xref: /openbmc/qemu/hw/usb/dev-serial.c (revision d40d3da0)
1 /*
2  * FTDI FT232BM Device emulation
3  *
4  * Copyright (c) 2006 CodeSourcery.
5  * Copyright (c) 2008 Samuel Thibault <samuel.thibault@ens-lyon.org>
6  * Written by Paul Brook, reused for FTDI by Samuel Thibault
7  *
8  * This code is licensed under the LGPL.
9  */
10 
11 #include "qemu/osdep.h"
12 #include "qapi/error.h"
13 #include "qemu-common.h"
14 #include "qemu/cutils.h"
15 #include "qemu/error-report.h"
16 #include "hw/usb.h"
17 #include "hw/usb/desc.h"
18 #include "chardev/char-serial.h"
19 #include "chardev/char-fe.h"
20 
21 //#define DEBUG_Serial
22 
23 #ifdef DEBUG_Serial
24 #define DPRINTF(fmt, ...) \
25 do { printf("usb-serial: " fmt , ## __VA_ARGS__); } while (0)
26 #else
27 #define DPRINTF(fmt, ...) do {} while(0)
28 #endif
29 
30 #define RECV_BUF 384
31 
32 /* Commands */
33 #define FTDI_RESET		0
34 #define FTDI_SET_MDM_CTRL	1
35 #define FTDI_SET_FLOW_CTRL	2
36 #define FTDI_SET_BAUD		3
37 #define FTDI_SET_DATA		4
38 #define FTDI_GET_MDM_ST		5
39 #define FTDI_SET_EVENT_CHR	6
40 #define FTDI_SET_ERROR_CHR	7
41 #define FTDI_SET_LATENCY	9
42 #define FTDI_GET_LATENCY	10
43 
44 #define DeviceOutVendor	((USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_DEVICE)<<8)
45 #define DeviceInVendor	((USB_DIR_IN |USB_TYPE_VENDOR|USB_RECIP_DEVICE)<<8)
46 
47 /* RESET */
48 
49 #define FTDI_RESET_SIO	0
50 #define FTDI_RESET_RX	1
51 #define FTDI_RESET_TX	2
52 
53 /* SET_MDM_CTRL */
54 
55 #define FTDI_DTR	1
56 #define FTDI_SET_DTR	(FTDI_DTR << 8)
57 #define FTDI_RTS	2
58 #define FTDI_SET_RTS	(FTDI_RTS << 8)
59 
60 /* SET_FLOW_CTRL */
61 
62 #define FTDI_RTS_CTS_HS		1
63 #define FTDI_DTR_DSR_HS		2
64 #define FTDI_XON_XOFF_HS	4
65 
66 /* SET_DATA */
67 
68 #define FTDI_PARITY	(0x7 << 8)
69 #define FTDI_ODD	(0x1 << 8)
70 #define FTDI_EVEN	(0x2 << 8)
71 #define FTDI_MARK	(0x3 << 8)
72 #define FTDI_SPACE	(0x4 << 8)
73 
74 #define FTDI_STOP	(0x3 << 11)
75 #define FTDI_STOP1	(0x0 << 11)
76 #define FTDI_STOP15	(0x1 << 11)
77 #define FTDI_STOP2	(0x2 << 11)
78 
79 /* GET_MDM_ST */
80 /* TODO: should be sent every 40ms */
81 #define FTDI_CTS  (1<<4)        // CTS line status
82 #define FTDI_DSR  (1<<5)        // DSR line status
83 #define FTDI_RI   (1<<6)        // RI line status
84 #define FTDI_RLSD (1<<7)        // Receive Line Signal Detect
85 
86 /* Status */
87 
88 #define FTDI_DR   (1<<0)        // Data Ready
89 #define FTDI_OE   (1<<1)        // Overrun Err
90 #define FTDI_PE   (1<<2)        // Parity Err
91 #define FTDI_FE   (1<<3)        // Framing Err
92 #define FTDI_BI   (1<<4)        // Break Interrupt
93 #define FTDI_THRE (1<<5)        // Transmitter Holding Register
94 #define FTDI_TEMT (1<<6)        // Transmitter Empty
95 #define FTDI_FIFO (1<<7)        // Error in FIFO
96 
97 typedef struct {
98     USBDevice dev;
99     uint8_t recv_buf[RECV_BUF];
100     uint16_t recv_ptr;
101     uint16_t recv_used;
102     uint8_t event_chr;
103     uint8_t error_chr;
104     uint8_t event_trigger;
105     QEMUSerialSetParams params;
106     int latency;        /* ms */
107     CharBackend cs;
108 } USBSerialState;
109 
110 #define TYPE_USB_SERIAL "usb-serial-dev"
111 #define USB_SERIAL_DEV(obj) OBJECT_CHECK(USBSerialState, (obj), TYPE_USB_SERIAL)
112 
113 enum {
114     STR_MANUFACTURER = 1,
115     STR_PRODUCT_SERIAL,
116     STR_PRODUCT_BRAILLE,
117     STR_SERIALNUMBER,
118 };
119 
120 static const USBDescStrings desc_strings = {
121     [STR_MANUFACTURER]    = "QEMU",
122     [STR_PRODUCT_SERIAL]  = "QEMU USB SERIAL",
123     [STR_PRODUCT_BRAILLE] = "QEMU USB BAUM BRAILLE",
124     [STR_SERIALNUMBER]    = "1",
125 };
126 
127 static const USBDescIface desc_iface0 = {
128     .bInterfaceNumber              = 0,
129     .bNumEndpoints                 = 2,
130     .bInterfaceClass               = 0xff,
131     .bInterfaceSubClass            = 0xff,
132     .bInterfaceProtocol            = 0xff,
133     .eps = (USBDescEndpoint[]) {
134         {
135             .bEndpointAddress      = USB_DIR_IN | 0x01,
136             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
137             .wMaxPacketSize        = 64,
138         },{
139             .bEndpointAddress      = USB_DIR_OUT | 0x02,
140             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
141             .wMaxPacketSize        = 64,
142         },
143     }
144 };
145 
146 static const USBDescDevice desc_device = {
147     .bcdUSB                        = 0x0200,
148     .bMaxPacketSize0               = 8,
149     .bNumConfigurations            = 1,
150     .confs = (USBDescConfig[]) {
151         {
152             .bNumInterfaces        = 1,
153             .bConfigurationValue   = 1,
154             .bmAttributes          = USB_CFG_ATT_ONE,
155             .bMaxPower             = 50,
156             .nif = 1,
157             .ifs = &desc_iface0,
158         },
159     },
160 };
161 
162 static const USBDesc desc_serial = {
163     .id = {
164         .idVendor          = 0x0403,
165         .idProduct         = 0x6001,
166         .bcdDevice         = 0x0400,
167         .iManufacturer     = STR_MANUFACTURER,
168         .iProduct          = STR_PRODUCT_SERIAL,
169         .iSerialNumber     = STR_SERIALNUMBER,
170     },
171     .full = &desc_device,
172     .str  = desc_strings,
173 };
174 
175 static const USBDesc desc_braille = {
176     .id = {
177         .idVendor          = 0x0403,
178         .idProduct         = 0xfe72,
179         .bcdDevice         = 0x0400,
180         .iManufacturer     = STR_MANUFACTURER,
181         .iProduct          = STR_PRODUCT_BRAILLE,
182         .iSerialNumber     = STR_SERIALNUMBER,
183     },
184     .full = &desc_device,
185     .str  = desc_strings,
186 };
187 
188 static void usb_serial_reset(USBSerialState *s)
189 {
190     /* TODO: Set flow control to none */
191     s->event_chr = 0x0d;
192     s->event_trigger = 0;
193     s->recv_ptr = 0;
194     s->recv_used = 0;
195     /* TODO: purge in char driver */
196 }
197 
198 static void usb_serial_handle_reset(USBDevice *dev)
199 {
200     USBSerialState *s = (USBSerialState *)dev;
201 
202     DPRINTF("Reset\n");
203 
204     usb_serial_reset(s);
205     /* TODO: Reset char device, send BREAK? */
206 }
207 
208 static uint8_t usb_get_modem_lines(USBSerialState *s)
209 {
210     int flags;
211     uint8_t ret;
212 
213     if (qemu_chr_fe_ioctl(&s->cs,
214                           CHR_IOCTL_SERIAL_GET_TIOCM, &flags) == -ENOTSUP) {
215         return FTDI_CTS|FTDI_DSR|FTDI_RLSD;
216     }
217 
218     ret = 0;
219     if (flags & CHR_TIOCM_CTS)
220         ret |= FTDI_CTS;
221     if (flags & CHR_TIOCM_DSR)
222         ret |= FTDI_DSR;
223     if (flags & CHR_TIOCM_RI)
224         ret |= FTDI_RI;
225     if (flags & CHR_TIOCM_CAR)
226         ret |= FTDI_RLSD;
227 
228     return ret;
229 }
230 
231 static void usb_serial_handle_control(USBDevice *dev, USBPacket *p,
232                int request, int value, int index, int length, uint8_t *data)
233 {
234     USBSerialState *s = (USBSerialState *)dev;
235     int ret;
236 
237     DPRINTF("got control %x, value %x\n",request, value);
238     ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
239     if (ret >= 0) {
240         return;
241     }
242 
243     switch (request) {
244     case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
245         break;
246 
247         /* Class specific requests.  */
248     case DeviceOutVendor | FTDI_RESET:
249         switch (value) {
250         case FTDI_RESET_SIO:
251             usb_serial_reset(s);
252             break;
253         case FTDI_RESET_RX:
254             s->recv_ptr = 0;
255             s->recv_used = 0;
256             /* TODO: purge from char device */
257             break;
258         case FTDI_RESET_TX:
259             /* TODO: purge from char device */
260             break;
261         }
262         break;
263     case DeviceOutVendor | FTDI_SET_MDM_CTRL:
264     {
265         static int flags;
266         qemu_chr_fe_ioctl(&s->cs, CHR_IOCTL_SERIAL_GET_TIOCM, &flags);
267         if (value & FTDI_SET_RTS) {
268             if (value & FTDI_RTS)
269                 flags |= CHR_TIOCM_RTS;
270             else
271                 flags &= ~CHR_TIOCM_RTS;
272         }
273         if (value & FTDI_SET_DTR) {
274             if (value & FTDI_DTR)
275                 flags |= CHR_TIOCM_DTR;
276             else
277                 flags &= ~CHR_TIOCM_DTR;
278         }
279         qemu_chr_fe_ioctl(&s->cs, CHR_IOCTL_SERIAL_SET_TIOCM, &flags);
280         break;
281     }
282     case DeviceOutVendor | FTDI_SET_FLOW_CTRL:
283         /* TODO: ioctl */
284         break;
285     case DeviceOutVendor | FTDI_SET_BAUD: {
286         static const int subdivisors8[8] = { 0, 4, 2, 1, 3, 5, 6, 7 };
287         int subdivisor8 = subdivisors8[((value & 0xc000) >> 14)
288                                      | ((index & 1) << 2)];
289         int divisor = value & 0x3fff;
290 
291         /* chip special cases */
292         if (divisor == 1 && subdivisor8 == 0)
293             subdivisor8 = 4;
294         if (divisor == 0 && subdivisor8 == 0)
295             divisor = 1;
296 
297         s->params.speed = (48000000 / 2) / (8 * divisor + subdivisor8);
298         qemu_chr_fe_ioctl(&s->cs, CHR_IOCTL_SERIAL_SET_PARAMS, &s->params);
299         break;
300     }
301     case DeviceOutVendor | FTDI_SET_DATA:
302         switch (value & FTDI_PARITY) {
303             case 0:
304                 s->params.parity = 'N';
305                 break;
306             case FTDI_ODD:
307                 s->params.parity = 'O';
308                 break;
309             case FTDI_EVEN:
310                 s->params.parity = 'E';
311                 break;
312             default:
313                 DPRINTF("unsupported parity %d\n", value & FTDI_PARITY);
314                 goto fail;
315         }
316         switch (value & FTDI_STOP) {
317             case FTDI_STOP1:
318                 s->params.stop_bits = 1;
319                 break;
320             case FTDI_STOP2:
321                 s->params.stop_bits = 2;
322                 break;
323             default:
324                 DPRINTF("unsupported stop bits %d\n", value & FTDI_STOP);
325                 goto fail;
326         }
327         qemu_chr_fe_ioctl(&s->cs, CHR_IOCTL_SERIAL_SET_PARAMS, &s->params);
328         /* TODO: TX ON/OFF */
329         break;
330     case DeviceInVendor | FTDI_GET_MDM_ST:
331         data[0] = usb_get_modem_lines(s) | 1;
332         data[1] = 0;
333         p->actual_length = 2;
334         break;
335     case DeviceOutVendor | FTDI_SET_EVENT_CHR:
336         /* TODO: handle it */
337         s->event_chr = value;
338         break;
339     case DeviceOutVendor | FTDI_SET_ERROR_CHR:
340         /* TODO: handle it */
341         s->error_chr = value;
342         break;
343     case DeviceOutVendor | FTDI_SET_LATENCY:
344         s->latency = value;
345         break;
346     case DeviceInVendor | FTDI_GET_LATENCY:
347         data[0] = s->latency;
348         p->actual_length = 1;
349         break;
350     default:
351     fail:
352         DPRINTF("got unsupported/bogus control %x, value %x\n", request, value);
353         p->status = USB_RET_STALL;
354         break;
355     }
356 }
357 
358 static void usb_serial_handle_data(USBDevice *dev, USBPacket *p)
359 {
360     USBSerialState *s = (USBSerialState *)dev;
361     uint8_t devep = p->ep->nr;
362     struct iovec *iov;
363     uint8_t header[2];
364     int i, first_len, len;
365 
366     switch (p->pid) {
367     case USB_TOKEN_OUT:
368         if (devep != 2)
369             goto fail;
370         for (i = 0; i < p->iov.niov; i++) {
371             iov = p->iov.iov + i;
372             /* XXX this blocks entire thread. Rewrite to use
373              * qemu_chr_fe_write and background I/O callbacks */
374             qemu_chr_fe_write_all(&s->cs, iov->iov_base, iov->iov_len);
375         }
376         p->actual_length = p->iov.size;
377         break;
378 
379     case USB_TOKEN_IN:
380         if (devep != 1)
381             goto fail;
382         first_len = RECV_BUF - s->recv_ptr;
383         len = p->iov.size;
384         if (len <= 2) {
385             p->status = USB_RET_NAK;
386             break;
387         }
388         header[0] = usb_get_modem_lines(s) | 1;
389         /* We do not have the uart details */
390         /* handle serial break */
391         if (s->event_trigger && s->event_trigger & FTDI_BI) {
392             s->event_trigger &= ~FTDI_BI;
393             header[1] = FTDI_BI;
394             usb_packet_copy(p, header, 2);
395             break;
396         } else {
397             header[1] = 0;
398         }
399         len -= 2;
400         if (len > s->recv_used)
401             len = s->recv_used;
402         if (!len) {
403             p->status = USB_RET_NAK;
404             break;
405         }
406         if (first_len > len)
407             first_len = len;
408         usb_packet_copy(p, header, 2);
409         usb_packet_copy(p, s->recv_buf + s->recv_ptr, first_len);
410         if (len > first_len)
411             usb_packet_copy(p, s->recv_buf, len - first_len);
412         s->recv_used -= len;
413         s->recv_ptr = (s->recv_ptr + len) % RECV_BUF;
414         break;
415 
416     default:
417         DPRINTF("Bad token\n");
418     fail:
419         p->status = USB_RET_STALL;
420         break;
421     }
422 }
423 
424 static int usb_serial_can_read(void *opaque)
425 {
426     USBSerialState *s = opaque;
427 
428     if (!s->dev.attached) {
429         return 0;
430     }
431     return RECV_BUF - s->recv_used;
432 }
433 
434 static void usb_serial_read(void *opaque, const uint8_t *buf, int size)
435 {
436     USBSerialState *s = opaque;
437     int first_size, start;
438 
439     /* room in the buffer? */
440     if (size > (RECV_BUF - s->recv_used))
441         size = RECV_BUF - s->recv_used;
442 
443     start = s->recv_ptr + s->recv_used;
444     if (start < RECV_BUF) {
445         /* copy data to end of buffer */
446         first_size = RECV_BUF - start;
447         if (first_size > size)
448             first_size = size;
449 
450         memcpy(s->recv_buf + start, buf, first_size);
451 
452         /* wrap around to front if needed */
453         if (size > first_size)
454             memcpy(s->recv_buf, buf + first_size, size - first_size);
455     } else {
456         start -= RECV_BUF;
457         memcpy(s->recv_buf + start, buf, size);
458     }
459     s->recv_used += size;
460 }
461 
462 static void usb_serial_event(void *opaque, int event)
463 {
464     USBSerialState *s = opaque;
465 
466     switch (event) {
467         case CHR_EVENT_BREAK:
468             s->event_trigger |= FTDI_BI;
469             break;
470         case CHR_EVENT_OPENED:
471             if (!s->dev.attached) {
472                 usb_device_attach(&s->dev, &error_abort);
473             }
474             break;
475         case CHR_EVENT_CLOSED:
476             if (s->dev.attached) {
477                 usb_device_detach(&s->dev);
478             }
479             break;
480     }
481 }
482 
483 static void usb_serial_realize(USBDevice *dev, Error **errp)
484 {
485     USBSerialState *s = USB_SERIAL_DEV(dev);
486     Error *local_err = NULL;
487 
488     usb_desc_create_serial(dev);
489     usb_desc_init(dev);
490     dev->auto_attach = 0;
491 
492     if (!qemu_chr_fe_backend_connected(&s->cs)) {
493         error_setg(errp, "Property chardev is required");
494         return;
495     }
496 
497     usb_check_attach(dev, &local_err);
498     if (local_err) {
499         error_propagate(errp, local_err);
500         return;
501     }
502 
503     qemu_chr_fe_set_handlers(&s->cs, usb_serial_can_read, usb_serial_read,
504                              usb_serial_event, NULL, s, NULL, true);
505     usb_serial_handle_reset(dev);
506 
507     if (qemu_chr_fe_backend_open(&s->cs) && !dev->attached) {
508         usb_device_attach(dev, &error_abort);
509     }
510 }
511 
512 static USBDevice *usb_serial_init(USBBus *bus, const char *filename)
513 {
514     USBDevice *dev;
515     Chardev *cdrv;
516     char label[32];
517     static int index;
518 
519     if (*filename == ':') {
520         filename++;
521     } else if (*filename) {
522         error_report("unrecognized serial USB option %s", filename);
523         return NULL;
524     }
525     if (!*filename) {
526         error_report("character device specification needed");
527         return NULL;
528     }
529 
530     snprintf(label, sizeof(label), "usbserial%d", index++);
531     cdrv = qemu_chr_new(label, filename);
532     if (!cdrv)
533         return NULL;
534 
535     dev = usb_create(bus, "usb-serial");
536     qdev_prop_set_chr(&dev->qdev, "chardev", cdrv);
537 
538     return dev;
539 }
540 
541 static USBDevice *usb_braille_init(USBBus *bus, const char *unused)
542 {
543     USBDevice *dev;
544     Chardev *cdrv;
545 
546     cdrv = qemu_chr_new("braille", "braille");
547     if (!cdrv)
548         return NULL;
549 
550     dev = usb_create(bus, "usb-braille");
551     qdev_prop_set_chr(&dev->qdev, "chardev", cdrv);
552     return dev;
553 }
554 
555 static const VMStateDescription vmstate_usb_serial = {
556     .name = "usb-serial",
557     .unmigratable = 1,
558 };
559 
560 static Property serial_properties[] = {
561     DEFINE_PROP_CHR("chardev", USBSerialState, cs),
562     DEFINE_PROP_END_OF_LIST(),
563 };
564 
565 static void usb_serial_dev_class_init(ObjectClass *klass, void *data)
566 {
567     DeviceClass *dc = DEVICE_CLASS(klass);
568     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
569 
570     uc->realize        = usb_serial_realize;
571     uc->handle_reset   = usb_serial_handle_reset;
572     uc->handle_control = usb_serial_handle_control;
573     uc->handle_data    = usb_serial_handle_data;
574     dc->vmsd = &vmstate_usb_serial;
575     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
576 }
577 
578 static const TypeInfo usb_serial_dev_type_info = {
579     .name = TYPE_USB_SERIAL,
580     .parent = TYPE_USB_DEVICE,
581     .instance_size = sizeof(USBSerialState),
582     .abstract = true,
583     .class_init = usb_serial_dev_class_init,
584 };
585 
586 static void usb_serial_class_initfn(ObjectClass *klass, void *data)
587 {
588     DeviceClass *dc = DEVICE_CLASS(klass);
589     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
590 
591     uc->product_desc   = "QEMU USB Serial";
592     uc->usb_desc       = &desc_serial;
593     dc->props = serial_properties;
594 }
595 
596 static const TypeInfo serial_info = {
597     .name          = "usb-serial",
598     .parent        = TYPE_USB_SERIAL,
599     .class_init    = usb_serial_class_initfn,
600 };
601 
602 static Property braille_properties[] = {
603     DEFINE_PROP_CHR("chardev", USBSerialState, cs),
604     DEFINE_PROP_END_OF_LIST(),
605 };
606 
607 static void usb_braille_class_initfn(ObjectClass *klass, void *data)
608 {
609     DeviceClass *dc = DEVICE_CLASS(klass);
610     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
611 
612     uc->product_desc   = "QEMU USB Braille";
613     uc->usb_desc       = &desc_braille;
614     dc->props = braille_properties;
615 }
616 
617 static const TypeInfo braille_info = {
618     .name          = "usb-braille",
619     .parent        = TYPE_USB_SERIAL,
620     .class_init    = usb_braille_class_initfn,
621 };
622 
623 static void usb_serial_register_types(void)
624 {
625     type_register_static(&usb_serial_dev_type_info);
626     type_register_static(&serial_info);
627     usb_legacy_register("usb-serial", "serial", usb_serial_init);
628     type_register_static(&braille_info);
629     usb_legacy_register("usb-braille", "braille", usb_braille_init);
630 }
631 
632 type_init(usb_serial_register_types)
633