1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * UART driver for the Greybus "generic" UART module. 4 * 5 * Copyright 2014 Google Inc. 6 * Copyright 2014 Linaro Ltd. 7 * 8 * Heavily based on drivers/usb/class/cdc-acm.c and 9 * drivers/usb/serial/usb-serial.c. 10 */ 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <linux/kernel.h> 14 #include <linux/errno.h> 15 #include <linux/module.h> 16 #include <linux/sched/signal.h> 17 #include <linux/wait.h> 18 #include <linux/slab.h> 19 #include <linux/uaccess.h> 20 #include <linux/mutex.h> 21 #include <linux/tty.h> 22 #include <linux/serial.h> 23 #include <linux/tty_driver.h> 24 #include <linux/tty_flip.h> 25 #include <linux/idr.h> 26 #include <linux/fs.h> 27 #include <linux/kdev_t.h> 28 #include <linux/kfifo.h> 29 #include <linux/workqueue.h> 30 #include <linux/completion.h> 31 #include <linux/greybus.h> 32 33 #include "gbphy.h" 34 35 #define GB_NUM_MINORS 16 /* 16 is more than enough */ 36 #define GB_NAME "ttyGB" 37 38 #define GB_UART_WRITE_FIFO_SIZE PAGE_SIZE 39 #define GB_UART_WRITE_ROOM_MARGIN 1 /* leave some space in fifo */ 40 #define GB_UART_FIRMWARE_CREDITS 4096 41 #define GB_UART_CREDIT_WAIT_TIMEOUT_MSEC 10000 42 43 struct gb_tty { 44 struct gbphy_device *gbphy_dev; 45 struct tty_port port; 46 void *buffer; 47 size_t buffer_payload_max; 48 struct gb_connection *connection; 49 u16 cport_id; 50 unsigned int minor; 51 unsigned char clocal; 52 bool disconnected; 53 spinlock_t read_lock; 54 spinlock_t write_lock; 55 struct async_icount iocount; 56 struct async_icount oldcount; 57 wait_queue_head_t wioctl; 58 struct mutex mutex; 59 u8 ctrlin; /* input control lines */ 60 u8 ctrlout; /* output control lines */ 61 struct gb_uart_set_line_coding_request line_coding; 62 struct work_struct tx_work; 63 struct kfifo write_fifo; 64 bool close_pending; 65 unsigned int credits; 66 struct completion credits_complete; 67 }; 68 69 static struct tty_driver *gb_tty_driver; 70 static DEFINE_IDR(tty_minors); 71 static DEFINE_MUTEX(table_lock); 72 73 static int gb_uart_receive_data_handler(struct gb_operation *op) 74 { 75 struct gb_connection *connection = op->connection; 76 struct gb_tty *gb_tty = gb_connection_get_data(connection); 77 struct tty_port *port = &gb_tty->port; 78 struct gb_message *request = op->request; 79 struct gb_uart_recv_data_request *receive_data; 80 u16 recv_data_size; 81 int count; 82 unsigned long tty_flags = TTY_NORMAL; 83 84 if (request->payload_size < sizeof(*receive_data)) { 85 dev_err(&gb_tty->gbphy_dev->dev, 86 "short receive-data request received (%zu < %zu)\n", 87 request->payload_size, sizeof(*receive_data)); 88 return -EINVAL; 89 } 90 91 receive_data = op->request->payload; 92 recv_data_size = le16_to_cpu(receive_data->size); 93 94 if (recv_data_size != request->payload_size - sizeof(*receive_data)) { 95 dev_err(&gb_tty->gbphy_dev->dev, 96 "malformed receive-data request received (%u != %zu)\n", 97 recv_data_size, 98 request->payload_size - sizeof(*receive_data)); 99 return -EINVAL; 100 } 101 102 if (!recv_data_size) 103 return -EINVAL; 104 105 if (receive_data->flags) { 106 if (receive_data->flags & GB_UART_RECV_FLAG_BREAK) 107 tty_flags = TTY_BREAK; 108 else if (receive_data->flags & GB_UART_RECV_FLAG_PARITY) 109 tty_flags = TTY_PARITY; 110 else if (receive_data->flags & GB_UART_RECV_FLAG_FRAMING) 111 tty_flags = TTY_FRAME; 112 113 /* overrun is special, not associated with a char */ 114 if (receive_data->flags & GB_UART_RECV_FLAG_OVERRUN) 115 tty_insert_flip_char(port, 0, TTY_OVERRUN); 116 } 117 count = tty_insert_flip_string_fixed_flag(port, receive_data->data, 118 tty_flags, recv_data_size); 119 if (count != recv_data_size) { 120 dev_err(&gb_tty->gbphy_dev->dev, 121 "UART: RX 0x%08x bytes only wrote 0x%08x\n", 122 recv_data_size, count); 123 } 124 if (count) 125 tty_flip_buffer_push(port); 126 return 0; 127 } 128 129 static int gb_uart_serial_state_handler(struct gb_operation *op) 130 { 131 struct gb_connection *connection = op->connection; 132 struct gb_tty *gb_tty = gb_connection_get_data(connection); 133 struct gb_message *request = op->request; 134 struct gb_uart_serial_state_request *serial_state; 135 136 if (request->payload_size < sizeof(*serial_state)) { 137 dev_err(&gb_tty->gbphy_dev->dev, 138 "short serial-state event received (%zu < %zu)\n", 139 request->payload_size, sizeof(*serial_state)); 140 return -EINVAL; 141 } 142 143 serial_state = request->payload; 144 gb_tty->ctrlin = serial_state->control; 145 146 return 0; 147 } 148 149 static int gb_uart_receive_credits_handler(struct gb_operation *op) 150 { 151 struct gb_connection *connection = op->connection; 152 struct gb_tty *gb_tty = gb_connection_get_data(connection); 153 struct gb_message *request = op->request; 154 struct gb_uart_receive_credits_request *credit_request; 155 unsigned long flags; 156 unsigned int incoming_credits; 157 int ret = 0; 158 159 if (request->payload_size < sizeof(*credit_request)) { 160 dev_err(&gb_tty->gbphy_dev->dev, 161 "short receive_credits event received (%zu < %zu)\n", 162 request->payload_size, 163 sizeof(*credit_request)); 164 return -EINVAL; 165 } 166 167 credit_request = request->payload; 168 incoming_credits = le16_to_cpu(credit_request->count); 169 170 spin_lock_irqsave(&gb_tty->write_lock, flags); 171 gb_tty->credits += incoming_credits; 172 if (gb_tty->credits > GB_UART_FIRMWARE_CREDITS) { 173 gb_tty->credits -= incoming_credits; 174 ret = -EINVAL; 175 } 176 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 177 178 if (ret) { 179 dev_err(&gb_tty->gbphy_dev->dev, 180 "invalid number of incoming credits: %d\n", 181 incoming_credits); 182 return ret; 183 } 184 185 if (!gb_tty->close_pending) 186 schedule_work(&gb_tty->tx_work); 187 188 /* 189 * the port the tty layer may be waiting for credits 190 */ 191 tty_port_tty_wakeup(&gb_tty->port); 192 193 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS) 194 complete(&gb_tty->credits_complete); 195 196 return ret; 197 } 198 199 static int gb_uart_request_handler(struct gb_operation *op) 200 { 201 struct gb_connection *connection = op->connection; 202 struct gb_tty *gb_tty = gb_connection_get_data(connection); 203 int type = op->type; 204 int ret; 205 206 switch (type) { 207 case GB_UART_TYPE_RECEIVE_DATA: 208 ret = gb_uart_receive_data_handler(op); 209 break; 210 case GB_UART_TYPE_SERIAL_STATE: 211 ret = gb_uart_serial_state_handler(op); 212 break; 213 case GB_UART_TYPE_RECEIVE_CREDITS: 214 ret = gb_uart_receive_credits_handler(op); 215 break; 216 default: 217 dev_err(&gb_tty->gbphy_dev->dev, 218 "unsupported unsolicited request: 0x%02x\n", type); 219 ret = -EINVAL; 220 } 221 222 return ret; 223 } 224 225 static void gb_uart_tx_write_work(struct work_struct *work) 226 { 227 struct gb_uart_send_data_request *request; 228 struct gb_tty *gb_tty; 229 unsigned long flags; 230 unsigned int send_size; 231 int ret; 232 233 gb_tty = container_of(work, struct gb_tty, tx_work); 234 request = gb_tty->buffer; 235 236 while (1) { 237 if (gb_tty->close_pending) 238 break; 239 240 spin_lock_irqsave(&gb_tty->write_lock, flags); 241 send_size = gb_tty->buffer_payload_max; 242 if (send_size > gb_tty->credits) 243 send_size = gb_tty->credits; 244 245 send_size = kfifo_out_peek(&gb_tty->write_fifo, 246 &request->data[0], 247 send_size); 248 if (!send_size) { 249 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 250 break; 251 } 252 253 gb_tty->credits -= send_size; 254 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 255 256 request->size = cpu_to_le16(send_size); 257 ret = gb_operation_sync(gb_tty->connection, 258 GB_UART_TYPE_SEND_DATA, 259 request, sizeof(*request) + send_size, 260 NULL, 0); 261 if (ret) { 262 dev_err(&gb_tty->gbphy_dev->dev, 263 "send data error: %d\n", ret); 264 spin_lock_irqsave(&gb_tty->write_lock, flags); 265 gb_tty->credits += send_size; 266 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 267 if (!gb_tty->close_pending) 268 schedule_work(work); 269 return; 270 } 271 272 spin_lock_irqsave(&gb_tty->write_lock, flags); 273 ret = kfifo_out(&gb_tty->write_fifo, &request->data[0], 274 send_size); 275 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 276 277 tty_port_tty_wakeup(&gb_tty->port); 278 } 279 } 280 281 static int send_line_coding(struct gb_tty *tty) 282 { 283 return gb_operation_sync(tty->connection, GB_UART_TYPE_SET_LINE_CODING, 284 &tty->line_coding, sizeof(tty->line_coding), 285 NULL, 0); 286 } 287 288 static int send_control(struct gb_tty *gb_tty, u8 control) 289 { 290 struct gb_uart_set_control_line_state_request request; 291 292 request.control = control; 293 return gb_operation_sync(gb_tty->connection, 294 GB_UART_TYPE_SET_CONTROL_LINE_STATE, 295 &request, sizeof(request), NULL, 0); 296 } 297 298 static int send_break(struct gb_tty *gb_tty, u8 state) 299 { 300 struct gb_uart_set_break_request request; 301 302 if ((state != 0) && (state != 1)) { 303 dev_err(&gb_tty->gbphy_dev->dev, 304 "invalid break state of %d\n", state); 305 return -EINVAL; 306 } 307 308 request.state = state; 309 return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_SEND_BREAK, 310 &request, sizeof(request), NULL, 0); 311 } 312 313 static int gb_uart_wait_for_all_credits(struct gb_tty *gb_tty) 314 { 315 int ret; 316 317 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS) 318 return 0; 319 320 ret = wait_for_completion_timeout(&gb_tty->credits_complete, 321 msecs_to_jiffies(GB_UART_CREDIT_WAIT_TIMEOUT_MSEC)); 322 if (!ret) { 323 dev_err(&gb_tty->gbphy_dev->dev, 324 "time out waiting for credits\n"); 325 return -ETIMEDOUT; 326 } 327 328 return 0; 329 } 330 331 static int gb_uart_flush(struct gb_tty *gb_tty, u8 flags) 332 { 333 struct gb_uart_serial_flush_request request; 334 335 request.flags = flags; 336 return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_FLUSH_FIFOS, 337 &request, sizeof(request), NULL, 0); 338 } 339 340 static struct gb_tty *get_gb_by_minor(unsigned int minor) 341 { 342 struct gb_tty *gb_tty; 343 344 mutex_lock(&table_lock); 345 gb_tty = idr_find(&tty_minors, minor); 346 if (gb_tty) { 347 mutex_lock(&gb_tty->mutex); 348 if (gb_tty->disconnected) { 349 mutex_unlock(&gb_tty->mutex); 350 gb_tty = NULL; 351 } else { 352 tty_port_get(&gb_tty->port); 353 mutex_unlock(&gb_tty->mutex); 354 } 355 } 356 mutex_unlock(&table_lock); 357 return gb_tty; 358 } 359 360 static int alloc_minor(struct gb_tty *gb_tty) 361 { 362 int minor; 363 364 mutex_lock(&table_lock); 365 minor = idr_alloc(&tty_minors, gb_tty, 0, GB_NUM_MINORS, GFP_KERNEL); 366 mutex_unlock(&table_lock); 367 if (minor >= 0) 368 gb_tty->minor = minor; 369 return minor; 370 } 371 372 static void release_minor(struct gb_tty *gb_tty) 373 { 374 int minor = gb_tty->minor; 375 376 gb_tty->minor = 0; /* Maybe should use an invalid value instead */ 377 mutex_lock(&table_lock); 378 idr_remove(&tty_minors, minor); 379 mutex_unlock(&table_lock); 380 } 381 382 static int gb_tty_install(struct tty_driver *driver, struct tty_struct *tty) 383 { 384 struct gb_tty *gb_tty; 385 int retval; 386 387 gb_tty = get_gb_by_minor(tty->index); 388 if (!gb_tty) 389 return -ENODEV; 390 391 retval = tty_standard_install(driver, tty); 392 if (retval) 393 goto error; 394 395 tty->driver_data = gb_tty; 396 return 0; 397 error: 398 tty_port_put(&gb_tty->port); 399 return retval; 400 } 401 402 static int gb_tty_open(struct tty_struct *tty, struct file *file) 403 { 404 struct gb_tty *gb_tty = tty->driver_data; 405 406 return tty_port_open(&gb_tty->port, tty, file); 407 } 408 409 static void gb_tty_close(struct tty_struct *tty, struct file *file) 410 { 411 struct gb_tty *gb_tty = tty->driver_data; 412 413 tty_port_close(&gb_tty->port, tty, file); 414 } 415 416 static void gb_tty_cleanup(struct tty_struct *tty) 417 { 418 struct gb_tty *gb_tty = tty->driver_data; 419 420 tty_port_put(&gb_tty->port); 421 } 422 423 static void gb_tty_hangup(struct tty_struct *tty) 424 { 425 struct gb_tty *gb_tty = tty->driver_data; 426 427 tty_port_hangup(&gb_tty->port); 428 } 429 430 static int gb_tty_write(struct tty_struct *tty, const unsigned char *buf, 431 int count) 432 { 433 struct gb_tty *gb_tty = tty->driver_data; 434 435 count = kfifo_in_spinlocked(&gb_tty->write_fifo, buf, count, 436 &gb_tty->write_lock); 437 if (count && !gb_tty->close_pending) 438 schedule_work(&gb_tty->tx_work); 439 440 return count; 441 } 442 443 static unsigned int gb_tty_write_room(struct tty_struct *tty) 444 { 445 struct gb_tty *gb_tty = tty->driver_data; 446 unsigned long flags; 447 int room; 448 449 spin_lock_irqsave(&gb_tty->write_lock, flags); 450 room = kfifo_avail(&gb_tty->write_fifo); 451 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 452 453 room -= GB_UART_WRITE_ROOM_MARGIN; 454 if (room < 0) 455 return 0; 456 457 return room; 458 } 459 460 static unsigned int gb_tty_chars_in_buffer(struct tty_struct *tty) 461 { 462 struct gb_tty *gb_tty = tty->driver_data; 463 unsigned long flags; 464 unsigned int chars; 465 466 spin_lock_irqsave(&gb_tty->write_lock, flags); 467 chars = kfifo_len(&gb_tty->write_fifo); 468 if (gb_tty->credits < GB_UART_FIRMWARE_CREDITS) 469 chars += GB_UART_FIRMWARE_CREDITS - gb_tty->credits; 470 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 471 472 return chars; 473 } 474 475 static int gb_tty_break_ctl(struct tty_struct *tty, int state) 476 { 477 struct gb_tty *gb_tty = tty->driver_data; 478 479 return send_break(gb_tty, state ? 1 : 0); 480 } 481 482 static void gb_tty_set_termios(struct tty_struct *tty, 483 const struct ktermios *termios_old) 484 { 485 struct gb_uart_set_line_coding_request newline; 486 struct gb_tty *gb_tty = tty->driver_data; 487 struct ktermios *termios = &tty->termios; 488 u8 newctrl = gb_tty->ctrlout; 489 490 newline.rate = cpu_to_le32(tty_get_baud_rate(tty)); 491 newline.format = termios->c_cflag & CSTOPB ? 492 GB_SERIAL_2_STOP_BITS : GB_SERIAL_1_STOP_BITS; 493 newline.parity = termios->c_cflag & PARENB ? 494 (termios->c_cflag & PARODD ? 1 : 2) + 495 (termios->c_cflag & CMSPAR ? 2 : 0) : 0; 496 497 newline.data_bits = tty_get_char_size(termios->c_cflag); 498 499 /* FIXME: needs to clear unsupported bits in the termios */ 500 gb_tty->clocal = ((termios->c_cflag & CLOCAL) != 0); 501 502 if (C_BAUD(tty) == B0) { 503 newline.rate = gb_tty->line_coding.rate; 504 newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 505 } else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) { 506 newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 507 } 508 509 if (newctrl != gb_tty->ctrlout) { 510 gb_tty->ctrlout = newctrl; 511 send_control(gb_tty, newctrl); 512 } 513 514 if (C_CRTSCTS(tty) && C_BAUD(tty) != B0) 515 newline.flow_control = GB_SERIAL_AUTO_RTSCTS_EN; 516 else 517 newline.flow_control = 0; 518 519 if (memcmp(&gb_tty->line_coding, &newline, sizeof(newline))) { 520 memcpy(&gb_tty->line_coding, &newline, sizeof(newline)); 521 send_line_coding(gb_tty); 522 } 523 } 524 525 static int gb_tty_tiocmget(struct tty_struct *tty) 526 { 527 struct gb_tty *gb_tty = tty->driver_data; 528 529 return (gb_tty->ctrlout & GB_UART_CTRL_DTR ? TIOCM_DTR : 0) | 530 (gb_tty->ctrlout & GB_UART_CTRL_RTS ? TIOCM_RTS : 0) | 531 (gb_tty->ctrlin & GB_UART_CTRL_DSR ? TIOCM_DSR : 0) | 532 (gb_tty->ctrlin & GB_UART_CTRL_RI ? TIOCM_RI : 0) | 533 (gb_tty->ctrlin & GB_UART_CTRL_DCD ? TIOCM_CD : 0) | 534 TIOCM_CTS; 535 } 536 537 static int gb_tty_tiocmset(struct tty_struct *tty, unsigned int set, 538 unsigned int clear) 539 { 540 struct gb_tty *gb_tty = tty->driver_data; 541 u8 newctrl = gb_tty->ctrlout; 542 543 set = (set & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) | 544 (set & TIOCM_RTS ? GB_UART_CTRL_RTS : 0); 545 clear = (clear & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) | 546 (clear & TIOCM_RTS ? GB_UART_CTRL_RTS : 0); 547 548 newctrl = (newctrl & ~clear) | set; 549 if (gb_tty->ctrlout == newctrl) 550 return 0; 551 552 gb_tty->ctrlout = newctrl; 553 return send_control(gb_tty, newctrl); 554 } 555 556 static void gb_tty_throttle(struct tty_struct *tty) 557 { 558 struct gb_tty *gb_tty = tty->driver_data; 559 unsigned char stop_char; 560 int retval; 561 562 if (I_IXOFF(tty)) { 563 stop_char = STOP_CHAR(tty); 564 retval = gb_tty_write(tty, &stop_char, 1); 565 if (retval <= 0) 566 return; 567 } 568 569 if (tty->termios.c_cflag & CRTSCTS) { 570 gb_tty->ctrlout &= ~GB_UART_CTRL_RTS; 571 retval = send_control(gb_tty, gb_tty->ctrlout); 572 } 573 } 574 575 static void gb_tty_unthrottle(struct tty_struct *tty) 576 { 577 struct gb_tty *gb_tty = tty->driver_data; 578 unsigned char start_char; 579 int retval; 580 581 if (I_IXOFF(tty)) { 582 start_char = START_CHAR(tty); 583 retval = gb_tty_write(tty, &start_char, 1); 584 if (retval <= 0) 585 return; 586 } 587 588 if (tty->termios.c_cflag & CRTSCTS) { 589 gb_tty->ctrlout |= GB_UART_CTRL_RTS; 590 retval = send_control(gb_tty, gb_tty->ctrlout); 591 } 592 } 593 594 static int get_serial_info(struct tty_struct *tty, 595 struct serial_struct *ss) 596 { 597 struct gb_tty *gb_tty = tty->driver_data; 598 599 ss->line = gb_tty->minor; 600 ss->close_delay = jiffies_to_msecs(gb_tty->port.close_delay) / 10; 601 ss->closing_wait = 602 gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? 603 ASYNC_CLOSING_WAIT_NONE : 604 jiffies_to_msecs(gb_tty->port.closing_wait) / 10; 605 606 return 0; 607 } 608 609 static int set_serial_info(struct tty_struct *tty, 610 struct serial_struct *ss) 611 { 612 struct gb_tty *gb_tty = tty->driver_data; 613 unsigned int closing_wait; 614 unsigned int close_delay; 615 int retval = 0; 616 617 close_delay = msecs_to_jiffies(ss->close_delay * 10); 618 closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 619 ASYNC_CLOSING_WAIT_NONE : 620 msecs_to_jiffies(ss->closing_wait * 10); 621 622 mutex_lock(&gb_tty->port.mutex); 623 if (!capable(CAP_SYS_ADMIN)) { 624 if ((close_delay != gb_tty->port.close_delay) || 625 (closing_wait != gb_tty->port.closing_wait)) 626 retval = -EPERM; 627 } else { 628 gb_tty->port.close_delay = close_delay; 629 gb_tty->port.closing_wait = closing_wait; 630 } 631 mutex_unlock(&gb_tty->port.mutex); 632 return retval; 633 } 634 635 static int wait_serial_change(struct gb_tty *gb_tty, unsigned long arg) 636 { 637 int retval = 0; 638 DECLARE_WAITQUEUE(wait, current); 639 struct async_icount old; 640 struct async_icount new; 641 642 if (!(arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD))) 643 return -EINVAL; 644 645 do { 646 spin_lock_irq(&gb_tty->read_lock); 647 old = gb_tty->oldcount; 648 new = gb_tty->iocount; 649 gb_tty->oldcount = new; 650 spin_unlock_irq(&gb_tty->read_lock); 651 652 if ((arg & TIOCM_DSR) && (old.dsr != new.dsr)) 653 break; 654 if ((arg & TIOCM_CD) && (old.dcd != new.dcd)) 655 break; 656 if ((arg & TIOCM_RI) && (old.rng != new.rng)) 657 break; 658 659 add_wait_queue(&gb_tty->wioctl, &wait); 660 set_current_state(TASK_INTERRUPTIBLE); 661 schedule(); 662 remove_wait_queue(&gb_tty->wioctl, &wait); 663 if (gb_tty->disconnected) { 664 if (arg & TIOCM_CD) 665 break; 666 retval = -ENODEV; 667 } else if (signal_pending(current)) { 668 retval = -ERESTARTSYS; 669 } 670 } while (!retval); 671 672 return retval; 673 } 674 675 static int gb_tty_get_icount(struct tty_struct *tty, 676 struct serial_icounter_struct *icount) 677 { 678 struct gb_tty *gb_tty = tty->driver_data; 679 680 icount->dsr = gb_tty->iocount.dsr; 681 icount->rng = gb_tty->iocount.rng; 682 icount->dcd = gb_tty->iocount.dcd; 683 icount->frame = gb_tty->iocount.frame; 684 icount->overrun = gb_tty->iocount.overrun; 685 icount->parity = gb_tty->iocount.parity; 686 icount->brk = gb_tty->iocount.brk; 687 688 return 0; 689 } 690 691 static int gb_tty_ioctl(struct tty_struct *tty, unsigned int cmd, 692 unsigned long arg) 693 { 694 struct gb_tty *gb_tty = tty->driver_data; 695 696 switch (cmd) { 697 case TIOCMIWAIT: 698 return wait_serial_change(gb_tty, arg); 699 } 700 701 return -ENOIOCTLCMD; 702 } 703 704 static void gb_tty_dtr_rts(struct tty_port *port, bool active) 705 { 706 struct gb_tty *gb_tty; 707 u8 newctrl; 708 709 gb_tty = container_of(port, struct gb_tty, port); 710 newctrl = gb_tty->ctrlout; 711 712 if (active) 713 newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 714 else 715 newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 716 717 gb_tty->ctrlout = newctrl; 718 send_control(gb_tty, newctrl); 719 } 720 721 static int gb_tty_port_activate(struct tty_port *port, 722 struct tty_struct *tty) 723 { 724 struct gb_tty *gb_tty; 725 726 gb_tty = container_of(port, struct gb_tty, port); 727 728 return gbphy_runtime_get_sync(gb_tty->gbphy_dev); 729 } 730 731 static void gb_tty_port_shutdown(struct tty_port *port) 732 { 733 struct gb_tty *gb_tty; 734 unsigned long flags; 735 int ret; 736 737 gb_tty = container_of(port, struct gb_tty, port); 738 739 gb_tty->close_pending = true; 740 741 cancel_work_sync(&gb_tty->tx_work); 742 743 spin_lock_irqsave(&gb_tty->write_lock, flags); 744 kfifo_reset_out(&gb_tty->write_fifo); 745 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 746 747 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS) 748 goto out; 749 750 ret = gb_uart_flush(gb_tty, GB_SERIAL_FLAG_FLUSH_TRANSMITTER); 751 if (ret) { 752 dev_err(&gb_tty->gbphy_dev->dev, 753 "error flushing transmitter: %d\n", ret); 754 } 755 756 gb_uart_wait_for_all_credits(gb_tty); 757 758 out: 759 gb_tty->close_pending = false; 760 761 gbphy_runtime_put_autosuspend(gb_tty->gbphy_dev); 762 } 763 764 static void gb_tty_port_destruct(struct tty_port *port) 765 { 766 struct gb_tty *gb_tty = container_of(port, struct gb_tty, port); 767 768 if (gb_tty->minor != GB_NUM_MINORS) 769 release_minor(gb_tty); 770 kfifo_free(&gb_tty->write_fifo); 771 kfree(gb_tty->buffer); 772 kfree(gb_tty); 773 } 774 775 static const struct tty_operations gb_ops = { 776 .install = gb_tty_install, 777 .open = gb_tty_open, 778 .close = gb_tty_close, 779 .cleanup = gb_tty_cleanup, 780 .hangup = gb_tty_hangup, 781 .write = gb_tty_write, 782 .write_room = gb_tty_write_room, 783 .ioctl = gb_tty_ioctl, 784 .throttle = gb_tty_throttle, 785 .unthrottle = gb_tty_unthrottle, 786 .chars_in_buffer = gb_tty_chars_in_buffer, 787 .break_ctl = gb_tty_break_ctl, 788 .set_termios = gb_tty_set_termios, 789 .tiocmget = gb_tty_tiocmget, 790 .tiocmset = gb_tty_tiocmset, 791 .get_icount = gb_tty_get_icount, 792 .set_serial = set_serial_info, 793 .get_serial = get_serial_info, 794 }; 795 796 static const struct tty_port_operations gb_port_ops = { 797 .dtr_rts = gb_tty_dtr_rts, 798 .activate = gb_tty_port_activate, 799 .shutdown = gb_tty_port_shutdown, 800 .destruct = gb_tty_port_destruct, 801 }; 802 803 static int gb_uart_probe(struct gbphy_device *gbphy_dev, 804 const struct gbphy_device_id *id) 805 { 806 struct gb_connection *connection; 807 size_t max_payload; 808 struct gb_tty *gb_tty; 809 struct device *tty_dev; 810 int retval; 811 int minor; 812 813 connection = gb_connection_create(gbphy_dev->bundle, 814 le16_to_cpu(gbphy_dev->cport_desc->id), 815 gb_uart_request_handler); 816 if (IS_ERR(connection)) 817 return PTR_ERR(connection); 818 819 max_payload = gb_operation_get_payload_size_max(connection); 820 if (max_payload < sizeof(struct gb_uart_send_data_request)) { 821 retval = -EINVAL; 822 goto exit_connection_destroy; 823 } 824 825 gb_tty = kzalloc(sizeof(*gb_tty), GFP_KERNEL); 826 if (!gb_tty) { 827 retval = -ENOMEM; 828 goto exit_connection_destroy; 829 } 830 831 tty_port_init(&gb_tty->port); 832 gb_tty->port.ops = &gb_port_ops; 833 gb_tty->minor = GB_NUM_MINORS; 834 835 gb_tty->buffer_payload_max = max_payload - 836 sizeof(struct gb_uart_send_data_request); 837 838 gb_tty->buffer = kzalloc(gb_tty->buffer_payload_max, GFP_KERNEL); 839 if (!gb_tty->buffer) { 840 retval = -ENOMEM; 841 goto exit_put_port; 842 } 843 844 INIT_WORK(&gb_tty->tx_work, gb_uart_tx_write_work); 845 846 retval = kfifo_alloc(&gb_tty->write_fifo, GB_UART_WRITE_FIFO_SIZE, 847 GFP_KERNEL); 848 if (retval) 849 goto exit_put_port; 850 851 gb_tty->credits = GB_UART_FIRMWARE_CREDITS; 852 init_completion(&gb_tty->credits_complete); 853 854 minor = alloc_minor(gb_tty); 855 if (minor < 0) { 856 if (minor == -ENOSPC) { 857 dev_err(&gbphy_dev->dev, 858 "no more free minor numbers\n"); 859 retval = -ENODEV; 860 } else { 861 retval = minor; 862 } 863 goto exit_put_port; 864 } 865 866 gb_tty->minor = minor; 867 spin_lock_init(&gb_tty->write_lock); 868 spin_lock_init(&gb_tty->read_lock); 869 init_waitqueue_head(&gb_tty->wioctl); 870 mutex_init(&gb_tty->mutex); 871 872 gb_tty->connection = connection; 873 gb_tty->gbphy_dev = gbphy_dev; 874 gb_connection_set_data(connection, gb_tty); 875 gb_gbphy_set_data(gbphy_dev, gb_tty); 876 877 retval = gb_connection_enable_tx(connection); 878 if (retval) 879 goto exit_put_port; 880 881 send_control(gb_tty, gb_tty->ctrlout); 882 883 /* initialize the uart to be 9600n81 */ 884 gb_tty->line_coding.rate = cpu_to_le32(9600); 885 gb_tty->line_coding.format = GB_SERIAL_1_STOP_BITS; 886 gb_tty->line_coding.parity = GB_SERIAL_NO_PARITY; 887 gb_tty->line_coding.data_bits = 8; 888 send_line_coding(gb_tty); 889 890 retval = gb_connection_enable(connection); 891 if (retval) 892 goto exit_connection_disable; 893 894 tty_dev = tty_port_register_device(&gb_tty->port, gb_tty_driver, minor, 895 &gbphy_dev->dev); 896 if (IS_ERR(tty_dev)) { 897 retval = PTR_ERR(tty_dev); 898 goto exit_connection_disable; 899 } 900 901 gbphy_runtime_put_autosuspend(gbphy_dev); 902 return 0; 903 904 exit_connection_disable: 905 gb_connection_disable(connection); 906 exit_put_port: 907 tty_port_put(&gb_tty->port); 908 exit_connection_destroy: 909 gb_connection_destroy(connection); 910 911 return retval; 912 } 913 914 static void gb_uart_remove(struct gbphy_device *gbphy_dev) 915 { 916 struct gb_tty *gb_tty = gb_gbphy_get_data(gbphy_dev); 917 struct gb_connection *connection = gb_tty->connection; 918 struct tty_struct *tty; 919 int ret; 920 921 ret = gbphy_runtime_get_sync(gbphy_dev); 922 if (ret) 923 gbphy_runtime_get_noresume(gbphy_dev); 924 925 mutex_lock(&gb_tty->mutex); 926 gb_tty->disconnected = true; 927 928 wake_up_all(&gb_tty->wioctl); 929 mutex_unlock(&gb_tty->mutex); 930 931 tty = tty_port_tty_get(&gb_tty->port); 932 if (tty) { 933 tty_vhangup(tty); 934 tty_kref_put(tty); 935 } 936 937 gb_connection_disable_rx(connection); 938 tty_unregister_device(gb_tty_driver, gb_tty->minor); 939 940 gb_connection_disable(connection); 941 gb_connection_destroy(connection); 942 943 tty_port_put(&gb_tty->port); 944 } 945 946 static int gb_tty_init(void) 947 { 948 int retval = 0; 949 950 gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, 0); 951 if (IS_ERR(gb_tty_driver)) { 952 pr_err("Can not allocate tty driver\n"); 953 retval = -ENOMEM; 954 goto fail_unregister_dev; 955 } 956 957 gb_tty_driver->driver_name = "gb"; 958 gb_tty_driver->name = GB_NAME; 959 gb_tty_driver->major = 0; 960 gb_tty_driver->minor_start = 0; 961 gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; 962 gb_tty_driver->subtype = SERIAL_TYPE_NORMAL; 963 gb_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; 964 gb_tty_driver->init_termios = tty_std_termios; 965 gb_tty_driver->init_termios.c_cflag = B9600 | CS8 | 966 CREAD | HUPCL | CLOCAL; 967 tty_set_operations(gb_tty_driver, &gb_ops); 968 969 retval = tty_register_driver(gb_tty_driver); 970 if (retval) { 971 pr_err("Can not register tty driver: %d\n", retval); 972 goto fail_put_gb_tty; 973 } 974 975 return 0; 976 977 fail_put_gb_tty: 978 tty_driver_kref_put(gb_tty_driver); 979 fail_unregister_dev: 980 return retval; 981 } 982 983 static void gb_tty_exit(void) 984 { 985 tty_unregister_driver(gb_tty_driver); 986 tty_driver_kref_put(gb_tty_driver); 987 idr_destroy(&tty_minors); 988 } 989 990 static const struct gbphy_device_id gb_uart_id_table[] = { 991 { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_UART) }, 992 { }, 993 }; 994 MODULE_DEVICE_TABLE(gbphy, gb_uart_id_table); 995 996 static struct gbphy_driver uart_driver = { 997 .name = "uart", 998 .probe = gb_uart_probe, 999 .remove = gb_uart_remove, 1000 .id_table = gb_uart_id_table, 1001 }; 1002 1003 static int gb_uart_driver_init(void) 1004 { 1005 int ret; 1006 1007 ret = gb_tty_init(); 1008 if (ret) 1009 return ret; 1010 1011 ret = gb_gbphy_register(&uart_driver); 1012 if (ret) { 1013 gb_tty_exit(); 1014 return ret; 1015 } 1016 1017 return 0; 1018 } 1019 module_init(gb_uart_driver_init); 1020 1021 static void gb_uart_driver_exit(void) 1022 { 1023 gb_gbphy_deregister(&uart_driver); 1024 gb_tty_exit(); 1025 } 1026 1027 module_exit(gb_uart_driver_exit); 1028 MODULE_LICENSE("GPL v2"); 1029