xref: /openbmc/linux/drivers/most/most_usb.c (revision b4e18b29)
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), 5 * HZ);
153 	*buf = le16_to_cpu(*dma_buf);
154 	kfree(dma_buf);
155 
156 	if (retval < 0)
157 		return retval;
158 	return 0;
159 }
160 
161 /**
162  * drci_wr_reg - write a DCI register
163  * @dev: usb device
164  * @reg: register address
165  * @data: data to write
166  *
167  * This is writes data to INIC's direct register communication interface
168  */
169 static inline int drci_wr_reg(struct usb_device *dev, u16 reg, u16 data)
170 {
171 	return usb_control_msg(dev,
172 			       usb_sndctrlpipe(dev, 0),
173 			       DRCI_WRITE_REQ,
174 			       USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
175 			       data,
176 			       reg,
177 			       NULL,
178 			       0,
179 			       5 * HZ);
180 }
181 
182 static inline int start_sync_ep(struct usb_device *usb_dev, u16 ep)
183 {
184 	return drci_wr_reg(usb_dev, DRCI_REG_BASE + DRCI_COMMAND + ep * 16, 1);
185 }
186 
187 /**
188  * get_stream_frame_size - calculate frame size of current configuration
189  * @dev: device structure
190  * @cfg: channel configuration
191  */
192 static unsigned int get_stream_frame_size(struct device *dev,
193 					  struct most_channel_config *cfg)
194 {
195 	unsigned int frame_size;
196 	unsigned int sub_size = cfg->subbuffer_size;
197 
198 	if (!sub_size) {
199 		dev_warn(dev, "Misconfig: Subbuffer size zero.\n");
200 		return 0;
201 	}
202 	switch (cfg->data_type) {
203 	case MOST_CH_ISOC:
204 		frame_size = AV_PACKETS_PER_XACT * sub_size;
205 		break;
206 	case MOST_CH_SYNC:
207 		if (cfg->packets_per_xact == 0) {
208 			dev_warn(dev, "Misconfig: Packets per XACT zero\n");
209 			frame_size = 0;
210 		} else if (cfg->packets_per_xact == 0xFF) {
211 			frame_size = (USB_MTU / sub_size) * sub_size;
212 		} else {
213 			frame_size = cfg->packets_per_xact * sub_size;
214 		}
215 		break;
216 	default:
217 		dev_warn(dev, "Query frame size of non-streaming channel\n");
218 		frame_size = 0;
219 		break;
220 	}
221 	return frame_size;
222 }
223 
224 /**
225  * hdm_poison_channel - mark buffers of this channel as invalid
226  * @iface: pointer to the interface
227  * @channel: channel ID
228  *
229  * This unlinks all URBs submitted to the HCD,
230  * calls the associated completion function of the core and removes
231  * them from the list.
232  *
233  * Returns 0 on success or error code otherwise.
234  */
235 static int hdm_poison_channel(struct most_interface *iface, int channel)
236 {
237 	struct most_dev *mdev = to_mdev(iface);
238 	unsigned long flags;
239 	spinlock_t *lock; /* temp. lock */
240 
241 	if (channel < 0 || channel >= iface->num_channels) {
242 		dev_warn(&mdev->usb_device->dev, "Channel ID out of range.\n");
243 		return -ECHRNG;
244 	}
245 
246 	lock = mdev->channel_lock + channel;
247 	spin_lock_irqsave(lock, flags);
248 	mdev->is_channel_healthy[channel] = false;
249 	spin_unlock_irqrestore(lock, flags);
250 
251 	cancel_work_sync(&mdev->clear_work[channel].ws);
252 
253 	mutex_lock(&mdev->io_mutex);
254 	usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
255 	if (mdev->padding_active[channel])
256 		mdev->padding_active[channel] = false;
257 
258 	if (mdev->conf[channel].data_type == MOST_CH_ASYNC) {
259 		del_timer_sync(&mdev->link_stat_timer);
260 		cancel_work_sync(&mdev->poll_work_obj);
261 	}
262 	mutex_unlock(&mdev->io_mutex);
263 	return 0;
264 }
265 
266 /**
267  * hdm_add_padding - add padding bytes
268  * @mdev: most device
269  * @channel: channel ID
270  * @mbo: buffer object
271  *
272  * This inserts the INIC hardware specific padding bytes into a streaming
273  * channel's buffer
274  */
275 static int hdm_add_padding(struct most_dev *mdev, int channel, struct mbo *mbo)
276 {
277 	struct most_channel_config *conf = &mdev->conf[channel];
278 	unsigned int frame_size = get_stream_frame_size(&mdev->dev, conf);
279 	unsigned int j, num_frames;
280 
281 	if (!frame_size)
282 		return -EINVAL;
283 	num_frames = mbo->buffer_length / frame_size;
284 
285 	if (num_frames < 1) {
286 		dev_err(&mdev->usb_device->dev,
287 			"Missed minimal transfer unit.\n");
288 		return -EINVAL;
289 	}
290 
291 	for (j = num_frames - 1; j > 0; j--)
292 		memmove(mbo->virt_address + j * USB_MTU,
293 			mbo->virt_address + j * frame_size,
294 			frame_size);
295 	mbo->buffer_length = num_frames * USB_MTU;
296 	return 0;
297 }
298 
299 /**
300  * hdm_remove_padding - remove padding bytes
301  * @mdev: most device
302  * @channel: channel ID
303  * @mbo: buffer object
304  *
305  * This takes the INIC hardware specific padding bytes off a streaming
306  * channel's buffer.
307  */
308 static int hdm_remove_padding(struct most_dev *mdev, int channel,
309 			      struct mbo *mbo)
310 {
311 	struct most_channel_config *const conf = &mdev->conf[channel];
312 	unsigned int frame_size = get_stream_frame_size(&mdev->dev, conf);
313 	unsigned int j, num_frames;
314 
315 	if (!frame_size)
316 		return -EINVAL;
317 	num_frames = mbo->processed_length / USB_MTU;
318 
319 	for (j = 1; j < num_frames; j++)
320 		memmove(mbo->virt_address + frame_size * j,
321 			mbo->virt_address + USB_MTU * j,
322 			frame_size);
323 
324 	mbo->processed_length = frame_size * num_frames;
325 	return 0;
326 }
327 
328 /**
329  * hdm_write_completion - completion function for submitted Tx URBs
330  * @urb: the URB that has been completed
331  *
332  * This checks the status of the completed URB. In case the URB has been
333  * unlinked before, it is immediately freed. On any other error the MBO
334  * transfer flag is set. On success it frees allocated resources and calls
335  * the completion function.
336  *
337  * Context: interrupt!
338  */
339 static void hdm_write_completion(struct urb *urb)
340 {
341 	struct mbo *mbo = urb->context;
342 	struct most_dev *mdev = to_mdev(mbo->ifp);
343 	unsigned int channel = mbo->hdm_channel_id;
344 	spinlock_t *lock = mdev->channel_lock + channel;
345 	unsigned long flags;
346 
347 	spin_lock_irqsave(lock, flags);
348 
349 	mbo->processed_length = 0;
350 	mbo->status = MBO_E_INVAL;
351 	if (likely(mdev->is_channel_healthy[channel])) {
352 		switch (urb->status) {
353 		case 0:
354 		case -ESHUTDOWN:
355 			mbo->processed_length = urb->actual_length;
356 			mbo->status = MBO_SUCCESS;
357 			break;
358 		case -EPIPE:
359 			dev_warn(&mdev->usb_device->dev,
360 				 "Broken pipe on ep%02x\n",
361 				 mdev->ep_address[channel]);
362 			mdev->is_channel_healthy[channel] = false;
363 			mdev->clear_work[channel].pipe = urb->pipe;
364 			schedule_work(&mdev->clear_work[channel].ws);
365 			break;
366 		case -ENODEV:
367 		case -EPROTO:
368 			mbo->status = MBO_E_CLOSE;
369 			break;
370 		}
371 	}
372 
373 	spin_unlock_irqrestore(lock, flags);
374 
375 	if (likely(mbo->complete))
376 		mbo->complete(mbo);
377 	usb_free_urb(urb);
378 }
379 
380 /**
381  * hdm_read_completion - completion function for submitted Rx URBs
382  * @urb: the URB that has been completed
383  *
384  * This checks the status of the completed URB. In case the URB has been
385  * unlinked before it is immediately freed. On any other error the MBO transfer
386  * flag is set. On success it frees allocated resources, removes
387  * padding bytes -if necessary- and calls the completion function.
388  *
389  * Context: interrupt!
390  */
391 static void hdm_read_completion(struct urb *urb)
392 {
393 	struct mbo *mbo = urb->context;
394 	struct most_dev *mdev = to_mdev(mbo->ifp);
395 	unsigned int channel = mbo->hdm_channel_id;
396 	struct device *dev = &mdev->usb_device->dev;
397 	spinlock_t *lock = mdev->channel_lock + channel;
398 	unsigned long flags;
399 
400 	spin_lock_irqsave(lock, flags);
401 
402 	mbo->processed_length = 0;
403 	mbo->status = MBO_E_INVAL;
404 	if (likely(mdev->is_channel_healthy[channel])) {
405 		switch (urb->status) {
406 		case 0:
407 		case -ESHUTDOWN:
408 			mbo->processed_length = urb->actual_length;
409 			mbo->status = MBO_SUCCESS;
410 			if (mdev->padding_active[channel] &&
411 			    hdm_remove_padding(mdev, channel, mbo)) {
412 				mbo->processed_length = 0;
413 				mbo->status = MBO_E_INVAL;
414 			}
415 			break;
416 		case -EPIPE:
417 			dev_warn(dev, "Broken pipe on ep%02x\n",
418 				 mdev->ep_address[channel]);
419 			mdev->is_channel_healthy[channel] = false;
420 			mdev->clear_work[channel].pipe = urb->pipe;
421 			schedule_work(&mdev->clear_work[channel].ws);
422 			break;
423 		case -ENODEV:
424 		case -EPROTO:
425 			mbo->status = MBO_E_CLOSE;
426 			break;
427 		case -EOVERFLOW:
428 			dev_warn(dev, "Babble on ep%02x\n",
429 				 mdev->ep_address[channel]);
430 			break;
431 		}
432 	}
433 
434 	spin_unlock_irqrestore(lock, flags);
435 
436 	if (likely(mbo->complete))
437 		mbo->complete(mbo);
438 	usb_free_urb(urb);
439 }
440 
441 /**
442  * hdm_enqueue - receive a buffer to be used for data transfer
443  * @iface: interface to enqueue to
444  * @channel: ID of the channel
445  * @mbo: pointer to the buffer object
446  *
447  * This allocates a new URB and fills it according to the channel
448  * that is being used for transmission of data. Before the URB is
449  * submitted it is stored in the private anchor list.
450  *
451  * Returns 0 on success. On any error the URB is freed and a error code
452  * is returned.
453  *
454  * Context: Could in _some_ cases be interrupt!
455  */
456 static int hdm_enqueue(struct most_interface *iface, int channel,
457 		       struct mbo *mbo)
458 {
459 	struct most_dev *mdev = to_mdev(iface);
460 	struct most_channel_config *conf;
461 	int retval = 0;
462 	struct urb *urb;
463 	unsigned long length;
464 	void *virt_address;
465 
466 	if (!mbo)
467 		return -EINVAL;
468 	if (iface->num_channels <= channel || channel < 0)
469 		return -ECHRNG;
470 
471 	urb = usb_alloc_urb(NO_ISOCHRONOUS_URB, GFP_KERNEL);
472 	if (!urb)
473 		return -ENOMEM;
474 
475 	conf = &mdev->conf[channel];
476 
477 	mutex_lock(&mdev->io_mutex);
478 	if (!mdev->usb_device) {
479 		retval = -ENODEV;
480 		goto err_free_urb;
481 	}
482 
483 	if ((conf->direction & MOST_CH_TX) && mdev->padding_active[channel] &&
484 	    hdm_add_padding(mdev, channel, mbo)) {
485 		retval = -EINVAL;
486 		goto err_free_urb;
487 	}
488 
489 	urb->transfer_dma = mbo->bus_address;
490 	virt_address = mbo->virt_address;
491 	length = mbo->buffer_length;
492 
493 	if (conf->direction & MOST_CH_TX) {
494 		usb_fill_bulk_urb(urb, mdev->usb_device,
495 				  usb_sndbulkpipe(mdev->usb_device,
496 						  mdev->ep_address[channel]),
497 				  virt_address,
498 				  length,
499 				  hdm_write_completion,
500 				  mbo);
501 		if (conf->data_type != MOST_CH_ISOC &&
502 		    conf->data_type != MOST_CH_SYNC)
503 			urb->transfer_flags |= URB_ZERO_PACKET;
504 	} else {
505 		usb_fill_bulk_urb(urb, mdev->usb_device,
506 				  usb_rcvbulkpipe(mdev->usb_device,
507 						  mdev->ep_address[channel]),
508 				  virt_address,
509 				  length + conf->extra_len,
510 				  hdm_read_completion,
511 				  mbo);
512 	}
513 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
514 
515 	usb_anchor_urb(urb, &mdev->busy_urbs[channel]);
516 
517 	retval = usb_submit_urb(urb, GFP_KERNEL);
518 	if (retval) {
519 		dev_err(&mdev->usb_device->dev,
520 			"URB submit failed with error %d.\n", retval);
521 		goto err_unanchor_urb;
522 	}
523 	mutex_unlock(&mdev->io_mutex);
524 	return 0;
525 
526 err_unanchor_urb:
527 	usb_unanchor_urb(urb);
528 err_free_urb:
529 	usb_free_urb(urb);
530 	mutex_unlock(&mdev->io_mutex);
531 	return retval;
532 }
533 
534 static void *hdm_dma_alloc(struct mbo *mbo, u32 size)
535 {
536 	struct most_dev *mdev = to_mdev(mbo->ifp);
537 
538 	return usb_alloc_coherent(mdev->usb_device, size, GFP_KERNEL,
539 				  &mbo->bus_address);
540 }
541 
542 static void hdm_dma_free(struct mbo *mbo, u32 size)
543 {
544 	struct most_dev *mdev = to_mdev(mbo->ifp);
545 
546 	usb_free_coherent(mdev->usb_device, size, mbo->virt_address,
547 			  mbo->bus_address);
548 }
549 
550 /**
551  * hdm_configure_channel - receive channel configuration from core
552  * @iface: interface
553  * @channel: channel ID
554  * @conf: structure that holds the configuration information
555  *
556  * The attached network interface controller (NIC) supports a padding mode
557  * to avoid short packets on USB, hence increasing the performance due to a
558  * lower interrupt load. This mode is default for synchronous data and can
559  * be switched on for isochronous data. In case padding is active the
560  * driver needs to know the frame size of the payload in order to calculate
561  * the number of bytes it needs to pad when transmitting or to cut off when
562  * receiving data.
563  *
564  */
565 static int hdm_configure_channel(struct most_interface *iface, int channel,
566 				 struct most_channel_config *conf)
567 {
568 	unsigned int num_frames;
569 	unsigned int frame_size;
570 	struct most_dev *mdev = to_mdev(iface);
571 	struct device *dev = &mdev->usb_device->dev;
572 
573 	if (!conf) {
574 		dev_err(dev, "Bad config pointer.\n");
575 		return -EINVAL;
576 	}
577 	if (channel < 0 || channel >= iface->num_channels) {
578 		dev_err(dev, "Channel ID out of range.\n");
579 		return -EINVAL;
580 	}
581 
582 	mdev->is_channel_healthy[channel] = true;
583 	mdev->clear_work[channel].channel = channel;
584 	mdev->clear_work[channel].mdev = mdev;
585 	INIT_WORK(&mdev->clear_work[channel].ws, wq_clear_halt);
586 
587 	if (!conf->num_buffers || !conf->buffer_size) {
588 		dev_err(dev, "Misconfig: buffer size or #buffers zero.\n");
589 		return -EINVAL;
590 	}
591 
592 	if (conf->data_type != MOST_CH_SYNC &&
593 	    !(conf->data_type == MOST_CH_ISOC &&
594 	      conf->packets_per_xact != 0xFF)) {
595 		mdev->padding_active[channel] = false;
596 		/*
597 		 * Since the NIC's padding mode is not going to be
598 		 * used, we can skip the frame size calculations and
599 		 * move directly on to exit.
600 		 */
601 		goto exit;
602 	}
603 
604 	mdev->padding_active[channel] = true;
605 
606 	frame_size = get_stream_frame_size(&mdev->dev, conf);
607 	if (frame_size == 0 || frame_size > USB_MTU) {
608 		dev_warn(dev, "Misconfig: frame size wrong\n");
609 		return -EINVAL;
610 	}
611 
612 	num_frames = conf->buffer_size / frame_size;
613 
614 	if (conf->buffer_size % frame_size) {
615 		u16 old_size = conf->buffer_size;
616 
617 		conf->buffer_size = num_frames * frame_size;
618 		dev_warn(dev, "%s: fixed buffer size (%d -> %d)\n",
619 			 mdev->suffix[channel], old_size, conf->buffer_size);
620 	}
621 
622 	/* calculate extra length to comply w/ HW padding */
623 	conf->extra_len = num_frames * (USB_MTU - frame_size);
624 
625 exit:
626 	mdev->conf[channel] = *conf;
627 	if (conf->data_type == MOST_CH_ASYNC) {
628 		u16 ep = mdev->ep_address[channel];
629 
630 		if (start_sync_ep(mdev->usb_device, ep) < 0)
631 			dev_warn(dev, "sync for ep%02x failed", ep);
632 	}
633 	return 0;
634 }
635 
636 /**
637  * hdm_request_netinfo - request network information
638  * @iface: pointer to interface
639  * @channel: channel ID
640  *
641  * This is used as trigger to set up the link status timer that
642  * polls for the NI state of the INIC every 2 seconds.
643  *
644  */
645 static void hdm_request_netinfo(struct most_interface *iface, int channel,
646 				void (*on_netinfo)(struct most_interface *,
647 						   unsigned char,
648 						   unsigned char *))
649 {
650 	struct most_dev *mdev = to_mdev(iface);
651 
652 	mdev->on_netinfo = on_netinfo;
653 	if (!on_netinfo)
654 		return;
655 
656 	mdev->link_stat_timer.expires = jiffies + HZ;
657 	mod_timer(&mdev->link_stat_timer, mdev->link_stat_timer.expires);
658 }
659 
660 /**
661  * link_stat_timer_handler - schedule work obtaining mac address and link status
662  * @data: pointer to USB device instance
663  *
664  * The handler runs in interrupt context. That's why we need to defer the
665  * tasks to a work queue.
666  */
667 static void link_stat_timer_handler(struct timer_list *t)
668 {
669 	struct most_dev *mdev = from_timer(mdev, t, link_stat_timer);
670 
671 	schedule_work(&mdev->poll_work_obj);
672 	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
673 	add_timer(&mdev->link_stat_timer);
674 }
675 
676 /**
677  * wq_netinfo - work queue function to deliver latest networking information
678  * @wq_obj: object that holds data for our deferred work to do
679  *
680  * This retrieves the network interface status of the USB INIC
681  */
682 static void wq_netinfo(struct work_struct *wq_obj)
683 {
684 	struct most_dev *mdev = to_mdev_from_work(wq_obj);
685 	struct usb_device *usb_device = mdev->usb_device;
686 	struct device *dev = &usb_device->dev;
687 	u16 hi, mi, lo, link;
688 	u8 hw_addr[6];
689 
690 	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi)) {
691 		dev_err(dev, "Vendor request 'hw_addr_hi' failed\n");
692 		return;
693 	}
694 
695 	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi)) {
696 		dev_err(dev, "Vendor request 'hw_addr_mid' failed\n");
697 		return;
698 	}
699 
700 	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo)) {
701 		dev_err(dev, "Vendor request 'hw_addr_low' failed\n");
702 		return;
703 	}
704 
705 	if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link)) {
706 		dev_err(dev, "Vendor request 'link status' failed\n");
707 		return;
708 	}
709 
710 	hw_addr[0] = hi >> 8;
711 	hw_addr[1] = hi;
712 	hw_addr[2] = mi >> 8;
713 	hw_addr[3] = mi;
714 	hw_addr[4] = lo >> 8;
715 	hw_addr[5] = lo;
716 
717 	if (mdev->on_netinfo)
718 		mdev->on_netinfo(&mdev->iface, link, hw_addr);
719 }
720 
721 /**
722  * wq_clear_halt - work queue function
723  * @wq_obj: work_struct object to execute
724  *
725  * This sends a clear_halt to the given USB pipe.
726  */
727 static void wq_clear_halt(struct work_struct *wq_obj)
728 {
729 	struct clear_hold_work *clear_work = to_clear_hold_work(wq_obj);
730 	struct most_dev *mdev = clear_work->mdev;
731 	unsigned int channel = clear_work->channel;
732 	int pipe = clear_work->pipe;
733 	int snd_pipe;
734 	int peer;
735 
736 	mutex_lock(&mdev->io_mutex);
737 	most_stop_enqueue(&mdev->iface, channel);
738 	usb_kill_anchored_urbs(&mdev->busy_urbs[channel]);
739 	if (usb_clear_halt(mdev->usb_device, pipe))
740 		dev_warn(&mdev->usb_device->dev, "Failed to reset endpoint.\n");
741 
742 	/* If the functional Stall condition has been set on an
743 	 * asynchronous rx channel, we need to clear the tx channel
744 	 * too, since the hardware runs its clean-up sequence on both
745 	 * channels, as they are physically one on the network.
746 	 *
747 	 * The USB interface that exposes the asynchronous channels
748 	 * contains always two endpoints, and two only.
749 	 */
750 	if (mdev->conf[channel].data_type == MOST_CH_ASYNC &&
751 	    mdev->conf[channel].direction == MOST_CH_RX) {
752 		if (channel == 0)
753 			peer = 1;
754 		else
755 			peer = 0;
756 		snd_pipe = usb_sndbulkpipe(mdev->usb_device,
757 					   mdev->ep_address[peer]);
758 		usb_clear_halt(mdev->usb_device, snd_pipe);
759 	}
760 	mdev->is_channel_healthy[channel] = true;
761 	most_resume_enqueue(&mdev->iface, channel);
762 	mutex_unlock(&mdev->io_mutex);
763 }
764 
765 /**
766  * hdm_usb_fops - file operation table for USB driver
767  */
768 static const struct file_operations hdm_usb_fops = {
769 	.owner = THIS_MODULE,
770 };
771 
772 /**
773  * usb_device_id - ID table for HCD device probing
774  */
775 static const struct usb_device_id usbid[] = {
776 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_BRDG), },
777 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81118), },
778 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81119), },
779 	{ USB_DEVICE(USB_VENDOR_ID_SMSC, USB_DEV_ID_OS81210), },
780 	{ } /* Terminating entry */
781 };
782 
783 struct regs {
784 	const char *name;
785 	u16 reg;
786 };
787 
788 static const struct regs ro_regs[] = {
789 	{ "ni_state", DRCI_REG_NI_STATE },
790 	{ "packet_bandwidth", DRCI_REG_PACKET_BW },
791 	{ "node_address", DRCI_REG_NODE_ADDR },
792 	{ "node_position", DRCI_REG_NODE_POS },
793 };
794 
795 static const struct regs rw_regs[] = {
796 	{ "mep_filter", DRCI_REG_MEP_FILTER },
797 	{ "mep_hash0", DRCI_REG_HASH_TBL0 },
798 	{ "mep_hash1", DRCI_REG_HASH_TBL1 },
799 	{ "mep_hash2", DRCI_REG_HASH_TBL2 },
800 	{ "mep_hash3", DRCI_REG_HASH_TBL3 },
801 	{ "mep_eui48_hi", DRCI_REG_HW_ADDR_HI },
802 	{ "mep_eui48_mi", DRCI_REG_HW_ADDR_MI },
803 	{ "mep_eui48_lo", DRCI_REG_HW_ADDR_LO },
804 };
805 
806 static int get_stat_reg_addr(const struct regs *regs, int size,
807 			     const char *name, u16 *reg_addr)
808 {
809 	int i;
810 
811 	for (i = 0; i < size; i++) {
812 		if (sysfs_streq(name, regs[i].name)) {
813 			*reg_addr = regs[i].reg;
814 			return 0;
815 		}
816 	}
817 	return -EINVAL;
818 }
819 
820 #define get_static_reg_addr(regs, name, reg_addr) \
821 	get_stat_reg_addr(regs, ARRAY_SIZE(regs), name, reg_addr)
822 
823 static ssize_t value_show(struct device *dev, struct device_attribute *attr,
824 			  char *buf)
825 {
826 	const char *name = attr->attr.name;
827 	struct most_dci_obj *dci_obj = to_dci_obj(dev);
828 	u16 val;
829 	u16 reg_addr;
830 	int err;
831 
832 	if (sysfs_streq(name, "arb_address"))
833 		return snprintf(buf, PAGE_SIZE, "%04x\n", dci_obj->reg_addr);
834 
835 	if (sysfs_streq(name, "arb_value"))
836 		reg_addr = dci_obj->reg_addr;
837 	else if (get_static_reg_addr(ro_regs, name, &reg_addr) &&
838 		 get_static_reg_addr(rw_regs, name, &reg_addr))
839 		return -EINVAL;
840 
841 	err = drci_rd_reg(dci_obj->usb_device, reg_addr, &val);
842 	if (err < 0)
843 		return err;
844 
845 	return snprintf(buf, PAGE_SIZE, "%04x\n", val);
846 }
847 
848 static ssize_t value_store(struct device *dev, struct device_attribute *attr,
849 			   const char *buf, size_t count)
850 {
851 	u16 val;
852 	u16 reg_addr;
853 	const char *name = attr->attr.name;
854 	struct most_dci_obj *dci_obj = to_dci_obj(dev);
855 	struct usb_device *usb_dev = dci_obj->usb_device;
856 	int err;
857 
858 	err = kstrtou16(buf, 16, &val);
859 	if (err)
860 		return err;
861 
862 	if (sysfs_streq(name, "arb_address")) {
863 		dci_obj->reg_addr = val;
864 		return count;
865 	}
866 
867 	if (sysfs_streq(name, "arb_value"))
868 		err = drci_wr_reg(usb_dev, dci_obj->reg_addr, val);
869 	else if (sysfs_streq(name, "sync_ep"))
870 		err = start_sync_ep(usb_dev, val);
871 	else if (!get_static_reg_addr(rw_regs, name, &reg_addr))
872 		err = drci_wr_reg(usb_dev, reg_addr, val);
873 	else
874 		return -EINVAL;
875 
876 	if (err < 0)
877 		return err;
878 
879 	return count;
880 }
881 
882 static DEVICE_ATTR(ni_state, 0444, value_show, NULL);
883 static DEVICE_ATTR(packet_bandwidth, 0444, value_show, NULL);
884 static DEVICE_ATTR(node_address, 0444, value_show, NULL);
885 static DEVICE_ATTR(node_position, 0444, value_show, NULL);
886 static DEVICE_ATTR(sync_ep, 0200, NULL, value_store);
887 static DEVICE_ATTR(mep_filter, 0644, value_show, value_store);
888 static DEVICE_ATTR(mep_hash0, 0644, value_show, value_store);
889 static DEVICE_ATTR(mep_hash1, 0644, value_show, value_store);
890 static DEVICE_ATTR(mep_hash2, 0644, value_show, value_store);
891 static DEVICE_ATTR(mep_hash3, 0644, value_show, value_store);
892 static DEVICE_ATTR(mep_eui48_hi, 0644, value_show, value_store);
893 static DEVICE_ATTR(mep_eui48_mi, 0644, value_show, value_store);
894 static DEVICE_ATTR(mep_eui48_lo, 0644, value_show, value_store);
895 static DEVICE_ATTR(arb_address, 0644, value_show, value_store);
896 static DEVICE_ATTR(arb_value, 0644, value_show, value_store);
897 
898 static struct attribute *dci_attrs[] = {
899 	&dev_attr_ni_state.attr,
900 	&dev_attr_packet_bandwidth.attr,
901 	&dev_attr_node_address.attr,
902 	&dev_attr_node_position.attr,
903 	&dev_attr_sync_ep.attr,
904 	&dev_attr_mep_filter.attr,
905 	&dev_attr_mep_hash0.attr,
906 	&dev_attr_mep_hash1.attr,
907 	&dev_attr_mep_hash2.attr,
908 	&dev_attr_mep_hash3.attr,
909 	&dev_attr_mep_eui48_hi.attr,
910 	&dev_attr_mep_eui48_mi.attr,
911 	&dev_attr_mep_eui48_lo.attr,
912 	&dev_attr_arb_address.attr,
913 	&dev_attr_arb_value.attr,
914 	NULL,
915 };
916 
917 ATTRIBUTE_GROUPS(dci);
918 
919 static void release_dci(struct device *dev)
920 {
921 	struct most_dci_obj *dci = to_dci_obj(dev);
922 
923 	put_device(dev->parent);
924 	kfree(dci);
925 }
926 
927 static void release_mdev(struct device *dev)
928 {
929 	struct most_dev *mdev = to_mdev_from_dev(dev);
930 
931 	kfree(mdev);
932 }
933 /**
934  * hdm_probe - probe function of USB device driver
935  * @interface: Interface of the attached USB device
936  * @id: Pointer to the USB ID table.
937  *
938  * This allocates and initializes the device instance, adds the new
939  * entry to the internal list, scans the USB descriptors and registers
940  * the interface with the core.
941  * Additionally, the DCI objects are created and the hardware is sync'd.
942  *
943  * Return 0 on success. In case of an error a negative number is returned.
944  */
945 static int
946 hdm_probe(struct usb_interface *interface, const struct usb_device_id *id)
947 {
948 	struct usb_host_interface *usb_iface_desc = interface->cur_altsetting;
949 	struct usb_device *usb_dev = interface_to_usbdev(interface);
950 	struct device *dev = &usb_dev->dev;
951 	struct most_dev *mdev;
952 	unsigned int i;
953 	unsigned int num_endpoints;
954 	struct most_channel_capability *tmp_cap;
955 	struct usb_endpoint_descriptor *ep_desc;
956 	int ret = -ENOMEM;
957 
958 	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
959 	if (!mdev)
960 		return -ENOMEM;
961 
962 	usb_set_intfdata(interface, mdev);
963 	num_endpoints = usb_iface_desc->desc.bNumEndpoints;
964 	if (num_endpoints > MAX_NUM_ENDPOINTS) {
965 		kfree(mdev);
966 		return -EINVAL;
967 	}
968 	mutex_init(&mdev->io_mutex);
969 	INIT_WORK(&mdev->poll_work_obj, wq_netinfo);
970 	timer_setup(&mdev->link_stat_timer, link_stat_timer_handler, 0);
971 
972 	mdev->usb_device = usb_dev;
973 	mdev->link_stat_timer.expires = jiffies + (2 * HZ);
974 
975 	mdev->iface.mod = hdm_usb_fops.owner;
976 	mdev->iface.dev = &mdev->dev;
977 	mdev->iface.driver_dev = &interface->dev;
978 	mdev->iface.interface = ITYPE_USB;
979 	mdev->iface.configure = hdm_configure_channel;
980 	mdev->iface.request_netinfo = hdm_request_netinfo;
981 	mdev->iface.enqueue = hdm_enqueue;
982 	mdev->iface.poison_channel = hdm_poison_channel;
983 	mdev->iface.dma_alloc = hdm_dma_alloc;
984 	mdev->iface.dma_free = hdm_dma_free;
985 	mdev->iface.description = mdev->description;
986 	mdev->iface.num_channels = num_endpoints;
987 
988 	snprintf(mdev->description, sizeof(mdev->description),
989 		 "%d-%s:%d.%d",
990 		 usb_dev->bus->busnum,
991 		 usb_dev->devpath,
992 		 usb_dev->config->desc.bConfigurationValue,
993 		 usb_iface_desc->desc.bInterfaceNumber);
994 
995 	mdev->dev.init_name = mdev->description;
996 	mdev->dev.parent = &interface->dev;
997 	mdev->dev.release = release_mdev;
998 	mdev->conf = kcalloc(num_endpoints, sizeof(*mdev->conf), GFP_KERNEL);
999 	if (!mdev->conf)
1000 		goto err_free_mdev;
1001 
1002 	mdev->cap = kcalloc(num_endpoints, sizeof(*mdev->cap), GFP_KERNEL);
1003 	if (!mdev->cap)
1004 		goto err_free_conf;
1005 
1006 	mdev->iface.channel_vector = mdev->cap;
1007 	mdev->ep_address =
1008 		kcalloc(num_endpoints, sizeof(*mdev->ep_address), GFP_KERNEL);
1009 	if (!mdev->ep_address)
1010 		goto err_free_cap;
1011 
1012 	mdev->busy_urbs =
1013 		kcalloc(num_endpoints, sizeof(*mdev->busy_urbs), GFP_KERNEL);
1014 	if (!mdev->busy_urbs)
1015 		goto err_free_ep_address;
1016 
1017 	tmp_cap = mdev->cap;
1018 	for (i = 0; i < num_endpoints; i++) {
1019 		ep_desc = &usb_iface_desc->endpoint[i].desc;
1020 		mdev->ep_address[i] = ep_desc->bEndpointAddress;
1021 		mdev->padding_active[i] = false;
1022 		mdev->is_channel_healthy[i] = true;
1023 
1024 		snprintf(&mdev->suffix[i][0], MAX_SUFFIX_LEN, "ep%02x",
1025 			 mdev->ep_address[i]);
1026 
1027 		tmp_cap->name_suffix = &mdev->suffix[i][0];
1028 		tmp_cap->buffer_size_packet = MAX_BUF_SIZE;
1029 		tmp_cap->buffer_size_streaming = MAX_BUF_SIZE;
1030 		tmp_cap->num_buffers_packet = BUF_CHAIN_SIZE;
1031 		tmp_cap->num_buffers_streaming = BUF_CHAIN_SIZE;
1032 		tmp_cap->data_type = MOST_CH_CONTROL | MOST_CH_ASYNC |
1033 				     MOST_CH_ISOC | MOST_CH_SYNC;
1034 		if (usb_endpoint_dir_in(ep_desc))
1035 			tmp_cap->direction = MOST_CH_RX;
1036 		else
1037 			tmp_cap->direction = MOST_CH_TX;
1038 		tmp_cap++;
1039 		init_usb_anchor(&mdev->busy_urbs[i]);
1040 		spin_lock_init(&mdev->channel_lock[i]);
1041 	}
1042 	dev_dbg(dev, "claimed gadget: Vendor=%4.4x ProdID=%4.4x Bus=%02x Device=%02x\n",
1043 		le16_to_cpu(usb_dev->descriptor.idVendor),
1044 		le16_to_cpu(usb_dev->descriptor.idProduct),
1045 		usb_dev->bus->busnum,
1046 		usb_dev->devnum);
1047 
1048 	dev_dbg(dev, "device path: /sys/bus/usb/devices/%d-%s:%d.%d\n",
1049 		usb_dev->bus->busnum,
1050 		usb_dev->devpath,
1051 		usb_dev->config->desc.bConfigurationValue,
1052 		usb_iface_desc->desc.bInterfaceNumber);
1053 
1054 	ret = most_register_interface(&mdev->iface);
1055 	if (ret)
1056 		goto err_free_busy_urbs;
1057 
1058 	mutex_lock(&mdev->io_mutex);
1059 	if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81118 ||
1060 	    le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81119 ||
1061 	    le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81210) {
1062 		mdev->dci = kzalloc(sizeof(*mdev->dci), GFP_KERNEL);
1063 		if (!mdev->dci) {
1064 			mutex_unlock(&mdev->io_mutex);
1065 			most_deregister_interface(&mdev->iface);
1066 			ret = -ENOMEM;
1067 			goto err_free_busy_urbs;
1068 		}
1069 
1070 		mdev->dci->dev.init_name = "dci";
1071 		mdev->dci->dev.parent = get_device(mdev->iface.dev);
1072 		mdev->dci->dev.groups = dci_groups;
1073 		mdev->dci->dev.release = release_dci;
1074 		if (device_register(&mdev->dci->dev)) {
1075 			mutex_unlock(&mdev->io_mutex);
1076 			most_deregister_interface(&mdev->iface);
1077 			ret = -ENOMEM;
1078 			goto err_free_dci;
1079 		}
1080 		mdev->dci->usb_device = mdev->usb_device;
1081 	}
1082 	mutex_unlock(&mdev->io_mutex);
1083 	return 0;
1084 err_free_dci:
1085 	put_device(&mdev->dci->dev);
1086 err_free_busy_urbs:
1087 	kfree(mdev->busy_urbs);
1088 err_free_ep_address:
1089 	kfree(mdev->ep_address);
1090 err_free_cap:
1091 	kfree(mdev->cap);
1092 err_free_conf:
1093 	kfree(mdev->conf);
1094 err_free_mdev:
1095 	put_device(&mdev->dev);
1096 	return ret;
1097 }
1098 
1099 /**
1100  * hdm_disconnect - disconnect function of USB device driver
1101  * @interface: Interface of the attached USB device
1102  *
1103  * This deregisters the interface with the core, removes the kernel timer
1104  * and frees resources.
1105  *
1106  * Context: hub kernel thread
1107  */
1108 static void hdm_disconnect(struct usb_interface *interface)
1109 {
1110 	struct most_dev *mdev = usb_get_intfdata(interface);
1111 
1112 	mutex_lock(&mdev->io_mutex);
1113 	usb_set_intfdata(interface, NULL);
1114 	mdev->usb_device = NULL;
1115 	mutex_unlock(&mdev->io_mutex);
1116 
1117 	del_timer_sync(&mdev->link_stat_timer);
1118 	cancel_work_sync(&mdev->poll_work_obj);
1119 
1120 	if (mdev->dci)
1121 		device_unregister(&mdev->dci->dev);
1122 	most_deregister_interface(&mdev->iface);
1123 
1124 	kfree(mdev->busy_urbs);
1125 	kfree(mdev->cap);
1126 	kfree(mdev->conf);
1127 	kfree(mdev->ep_address);
1128 	put_device(&mdev->dci->dev);
1129 	put_device(&mdev->dev);
1130 }
1131 
1132 static int hdm_suspend(struct usb_interface *interface, pm_message_t message)
1133 {
1134 	struct most_dev *mdev = usb_get_intfdata(interface);
1135 	int i;
1136 
1137 	mutex_lock(&mdev->io_mutex);
1138 	for (i = 0; i < mdev->iface.num_channels; i++) {
1139 		most_stop_enqueue(&mdev->iface, i);
1140 		usb_kill_anchored_urbs(&mdev->busy_urbs[i]);
1141 	}
1142 	mutex_unlock(&mdev->io_mutex);
1143 	return 0;
1144 }
1145 
1146 static int hdm_resume(struct usb_interface *interface)
1147 {
1148 	struct most_dev *mdev = usb_get_intfdata(interface);
1149 	int i;
1150 
1151 	mutex_lock(&mdev->io_mutex);
1152 	for (i = 0; i < mdev->iface.num_channels; i++)
1153 		most_resume_enqueue(&mdev->iface, i);
1154 	mutex_unlock(&mdev->io_mutex);
1155 	return 0;
1156 }
1157 
1158 static struct usb_driver hdm_usb = {
1159 	.name = "hdm_usb",
1160 	.id_table = usbid,
1161 	.probe = hdm_probe,
1162 	.disconnect = hdm_disconnect,
1163 	.resume = hdm_resume,
1164 	.suspend = hdm_suspend,
1165 };
1166 
1167 module_usb_driver(hdm_usb);
1168 MODULE_LICENSE("GPL");
1169 MODULE_AUTHOR("Christian Gromm <christian.gromm@microchip.com>");
1170 MODULE_DESCRIPTION("HDM_4_USB");
1171