true;
359	}
360
361	rxs = &dln2->mod_rx_slots[handle];
362
363	spin_lock_irqsave(&rxs->lock, flags);
364
365	*slot = find_first_zero_bit(rxs->bmap, DLN2_MAX_RX_SLOTS);
366
367	if (*slot < DLN2_MAX_RX_SLOTS) {
368		struct dln2_rx_context *rxc = &rxs->slots[*slot];
369
370		set_bit(*slot, rxs->bmap);
371		rxc->in_use = true;
372	}
373
374	spin_unlock_irqrestore(&rxs->lock, flags);
375
376	return *slot < DLN2_MAX_RX_SLOTS;
377}
378
379static int alloc_rx_slot(struct dln2_dev *dln2, u16 handle)
380{
381	int ret;
382	int slot;
383
384	/*
385	 * No need to timeout here, the wait is bounded by the timeout in
386	 * _dln2_transfer.
387	 */
388	ret = wait_event_interruptible(dln2->mod_rx_slots[handle].wq,
389				       find_free_slot(dln2, handle, &slot));
390	if (ret < 0)
391		return ret;
392
393	return slot;
394}
395
396static void free_rx_slot(struct dln2_dev *dln2, u16 handle, int slot)
397{
398	struct dln2_mod_rx_slots *rxs;
399	struct urb *urb = NULL;
400	unsigned long flags;
401	struct dln2_rx_context *rxc;
402
403	rxs = &dln2->mod_rx_slots[handle];
404
405	spin_lock_irqsave(&rxs->lock, flags);
406
407	clear_bit(slot, rxs->bmap);
408
409	rxc = &rxs->slots[slot];
410	rxc->in_use = false;
411	urb = rxc->urb;
412	rxc->urb = NULL;
413	reinit_completion(&rxc->done);
414
415	spin_unlock_irqrestore(&rxs->lock, flags);
416
417	if (urb) {
418		int err;
419		struct device *dev = &dln2->interface->dev;
420
421		err = usb_submit_urb(urb, GFP_KERNEL);
422		if (err < 0)
423			dev_err(dev, "failed to resubmit RX URB: %d\n", err);
424	}
425
426	wake_up_interruptible(&rxs->wq);
427}
428
429static int _dln2_transfer(struct dln2_dev *dln2, u16 handle, u16 cmd,
430			  const void *obuf, unsigned obuf_len,
431			  void *ibuf, unsigned *ibuf_len)
432{
433	int ret = 0;
434	int rx_slot;
435	struct dln2_response *rsp;
436	struct dln2_rx_context *rxc;
437	struct device *dev = &dln2->interface->dev;
438	const unsigned long timeout = msecs_to_jiffies(DLN2_USB_TIMEOUT);
439	struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[handle];
440	int size;
441
442	spin_lock(&dln2->disconnect_lock);
443	if (!dln2->disconnect)
444		dln2->active_transfers++;
445	else
446		ret = -ENODEV;
447	spin_unlock(&dln2->disconnect_lock);
448
449	if (ret)
450		return ret;
451
452	rx_slot = alloc_rx_slot(dln2, handle);
453	if (rx_slot < 0) {
454		ret = rx_slot;
455		goto out_decr;
456	}
457
458	ret = dln2_send_wait(dln2, handle, cmd, rx_slot, obuf, obuf_len);
459	if (ret < 0) {
460		dev_err(dev, "USB write failed: %d\n", ret);
461		goto out_free_rx_slot;
462	}
463
464	rxc = &rxs->slots[rx_slot];
465
466	ret = wait_for_completion_interruptible_timeout(&rxc->done, timeout);
467	if (ret <= 0) {
468		if (!ret)
469			ret = -ETIMEDOUT;
470		goto out_free_rx_slot;
471	} else {
472		ret = 0;
473	}
474
475	if (dln2->disconnect) {
476		ret = -ENODEV;
477		goto out_free_rx_slot;
478	}
479
480	/* if we got here we know that the response header has been checked */
481	rsp = rxc->urb->transfer_buffer;
482	size = le16_to_cpu(rsp->hdr.size);
483
484	if (size < sizeof(*rsp)) {
485		ret = -EPROTO;
486		goto out_free_rx_slot;
487	}
488
489	if (le16_to_cpu(rsp->result) > 0x80) {
490		dev_dbg(dev, "%d received response with error %d\n",
491			handle, le16_to_cpu(rsp->result));
492		ret = -EREMOTEIO;
493		goto out_free_rx_slot;
494	}
495
496	if (!ibuf)
497		goto out_free_rx_slot;
498
499	if (*ibuf_len > size - sizeof(*rsp))
500		*ibuf_len = size - sizeof(*rsp);
501
502	memcpy(ibuf, rsp + 1, *ibuf_len);
503
504out_free_rx_slot:
505	free_rx_slot(dln2, handle, rx_slot);
506out_decr:
507	spin_lock(&dln2->disconnect_lock);
508	dln2->active_transfers--;
509	spin_unlock(&dln2->disconnect_lock);
510	if (dln2->disconnect)
511		wake_up(&dln2->disconnect_wq);
512
513	return ret;
514}
515
516int dln2_transfer(struct platform_device *pdev, u16 cmd,
517		  const void *obuf, unsigned obuf_len,
518		  void *ibuf, unsigned *ibuf_len)
519{
520	struct dln2_platform_data *dln2_pdata;
521	struct dln2_dev *dln2;
522	u16 handle;
523
524	dln2 = dev_get_drvdata(pdev->dev.parent);
525	dln2_pdata = dev_get_platdata(&pdev->dev);
526	handle = dln2_pdata->handle;
527
528	return _dln2_transfer(dln2, handle, cmd, obuf, obuf_len, ibuf,
529			      ibuf_len);
530}
531EXPORT_SYMBOL(dln2_transfer);
532
533static int dln2_check_hw(struct dln2_dev *dln2)
534{
535	int ret;
536	__le32 hw_type;
537	int len = sizeof(hw_type);
538
539	ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_VER,
540			     NULL, 0, &hw_type, &len);
541	if (ret < 0)
542		return ret;
543	if (len < sizeof(hw_type))
544		return -EREMOTEIO;
545
546	if (le32_to_cpu(hw_type) != DLN2_HW_ID) {
547		dev_err(&dln2->interface->dev, "Device ID 0x%x not supported\n",
548			le32_to_cpu(hw_type));
549		return -ENODEV;
550	}
551
552	return 0;
553}
554
555static int dln2_print_serialno(struct dln2_dev *dln2)
556{
557	int ret;
558	__le32 serial_no;
559	int len = sizeof(serial_no);
560	struct device *dev = &dln2->interface->dev;
561
562	ret = _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_GET_DEVICE_SN, NULL, 0,
563			     &serial_no, &len);
564	if (ret < 0)
565		return ret;
566	if (len < sizeof(serial_no))
567		return -EREMOTEIO;
568
569	dev_info(dev, "Diolan DLN2 serial %u\n", le32_to_cpu(serial_no));
570
571	return 0;
572}
573
574static int dln2_hw_init(struct dln2_dev *dln2)
575{
576	int ret;
577
578	ret = dln2_check_hw(dln2);
579	if (ret < 0)
580		return ret;
581
582	return dln2_print_serialno(dln2);
583}
584
585static void dln2_free_rx_urbs(struct dln2_dev *dln2)
586{
587	int i;
588
589	for (i = 0; i < DLN2_MAX_URBS; i++) {
590		usb_free_urb(dln2->rx_urb[i]);
591		kfree(dln2->rx_buf[i]);
592	}
593}
594
595static void dln2_stop_rx_urbs(struct dln2_dev *dln2)
596{
597	int i;
598
599	for (i = 0; i < DLN2_MAX_URBS; i++)
600		usb_kill_urb(dln2->rx_urb[i]);
601}
602
603static void dln2_free(struct dln2_dev *dln2)
604{
605	dln2_free_rx_urbs(dln2);
606	usb_put_dev(dln2->usb_dev);
607	kfree(dln2);
608}
609
610static int dln2_setup_rx_urbs(struct dln2_dev *dln2,
611			      struct usb_host_interface *hostif)
612{
613	int i;
614	const int rx_max_size = DLN2_RX_BUF_SIZE;
615
616	for (i = 0; i < DLN2_MAX_URBS; i++) {
617		dln2->rx_buf[i] = kmalloc(rx_max_size, GFP_KERNEL);
618		if (!dln2->rx_buf[i])
619			return -ENOMEM;
620
621		dln2->rx_urb[i] = usb_alloc_urb(0, GFP_KERNEL);
622		if (!dln2->rx_urb[i])
623			return -ENOMEM;
624
625		usb_fill_bulk_urb(dln2->rx_urb[i], dln2->usb_dev,
626				  usb_rcvbulkpipe(dln2->usb_dev, dln2->ep_in),
627				  dln2->rx_buf[i], rx_max_size, dln2_rx, dln2);
628	}
629
630	return 0;
631}
632
633static int dln2_start_rx_urbs(struct dln2_dev *dln2, gfp_t gfp)
634{
635	struct device *dev = &dln2->interface->dev;
636	int ret;
637	int i;
638
639	for (i = 0; i < DLN2_MAX_URBS; i++) {
640		ret = usb_submit_urb(dln2->rx_urb[i], gfp);
641		if (ret < 0) {
642			dev_err(dev, "failed to submit RX URB: %d\n", ret);
643			return ret;
644		}
645	}
646
647	return 0;
648}
649
650static struct dln2_platform_data dln2_pdata_gpio = {
651	.handle = DLN2_HANDLE_GPIO,
652};
653
654/* Only one I2C port seems to be supported on current hardware */
655static struct dln2_platform_data dln2_pdata_i2c = {
656	.handle = DLN2_HANDLE_I2C,
657	.port = 0,
658};
659
660/* Only one SPI port supported */
661static struct dln2_platform_data dln2_pdata_spi = {
662	.handle = DLN2_HANDLE_SPI,
663	.port = 0,
664};
665
666static const struct mfd_cell dln2_devs[] = {
667	{
668		.name = "dln2-gpio",
669		.platform_data = &dln2_pdata_gpio,
670		.pdata_size = sizeof(struct dln2_platform_data),
671	},
672	{
673		.name = "dln2-i2c",
674		.platform_data = &dln2_pdata_i2c,
675		.pdata_size = sizeof(struct dln2_platform_data),
676	},
677	{
678		.name = "dln2-spi",
679		.platform_data = &dln2_pdata_spi,
680		.pdata_size = sizeof(struct dln2_platform_data),
681	},
682};
683
684static void dln2_stop(struct dln2_dev *dln2)
685{
686	int i, j;
687
688	/* don't allow starting new transfers */
689	spin_lock(&dln2->disconnect_lock);
690	dln2->disconnect = true;
691	spin_unlock(&dln2->disconnect_lock);
692
693	/* cancel in progress transfers */
694	for (i = 0; i < DLN2_HANDLES; i++) {
695		struct dln2_mod_rx_slots *rxs = &dln2->mod_rx_slots[i];
696		unsigned long flags;
697
698		spin_lock_irqsave(&rxs->lock, flags);
699
700		/* cancel all response waiters */
701		for (j = 0; j < DLN2_MAX_RX_SLOTS; j++) {
702			struct dln2_rx_context *rxc = &rxs->slots[j];
703
704			if (rxc->in_use)
705				complete(&rxc->done);
706		}
707
708		spin_unlock_irqrestore(&rxs->lock, flags);
709	}
710
711	/* wait for transfers to end */
712	wait_event(dln2->disconnect_wq, !dln2->active_transfers);
713
714	dln2_stop_rx_urbs(dln2);
715}
716
717static void dln2_disconnect(struct usb_interface *interface)
718{
719	struct dln2_dev *dln2 = usb_get_intfdata(interface);
720
721	dln2_stop(dln2);
722
723	mfd_remove_devices(&interface->dev);
724
725	dln2_free(dln2);
726}
727
728static int dln2_probe(struct usb_interface *interface,
729		      const struct usb_device_id *usb_id)
730{
731	struct usb_host_interface *hostif = interface->cur_altsetting;
732	struct device *dev = &interface->dev;
733	struct dln2_dev *dln2;
734	int ret;
735	int i, j;
736
737	if (hostif->desc.bInterfaceNumber != 0 ||
738	    hostif->desc.bNumEndpoints < 2)
739		return -ENODEV;
740
741	dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
742	if (!dln2)
743		return -ENOMEM;
744
745	dln2->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
746	dln2->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
747	dln2->usb_dev = usb_get_dev(interface_to_usbdev(interface));
748	dln2->interface = interface;
749	usb_set_intfdata(interface, dln2);
750	init_waitqueue_head(&dln2->disconnect_wq);
751
752	for (i = 0; i < DLN2_HANDLES; i++) {
753		init_waitqueue_head(&dln2->mod_rx_slots[i].wq);
754		spin_lock_init(&dln2->mod_rx_slots[i].lock);
755		for (j = 0; j < DLN2_MAX_RX_SLOTS; j++)
756			init_completion(&dln2->mod_rx_slots[i].slots[j].done);
757	}
758
759	spin_lock_init(&dln2->event_cb_lock);
760	spin_lock_init(&dln2->disconnect_lock);
761	INIT_LIST_HEAD(&dln2->event_cb_list);
762
763	ret = dln2_setup_rx_urbs(dln2, hostif);
764	if (ret)
765		goto out_free;
766
767	ret = dln2_start_rx_urbs(dln2, GFP_KERNEL);
768	if (ret)
769		goto out_stop_rx;
770
771	ret = dln2_hw_init(dln2);
772	if (ret < 0) {
773		dev_err(dev, "failed to initialize hardware\n");
774		goto out_stop_rx;
775	}
776
777	ret = mfd_add_hotplug_devices(dev, dln2_devs, ARRAY_SIZE(dln2_devs));
778	if (ret != 0) {
779		dev_err(dev, "failed to add mfd devices to core\n");
780		goto out_stop_rx;
781	}
782
783	return 0;
784
785out_stop_rx:
786	dln2_stop_rx_urbs(dln2);
787
788out_free:
789	dln2_free(dln2);
790
791	return ret;
792}
793
794static int dln2_suspend(struct usb_interface *iface, pm_message_t message)
795{
796	struct dln2_dev *dln2 = usb_get_intfdata(iface);
797
798	dln2_stop(dln2);
799
800	return 0;
801}
802
803static int dln2_resume(struct usb_interface *iface)
804{
805	struct dln2_dev *dln2 = usb_get_intfdata(iface);
806
807	dln2->disconnect = false;
808
809	return dln2_start_rx_urbs(dln2, GFP_NOIO);
810}
811
812static const struct usb_device_id dln2_table[] = {
813	{ USB_DEVICE(0xa257, 0x2013) },
814	{ }
815};
816
817MODULE_DEVICE_TABLE(usb, dln2_table);
818
819static struct usb_driver dln2_driver = {
820	.name = "dln2",
821	.probe = dln2_probe,
822	.disconnect = dln2_disconnect,
823	.id_table = dln2_table,
824	.suspend = dln2_suspend,
825	.resume = dln2_resume,
826};
827
828module_usb_driver(dln2_driver);
829
830MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
831MODULE_DESCRIPTION("Core driver for the Diolan DLN2 interface adapter");
832MODULE_LICENSE("GPL v2");
833