summaryrefslogtreecommitdiffstats
path: root/firmware/usbstack/usb_serial.c
blob: c96936f1d401d6afa4fe21410b544678ae5919e4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2007 by Christian Gmeiner
 * Copyright (C) 2021 by Tomasz Moń
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "string.h"
#include "system.h"
#include "usb_core.h"
#include "usb_drv.h"
#include "kernel.h"
#include "usb_serial.h"
#include "usb_class_driver.h"
/*#define LOGF_ENABLE*/
#include "logf.h"

#define CDC_SUBCLASS_ACM         0x02
#define CDC_PROTOCOL_NONE        0x00

/* Class-Specific Request Codes */
#define SET_LINE_CODING          0x20
#define GET_LINE_CODING          0x21
#define SET_CONTROL_LINE_STATE   0x22

#define SUBTYPE_HEADER           0x00
#define SUBTYPE_CALL_MANAGEMENT  0x01
#define SUBTYPE_ACM              0x02
#define SUBTYPE_UNION            0x06

/* Support SET_LINE_CODING, GET_LINE_CODING, SET_CONTROL_LINE_STATE requests
 * and SERIAL_STATE notification.
 */
#define ACM_CAP_LINE_CODING      0x02

struct cdc_header_descriptor {
    uint8_t  bFunctionLength;
    uint8_t  bDescriptorType;
    uint8_t  bDescriptorSubtype;
    uint16_t bcdCDC;
} __attribute__((packed));

struct cdc_call_management_descriptor {
    uint8_t bFunctionLength;
    uint8_t bDescriptorType;
    uint8_t bDescriptorSubtype;
    uint8_t bmCapabilities;
    uint8_t bDataInterface;
} __attribute__((packed));

struct cdc_acm_descriptor {
    uint8_t bFunctionLength;
    uint8_t bDescriptorType;
    uint8_t bDescriptorSubtype;
    uint8_t bmCapabilities;
} __attribute__((packed));

struct cdc_union_descriptor {
    uint8_t  bFunctionLength;
    uint8_t  bDescriptorType;
    uint8_t  bDescriptorSubtype;
    uint8_t  bControlInterface;
    uint8_t  bSubordinateInterface0;
} __attribute__((packed));

struct cdc_line_coding {
    uint32_t dwDTERate;
    uint8_t bCharFormat;
    uint8_t bParityType;
    uint8_t bDataBits;
} __attribute__((packed));

static struct usb_interface_assoc_descriptor
    association_descriptor =
{
    .bLength            = sizeof(struct usb_interface_assoc_descriptor),
    .bDescriptorType    = USB_DT_INTERFACE_ASSOCIATION,
    .bFirstInterface    = 0,
    .bInterfaceCount    = 2,
    .bFunctionClass     = USB_CLASS_COMM,
    .bFunctionSubClass  = CDC_SUBCLASS_ACM,
    .bFunctionProtocol  = CDC_PROTOCOL_NONE,
    .iFunction          = 0
};

static struct usb_interface_descriptor
    control_interface_descriptor =
{
    .bLength            = sizeof(struct usb_interface_descriptor),
    .bDescriptorType    = USB_DT_INTERFACE,
    .bInterfaceNumber   = 0,
    .bAlternateSetting  = 0,
    .bNumEndpoints      = 1,
    .bInterfaceClass    = USB_CLASS_COMM,
    .bInterfaceSubClass = CDC_SUBCLASS_ACM,
    .bInterfaceProtocol = CDC_PROTOCOL_NONE,
    .iInterface         = 0
};

static struct cdc_header_descriptor
    header_descriptor =
{
    .bFunctionLength    = sizeof(struct cdc_header_descriptor),
    .bDescriptorType    = USB_DT_CS_INTERFACE,
    .bDescriptorSubtype = SUBTYPE_HEADER,
    .bcdCDC             = 0x0110
};

static struct cdc_call_management_descriptor
    call_management_descriptor =
{
    .bFunctionLength    = sizeof(struct cdc_call_management_descriptor),
    .bDescriptorType    = USB_DT_CS_INTERFACE,
    .bDescriptorSubtype = SUBTYPE_CALL_MANAGEMENT,
    .bmCapabilities     = 0,
    .bDataInterface     = 0
};

static struct cdc_acm_descriptor
    acm_descriptor =
{
    .bFunctionLength    = sizeof(struct cdc_acm_descriptor),
    .bDescriptorType    = USB_DT_CS_INTERFACE,
    .bDescriptorSubtype = SUBTYPE_ACM,
    .bmCapabilities     = ACM_CAP_LINE_CODING
};

static struct cdc_union_descriptor
    union_descriptor =
{
    .bFunctionLength        = sizeof(struct cdc_union_descriptor),
    .bDescriptorType        = USB_DT_CS_INTERFACE,
    .bDescriptorSubtype     = SUBTYPE_UNION,
    .bControlInterface      = 0,
    .bSubordinateInterface0 = 0
};

static struct usb_interface_descriptor
    data_interface_descriptor =
{
    .bLength            = sizeof(struct usb_interface_descriptor),
    .bDescriptorType    = USB_DT_INTERFACE,
    .bInterfaceNumber   = 0,
    .bAlternateSetting  = 0,
    .bNumEndpoints      = 2,
    .bInterfaceClass    = USB_CLASS_CDC_DATA,
    .bInterfaceSubClass = 0,
    .bInterfaceProtocol = 0,
    .iInterface         = 0
};

static struct usb_endpoint_descriptor
    endpoint_descriptor =
{
    .bLength          = sizeof(struct usb_endpoint_descriptor),
    .bDescriptorType  = USB_DT_ENDPOINT,
    .bEndpointAddress = 0,
    .bmAttributes     = USB_ENDPOINT_XFER_BULK,
    .wMaxPacketSize   = 0,
    .bInterval        = 0
};

static struct cdc_line_coding line_coding;

/* send_buffer: local ring buffer.
 * transit_buffer: used to store aligned data that will be sent by the USB
 * driver. PP502x needs boost for high speed USB, but still works up to
 * around 100 bytes without boost, we play safe and limit packet size to 32
 * bytes, it doesn't hurt because data can be sent over several transfers.
 */
#define BUFFER_SIZE 512
#define TRANSIT_BUFFER_SIZE 32
static unsigned char send_buffer[BUFFER_SIZE];
static unsigned char transit_buffer[TRANSIT_BUFFER_SIZE]
    USB_DEVBSS_ATTR __attribute__((aligned(4)));
static unsigned char receive_buffer[32]
    USB_DEVBSS_ATTR __attribute__((aligned(32)));

static void sendout(void);

static int buffer_start;
/* The number of bytes to transfer that haven't been given to the USB stack yet */
static int buffer_length;
/* The number of bytes to transfer that have been given to the USB stack */
static int buffer_transitlength;
static bool active = false;

static int ep_in, ep_out, ep_int;
static int control_interface, data_interface;

int usb_serial_request_endpoints(struct usb_class_driver *drv)
{
    ep_in = usb_core_request_endpoint(USB_ENDPOINT_XFER_BULK, USB_DIR_IN, drv);
    if (ep_in < 0)
        return -1;

    ep_out = usb_core_request_endpoint(USB_ENDPOINT_XFER_BULK, USB_DIR_OUT,
            drv);
    if (ep_out < 0) {
        usb_core_release_endpoint(ep_in);
        return -1;
    }

    /* Optional interrupt endpoint. While the code does not actively use it,
     * it is needed to get out-of-the-box serial port experience on Windows
     * and Linux. If this endpoint is not available, only CDC Data interface
     * will be exported (can still work on Linux with manual modprobe).
     */
    ep_int = usb_core_request_endpoint(USB_ENDPOINT_XFER_INT, USB_DIR_IN, drv);

    return 0;
}

int usb_serial_set_first_interface(int interface)
{
    control_interface = interface;
    data_interface = interface + 1;
    return interface + 2;
}

int usb_serial_get_config_descriptor(unsigned char *dest, int max_packet_size)
{
    unsigned char *orig_dest = dest;

    association_descriptor.bFirstInterface         = control_interface;
    control_interface_descriptor.bInterfaceNumber  = control_interface;
    call_management_descriptor.bDataInterface      = data_interface;
    union_descriptor.bControlInterface             = control_interface;
    union_descriptor.bSubordinateInterface0        = data_interface;
    data_interface_descriptor.bInterfaceNumber     = data_interface;

    if (ep_int > 0)
    {
        PACK_DATA(&dest, association_descriptor);
        PACK_DATA(&dest, control_interface_descriptor);
        PACK_DATA(&dest, header_descriptor);
        PACK_DATA(&dest, call_management_descriptor);
        PACK_DATA(&dest, acm_descriptor);
        PACK_DATA(&dest, union_descriptor);

        /* Notification endpoint. Set wMaxPacketSize to 64 as it is valid
         * both on Full and High speed. Note that max_packet_size is for bulk.
         * Maximum bInterval for High Speed is 16 and for Full Speed is 255.
         */
        endpoint_descriptor.bEndpointAddress = ep_int;
        endpoint_descriptor.bmAttributes     = USB_ENDPOINT_XFER_INT;
        endpoint_descriptor.wMaxPacketSize   = 64;
        endpoint_descriptor.bInterval        = 16;
        PACK_DATA(&dest, endpoint_descriptor);
    }

    PACK_DATA(&dest, data_interface_descriptor);
    endpoint_descriptor.bEndpointAddress = ep_in;
    endpoint_descriptor.bmAttributes     = USB_ENDPOINT_XFER_BULK;
    endpoint_descriptor.wMaxPacketSize   = max_packet_size;
    endpoint_descriptor.bInterval        = 0;
    PACK_DATA(&dest, endpoint_descriptor);

    endpoint_descriptor.bEndpointAddress = ep_out;
    PACK_DATA(&dest, endpoint_descriptor);

    return (dest - orig_dest);
}

/* called by usb_core_control_request() */
bool usb_serial_control_request(struct usb_ctrlrequest* req, unsigned char* dest)
{
    bool handled = false;

    (void)dest;
    if (req->wIndex != control_interface)
    {
        return false;
    }

    if (req->bRequestType == (USB_DIR_OUT|USB_TYPE_CLASS|USB_RECIP_INTERFACE))
    {
        if (req->bRequest == SET_LINE_CODING)
        {
            if (req->wLength == sizeof(line_coding))
            {
                /* Receive line coding into local copy */
                usb_drv_recv_nonblocking(EP_CONTROL, &line_coding, sizeof(line_coding));
                usb_drv_send(EP_CONTROL, NULL, 0); /* ack */
                handled = true;
            }
        }
        else if (req->bRequest == SET_CONTROL_LINE_STATE)
        {
            if (req->wLength == 0)
            {
                /* wValue holds Control Signal Bitmap that is simply ignored here */
                usb_drv_send(EP_CONTROL, NULL, 0); /* ack */
                handled = true;
            }
        }
    }
    else if (req->bRequestType == (USB_DIR_IN|USB_TYPE_CLASS|USB_RECIP_INTERFACE))
    {
        if (req->bRequest == GET_LINE_CODING)
        {
            if (req->wLength == sizeof(line_coding))
            {
                /* Send back line coding so host is happy */
                usb_drv_recv_nonblocking(EP_CONTROL, NULL, 0); /* ack */
                usb_drv_send(EP_CONTROL, &line_coding, sizeof(line_coding));
                handled = true;
            }
        }
    }

    return handled;
}

void usb_serial_init_connection(void)
{
    /* prime rx endpoint */
    usb_drv_recv_nonblocking(ep_out, receive_buffer, sizeof receive_buffer);

    /* we come here too after a bus reset, so reset some data */
    buffer_transitlength = 0;
    if(buffer_length>0)
    {
        sendout();
    }
    active=true;
}

/* called by usb_code_init() */
void usb_serial_init(void)
{
    logf("serial: init");
    buffer_start = 0;
    buffer_length = 0;
    buffer_transitlength = 0;
}

void usb_serial_disconnect(void)
{
    active = false;
}

static void sendout(void)
{
    buffer_transitlength = MIN(buffer_length,BUFFER_SIZE-buffer_start);
    if(buffer_transitlength > 0)
    {
        buffer_transitlength = MIN(buffer_transitlength,TRANSIT_BUFFER_SIZE);
        buffer_length -= buffer_transitlength;
        memcpy(transit_buffer,&send_buffer[buffer_start],buffer_transitlength);
        usb_drv_send_nonblocking(ep_in,transit_buffer,buffer_transitlength);
    }
}

void usb_serial_send(const unsigned char *data,int length)
{
    int freestart, available_end_space, i;

    if (!active||length<=0)
        return;

    i=buffer_start+buffer_length+buffer_transitlength;
    freestart=i%BUFFER_SIZE;
    available_end_space=BUFFER_SIZE-i;

    if (0>=available_end_space)
    {
        /* current buffer wraps, so new data can't wrap */
        int available_space = BUFFER_SIZE -
            (buffer_length + buffer_transitlength);

        length = MIN(length,available_space);
        memcpy(&send_buffer[freestart],data,length);
        buffer_length+=length;
    }
    else
    {
        /* current buffer doesn't wrap, so new data might */
        int first_chunk = MIN(length,available_end_space);

        memcpy(&send_buffer[freestart],data,first_chunk);
        length-=first_chunk;
        buffer_length+=first_chunk;
        if(length>0)
        {
            /* wrap */
            memcpy(&send_buffer[0],&data[first_chunk],MIN(length,buffer_start));
            buffer_length+=MIN(length,buffer_start);
        }
    }

    if (buffer_transitlength==0)
        sendout();
    /* else do nothing. The transfer completion handler will pick it up */
}

/* called by usb_core_transfer_complete() */
void usb_serial_transfer_complete(int ep,int dir, int status, int length)
{
    (void)ep;
    (void)length;

    switch (dir) {
        case USB_DIR_OUT:
            logf("serial: %s", receive_buffer);
            /* Data received. TODO : Do something with it ? */

            /* Get the next bit */
            usb_drv_recv_nonblocking(ep_out, receive_buffer, sizeof receive_buffer);
            break;

        case USB_DIR_IN:
            /* Data sent out. Update circular buffer */
            if(status == 0)
            {
                /* TODO: Handle (length != buffer_transitlength) */

                buffer_start=(buffer_start+buffer_transitlength)%BUFFER_SIZE;
                buffer_transitlength = 0;
            }

            if(buffer_length>0)
                sendout();
            break;
    }
}