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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_acm.c -- USB CDC serial (ACM) function driver
4 *
5 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
6 * Copyright (C) 2008 by David Brownell
7 * Copyright (C) 2008 by Nokia Corporation
8 * Copyright (C) 2009 by Samsung Electronics
9 * Author: Michal Nazarewicz (mina86@mina86.com)
10 */
11
12/* #define VERBOSE_DEBUG */
13
14#include <linux/slab.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/device.h>
18#include <linux/err.h>
19
20#include "u_serial.h"
21
22
23/*
24 * This CDC ACM function support just wraps control functions and
25 * notifications around the generic serial-over-usb code.
26 *
27 * Because CDC ACM is standardized by the USB-IF, many host operating
28 * systems have drivers for it. Accordingly, ACM is the preferred
29 * interop solution for serial-port type connections. The control
30 * models are often not necessary, and in any case don't do much in
31 * this bare-bones implementation.
32 *
33 * Note that even MS-Windows has some support for ACM. However, that
34 * support is somewhat broken because when you use ACM in a composite
35 * device, having multiple interfaces confuses the poor OS. It doesn't
36 * seem to understand CDC Union descriptors. The new "association"
37 * descriptors (roughly equivalent to CDC Unions) may sometimes help.
38 */
39
40struct f_acm {
41 struct gserial port;
42 u8 ctrl_id, data_id;
43 u8 port_num;
44
45 u8 pending;
46
47 /* lock is mostly for pending and notify_req ... they get accessed
48 * by callbacks both from tty (open/close/break) under its spinlock,
49 * and notify_req.complete() which can't use that lock.
50 */
51 spinlock_t lock;
52
53 struct usb_ep *notify;
54 struct usb_request *notify_req;
55
56 struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
57
58 /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
59 u16 port_handshake_bits;
60 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
61 u16 serial_state;
62};
63
64static inline struct f_acm *func_to_acm(struct usb_function *f)
65{
66 return container_of(f, struct f_acm, port.func);
67}
68
69static inline struct f_acm *port_to_acm(struct gserial *p)
70{
71 return container_of(p, struct f_acm, port);
72}
73
74/*-------------------------------------------------------------------------*/
75
76/* notification endpoint uses smallish and infrequent fixed-size messages */
77
78#define GS_NOTIFY_INTERVAL_MS 32
79#define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
80
81/* interface and class descriptors: */
82
83static struct usb_interface_assoc_descriptor
84acm_iad_descriptor = {
85 .bLength = sizeof acm_iad_descriptor,
86 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
87
88 /* .bFirstInterface = DYNAMIC, */
89 .bInterfaceCount = 2, // control + data
90 .bFunctionClass = USB_CLASS_COMM,
91 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM,
92 .bFunctionProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
93 /* .iFunction = DYNAMIC */
94};
95
96
97static struct usb_interface_descriptor acm_control_interface_desc = {
98 .bLength = USB_DT_INTERFACE_SIZE,
99 .bDescriptorType = USB_DT_INTERFACE,
100 /* .bInterfaceNumber = DYNAMIC */
101 .bNumEndpoints = 1,
102 .bInterfaceClass = USB_CLASS_COMM,
103 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
104 .bInterfaceProtocol = USB_CDC_ACM_PROTO_AT_V25TER,
105 /* .iInterface = DYNAMIC */
106};
107
108static struct usb_interface_descriptor acm_data_interface_desc = {
109 .bLength = USB_DT_INTERFACE_SIZE,
110 .bDescriptorType = USB_DT_INTERFACE,
111 /* .bInterfaceNumber = DYNAMIC */
112 .bNumEndpoints = 2,
113 .bInterfaceClass = USB_CLASS_CDC_DATA,
114 .bInterfaceSubClass = 0,
115 .bInterfaceProtocol = 0,
116 /* .iInterface = DYNAMIC */
117};
118
119static struct usb_cdc_header_desc acm_header_desc = {
120 .bLength = sizeof(acm_header_desc),
121 .bDescriptorType = USB_DT_CS_INTERFACE,
122 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
123 .bcdCDC = cpu_to_le16(0x0110),
124};
125
126static struct usb_cdc_call_mgmt_descriptor
127acm_call_mgmt_descriptor = {
128 .bLength = sizeof(acm_call_mgmt_descriptor),
129 .bDescriptorType = USB_DT_CS_INTERFACE,
130 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
131 .bmCapabilities = 0,
132 /* .bDataInterface = DYNAMIC */
133};
134
135static struct usb_cdc_acm_descriptor acm_descriptor = {
136 .bLength = sizeof(acm_descriptor),
137 .bDescriptorType = USB_DT_CS_INTERFACE,
138 .bDescriptorSubType = USB_CDC_ACM_TYPE,
139 .bmCapabilities = USB_CDC_CAP_LINE,
140};
141
142static struct usb_cdc_union_desc acm_union_desc = {
143 .bLength = sizeof(acm_union_desc),
144 .bDescriptorType = USB_DT_CS_INTERFACE,
145 .bDescriptorSubType = USB_CDC_UNION_TYPE,
146 /* .bMasterInterface0 = DYNAMIC */
147 /* .bSlaveInterface0 = DYNAMIC */
148};
149
150/* full speed support: */
151
152static struct usb_endpoint_descriptor acm_fs_notify_desc = {
153 .bLength = USB_DT_ENDPOINT_SIZE,
154 .bDescriptorType = USB_DT_ENDPOINT,
155 .bEndpointAddress = USB_DIR_IN,
156 .bmAttributes = USB_ENDPOINT_XFER_INT,
157 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
158 .bInterval = GS_NOTIFY_INTERVAL_MS,
159};
160
161static struct usb_endpoint_descriptor acm_fs_in_desc = {
162 .bLength = USB_DT_ENDPOINT_SIZE,
163 .bDescriptorType = USB_DT_ENDPOINT,
164 .bEndpointAddress = USB_DIR_IN,
165 .bmAttributes = USB_ENDPOINT_XFER_BULK,
166};
167
168static struct usb_endpoint_descriptor acm_fs_out_desc = {
169 .bLength = USB_DT_ENDPOINT_SIZE,
170 .bDescriptorType = USB_DT_ENDPOINT,
171 .bEndpointAddress = USB_DIR_OUT,
172 .bmAttributes = USB_ENDPOINT_XFER_BULK,
173};
174
175static struct usb_descriptor_header *acm_fs_function[] = {
176 (struct usb_descriptor_header *) &acm_iad_descriptor,
177 (struct usb_descriptor_header *) &acm_control_interface_desc,
178 (struct usb_descriptor_header *) &acm_header_desc,
179 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
180 (struct usb_descriptor_header *) &acm_descriptor,
181 (struct usb_descriptor_header *) &acm_union_desc,
182 (struct usb_descriptor_header *) &acm_fs_notify_desc,
183 (struct usb_descriptor_header *) &acm_data_interface_desc,
184 (struct usb_descriptor_header *) &acm_fs_in_desc,
185 (struct usb_descriptor_header *) &acm_fs_out_desc,
186 NULL,
187};
188
189/* high speed support: */
190static struct usb_endpoint_descriptor acm_hs_notify_desc = {
191 .bLength = USB_DT_ENDPOINT_SIZE,
192 .bDescriptorType = USB_DT_ENDPOINT,
193 .bEndpointAddress = USB_DIR_IN,
194 .bmAttributes = USB_ENDPOINT_XFER_INT,
195 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
196 .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
197};
198
199static struct usb_endpoint_descriptor acm_hs_in_desc = {
200 .bLength = USB_DT_ENDPOINT_SIZE,
201 .bDescriptorType = USB_DT_ENDPOINT,
202 .bmAttributes = USB_ENDPOINT_XFER_BULK,
203 .wMaxPacketSize = cpu_to_le16(512),
204};
205
206static struct usb_endpoint_descriptor acm_hs_out_desc = {
207 .bLength = USB_DT_ENDPOINT_SIZE,
208 .bDescriptorType = USB_DT_ENDPOINT,
209 .bmAttributes = USB_ENDPOINT_XFER_BULK,
210 .wMaxPacketSize = cpu_to_le16(512),
211};
212
213static struct usb_descriptor_header *acm_hs_function[] = {
214 (struct usb_descriptor_header *) &acm_iad_descriptor,
215 (struct usb_descriptor_header *) &acm_control_interface_desc,
216 (struct usb_descriptor_header *) &acm_header_desc,
217 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
218 (struct usb_descriptor_header *) &acm_descriptor,
219 (struct usb_descriptor_header *) &acm_union_desc,
220 (struct usb_descriptor_header *) &acm_hs_notify_desc,
221 (struct usb_descriptor_header *) &acm_data_interface_desc,
222 (struct usb_descriptor_header *) &acm_hs_in_desc,
223 (struct usb_descriptor_header *) &acm_hs_out_desc,
224 NULL,
225};
226
227static struct usb_endpoint_descriptor acm_ss_in_desc = {
228 .bLength = USB_DT_ENDPOINT_SIZE,
229 .bDescriptorType = USB_DT_ENDPOINT,
230 .bmAttributes = USB_ENDPOINT_XFER_BULK,
231 .wMaxPacketSize = cpu_to_le16(1024),
232};
233
234static struct usb_endpoint_descriptor acm_ss_out_desc = {
235 .bLength = USB_DT_ENDPOINT_SIZE,
236 .bDescriptorType = USB_DT_ENDPOINT,
237 .bmAttributes = USB_ENDPOINT_XFER_BULK,
238 .wMaxPacketSize = cpu_to_le16(1024),
239};
240
241static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
242 .bLength = sizeof acm_ss_bulk_comp_desc,
243 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
244};
245
246static struct usb_descriptor_header *acm_ss_function[] = {
247 (struct usb_descriptor_header *) &acm_iad_descriptor,
248 (struct usb_descriptor_header *) &acm_control_interface_desc,
249 (struct usb_descriptor_header *) &acm_header_desc,
250 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
251 (struct usb_descriptor_header *) &acm_descriptor,
252 (struct usb_descriptor_header *) &acm_union_desc,
253 (struct usb_descriptor_header *) &acm_hs_notify_desc,
254 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
255 (struct usb_descriptor_header *) &acm_data_interface_desc,
256 (struct usb_descriptor_header *) &acm_ss_in_desc,
257 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
258 (struct usb_descriptor_header *) &acm_ss_out_desc,
259 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
260 NULL,
261};
262
263/* string descriptors: */
264
265#define ACM_CTRL_IDX 0
266#define ACM_DATA_IDX 1
267#define ACM_IAD_IDX 2
268
269/* static strings, in UTF-8 */
270static struct usb_string acm_string_defs[] = {
271 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
272 [ACM_DATA_IDX].s = "CDC ACM Data",
273 [ACM_IAD_IDX ].s = "CDC Serial",
274 { } /* end of list */
275};
276
277static struct usb_gadget_strings acm_string_table = {
278 .language = 0x0409, /* en-us */
279 .strings = acm_string_defs,
280};
281
282static struct usb_gadget_strings *acm_strings[] = {
283 &acm_string_table,
284 NULL,
285};
286
287/*-------------------------------------------------------------------------*/
288
289/* ACM control ... data handling is delegated to tty library code.
290 * The main task of this function is to activate and deactivate
291 * that code based on device state; track parameters like line
292 * speed, handshake state, and so on; and issue notifications.
293 */
294
295static void acm_complete_set_line_coding(struct usb_ep *ep,
296 struct usb_request *req)
297{
298 struct f_acm *acm = ep->driver_data;
299 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
300
301 if (req->status != 0) {
302 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n",
303 acm->port_num, req->status);
304 return;
305 }
306
307 /* normal completion */
308 if (req->actual != sizeof(acm->port_line_coding)) {
309 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n",
310 acm->port_num, req->actual);
311 usb_ep_set_halt(ep);
312 } else {
313 struct usb_cdc_line_coding *value = req->buf;
314
315 /* REVISIT: we currently just remember this data.
316 * If we change that, (a) validate it first, then
317 * (b) update whatever hardware needs updating,
318 * (c) worry about locking. This is information on
319 * the order of 9600-8-N-1 ... most of which means
320 * nothing unless we control a real RS232 line.
321 */
322 acm->port_line_coding = *value;
323 }
324}
325
326static int acm_send_break(struct gserial *port, int duration);
327
328static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
329{
330 struct f_acm *acm = func_to_acm(f);
331 struct usb_composite_dev *cdev = f->config->cdev;
332 struct usb_request *req = cdev->req;
333 int value = -EOPNOTSUPP;
334 u16 w_index = le16_to_cpu(ctrl->wIndex);
335 u16 w_value = le16_to_cpu(ctrl->wValue);
336 u16 w_length = le16_to_cpu(ctrl->wLength);
337
338 /* composite driver infrastructure handles everything except
339 * CDC class messages; interface activation uses set_alt().
340 *
341 * Note CDC spec table 4 lists the ACM request profile. It requires
342 * encapsulated command support ... we don't handle any, and respond
343 * to them by stalling. Options include get/set/clear comm features
344 * (not that useful) and SEND_BREAK.
345 */
346 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
347
348 /* SET_LINE_CODING ... just read and save what the host sends */
349 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
350 | USB_CDC_REQ_SET_LINE_CODING:
351 if (w_length != sizeof(struct usb_cdc_line_coding)
352 || w_index != acm->ctrl_id)
353 goto invalid;
354
355 value = w_length;
356 cdev->gadget->ep0->driver_data = acm;
357 req->complete = acm_complete_set_line_coding;
358 break;
359
360 /* GET_LINE_CODING ... return what host sent, or initial value */
361 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
362 | USB_CDC_REQ_GET_LINE_CODING:
363 if (w_index != acm->ctrl_id)
364 goto invalid;
365
366 value = min_t(unsigned, w_length,
367 sizeof(struct usb_cdc_line_coding));
368 memcpy(req->buf, &acm->port_line_coding, value);
369 break;
370
371 /* SET_CONTROL_LINE_STATE ... save what the host sent */
372 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
373 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
374 if (w_index != acm->ctrl_id)
375 goto invalid;
376
377 value = 0;
378
379 /* FIXME we should not allow data to flow until the
380 * host sets the USB_CDC_CTRL_DTR bit; and when it clears
381 * that bit, we should return to that no-flow state.
382 */
383 acm->port_handshake_bits = w_value;
384 break;
385
386 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
387 | USB_CDC_REQ_SEND_BREAK:
388 if (w_index != acm->ctrl_id)
389 goto invalid;
390
391 acm_send_break(&acm->port, w_value);
392 break;
393
394 default:
395invalid:
396 dev_vdbg(&cdev->gadget->dev,
397 "invalid control req%02x.%02x v%04x i%04x l%d\n",
398 ctrl->bRequestType, ctrl->bRequest,
399 w_value, w_index, w_length);
400 }
401
402 /* respond with data transfer or status phase? */
403 if (value >= 0) {
404 dev_dbg(&cdev->gadget->dev,
405 "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
406 acm->port_num, ctrl->bRequestType, ctrl->bRequest,
407 w_value, w_index, w_length);
408 req->zero = 0;
409 req->length = value;
410 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
411 if (value < 0)
412 ERROR(cdev, "acm response on ttyGS%d, err %d\n",
413 acm->port_num, value);
414 }
415
416 /* device either stalls (value < 0) or reports success */
417 return value;
418}
419
420static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
421{
422 struct f_acm *acm = func_to_acm(f);
423 struct usb_composite_dev *cdev = f->config->cdev;
424
425 /* we know alt == 0, so this is an activation or a reset */
426
427 if (intf == acm->ctrl_id) {
428 if (acm->notify->enabled) {
429 dev_vdbg(&cdev->gadget->dev,
430 "reset acm control interface %d\n", intf);
431 usb_ep_disable(acm->notify);
432 }
433
434 if (!acm->notify->desc)
435 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
436 return -EINVAL;
437
438 usb_ep_enable(acm->notify);
439
440 } else if (intf == acm->data_id) {
441 if (acm->notify->enabled) {
442 dev_dbg(&cdev->gadget->dev,
443 "reset acm ttyGS%d\n", acm->port_num);
444 gserial_disconnect(&acm->port);
445 }
446 if (!acm->port.in->desc || !acm->port.out->desc) {
447 dev_dbg(&cdev->gadget->dev,
448 "activate acm ttyGS%d\n", acm->port_num);
449 if (config_ep_by_speed(cdev->gadget, f,
450 acm->port.in) ||
451 config_ep_by_speed(cdev->gadget, f,
452 acm->port.out)) {
453 acm->port.in->desc = NULL;
454 acm->port.out->desc = NULL;
455 return -EINVAL;
456 }
457 }
458 gserial_connect(&acm->port, acm->port_num);
459
460 } else
461 return -EINVAL;
462
463 return 0;
464}
465
466static void acm_disable(struct usb_function *f)
467{
468 struct f_acm *acm = func_to_acm(f);
469 struct usb_composite_dev *cdev = f->config->cdev;
470
471 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
472 gserial_disconnect(&acm->port);
473 usb_ep_disable(acm->notify);
474}
475
476/*-------------------------------------------------------------------------*/
477
478/**
479 * acm_cdc_notify - issue CDC notification to host
480 * @acm: wraps host to be notified
481 * @type: notification type
482 * @value: Refer to cdc specs, wValue field.
483 * @data: data to be sent
484 * @length: size of data
485 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
486 *
487 * Returns zero on success or a negative errno.
488 *
489 * See section 6.3.5 of the CDC 1.1 specification for information
490 * about the only notification we issue: SerialState change.
491 */
492static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
493 void *data, unsigned length)
494{
495 struct usb_ep *ep = acm->notify;
496 struct usb_request *req;
497 struct usb_cdc_notification *notify;
498 const unsigned len = sizeof(*notify) + length;
499 void *buf;
500 int status;
501
502 req = acm->notify_req;
503 acm->notify_req = NULL;
504 acm->pending = false;
505
506 req->length = len;
507 notify = req->buf;
508 buf = notify + 1;
509
510 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
511 | USB_RECIP_INTERFACE;
512 notify->bNotificationType = type;
513 notify->wValue = cpu_to_le16(value);
514 notify->wIndex = cpu_to_le16(acm->ctrl_id);
515 notify->wLength = cpu_to_le16(length);
516 memcpy(buf, data, length);
517
518 /* ep_queue() can complete immediately if it fills the fifo... */
519 spin_unlock(&acm->lock);
520 status = usb_ep_queue(ep, req, GFP_ATOMIC);
521 spin_lock(&acm->lock);
522
523 if (status < 0) {
524 ERROR(acm->port.func.config->cdev,
525 "acm ttyGS%d can't notify serial state, %d\n",
526 acm->port_num, status);
527 acm->notify_req = req;
528 }
529
530 return status;
531}
532
533static int acm_notify_serial_state(struct f_acm *acm)
534{
535 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
536 int status;
537 __le16 serial_state;
538
539 spin_lock(&acm->lock);
540 if (acm->notify_req) {
541 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
542 acm->port_num, acm->serial_state);
543 serial_state = cpu_to_le16(acm->serial_state);
544 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
545 0, &serial_state, sizeof(acm->serial_state));
546 } else {
547 acm->pending = true;
548 status = 0;
549 }
550 spin_unlock(&acm->lock);
551 return status;
552}
553
554static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
555{
556 struct f_acm *acm = req->context;
557 u8 doit = false;
558
559 /* on this call path we do NOT hold the port spinlock,
560 * which is why ACM needs its own spinlock
561 */
562 spin_lock(&acm->lock);
563 if (req->status != -ESHUTDOWN)
564 doit = acm->pending;
565 acm->notify_req = req;
566 spin_unlock(&acm->lock);
567
568 if (doit)
569 acm_notify_serial_state(acm);
570}
571
572/* connect == the TTY link is open */
573
574static void acm_connect(struct gserial *port)
575{
576 struct f_acm *acm = port_to_acm(port);
577
578 acm->serial_state |= USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD;
579 acm_notify_serial_state(acm);
580}
581
582static void acm_disconnect(struct gserial *port)
583{
584 struct f_acm *acm = port_to_acm(port);
585
586 acm->serial_state &= ~(USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD);
587 acm_notify_serial_state(acm);
588}
589
590static int acm_send_break(struct gserial *port, int duration)
591{
592 struct f_acm *acm = port_to_acm(port);
593 u16 state;
594
595 state = acm->serial_state;
596 state &= ~USB_CDC_SERIAL_STATE_BREAK;
597 if (duration)
598 state |= USB_CDC_SERIAL_STATE_BREAK;
599
600 acm->serial_state = state;
601 return acm_notify_serial_state(acm);
602}
603
604/*-------------------------------------------------------------------------*/
605
606/* ACM function driver setup/binding */
607static int
608acm_bind(struct usb_configuration *c, struct usb_function *f)
609{
610 struct usb_composite_dev *cdev = c->cdev;
611 struct f_acm *acm = func_to_acm(f);
612 struct usb_string *us;
613 int status;
614 struct usb_ep *ep;
615
616 /* REVISIT might want instance-specific strings to help
617 * distinguish instances ...
618 */
619
620 /* maybe allocate device-global string IDs, and patch descriptors */
621 us = usb_gstrings_attach(cdev, acm_strings,
622 ARRAY_SIZE(acm_string_defs));
623 if (IS_ERR(us))
624 return PTR_ERR(us);
625 acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
626 acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
627 acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
628
629 /* allocate instance-specific interface IDs, and patch descriptors */
630 status = usb_interface_id(c, f);
631 if (status < 0)
632 goto fail;
633 acm->ctrl_id = status;
634 acm_iad_descriptor.bFirstInterface = status;
635
636 acm_control_interface_desc.bInterfaceNumber = status;
637 acm_union_desc .bMasterInterface0 = status;
638
639 status = usb_interface_id(c, f);
640 if (status < 0)
641 goto fail;
642 acm->data_id = status;
643
644 acm_data_interface_desc.bInterfaceNumber = status;
645 acm_union_desc.bSlaveInterface0 = status;
646 acm_call_mgmt_descriptor.bDataInterface = status;
647
648 status = -ENODEV;
649
650 /* allocate instance-specific endpoints */
651 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
652 if (!ep)
653 goto fail;
654 acm->port.in = ep;
655
656 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
657 if (!ep)
658 goto fail;
659 acm->port.out = ep;
660
661 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
662 if (!ep)
663 goto fail;
664 acm->notify = ep;
665
666 /* allocate notification */
667 acm->notify_req = gs_alloc_req(ep,
668 sizeof(struct usb_cdc_notification) + 2,
669 GFP_KERNEL);
670 if (!acm->notify_req)
671 goto fail;
672
673 acm->notify_req->complete = acm_cdc_notify_complete;
674 acm->notify_req->context = acm;
675
676 /* support all relevant hardware speeds... we expect that when
677 * hardware is dual speed, all bulk-capable endpoints work at
678 * both speeds
679 */
680 acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
681 acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
682 acm_hs_notify_desc.bEndpointAddress =
683 acm_fs_notify_desc.bEndpointAddress;
684
685 acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
686 acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
687
688 status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
689 acm_ss_function, acm_ss_function);
690 if (status)
691 goto fail;
692
693 dev_dbg(&cdev->gadget->dev,
694 "acm ttyGS%d: IN/%s OUT/%s NOTIFY/%s\n",
695 acm->port_num,
696 acm->port.in->name, acm->port.out->name,
697 acm->notify->name);
698 return 0;
699
700fail:
701 if (acm->notify_req)
702 gs_free_req(acm->notify, acm->notify_req);
703
704 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
705
706 return status;
707}
708
709static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
710{
711 struct f_acm *acm = func_to_acm(f);
712
713 acm_string_defs[0].id = 0;
714 usb_free_all_descriptors(f);
715 if (acm->notify_req)
716 gs_free_req(acm->notify, acm->notify_req);
717}
718
719static void acm_free_func(struct usb_function *f)
720{
721 struct f_acm *acm = func_to_acm(f);
722
723 kfree(acm);
724}
725
726static void acm_resume(struct usb_function *f)
727{
728 struct f_acm *acm = func_to_acm(f);
729
730 gserial_resume(&acm->port);
731}
732
733static void acm_suspend(struct usb_function *f)
734{
735 struct f_acm *acm = func_to_acm(f);
736
737 gserial_suspend(&acm->port);
738}
739
740static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
741{
742 struct f_serial_opts *opts;
743 struct f_acm *acm;
744
745 acm = kzalloc(sizeof(*acm), GFP_KERNEL);
746 if (!acm)
747 return ERR_PTR(-ENOMEM);
748
749 spin_lock_init(&acm->lock);
750
751 acm->port.connect = acm_connect;
752 acm->port.disconnect = acm_disconnect;
753 acm->port.send_break = acm_send_break;
754
755 acm->port.func.name = "acm";
756 acm->port.func.strings = acm_strings;
757 /* descriptors are per-instance copies */
758 acm->port.func.bind = acm_bind;
759 acm->port.func.set_alt = acm_set_alt;
760 acm->port.func.setup = acm_setup;
761 acm->port.func.disable = acm_disable;
762
763 opts = container_of(fi, struct f_serial_opts, func_inst);
764 acm->port_num = opts->port_num;
765 acm->port.func.unbind = acm_unbind;
766 acm->port.func.free_func = acm_free_func;
767 acm->port.func.resume = acm_resume;
768 acm->port.func.suspend = acm_suspend;
769
770 return &acm->port.func;
771}
772
773static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
774{
775 return container_of(to_config_group(item), struct f_serial_opts,
776 func_inst.group);
777}
778
779static void acm_attr_release(struct config_item *item)
780{
781 struct f_serial_opts *opts = to_f_serial_opts(item);
782
783 usb_put_function_instance(&opts->func_inst);
784}
785
786static struct configfs_item_operations acm_item_ops = {
787 .release = acm_attr_release,
788};
789
790#ifdef CONFIG_U_SERIAL_CONSOLE
791
792static ssize_t f_acm_console_store(struct config_item *item,
793 const char *page, size_t count)
794{
795 return gserial_set_console(to_f_serial_opts(item)->port_num,
796 page, count);
797}
798
799static ssize_t f_acm_console_show(struct config_item *item, char *page)
800{
801 return gserial_get_console(to_f_serial_opts(item)->port_num, page);
802}
803
804CONFIGFS_ATTR(f_acm_, console);
805
806#endif /* CONFIG_U_SERIAL_CONSOLE */
807
808static ssize_t f_acm_port_num_show(struct config_item *item, char *page)
809{
810 return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
811}
812
813CONFIGFS_ATTR_RO(f_acm_, port_num);
814
815static struct configfs_attribute *acm_attrs[] = {
816#ifdef CONFIG_U_SERIAL_CONSOLE
817 &f_acm_attr_console,
818#endif
819 &f_acm_attr_port_num,
820 NULL,
821};
822
823static const struct config_item_type acm_func_type = {
824 .ct_item_ops = &acm_item_ops,
825 .ct_attrs = acm_attrs,
826 .ct_owner = THIS_MODULE,
827};
828
829static void acm_free_instance(struct usb_function_instance *fi)
830{
831 struct f_serial_opts *opts;
832
833 opts = container_of(fi, struct f_serial_opts, func_inst);
834 gserial_free_line(opts->port_num);
835 kfree(opts);
836}
837
838static struct usb_function_instance *acm_alloc_instance(void)
839{
840 struct f_serial_opts *opts;
841 int ret;
842
843 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
844 if (!opts)
845 return ERR_PTR(-ENOMEM);
846 opts->func_inst.free_func_inst = acm_free_instance;
847 ret = gserial_alloc_line(&opts->port_num);
848 if (ret) {
849 kfree(opts);
850 return ERR_PTR(ret);
851 }
852 config_group_init_type_name(&opts->func_inst.group, "",
853 &acm_func_type);
854 return &opts->func_inst;
855}
856DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
857MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_acm.c -- USB CDC serial (ACM) function driver
4 *
5 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
6 * Copyright (C) 2008 by David Brownell
7 * Copyright (C) 2008 by Nokia Corporation
8 * Copyright (C) 2009 by Samsung Electronics
9 * Author: Michal Nazarewicz (mina86@mina86.com)
10 */
11
12/* #define VERBOSE_DEBUG */
13
14#include <linux/slab.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/device.h>
18#include <linux/err.h>
19
20#include "u_serial.h"
21
22
23/*
24 * This CDC ACM function support just wraps control functions and
25 * notifications around the generic serial-over-usb code.
26 *
27 * Because CDC ACM is standardized by the USB-IF, many host operating
28 * systems have drivers for it. Accordingly, ACM is the preferred
29 * interop solution for serial-port type connections. The control
30 * models are often not necessary, and in any case don't do much in
31 * this bare-bones implementation.
32 *
33 * Note that even MS-Windows has some support for ACM. However, that
34 * support is somewhat broken because when you use ACM in a composite
35 * device, having multiple interfaces confuses the poor OS. It doesn't
36 * seem to understand CDC Union descriptors. The new "association"
37 * descriptors (roughly equivalent to CDC Unions) may sometimes help.
38 */
39
40struct f_acm {
41 struct gserial port;
42 u8 ctrl_id, data_id;
43 u8 port_num;
44 u8 bInterfaceProtocol;
45
46 u8 pending;
47
48 /* lock is mostly for pending and notify_req ... they get accessed
49 * by callbacks both from tty (open/close/break) under its spinlock,
50 * and notify_req.complete() which can't use that lock.
51 */
52 spinlock_t lock;
53
54 struct usb_ep *notify;
55 struct usb_request *notify_req;
56
57 struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
58
59 /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
60 u16 port_handshake_bits;
61 /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
62 u16 serial_state;
63};
64
65static inline struct f_acm *func_to_acm(struct usb_function *f)
66{
67 return container_of(f, struct f_acm, port.func);
68}
69
70static inline struct f_acm *port_to_acm(struct gserial *p)
71{
72 return container_of(p, struct f_acm, port);
73}
74
75/*-------------------------------------------------------------------------*/
76
77/* notification endpoint uses smallish and infrequent fixed-size messages */
78
79#define GS_NOTIFY_INTERVAL_MS 32
80#define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
81
82/* interface and class descriptors: */
83
84static struct usb_interface_assoc_descriptor
85acm_iad_descriptor = {
86 .bLength = sizeof acm_iad_descriptor,
87 .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
88
89 /* .bFirstInterface = DYNAMIC, */
90 .bInterfaceCount = 2, // control + data
91 .bFunctionClass = USB_CLASS_COMM,
92 .bFunctionSubClass = USB_CDC_SUBCLASS_ACM,
93 /* .bFunctionProtocol = DYNAMIC */
94 /* .iFunction = DYNAMIC */
95};
96
97
98static struct usb_interface_descriptor acm_control_interface_desc = {
99 .bLength = USB_DT_INTERFACE_SIZE,
100 .bDescriptorType = USB_DT_INTERFACE,
101 /* .bInterfaceNumber = DYNAMIC */
102 .bNumEndpoints = 1,
103 .bInterfaceClass = USB_CLASS_COMM,
104 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
105 /* .bInterfaceProtocol = DYNAMIC */
106 /* .iInterface = DYNAMIC */
107};
108
109static struct usb_interface_descriptor acm_data_interface_desc = {
110 .bLength = USB_DT_INTERFACE_SIZE,
111 .bDescriptorType = USB_DT_INTERFACE,
112 /* .bInterfaceNumber = DYNAMIC */
113 .bNumEndpoints = 2,
114 .bInterfaceClass = USB_CLASS_CDC_DATA,
115 .bInterfaceSubClass = 0,
116 .bInterfaceProtocol = 0,
117 /* .iInterface = DYNAMIC */
118};
119
120static struct usb_cdc_header_desc acm_header_desc = {
121 .bLength = sizeof(acm_header_desc),
122 .bDescriptorType = USB_DT_CS_INTERFACE,
123 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
124 .bcdCDC = cpu_to_le16(0x0110),
125};
126
127static struct usb_cdc_call_mgmt_descriptor
128acm_call_mgmt_descriptor = {
129 .bLength = sizeof(acm_call_mgmt_descriptor),
130 .bDescriptorType = USB_DT_CS_INTERFACE,
131 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
132 .bmCapabilities = 0,
133 /* .bDataInterface = DYNAMIC */
134};
135
136static struct usb_cdc_acm_descriptor acm_descriptor = {
137 .bLength = sizeof(acm_descriptor),
138 .bDescriptorType = USB_DT_CS_INTERFACE,
139 .bDescriptorSubType = USB_CDC_ACM_TYPE,
140 .bmCapabilities = USB_CDC_CAP_LINE,
141};
142
143static struct usb_cdc_union_desc acm_union_desc = {
144 .bLength = sizeof(acm_union_desc),
145 .bDescriptorType = USB_DT_CS_INTERFACE,
146 .bDescriptorSubType = USB_CDC_UNION_TYPE,
147 /* .bMasterInterface0 = DYNAMIC */
148 /* .bSlaveInterface0 = DYNAMIC */
149};
150
151/* full speed support: */
152
153static struct usb_endpoint_descriptor acm_fs_notify_desc = {
154 .bLength = USB_DT_ENDPOINT_SIZE,
155 .bDescriptorType = USB_DT_ENDPOINT,
156 .bEndpointAddress = USB_DIR_IN,
157 .bmAttributes = USB_ENDPOINT_XFER_INT,
158 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
159 .bInterval = GS_NOTIFY_INTERVAL_MS,
160};
161
162static struct usb_endpoint_descriptor acm_fs_in_desc = {
163 .bLength = USB_DT_ENDPOINT_SIZE,
164 .bDescriptorType = USB_DT_ENDPOINT,
165 .bEndpointAddress = USB_DIR_IN,
166 .bmAttributes = USB_ENDPOINT_XFER_BULK,
167};
168
169static struct usb_endpoint_descriptor acm_fs_out_desc = {
170 .bLength = USB_DT_ENDPOINT_SIZE,
171 .bDescriptorType = USB_DT_ENDPOINT,
172 .bEndpointAddress = USB_DIR_OUT,
173 .bmAttributes = USB_ENDPOINT_XFER_BULK,
174};
175
176static struct usb_descriptor_header *acm_fs_function[] = {
177 (struct usb_descriptor_header *) &acm_iad_descriptor,
178 (struct usb_descriptor_header *) &acm_control_interface_desc,
179 (struct usb_descriptor_header *) &acm_header_desc,
180 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
181 (struct usb_descriptor_header *) &acm_descriptor,
182 (struct usb_descriptor_header *) &acm_union_desc,
183 (struct usb_descriptor_header *) &acm_fs_notify_desc,
184 (struct usb_descriptor_header *) &acm_data_interface_desc,
185 (struct usb_descriptor_header *) &acm_fs_in_desc,
186 (struct usb_descriptor_header *) &acm_fs_out_desc,
187 NULL,
188};
189
190/* high speed support: */
191static struct usb_endpoint_descriptor acm_hs_notify_desc = {
192 .bLength = USB_DT_ENDPOINT_SIZE,
193 .bDescriptorType = USB_DT_ENDPOINT,
194 .bEndpointAddress = USB_DIR_IN,
195 .bmAttributes = USB_ENDPOINT_XFER_INT,
196 .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET),
197 .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS),
198};
199
200static struct usb_endpoint_descriptor acm_hs_in_desc = {
201 .bLength = USB_DT_ENDPOINT_SIZE,
202 .bDescriptorType = USB_DT_ENDPOINT,
203 .bmAttributes = USB_ENDPOINT_XFER_BULK,
204 .wMaxPacketSize = cpu_to_le16(512),
205};
206
207static struct usb_endpoint_descriptor acm_hs_out_desc = {
208 .bLength = USB_DT_ENDPOINT_SIZE,
209 .bDescriptorType = USB_DT_ENDPOINT,
210 .bmAttributes = USB_ENDPOINT_XFER_BULK,
211 .wMaxPacketSize = cpu_to_le16(512),
212};
213
214static struct usb_descriptor_header *acm_hs_function[] = {
215 (struct usb_descriptor_header *) &acm_iad_descriptor,
216 (struct usb_descriptor_header *) &acm_control_interface_desc,
217 (struct usb_descriptor_header *) &acm_header_desc,
218 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
219 (struct usb_descriptor_header *) &acm_descriptor,
220 (struct usb_descriptor_header *) &acm_union_desc,
221 (struct usb_descriptor_header *) &acm_hs_notify_desc,
222 (struct usb_descriptor_header *) &acm_data_interface_desc,
223 (struct usb_descriptor_header *) &acm_hs_in_desc,
224 (struct usb_descriptor_header *) &acm_hs_out_desc,
225 NULL,
226};
227
228static struct usb_endpoint_descriptor acm_ss_in_desc = {
229 .bLength = USB_DT_ENDPOINT_SIZE,
230 .bDescriptorType = USB_DT_ENDPOINT,
231 .bmAttributes = USB_ENDPOINT_XFER_BULK,
232 .wMaxPacketSize = cpu_to_le16(1024),
233};
234
235static struct usb_endpoint_descriptor acm_ss_out_desc = {
236 .bLength = USB_DT_ENDPOINT_SIZE,
237 .bDescriptorType = USB_DT_ENDPOINT,
238 .bmAttributes = USB_ENDPOINT_XFER_BULK,
239 .wMaxPacketSize = cpu_to_le16(1024),
240};
241
242static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = {
243 .bLength = sizeof acm_ss_bulk_comp_desc,
244 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
245};
246
247static struct usb_descriptor_header *acm_ss_function[] = {
248 (struct usb_descriptor_header *) &acm_iad_descriptor,
249 (struct usb_descriptor_header *) &acm_control_interface_desc,
250 (struct usb_descriptor_header *) &acm_header_desc,
251 (struct usb_descriptor_header *) &acm_call_mgmt_descriptor,
252 (struct usb_descriptor_header *) &acm_descriptor,
253 (struct usb_descriptor_header *) &acm_union_desc,
254 (struct usb_descriptor_header *) &acm_hs_notify_desc,
255 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
256 (struct usb_descriptor_header *) &acm_data_interface_desc,
257 (struct usb_descriptor_header *) &acm_ss_in_desc,
258 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
259 (struct usb_descriptor_header *) &acm_ss_out_desc,
260 (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc,
261 NULL,
262};
263
264/* string descriptors: */
265
266#define ACM_CTRL_IDX 0
267#define ACM_DATA_IDX 1
268#define ACM_IAD_IDX 2
269
270/* static strings, in UTF-8 */
271static struct usb_string acm_string_defs[] = {
272 [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)",
273 [ACM_DATA_IDX].s = "CDC ACM Data",
274 [ACM_IAD_IDX ].s = "CDC Serial",
275 { } /* end of list */
276};
277
278static struct usb_gadget_strings acm_string_table = {
279 .language = 0x0409, /* en-us */
280 .strings = acm_string_defs,
281};
282
283static struct usb_gadget_strings *acm_strings[] = {
284 &acm_string_table,
285 NULL,
286};
287
288/*-------------------------------------------------------------------------*/
289
290/* ACM control ... data handling is delegated to tty library code.
291 * The main task of this function is to activate and deactivate
292 * that code based on device state; track parameters like line
293 * speed, handshake state, and so on; and issue notifications.
294 */
295
296static void acm_complete_set_line_coding(struct usb_ep *ep,
297 struct usb_request *req)
298{
299 struct f_acm *acm = ep->driver_data;
300 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
301
302 if (req->status != 0) {
303 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n",
304 acm->port_num, req->status);
305 return;
306 }
307
308 /* normal completion */
309 if (req->actual != sizeof(acm->port_line_coding)) {
310 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n",
311 acm->port_num, req->actual);
312 usb_ep_set_halt(ep);
313 } else {
314 struct usb_cdc_line_coding *value = req->buf;
315
316 /* REVISIT: we currently just remember this data.
317 * If we change that, (a) validate it first, then
318 * (b) update whatever hardware needs updating,
319 * (c) worry about locking. This is information on
320 * the order of 9600-8-N-1 ... most of which means
321 * nothing unless we control a real RS232 line.
322 */
323 acm->port_line_coding = *value;
324 }
325}
326
327static int acm_send_break(struct gserial *port, int duration);
328
329static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
330{
331 struct f_acm *acm = func_to_acm(f);
332 struct usb_composite_dev *cdev = f->config->cdev;
333 struct usb_request *req = cdev->req;
334 int value = -EOPNOTSUPP;
335 u16 w_index = le16_to_cpu(ctrl->wIndex);
336 u16 w_value = le16_to_cpu(ctrl->wValue);
337 u16 w_length = le16_to_cpu(ctrl->wLength);
338
339 /* composite driver infrastructure handles everything except
340 * CDC class messages; interface activation uses set_alt().
341 *
342 * Note CDC spec table 4 lists the ACM request profile. It requires
343 * encapsulated command support ... we don't handle any, and respond
344 * to them by stalling. Options include get/set/clear comm features
345 * (not that useful) and SEND_BREAK.
346 */
347 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
348
349 /* SET_LINE_CODING ... just read and save what the host sends */
350 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
351 | USB_CDC_REQ_SET_LINE_CODING:
352 if (w_length != sizeof(struct usb_cdc_line_coding)
353 || w_index != acm->ctrl_id)
354 goto invalid;
355
356 value = w_length;
357 cdev->gadget->ep0->driver_data = acm;
358 req->complete = acm_complete_set_line_coding;
359 break;
360
361 /* GET_LINE_CODING ... return what host sent, or initial value */
362 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
363 | USB_CDC_REQ_GET_LINE_CODING:
364 if (w_index != acm->ctrl_id)
365 goto invalid;
366
367 value = min_t(unsigned, w_length,
368 sizeof(struct usb_cdc_line_coding));
369 memcpy(req->buf, &acm->port_line_coding, value);
370 break;
371
372 /* SET_CONTROL_LINE_STATE ... save what the host sent */
373 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
374 | USB_CDC_REQ_SET_CONTROL_LINE_STATE:
375 if (w_index != acm->ctrl_id)
376 goto invalid;
377
378 value = 0;
379
380 /* FIXME we should not allow data to flow until the
381 * host sets the USB_CDC_CTRL_DTR bit; and when it clears
382 * that bit, we should return to that no-flow state.
383 */
384 acm->port_handshake_bits = w_value;
385 break;
386
387 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
388 | USB_CDC_REQ_SEND_BREAK:
389 if (w_index != acm->ctrl_id)
390 goto invalid;
391
392 acm_send_break(&acm->port, w_value);
393 break;
394
395 default:
396invalid:
397 dev_vdbg(&cdev->gadget->dev,
398 "invalid control req%02x.%02x v%04x i%04x l%d\n",
399 ctrl->bRequestType, ctrl->bRequest,
400 w_value, w_index, w_length);
401 }
402
403 /* respond with data transfer or status phase? */
404 if (value >= 0) {
405 dev_dbg(&cdev->gadget->dev,
406 "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n",
407 acm->port_num, ctrl->bRequestType, ctrl->bRequest,
408 w_value, w_index, w_length);
409 req->zero = 0;
410 req->length = value;
411 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
412 if (value < 0)
413 ERROR(cdev, "acm response on ttyGS%d, err %d\n",
414 acm->port_num, value);
415 }
416
417 /* device either stalls (value < 0) or reports success */
418 return value;
419}
420
421static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
422{
423 struct f_acm *acm = func_to_acm(f);
424 struct usb_composite_dev *cdev = f->config->cdev;
425
426 /* we know alt == 0, so this is an activation or a reset */
427
428 if (intf == acm->ctrl_id) {
429 if (acm->notify->enabled) {
430 dev_vdbg(&cdev->gadget->dev,
431 "reset acm control interface %d\n", intf);
432 usb_ep_disable(acm->notify);
433 }
434
435 if (!acm->notify->desc)
436 if (config_ep_by_speed(cdev->gadget, f, acm->notify))
437 return -EINVAL;
438
439 usb_ep_enable(acm->notify);
440
441 } else if (intf == acm->data_id) {
442 if (acm->notify->enabled) {
443 dev_dbg(&cdev->gadget->dev,
444 "reset acm ttyGS%d\n", acm->port_num);
445 gserial_disconnect(&acm->port);
446 }
447 if (!acm->port.in->desc || !acm->port.out->desc) {
448 dev_dbg(&cdev->gadget->dev,
449 "activate acm ttyGS%d\n", acm->port_num);
450 if (config_ep_by_speed(cdev->gadget, f,
451 acm->port.in) ||
452 config_ep_by_speed(cdev->gadget, f,
453 acm->port.out)) {
454 acm->port.in->desc = NULL;
455 acm->port.out->desc = NULL;
456 return -EINVAL;
457 }
458 }
459 gserial_connect(&acm->port, acm->port_num);
460
461 } else
462 return -EINVAL;
463
464 return 0;
465}
466
467static void acm_disable(struct usb_function *f)
468{
469 struct f_acm *acm = func_to_acm(f);
470 struct usb_composite_dev *cdev = f->config->cdev;
471
472 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num);
473 gserial_disconnect(&acm->port);
474 usb_ep_disable(acm->notify);
475}
476
477/*-------------------------------------------------------------------------*/
478
479/**
480 * acm_cdc_notify - issue CDC notification to host
481 * @acm: wraps host to be notified
482 * @type: notification type
483 * @value: Refer to cdc specs, wValue field.
484 * @data: data to be sent
485 * @length: size of data
486 * Context: irqs blocked, acm->lock held, acm_notify_req non-null
487 *
488 * Returns zero on success or a negative errno.
489 *
490 * See section 6.3.5 of the CDC 1.1 specification for information
491 * about the only notification we issue: SerialState change.
492 */
493static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
494 void *data, unsigned length)
495{
496 struct usb_ep *ep = acm->notify;
497 struct usb_request *req;
498 struct usb_cdc_notification *notify;
499 const unsigned len = sizeof(*notify) + length;
500 void *buf;
501 int status;
502
503 req = acm->notify_req;
504 acm->notify_req = NULL;
505 acm->pending = false;
506
507 req->length = len;
508 notify = req->buf;
509 buf = notify + 1;
510
511 notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
512 | USB_RECIP_INTERFACE;
513 notify->bNotificationType = type;
514 notify->wValue = cpu_to_le16(value);
515 notify->wIndex = cpu_to_le16(acm->ctrl_id);
516 notify->wLength = cpu_to_le16(length);
517 memcpy(buf, data, length);
518
519 /* ep_queue() can complete immediately if it fills the fifo... */
520 spin_unlock(&acm->lock);
521 status = usb_ep_queue(ep, req, GFP_ATOMIC);
522 spin_lock(&acm->lock);
523
524 if (status < 0) {
525 ERROR(acm->port.func.config->cdev,
526 "acm ttyGS%d can't notify serial state, %d\n",
527 acm->port_num, status);
528 acm->notify_req = req;
529 }
530
531 return status;
532}
533
534static int acm_notify_serial_state(struct f_acm *acm)
535{
536 struct usb_composite_dev *cdev = acm->port.func.config->cdev;
537 int status;
538 __le16 serial_state;
539
540 spin_lock(&acm->lock);
541 if (acm->notify_req) {
542 dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n",
543 acm->port_num, acm->serial_state);
544 serial_state = cpu_to_le16(acm->serial_state);
545 status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
546 0, &serial_state, sizeof(acm->serial_state));
547 } else {
548 acm->pending = true;
549 status = 0;
550 }
551 spin_unlock(&acm->lock);
552 return status;
553}
554
555static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
556{
557 struct f_acm *acm = req->context;
558 u8 doit = false;
559
560 /* on this call path we do NOT hold the port spinlock,
561 * which is why ACM needs its own spinlock
562 */
563 spin_lock(&acm->lock);
564 if (req->status != -ESHUTDOWN)
565 doit = acm->pending;
566 acm->notify_req = req;
567 spin_unlock(&acm->lock);
568
569 if (doit)
570 acm_notify_serial_state(acm);
571}
572
573/* connect == the TTY link is open */
574
575static void acm_connect(struct gserial *port)
576{
577 struct f_acm *acm = port_to_acm(port);
578
579 acm->serial_state |= USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD;
580 acm_notify_serial_state(acm);
581}
582
583static void acm_disconnect(struct gserial *port)
584{
585 struct f_acm *acm = port_to_acm(port);
586
587 acm->serial_state &= ~(USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD);
588 acm_notify_serial_state(acm);
589}
590
591static int acm_send_break(struct gserial *port, int duration)
592{
593 struct f_acm *acm = port_to_acm(port);
594 u16 state;
595
596 state = acm->serial_state;
597 state &= ~USB_CDC_SERIAL_STATE_BREAK;
598 if (duration)
599 state |= USB_CDC_SERIAL_STATE_BREAK;
600
601 acm->serial_state = state;
602 return acm_notify_serial_state(acm);
603}
604
605/*-------------------------------------------------------------------------*/
606
607/* ACM function driver setup/binding */
608static int
609acm_bind(struct usb_configuration *c, struct usb_function *f)
610{
611 struct usb_composite_dev *cdev = c->cdev;
612 struct f_acm *acm = func_to_acm(f);
613 struct usb_string *us;
614 int status;
615 struct usb_ep *ep;
616
617 /* REVISIT might want instance-specific strings to help
618 * distinguish instances ...
619 */
620
621 /* maybe allocate device-global string IDs, and patch descriptors */
622 us = usb_gstrings_attach(cdev, acm_strings,
623 ARRAY_SIZE(acm_string_defs));
624 if (IS_ERR(us))
625 return PTR_ERR(us);
626 acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id;
627 acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id;
628 acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id;
629
630 /* allocate instance-specific interface IDs, and patch descriptors */
631 status = usb_interface_id(c, f);
632 if (status < 0)
633 goto fail;
634 acm->ctrl_id = status;
635 acm_iad_descriptor.bFirstInterface = status;
636
637 acm_control_interface_desc.bInterfaceNumber = status;
638 acm_union_desc .bMasterInterface0 = status;
639
640 status = usb_interface_id(c, f);
641 if (status < 0)
642 goto fail;
643 acm->data_id = status;
644
645 acm_data_interface_desc.bInterfaceNumber = status;
646 acm_union_desc.bSlaveInterface0 = status;
647 acm_call_mgmt_descriptor.bDataInterface = status;
648
649 status = -ENODEV;
650
651 /* allocate instance-specific endpoints */
652 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc);
653 if (!ep)
654 goto fail;
655 acm->port.in = ep;
656
657 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc);
658 if (!ep)
659 goto fail;
660 acm->port.out = ep;
661
662 ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc);
663 if (!ep)
664 goto fail;
665 acm->notify = ep;
666
667 acm_iad_descriptor.bFunctionProtocol = acm->bInterfaceProtocol;
668 acm_control_interface_desc.bInterfaceProtocol = acm->bInterfaceProtocol;
669
670 /* allocate notification */
671 acm->notify_req = gs_alloc_req(ep,
672 sizeof(struct usb_cdc_notification) + 2,
673 GFP_KERNEL);
674 if (!acm->notify_req)
675 goto fail;
676
677 acm->notify_req->complete = acm_cdc_notify_complete;
678 acm->notify_req->context = acm;
679
680 /* support all relevant hardware speeds... we expect that when
681 * hardware is dual speed, all bulk-capable endpoints work at
682 * both speeds
683 */
684 acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
685 acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
686 acm_hs_notify_desc.bEndpointAddress =
687 acm_fs_notify_desc.bEndpointAddress;
688
689 acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress;
690 acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress;
691
692 status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function,
693 acm_ss_function, acm_ss_function);
694 if (status)
695 goto fail;
696
697 dev_dbg(&cdev->gadget->dev,
698 "acm ttyGS%d: IN/%s OUT/%s NOTIFY/%s\n",
699 acm->port_num,
700 acm->port.in->name, acm->port.out->name,
701 acm->notify->name);
702 return 0;
703
704fail:
705 if (acm->notify_req)
706 gs_free_req(acm->notify, acm->notify_req);
707
708 ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status);
709
710 return status;
711}
712
713static void acm_unbind(struct usb_configuration *c, struct usb_function *f)
714{
715 struct f_acm *acm = func_to_acm(f);
716
717 acm_string_defs[0].id = 0;
718 usb_free_all_descriptors(f);
719 if (acm->notify_req)
720 gs_free_req(acm->notify, acm->notify_req);
721}
722
723static void acm_free_func(struct usb_function *f)
724{
725 struct f_acm *acm = func_to_acm(f);
726 struct f_serial_opts *opts;
727
728 opts = container_of(f->fi, struct f_serial_opts, func_inst);
729
730 kfree(acm);
731 mutex_lock(&opts->lock);
732 opts->instances--;
733 mutex_unlock(&opts->lock);
734}
735
736static void acm_resume(struct usb_function *f)
737{
738 struct f_acm *acm = func_to_acm(f);
739
740 gserial_resume(&acm->port);
741}
742
743static void acm_suspend(struct usb_function *f)
744{
745 struct f_acm *acm = func_to_acm(f);
746
747 gserial_suspend(&acm->port);
748}
749
750static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
751{
752 struct f_serial_opts *opts;
753 struct f_acm *acm;
754
755 acm = kzalloc(sizeof(*acm), GFP_KERNEL);
756 if (!acm)
757 return ERR_PTR(-ENOMEM);
758
759 spin_lock_init(&acm->lock);
760
761 acm->port.connect = acm_connect;
762 acm->port.disconnect = acm_disconnect;
763 acm->port.send_break = acm_send_break;
764
765 acm->port.func.name = "acm";
766 acm->port.func.strings = acm_strings;
767 /* descriptors are per-instance copies */
768 acm->port.func.bind = acm_bind;
769 acm->port.func.set_alt = acm_set_alt;
770 acm->port.func.setup = acm_setup;
771 acm->port.func.disable = acm_disable;
772
773 opts = container_of(fi, struct f_serial_opts, func_inst);
774 mutex_lock(&opts->lock);
775 acm->port_num = opts->port_num;
776 acm->bInterfaceProtocol = opts->protocol;
777 opts->instances++;
778 mutex_unlock(&opts->lock);
779 acm->port.func.unbind = acm_unbind;
780 acm->port.func.free_func = acm_free_func;
781 acm->port.func.resume = acm_resume;
782 acm->port.func.suspend = acm_suspend;
783
784 return &acm->port.func;
785}
786
787static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
788{
789 return container_of(to_config_group(item), struct f_serial_opts,
790 func_inst.group);
791}
792
793static void acm_attr_release(struct config_item *item)
794{
795 struct f_serial_opts *opts = to_f_serial_opts(item);
796
797 usb_put_function_instance(&opts->func_inst);
798}
799
800static struct configfs_item_operations acm_item_ops = {
801 .release = acm_attr_release,
802};
803
804#ifdef CONFIG_U_SERIAL_CONSOLE
805
806static ssize_t f_acm_console_store(struct config_item *item,
807 const char *page, size_t count)
808{
809 return gserial_set_console(to_f_serial_opts(item)->port_num,
810 page, count);
811}
812
813static ssize_t f_acm_console_show(struct config_item *item, char *page)
814{
815 return gserial_get_console(to_f_serial_opts(item)->port_num, page);
816}
817
818CONFIGFS_ATTR(f_acm_, console);
819
820#endif /* CONFIG_U_SERIAL_CONSOLE */
821
822static ssize_t f_acm_port_num_show(struct config_item *item, char *page)
823{
824 return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num);
825}
826
827CONFIGFS_ATTR_RO(f_acm_, port_num);
828
829static ssize_t f_acm_protocol_show(struct config_item *item, char *page)
830{
831 return sprintf(page, "%u\n", to_f_serial_opts(item)->protocol);
832}
833
834static ssize_t f_acm_protocol_store(struct config_item *item,
835 const char *page, size_t count)
836{
837 struct f_serial_opts *opts = to_f_serial_opts(item);
838 int ret;
839
840 mutex_lock(&opts->lock);
841
842 if (opts->instances) {
843 ret = -EBUSY;
844 goto out;
845 }
846
847 ret = kstrtou8(page, 0, &opts->protocol);
848 if (ret)
849 goto out;
850 ret = count;
851
852out:
853 mutex_unlock(&opts->lock);
854 return ret;
855}
856
857CONFIGFS_ATTR(f_acm_, protocol);
858
859static struct configfs_attribute *acm_attrs[] = {
860#ifdef CONFIG_U_SERIAL_CONSOLE
861 &f_acm_attr_console,
862#endif
863 &f_acm_attr_port_num,
864 &f_acm_attr_protocol,
865 NULL,
866};
867
868static const struct config_item_type acm_func_type = {
869 .ct_item_ops = &acm_item_ops,
870 .ct_attrs = acm_attrs,
871 .ct_owner = THIS_MODULE,
872};
873
874static void acm_free_instance(struct usb_function_instance *fi)
875{
876 struct f_serial_opts *opts;
877
878 opts = container_of(fi, struct f_serial_opts, func_inst);
879 gserial_free_line(opts->port_num);
880 mutex_destroy(&opts->lock);
881 kfree(opts);
882}
883
884static struct usb_function_instance *acm_alloc_instance(void)
885{
886 struct f_serial_opts *opts;
887 int ret;
888
889 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
890 if (!opts)
891 return ERR_PTR(-ENOMEM);
892 opts->protocol = USB_CDC_ACM_PROTO_AT_V25TER;
893 opts->func_inst.free_func_inst = acm_free_instance;
894 mutex_init(&opts->lock);
895 ret = gserial_alloc_line(&opts->port_num);
896 if (ret) {
897 kfree(opts);
898 return ERR_PTR(ret);
899 }
900 config_group_init_type_name(&opts->func_inst.group, "",
901 &acm_func_type);
902 return &opts->func_inst;
903}
904DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func);
905MODULE_DESCRIPTION("USB CDC serial (ACM) function driver");
906MODULE_LICENSE("GPL");