xref: /openbmc/linux/drivers/most/most_usb.c (revision a1117495)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * usb.c - Hardware dependent module for USB
4  *
5  * Copyright (C) 2013-2015 Microchip Technology Germany II GmbH & Co. KG
6  */
7 
8 #include <linux/module.h>
9 #include <linux/fs.h>
10 #include <linux/usb.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/cdev.h>
14 #include <linux/device.h>
15 #include <linux/list.h>
16 #include <linux/completion.h>
17 #include <linux/mutex.h>
18 #include <linux/spinlock.h>
19 #include <linux/interrupt.h>
20 #include <linux/workqueue.h>
21 #include <linux/sysfs.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/etherdevice.h>
24 #include <linux/uaccess.h>
25 #include <linux/most.h>
26 
27 #define USB_MTU			512
28 #define NO_ISOCHRONOUS_URB	0
29 #define AV_PACKETS_PER_XACT	2
30 #define BUF_CHAIN_SIZE		0xFFFF
31 #define MAX_NUM_ENDPOINTS	30
32 #define MAX_SUFFIX_LEN		10
33 #define MAX_STRING_LEN		80
34 #define MAX_BUF_SIZE		0xFFFF
35 
36 #define USB_VENDOR_ID_SMSC	0x0424  /* VID: SMSC */
37 #define USB_DEV_ID_BRDG		0xC001  /* PID: USB Bridge */
38 #define USB_DEV_ID_OS81118	0xCF18  /* PID: USB OS81118 */
39 #define USB_DEV_ID_OS81119	0xCF19  /* PID: USB OS81119 */
40 #define USB_DEV_ID_OS81210	0xCF30  /* PID: USB OS81210 */
41 /* DRCI Addresses */
42 #define DRCI_REG_NI_STATE	0x0100
43 #define DRCI_REG_PACKET_BW	0x0101
44 #define DRCI_REG_NODE_ADDR	0x0102
45 #define DRCI_REG_NODE_POS	0x0103
46 #define DRCI_REG_MEP_FILTER	0x0140
47 #define DRCI_REG_HASH_TBL0	0x0141
48 #define DRCI_REG_HASH_TBL1	0x0142
49 #define DRCI_REG_HASH_TBL2	0x0143
50 #define DRCI_REG_HASH_TBL3	0x0144
51 #define DRCI_REG_HW_ADDR_HI	0x0145
52 #define DRCI_REG_HW_ADDR_MI	0x0146
53 #define DRCI_REG_HW_ADDR_LO	0x0147
54 #define DRCI_REG_BASE		0x1100
55 #define DRCI_COMMAND		0x02
56 #define DRCI_READ_REQ		0xA0
57 #define DRCI_WRITE_REQ		0xA1
58 
59 /**
60  * struct most_dci_obj - Direct Communication Interface
61  * @kobj:position in sysfs
62  * @usb_device: pointer to the usb device
63  * @reg_addr: register address for arbitrary DCI access
64  */
65 struct most_dci_obj {
66 	struct device dev;
67 	struct usb_device *usb_device;
68 	u16 reg_addr;
69 };
70 
71 #define to_dci_obj(p) container_of(p, struct most_dci_obj, dev)
72 
73 struct most_dev;
74 
75 struct clear_hold_work {
76 	struct work_struct ws;
77 	struct most_dev *mdev;
78 	unsigned int channel;
79 	int pipe;
80 };
81 
82 #define to_clear_hold_work(w) container_of(w, struct clear_hold_work, ws)
83 
84 /**
85  * struct most_dev - holds all usb interface specific stuff
86  * @usb_device: pointer to usb device
87  * @iface: hardware interface
88  * @cap: channel capabilities
89  * @conf: channel configuration
90  * @dci: direct communication interface of hardware
91  * @ep_address: endpoint address table
92  * @description: device description
93  * @suffix: suffix for channel name
94  * @channel_lock: synchronize channel access
95  * @padding_active: indicates channel uses padding
96  * @is_channel_healthy: health status table of each channel
97  * @busy_urbs: list of anchored items
98  * @io_mutex: synchronize I/O with disconnect
99  * @link_stat_timer: timer for link status reports
100  * @poll_work_obj: work for polling link status
101  */
102 struct most_dev {
103 	struct device dev;
104 	struct usb_device *usb_device;
105 	struct most_interface iface;
106 	struct most_channel_capability *cap;
107 	struct most_channel_config *conf;
108 	struct most_dci_obj *dci;
109 	u8 *ep_address;
110 	char description[MAX_STRING_LEN];
111 	char suffix[MAX_NUM_ENDPOINTS][MAX_SUFFIX_LEN];
112 	spinlock_t channel_lock[MAX_NUM_ENDPOINTS]; /* sync channel access */
113 	bool padding_active[MAX_NUM_ENDPOINTS];
114 	bool is_channel_healthy[MAX_NUM_ENDPOINTS];
115 	struct clear_hold_work clear_work[MAX_NUM_ENDPOINTS];
116 	struct usb_anchor *busy_urbs;
117 	struct mutex io_mutex;
118 	struct timer_list link_stat_timer;
119 	struct work_struct poll_work_obj;
120 	void (*on_netinfo)(struct most_interface *most_iface,
121 			   unsigned char link_state, unsigned char *addrs);
122 };
123 
124 #define to_mdev(d) container_of(d, struct most_dev, iface)
125 #define to_mdev_from_dev(d) container_of(d, struct most_dev, dev)
126 #define to_mdev_from_work(w) container_of(w, struct most_dev, poll_work_obj)
127 
128 static void wq_clear_halt(struct work_struct *wq_obj);
129 static void wq_netinfo(struct work_struct *wq_obj);
130 
131 /**
132  * drci_rd_reg - read a DCI register
133  * @dev: usb device
134  * @reg: register address
135  * @buf: buffer to store data
136  *
137  * This is reads data from INIC's direct register communication interface
138  */
139 static inline int drci_rd_reg(struct usb_device *dev, u16 reg, u16 *buf)
140 {
141 	int retval;
142 	__le16 *dma_buf;
143 	u8 req_type = USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE;
144 
145 	dma_buf = kzalloc(sizeof(*dma_buf), GFP_KERNEL);
146 	if (!dma_buf)
147 		return -ENOMEM;
148 
149 	retval = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
150 				 DRCI_READ_REQ, req_type,
151 				 0x0000,
152 				 reg, dma_buf, sizeof(*dma_buf),
153 				 USB_CTRL_GET_TIMEOUT);
154 	*buf = le16_to_cpu(*dma_buf);
155 	kfree(dma_buf);
156 
157 	if (retval < 0)
158 		return retval;
159 	return 0;
160 }
161 
162 /**
163  * drci_wr_reg - write a DCI register
164  * @dev: usb device
165  * @reg: register address
166  * @data: data to write
167  *
168  * This is writes data to INIC's direct register communication interface
169  */
170 static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
171 {
172 	return usb_control_msg(dev,
173 			       usb_sndctrlpipe(dev, 0),
174 			       DRCI_WRITE_REQ,
175 			       USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
176 			       data,
177 			       reg,
178 			       NULL,
179 			       0,
180 			       USB_CTRL_SET_TIMEOUT);
181 }
182 
183 static inline int start_sync_ep(struct usb_device *usb_dev, u16 ep)
184 {
185 	return drci_wr_reg(usb_dev, DRCI_REG_BASE + DRCI_COMMAND + ep * 16, 1);
186 }
187 
188 /**
189  * get_stream_frame_size - calculate frame size of current configuration
190  * @dev: device structure
191  * @cfg: channel configuration
192  */
193 static unsigned int get_stream_frame_size(struct device *dev,
194 					  struct most_channel_config *cfg)
195 {
196 	unsigned int frame_size;
197 	unsigned int sub_size = cfg->subbuffer_size;
198 
199 	if (!sub_size) {
200 		dev_warn(dev, "Misconfig: Subbuffer size zero.\n");
201 		return 0;
202 	}
203 	switch (cfg->data_type) {
204 	case MOST_CH_ISOC:
205 		frame_size = AV_PACKETS_PER_XACT * sub_size;
206 		break;
207 	case MOST_CH_SYNC:
208 		if (cfg->packets_per_xact == 0) {
209 			dev_warn(dev, "Misconfig: Packets per XACT zero\n");
210 			frame_size = 0;
211 		} else if (cfg->packets_per_xact == 0xFF) {
212 			frame_size = (USB_MTU / sub_size) * sub_size;
213 		} else {
214 			frame_size = cfg->packets_per_xact * sub_size;
215 		}
216 		break;
217 	default:
218 		dev_warn(dev, "Query frame size of non-streaming channel\n");
219 		frame_size = 0;
220 		break;
221 	}
222 	return frame_size;
223 }
224 
225 /**
226  * hdm_poison_channel - mark buffers of this channel as invalid
227  * @iface: pointer to the interface
228  * @channel: channel ID
229  *
230  * This unlinks all URBs submitted to the HCD,
231  * calls the associated completion function of the core and removes
232  * them from the list.
233  *
234  * Returns 0 on success or error code otherwise.
235  */
236 static int hdm_poison_channel(struct most_interface *iface, int channel)
237 {
238 	struct most_dev *mdev = to_mdev(iface);
239 	unsigned long flags;
240 	spinlock_t *lock; /* temp. lock */
241 
242 	if (channel < 0 || channel >= iface->num_channels) {
243 		dev_warn(&mdev->usb_device->dev, "Channel ID out of range.\n");
244 		return -ECHRNG;
245 	}
246 
247 	lock = mdev->channel_lock + channel;
248 	spin_lock_irqsave(lock, flags);
249 	mdev->is_channel_healthy[channel] = false;
250 	spin_unlock_irqrestore(lock, flags);
251 
252 	cancel_work_sync(&mdev->clear_work[channel].ws);
253 
254 	mutex_lock(&mdev->io_mutex);
255 	usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
256 	if (mdev->padding_active[channel])
257 		mdev->padding_active[channel] = false;
258 
259 	if (mdev->conf[channel].data_type == MOST_CH_ASYNC) {
260 		del_timer_sync(&mdev->link_stat_timer);
261 		cancel_work_sync(&mdev->poll_work_obj);
262 	}
263 	mutex_unlock(&mdev->io_mutex);
264 	return 0;
265 }
266 
267 /**
268  * hdm_add_padding - add padding bytes
269  * @mdev: most device
270  * @channel: channel ID
271  * @mbo: buffer object
272  *
273  * This inserts the INIC hardware specific padding bytes into a streaming
274  * channel's buffer
275  */
276 static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
277 {
278 	struct most_channel_config *conf = &mdev->conf[channel];
279 	unsigned int frame_size = get_stream_frame_size(&mdev->dev, conf);
280 	unsigned int j, num_frames;
281 
282 	if (!frame_size)
283 		return -EINVAL;
284 	num_frames = mbo->buffer_length / frame_size;
285 
286 	if (num_frames < 1) {
287 		dev_err(&mdev->usb_device->dev,
288 			"Missed minimal transfer unit.\n");
289 		return -EINVAL;
290 	}
291 
292 	for (j = num_frames - 1; j > 0; j--)
293 		memmove(mbo->virt_address + j * USB_MTU,
294 			mbo->virt_address + j * frame_size,
295 			frame_size);
296 	mbo->buffer_length = num_frames * USB_MTU;
297 	return 0;
298 }
299 
300 /**
301  * hdm_remove_padding - remove padding bytes
302  * @mdev: most device
303  * @channel: channel ID
304  * @mbo: buffer object
305  *
306  * This takes the INIC hardware specific padding bytes off a streaming
307  * channel's buffer.
308  */
309 static int hdm_remove_padding(struct most_dev *mdev, int channel,
310 			      struct mbo *mbo)
311 {
312 	struct most_channel_config *const conf = &mdev->conf[channel];
313 	unsigned int frame_size = get_stream_frame_size(&mdev->dev, conf);
314 	unsigned int j, num_frames;
315 
316 	if (!frame_size)
317 		return -EINVAL;
318 	num_frames = mbo->processed_length / USB_MTU;
319 
320 	for (j = 1; j < num_frames; j++)
321 		memmove(mbo->virt_address + frame_size * j,
322 			mbo->virt_address + USB_MTU * j,
323 			frame_size);
324 
325 	mbo->processed_length = frame_size * num_frames;
326 	return 0;
327 }
328 
329 /**
330  * hdm_write_completion - completion function for submitted Tx URBs
331  * @urb: the URB that has been completed
332  *
333  * This checks the status of the completed URB. In case the URB has been
334  * unlinked before, it is immediately freed. On any other error the MBO
335  * transfer flag is set. On success it frees allocated resources and calls
336  * the completion function.
337  *
338  * Context: interrupt!
339  */
340 static void hdm_write_completion(struct urb *urb)
341 {
342 	struct mbo *mbo = urb->context;
343 	struct most_dev *mdev = to_mdev(mbo->ifp);
344 	unsigned int channel = mbo->hdm_channel_id;
345 	spinlock_t *lock = mdev->channel_lock + channel;
346 	unsigned long flags;
347 
348 	spin_lock_irqsave(lock, flags);
349 
350 	mbo->processed_length = 0;
351 	mbo->status = MBO_E_INVAL;
352 	if (likely(mdev->is_channel_healthy[channel])) {
353 		switch (urb->status) {
354 		case 0:
355 		case -ESHUTDOWN:
356 			mbo->processed_length = urb->actual_length;
357 			mbo->status = MBO_SUCCESS;
358 			break;
359 		case -EPIPE:
360 			dev_warn(&mdev->usb_device->dev,
361 				 "Broken pipe on ep%02x\n",
362 				 mdev->ep_address[channel]);
363 			mdev->is_channel_healthy[channel] = false;
364 			mdev->clear_work[channel].pipe = urb->pipe;
365 			schedule_work(&mdev->clear_work[channel].ws);
366 			break;
367 		case -ENODEV:
368 		case -EPROTO:
369 			mbo->status = MBO_E_CLOSE;
370 			break;
371 		}
372 	}
373 
374 	spin_unlock_irqrestore(lock, flags);
375 
376 	if (likely(mbo->complete))
377 		mbo->complete(mbo);
378 	usb_free_urb(urb);
379 }
380 
381 /**
382  * hdm_read_completion - completion function for submitted Rx URBs
383  * @urb: the URB that has been completed
384  *
385  * This checks the status of the completed URB. In case the URB has been
386  * unlinked before it is immediately freed. On any other error the MBO transfer
387  * flag is set. On success it frees allocated resources, removes
388  * padding bytes -if necessary- and calls the completion function.
389  *
390  * Context: interrupt!
391  */
392 static void hdm_read_completion(struct urb *urb)
393 {
394 	struct mbo *mbo = urb->context;
395 	struct most_dev *mdev = to_mdev(mbo->ifp);
396 	unsigned int channel = mbo->hdm_channel_id;
397 	struct device *dev = &mdev->usb_device->dev;
398 	spinlock_t *lock = mdev->channel_lock + channel;
399 	unsigned long flags;
400 
401 	spin_lock_irqsave(lock, flags);
402 
403 	mbo->processed_length = 0;
404 	mbo->status = MBO_E_INVAL;
405 	if (likely(mdev->is_channel_healthy[channel])) {
406 		switch (urb->status) {
407 		case 0:
408 		case -ESHUTDOWN:
409 			mbo->processed_length = urb->actual_length;
410 			mbo->status = MBO_SUCCESS;
411 			if (mdev->padding_active[channel] &&
412 			    hdm_remove_padding(mdev, channel, mbo)) {
413 				mbo->processed_length = 0;
414 				mbo->status = MBO_E_INVAL;
415 			}
416 			break;
417 		case -EPIPE:
418 			dev_warn(dev, "Broken pipe on ep%02x\n",
419 				 mdev->ep_address[channel]);
420 			mdev->is_channel_healthy[channel] = false;
421 			mdev->clear_work[channel].pipe = urb->pipe;
422 			schedule_work(&mdev->clear_work[channel].ws);
423 			break;
424 		case -ENODEV:
425 		case -EPROTO:
426 			mbo->status = MBO_E_CLOSE;
427 			break;
428 		case -EOVERFLOW:
429 			dev_warn(dev, "Babble on ep%02x\n",
430 				 mdev->ep_address[channel]);
431 			break;
432 		}
433 	}
434 
435 	spin_unlock_irqrestore(lock, flags);
436 
437 	if (likely(mbo->complete))
438 		mbo->complete(mbo);
439 	usb_free_urb(urb);
440 }
441 
442 /**
443  * hdm_enqueue - receive a buffer to be used for data transfer
444  * @iface: interface to enqueue to
445  * @channel: ID of the channel
446  * @mbo: pointer to the buffer object
447  *
448  * This allocates a new URB and fills it according to the channel
449  * that is being used for transmission of data. Before the URB is
450  * submitted it is stored in the private anchor list.
451  *
452  * Returns 0 on success. On any error the URB is freed and a error code
453  * is returned.
454  *
455  * Context: Could in _some_ cases be interrupt!
456  */
457 static int hdm_enqueue(struct most_interface *iface, int channel,
458 		       struct mbo *mbo)
459 {
460 	struct most_dev *mdev = to_mdev(iface);
461 	struct most_channel_config *conf;
462 	int retval = 0;
463 	struct urb *urb;
464 	unsigned long length;
465 	void *virt_address;
466 
467 	if (!mbo)
468 		return -EINVAL;
469 	if (iface->num_channels <= channel || channel < 0)
470 		return -ECHRNG;
471 
472 	urb = usb_alloc_urb(NO_ISOCHRONOUS_URB, GFP_KERNEL);
473 	if (!urb)
474 		return -ENOMEM;
475 
476 	conf = &mdev->conf[channel];
477 
478 	mutex_lock(&mdev->io_mutex);
479 	if (!mdev->usb_device) {
480 		retval = -ENODEV;
481 		goto err_free_urb;
482 	}
483 
484 	if ((conf->direction & MOST_CH_TX) && mdev->padding_active[channel] &&
485 	    hdm_add_padding(mdev, channel, mbo)) {
486 		retval = -EINVAL;
487 		goto err_free_urb;
488 	}
489 
490 	urb->transfer_dma = mbo->bus_address;
491 	virt_address = mbo->virt_address;
492 	length = mbo->buffer_length;
493 
494 	if (conf->direction & MOST_CH_TX) {
495 		usb_fill_bulk_urb(urb, mdev->usb_device,
496 				  usb_sndbulkpipe(mdev->usb_device,
497 						  mdev->ep_address[channel]),
498 				  virt_address,
499 				  length,
500 				  hdm_write_completion,
501 				  mbo);
502 		if (conf->data_type != MOST_CH_ISOC &&
503 		    conf->data_type != MOST_CH_SYNC)
504 			urb->transfer_flags |= URB_ZERO_PACKET;
505 	} else {
506 		usb_fill_bulk_urb(urb, mdev->usb_device,
507 				  usb_rcvbulkpipe(mdev->usb_device,
508 						  mdev->ep_address[channel]),
509 				  virt_address,
510 				  length + conf->extra_len,
511 				  hdm_read_completion,
512 				  mbo);
513 	}
514 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
515 
516 	usb_anchor_urb(urb, &mdev->busy_urbs[channel]);
517 
518 	retval = usb_submit_urb(urb, GFP_KERNEL);
519 	if (retval) {
520 		dev_err(&mdev->usb_device->dev,
521 			"URB submit failed with error %d.\n", retval);
522 		goto err_unanchor_urb;
523 	}
524 	mutex_unlock(&mdev->io_mutex);
525 	return 0;
526 
527 err_unanchor_urb:
528 	usb_unanchor_urb(urb);
529 err_free_urb:
530 	usb_free_urb(urb);
531 	mutex_unlock(&mdev->io_mutex);
532 	return retval;
533 }
534 
535 static void *hdm_dma_alloc(struct mbo *mbo, u32 size)
536 {
537 	struct most_dev *mdev = to_mdev(mbo->ifp);
538 
539 	return usb_alloc_coherent(mdev->usb_device, size, GFP_KERNEL,
540 				  &mbo->bus_address);
541 }
542 
543 static void hdm_dma_free(struct mbo *mbo, u32 size)
544 {
545 	struct most_dev *mdev = to_mdev(mbo->ifp);
546 
547 	usb_free_coherent(mdev->usb_device, size, mbo->virt_address,
548 			  mbo->bus_address);
549 }
550 
551 /**
552  * hdm_configure_channel - receive channel configuration from core
553  * @iface: interface
554  * @channel: channel ID
555  * @conf: structure that holds the configuration information
556  *
557  * The attached network interface controller (NIC) supports a padding mode
558  * to avoid short packets on USB, hence increasing the performance due to a
559  * lower interrupt load. This mode is default for synchronous data and can
560  * be switched on for isochronous data. In case padding is active the
561  * driver needs to know the frame size of the payload in order to calculate
562  * the number of bytes it needs to pad when transmitting or to cut off when
563  * receiving data.
564  *
565  */
566 static int hdm_configure_channel(struct most_interface *iface, int channel,
567 				 struct most_channel_config *conf)
568 {
569 	unsigned int num_frames;
570 	unsigned int frame_size;
571 	struct most_dev *mdev = to_mdev(iface);
572 	struct device *dev = &mdev->usb_device->dev;
573 
574 	if (!conf) {
575 		dev_err(dev, "Bad config pointer.\n");
576 		return -EINVAL;
577 	}
578 	if (channel < 0 || channel >= iface->num_channels) {
579 		dev_err(dev, "Channel ID out of range.\n");
580 		return -EINVAL;
581 	}
582 
583 	mdev->is_channel_healthy[channel] = true;
584 	mdev->clear_work[channel].channel = channel;
585 	mdev->clear_work[channel].mdev = mdev;
586 	INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);
587 
588 	if (!conf->num_buffers || !conf->buffer_size) {
589 		dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
590 		return -EINVAL;
591 	}
592 
593 	if (conf->data_type != MOST_CH_SYNC &&
594 	    !(conf->data_type == MOST_CH_ISOC &&
595 	      conf->packets_per_xact != 0xFF)) {
596 		mdev->padding_active[channel] = false;
597 		/*
598 		 * Since the NIC's padding mode is not going to be
599 		 * used, we can skip the frame size calculations and
600 		 * move directly on to exit.
601 		 */
602 		goto exit;
603 	}
604 
605 	mdev->padding_active[channel] = true;
606 
607 	frame_size = get_stream_frame_size(&mdev->dev, conf);
608 	if (frame_size == 0 || frame_size > USB_MTU) {
609 		dev_warn(dev, "Misconfig: frame size wrong\n");
610 		return -EINVAL;
611 	}
612 
613 	num_frames = conf->buffer_size / frame_size;
614 
615 	if (conf->buffer_size % frame_size) {
616 		u16 old_size = conf->buffer_size;
617 
618 		conf->buffer_size = num_frames * frame_size;
619 		dev_warn(dev, "%s: fixed buffer size (%d -> %d)\n",
620 			 mdev->suffix[channel], old_size, conf->buffer_size);
621 	}
622 
623 	/* calculate extra length to comply w/ HW padding */
624 	conf->extra_len = num_frames * (USB_MTU - frame_size);
625 
626 exit:
627 	mdev->conf[channel] = *conf;
628 	if (conf->data_type == MOST_CH_ASYNC) {
629 		u16 ep = mdev->ep_address[channel];
630 
631 		if (start_sync_ep(mdev->usb_device, ep) < 0)
632 			dev_warn(dev, "sync for ep%02x failed", ep);
633 	}
634 	return 0;
635 }
636 
637 /**
638  * hdm_request_netinfo - request network information
639  * @iface: pointer to interface
640  * @channel: channel ID
641  *
642  * This is used as trigger to set up the link status timer that
643  * polls for the NI state of the INIC every 2 seconds.
644  *
645  */
646 static void hdm_request_netinfo(struct most_interface *iface, int channel,
647 				void (*on_netinfo)(struct most_interface *,
648 						   unsigned char,
649 						   unsigned char *))
650 {
651 	struct most_dev *mdev = to_mdev(iface);
652 
653 	mdev->on_netinfo = on_netinfo;
654 	if (!on_netinfo)
655 		return;
656 
657 	mdev->link_stat_timer.expires = jiffies + HZ;
658 	mod_timer(&mdev->link_stat_timer, mdev->link_stat_timer.expires);
659 }
660 
661 /**
662  * link_stat_timer_handler - schedule work obtaining mac address and link status
663  * @data: pointer to USB device instance
664  *
665  * The handler runs in interrupt context. That's why we need to defer the
666  * tasks to a work queue.
667  */
668 static void link_stat_timer_handler(struct timer_list *t)
669 {
670 	struct most_dev *mdev = from_timer(mdev, t, link_stat_timer);
671 
672 	schedule_work(&mdev->poll_work_obj);
673 	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
674 	add_timer(&mdev->link_stat_timer);
675 }
676 
677 /**
678  * wq_netinfo - work queue function to deliver latest networking information
679  * @wq_obj: object that holds data for our deferred work to do
680  *
681  * This retrieves the network interface status of the USB INIC
682  */
683 static void wq_netinfo(struct work_struct *wq_obj)
684 {
685 	struct most_dev *mdev = to_mdev_from_work(wq_obj);
686 	struct usb_device *usb_device = mdev->usb_device;
687 	struct device *dev = &usb_device->dev;
688 	u16 hi, mi, lo, link;
689 	u8 hw_addr[6];
690 
691 	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi)) {
692 		dev_err(dev, "Vendor request 'hw_addr_hi' failed\n");
693 		return;
694 	}
695 
696 	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi)) {
697 		dev_err(dev, "Vendor request 'hw_addr_mid' failed\n");
698 		return;
699 	}
700 
701 	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo)) {
702 		dev_err(dev, "Vendor request 'hw_addr_low' failed\n");
703 		return;
704 	}
705 
706 	if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link)) {
707 		dev_err(dev, "Vendor request 'link status' failed\n");
708 		return;
709 	}
710 
711 	hw_addr[0] = hi >> 8;
712 	hw_addr[1] = hi;
713 	hw_addr[2] = mi >> 8;
714 	hw_addr[3] = mi;
715 	hw_addr[4] = lo >> 8;
716 	hw_addr[5] = lo;
717 
718 	if (mdev->on_netinfo)
719 		mdev->on_netinfo(&mdev->iface, link, hw_addr);
720 }
721 
722 /**
723  * wq_clear_halt - work queue function
724  * @wq_obj: work_struct object to execute
725  *
726  * This sends a clear_halt to the given USB pipe.
727  */
728 static void wq_clear_halt(struct work_struct *wq_obj)
729 {
730 	struct clear_hold_work *clear_work = to_clear_hold_work(wq_obj);
731 	struct most_dev *mdev = clear_work->mdev;
732 	unsigned int channel = clear_work->channel;
733 	int pipe = clear_work->pipe;
734 	int snd_pipe;
735 	int peer;
736 
737 	mutex_lock(&mdev->io_mutex);
738 	most_stop_enqueue(&mdev->iface, channel);
739 	usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
740 	if (usb_clear_halt(mdev->usb_device, pipe))
741 		dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");
742 
743 	/* If the functional Stall condition has been set on an
744 	 * asynchronous rx channel, we need to clear the tx channel
745 	 * too, since the hardware runs its clean-up sequence on both
746 	 * channels, as they are physically one on the network.
747 	 *
748 	 * The USB interface that exposes the asynchronous channels
749 	 * contains always two endpoints, and two only.
750 	 */
751 	if (mdev->conf[channel].data_type == MOST_CH_ASYNC &&
752 	    mdev->conf[channel].direction == MOST_CH_RX) {
753 		if (channel == 0)
754 			peer = 1;
755 		else
756 			peer = 0;
757 		snd_pipe = usb_sndbulkpipe(mdev->usb_device,
758 					   mdev->ep_address[peer]);
759 		usb_clear_halt(mdev->usb_device, snd_pipe);
760 	}
761 	mdev->is_channel_healthy[channel] = true;
762 	most_resume_enqueue(&mdev->iface, channel);
763 	mutex_unlock(&mdev->io_mutex);
764 }
765 
766 /**
767  * hdm_usb_fops - file operation table for USB driver
768  */
769 static const struct file_operations hdm_usb_fops = {
770 	.owner = THIS_MODULE,
771 };
772 
773 /**
774  * usb_device_id - ID table for HCD device probing
775  */
776 static const struct usb_device_id usbid[] = {
777 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_BRDG), },
778 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81118), },
779 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81119), },
780 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81210), },
781 	{ } /* Terminating entry */
782 };
783 
784 struct regs {
785 	const char *name;
786 	u16 reg;
787 };
788 
789 static const struct regs ro_regs[] = {
790 	{ "ni_state", DRCI_REG_NI_STATE },
791 	{ "packet_bandwidth", DRCI_REG_PACKET_BW },
792 	{ "node_address", DRCI_REG_NODE_ADDR },
793 	{ "node_position", DRCI_REG_NODE_POS },
794 };
795 
796 static const struct regs rw_regs[] = {
797 	{ "mep_filter", DRCI_REG_MEP_FILTER },
798 	{ "mep_hash0", DRCI_REG_HASH_TBL0 },
799 	{ "mep_hash1", DRCI_REG_HASH_TBL1 },
800 	{ "mep_hash2", DRCI_REG_HASH_TBL2 },
801 	{ "mep_hash3", DRCI_REG_HASH_TBL3 },
802 	{ "mep_eui48_hi", DRCI_REG_HW_ADDR_HI },
803 	{ "mep_eui48_mi", DRCI_REG_HW_ADDR_MI },
804 	{ "mep_eui48_lo", DRCI_REG_HW_ADDR_LO },
805 };
806 
807 static int get_stat_reg_addr(const struct regs *regs, int size,
808 			     const char *name, u16 *reg_addr)
809 {
810 	int i;
811 
812 	for (i = 0; i < size; i++) {
813 		if (sysfs_streq(name, regs[i].name)) {
814 			*reg_addr = regs[i].reg;
815 			return 0;
816 		}
817 	}
818 	return -EINVAL;
819 }
820 
821 #define get_static_reg_addr(regs, name, reg_addr) \
822 	get_stat_reg_addr(regs, ARRAY_SIZE(regs), name, reg_addr)
823 
824 static ssize_t value_show(struct device *dev, struct device_attribute *attr,
825 			  char *buf)
826 {
827 	const char *name = attr->attr.name;
828 	struct most_dci_obj *dci_obj = to_dci_obj(dev);
829 	u16 val;
830 	u16 reg_addr;
831 	int err;
832 
833 	if (sysfs_streq(name, "arb_address"))
834 		return snprintf(buf, PAGE_SIZE, "%04x\n", dci_obj->reg_addr);
835 
836 	if (sysfs_streq(name, "arb_value"))
837 		reg_addr = dci_obj->reg_addr;
838 	else if (get_static_reg_addr(ro_regs, name, &reg_addr) &&
839 		 get_static_reg_addr(rw_regs, name, &reg_addr))
840 		return -EINVAL;
841 
842 	err = drci_rd_reg(dci_obj->usb_device, reg_addr, &val);
843 	if (err < 0)
844 		return err;
845 
846 	return snprintf(buf, PAGE_SIZE, "%04x\n", val);
847 }
848 
849 static ssize_t value_store(struct device *dev, struct device_attribute *attr,
850 			   const char *buf, size_t count)
851 {
852 	u16 val;
853 	u16 reg_addr;
854 	const char *name = attr->attr.name;
855 	struct most_dci_obj *dci_obj = to_dci_obj(dev);
856 	struct usb_device *usb_dev = dci_obj->usb_device;
857 	int err;
858 
859 	err = kstrtou16(buf, 16, &val);
860 	if (err)
861 		return err;
862 
863 	if (sysfs_streq(name, "arb_address")) {
864 		dci_obj->reg_addr = val;
865 		return count;
866 	}
867 
868 	if (sysfs_streq(name, "arb_value"))
869 		err = drci_wr_reg(usb_dev, dci_obj->reg_addr, val);
870 	else if (sysfs_streq(name, "sync_ep"))
871 		err = start_sync_ep(usb_dev, val);
872 	else if (!get_static_reg_addr(rw_regs, name, &reg_addr))
873 		err = drci_wr_reg(usb_dev, reg_addr, val);
874 	else
875 		return -EINVAL;
876 
877 	if (err < 0)
878 		return err;
879 
880 	return count;
881 }
882 
883 static DEVICE_ATTR(ni_state, 0444, value_show, NULL);
884 static DEVICE_ATTR(packet_bandwidth, 0444, value_show, NULL);
885 static DEVICE_ATTR(node_address, 0444, value_show, NULL);
886 static DEVICE_ATTR(node_position, 0444, value_show, NULL);
887 static DEVICE_ATTR(sync_ep, 0200, NULL, value_store);
888 static DEVICE_ATTR(mep_filter, 0644, value_show, value_store);
889 static DEVICE_ATTR(mep_hash0, 0644, value_show, value_store);
890 static DEVICE_ATTR(mep_hash1, 0644, value_show, value_store);
891 static DEVICE_ATTR(mep_hash2, 0644, value_show, value_store);
892 static DEVICE_ATTR(mep_hash3, 0644, value_show, value_store);
893 static DEVICE_ATTR(mep_eui48_hi, 0644, value_show, value_store);
894 static DEVICE_ATTR(mep_eui48_mi, 0644, value_show, value_store);
895 static DEVICE_ATTR(mep_eui48_lo, 0644, value_show, value_store);
896 static DEVICE_ATTR(arb_address, 0644, value_show, value_store);
897 static DEVICE_ATTR(arb_value, 0644, value_show, value_store);
898 
899 static struct attribute *dci_attrs[] = {
900 	&dev_attr_ni_state.attr,
901 	&dev_attr_packet_bandwidth.attr,
902 	&dev_attr_node_address.attr,
903 	&dev_attr_node_position.attr,
904 	&dev_attr_sync_ep.attr,
905 	&dev_attr_mep_filter.attr,
906 	&dev_attr_mep_hash0.attr,
907 	&dev_attr_mep_hash1.attr,
908 	&dev_attr_mep_hash2.attr,
909 	&dev_attr_mep_hash3.attr,
910 	&dev_attr_mep_eui48_hi.attr,
911 	&dev_attr_mep_eui48_mi.attr,
912 	&dev_attr_mep_eui48_lo.attr,
913 	&dev_attr_arb_address.attr,
914 	&dev_attr_arb_value.attr,
915 	NULL,
916 };
917 
918 ATTRIBUTE_GROUPS(dci);
919 
920 static void release_dci(struct device *dev)
921 {
922 	struct most_dci_obj *dci = to_dci_obj(dev);
923 
924 	put_device(dev->parent);
925 	kfree(dci);
926 }
927 
928 static void release_mdev(struct device *dev)
929 {
930 	struct most_dev *mdev = to_mdev_from_dev(dev);
931 
932 	kfree(mdev);
933 }
934 /**
935  * hdm_probe - probe function of USB device driver
936  * @interface: Interface of the attached USB device
937  * @id: Pointer to the USB ID table.
938  *
939  * This allocates and initializes the device instance, adds the new
940  * entry to the internal list, scans the USB descriptors and registers
941  * the interface with the core.
942  * Additionally, the DCI objects are created and the hardware is sync'd.
943  *
944  * Return 0 on success. In case of an error a negative number is returned.
945  */
946 static int
947 hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
948 {
949 	struct usb_host_interface *usb_iface_desc = interface->cur_altsetting;
950 	struct usb_device *usb_dev = interface_to_usbdev(interface);
951 	struct device *dev = &usb_dev->dev;
952 	struct most_dev *mdev;
953 	unsigned int i;
954 	unsigned int num_endpoints;
955 	struct most_channel_capability *tmp_cap;
956 	struct usb_endpoint_descriptor *ep_desc;
957 	int ret = -ENOMEM;
958 
959 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
960 	if (!mdev)
961 		return -ENOMEM;
962 
963 	usb_set_intfdata(interface, mdev);
964 	num_endpoints = usb_iface_desc->desc.bNumEndpoints;
965 	if (num_endpoints > MAX_NUM_ENDPOINTS) {
966 		kfree(mdev);
967 		return -EINVAL;
968 	}
969 	mutex_init(&mdev->io_mutex);
970 	INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
971 	timer_setup(&mdev->link_stat_timer, link_stat_timer_handler, 0);
972 
973 	mdev->usb_device = usb_dev;
974 	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
975 
976 	mdev->iface.mod = hdm_usb_fops.owner;
977 	mdev->iface.dev = &mdev->dev;
978 	mdev->iface.driver_dev = &interface->dev;
979 	mdev->iface.interface = ITYPE_USB;
980 	mdev->iface.configure = hdm_configure_channel;
981 	mdev->iface.request_netinfo = hdm_request_netinfo;
982 	mdev->iface.enqueue = hdm_enqueue;
983 	mdev->iface.poison_channel = hdm_poison_channel;
984 	mdev->iface.dma_alloc = hdm_dma_alloc;
985 	mdev->iface.dma_free = hdm_dma_free;
986 	mdev->iface.description = mdev->description;
987 	mdev->iface.num_channels = num_endpoints;
988 
989 	snprintf(mdev->description, sizeof(mdev->description),
990 		 "%d-%s:%d.%d",
991 		 usb_dev->bus->busnum,
992 		 usb_dev->devpath,
993 		 usb_dev->config->desc.bConfigurationValue,
994 		 usb_iface_desc->desc.bInterfaceNumber);
995 
996 	mdev->dev.init_name = mdev->description;
997 	mdev->dev.parent = &interface->dev;
998 	mdev->dev.release = release_mdev;
999 	mdev->conf = kcalloc(num_endpoints, sizeof(*mdev->conf), GFP_KERNEL);
1000 	if (!mdev->conf)
1001 		goto err_free_mdev;
1002 
1003 	mdev->cap = kcalloc(num_endpoints, sizeof(*mdev->cap), GFP_KERNEL);
1004 	if (!mdev->cap)
1005 		goto err_free_conf;
1006 
1007 	mdev->iface.channel_vector = mdev->cap;
1008 	mdev->ep_address =
1009 		kcalloc(num_endpoints, sizeof(*mdev->ep_address), GFP_KERNEL);
1010 	if (!mdev->ep_address)
1011 		goto err_free_cap;
1012 
1013 	mdev->busy_urbs =
1014 		kcalloc(num_endpoints, sizeof(*mdev->busy_urbs), GFP_KERNEL);
1015 	if (!mdev->busy_urbs)
1016 		goto err_free_ep_address;
1017 
1018 	tmp_cap = mdev->cap;
1019 	for (i = 0; i < num_endpoints; i++) {
1020 		ep_desc = &usb_iface_desc->endpoint[i].desc;
1021 		mdev->ep_address[i] = ep_desc->bEndpointAddress;
1022 		mdev->padding_active[i] = false;
1023 		mdev->is_channel_healthy[i] = true;
1024 
1025 		snprintf(&mdev->suffix[i][0], MAX_SUFFIX_LEN, "ep%02x",
1026 			 mdev->ep_address[i]);
1027 
1028 		tmp_cap->name_suffix = &mdev->suffix[i][0];
1029 		tmp_cap->buffer_size_packet = MAX_BUF_SIZE;
1030 		tmp_cap->buffer_size_streaming = MAX_BUF_SIZE;
1031 		tmp_cap->num_buffers_packet = BUF_CHAIN_SIZE;
1032 		tmp_cap->num_buffers_streaming = BUF_CHAIN_SIZE;
1033 		tmp_cap->data_type = MOST_CH_CONTROL | MOST_CH_ASYNC |
1034 				     MOST_CH_ISOC | MOST_CH_SYNC;
1035 		if (usb_endpoint_dir_in(ep_desc))
1036 			tmp_cap->direction = MOST_CH_RX;
1037 		else
1038 			tmp_cap->direction = MOST_CH_TX;
1039 		tmp_cap++;
1040 		init_usb_anchor(&mdev->busy_urbs[i]);
1041 		spin_lock_init(&mdev->channel_lock[i]);
1042 	}
1043 	dev_dbg(dev, "claimed gadget: Vendor=%4.4x ProdID=%4.4x Bus=%02x Device=%02x\n",
1044 		le16_to_cpu(usb_dev->descriptor.idVendor),
1045 		le16_to_cpu(usb_dev->descriptor.idProduct),
1046 		usb_dev->bus->busnum,
1047 		usb_dev->devnum);
1048 
1049 	dev_dbg(dev, "device path: /sys/bus/usb/devices/%d-%s:%d.%d\n",
1050 		usb_dev->bus->busnum,
1051 		usb_dev->devpath,
1052 		usb_dev->config->desc.bConfigurationValue,
1053 		usb_iface_desc->desc.bInterfaceNumber);
1054 
1055 	ret = most_register_interface(&mdev->iface);
1056 	if (ret)
1057 		goto err_free_busy_urbs;
1058 
1059 	mutex_lock(&mdev->io_mutex);
1060 	if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81118 ||
1061 	    le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81119 ||
1062 	    le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81210) {
1063 		mdev->dci = kzalloc(sizeof(*mdev->dci), GFP_KERNEL);
1064 		if (!mdev->dci) {
1065 			mutex_unlock(&mdev->io_mutex);
1066 			most_deregister_interface(&mdev->iface);
1067 			ret = -ENOMEM;
1068 			goto err_free_busy_urbs;
1069 		}
1070 
1071 		mdev->dci->dev.init_name = "dci";
1072 		mdev->dci->dev.parent = get_device(mdev->iface.dev);
1073 		mdev->dci->dev.groups = dci_groups;
1074 		mdev->dci->dev.release = release_dci;
1075 		if (device_register(&mdev->dci->dev)) {
1076 			mutex_unlock(&mdev->io_mutex);
1077 			most_deregister_interface(&mdev->iface);
1078 			ret = -ENOMEM;
1079 			goto err_free_dci;
1080 		}
1081 		mdev->dci->usb_device = mdev->usb_device;
1082 	}
1083 	mutex_unlock(&mdev->io_mutex);
1084 	return 0;
1085 err_free_dci:
1086 	put_device(&mdev->dci->dev);
1087 err_free_busy_urbs:
1088 	kfree(mdev->busy_urbs);
1089 err_free_ep_address:
1090 	kfree(mdev->ep_address);
1091 err_free_cap:
1092 	kfree(mdev->cap);
1093 err_free_conf:
1094 	kfree(mdev->conf);
1095 err_free_mdev:
1096 	put_device(&mdev->dev);
1097 	return ret;
1098 }
1099 
1100 /**
1101  * hdm_disconnect - disconnect function of USB device driver
1102  * @interface: Interface of the attached USB device
1103  *
1104  * This deregisters the interface with the core, removes the kernel timer
1105  * and frees resources.
1106  *
1107  * Context: hub kernel thread
1108  */
1109 static void hdm_disconnect(struct usb_interface *interface)
1110 {
1111 	struct most_dev *mdev = usb_get_intfdata(interface);
1112 
1113 	mutex_lock(&mdev->io_mutex);
1114 	usb_set_intfdata(interface, NULL);
1115 	mdev->usb_device = NULL;
1116 	mutex_unlock(&mdev->io_mutex);
1117 
1118 	del_timer_sync(&mdev->link_stat_timer);
1119 	cancel_work_sync(&mdev->poll_work_obj);
1120 
1121 	if (mdev->dci)
1122 		device_unregister(&mdev->dci->dev);
1123 	most_deregister_interface(&mdev->iface);
1124 
1125 	kfree(mdev->busy_urbs);
1126 	kfree(mdev->cap);
1127 	kfree(mdev->conf);
1128 	kfree(mdev->ep_address);
1129 	put_device(&mdev->dci->dev);
1130 	put_device(&mdev->dev);
1131 }
1132 
1133 static int hdm_suspend(struct usb_interface *interface, pm_message_t message)
1134 {
1135 	struct most_dev *mdev = usb_get_intfdata(interface);
1136 	int i;
1137 
1138 	mutex_lock(&mdev->io_mutex);
1139 	for (i = 0; i < mdev->iface.num_channels; i++) {
1140 		most_stop_enqueue(&mdev->iface, i);
1141 		usb_kill_anchored_urbs(&mdev->busy_urbs[i]);
1142 	}
1143 	mutex_unlock(&mdev->io_mutex);
1144 	return 0;
1145 }
1146 
1147 static int hdm_resume(struct usb_interface *interface)
1148 {
1149 	struct most_dev *mdev = usb_get_intfdata(interface);
1150 	int i;
1151 
1152 	mutex_lock(&mdev->io_mutex);
1153 	for (i = 0; i < mdev->iface.num_channels; i++)
1154 		most_resume_enqueue(&mdev->iface, i);
1155 	mutex_unlock(&mdev->io_mutex);
1156 	return 0;
1157 }
1158 
1159 static struct usb_driver hdm_usb = {
1160 	.name = "hdm_usb",
1161 	.id_table = usbid,
1162 	.probe = hdm_probe,
1163 	.disconnect = hdm_disconnect,
1164 	.resume = hdm_resume,
1165 	.suspend = hdm_suspend,
1166 };
1167 
1168 module_usb_driver(hdm_usb);
1169 MODULE_LICENSE("GPL");
1170 MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
1171 MODULE_DESCRIPTION("HDM_4_USB");
1172