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 ssize_t gb_tty_write(struct tty_struct *tty, const u8 *buf, size_t count) 431 { 432 struct gb_tty *gb_tty = tty->driver_data; 433 434 count = kfifo_in_spinlocked(&gb_tty->write_fifo, buf, count, 435 &gb_tty->write_lock); 436 if (count && !gb_tty->close_pending) 437 schedule_work(&gb_tty->tx_work); 438 439 return count; 440 } 441 442 static unsigned int gb_tty_write_room(struct tty_struct *tty) 443 { 444 struct gb_tty *gb_tty = tty->driver_data; 445 unsigned long flags; 446 int room; 447 448 spin_lock_irqsave(&gb_tty->write_lock, flags); 449 room = kfifo_avail(&gb_tty->write_fifo); 450 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 451 452 room -= GB_UART_WRITE_ROOM_MARGIN; 453 if (room < 0) 454 return 0; 455 456 return room; 457 } 458 459 static unsigned int gb_tty_chars_in_buffer(struct tty_struct *tty) 460 { 461 struct gb_tty *gb_tty = tty->driver_data; 462 unsigned long flags; 463 unsigned int chars; 464 465 spin_lock_irqsave(&gb_tty->write_lock, flags); 466 chars = kfifo_len(&gb_tty->write_fifo); 467 if (gb_tty->credits < GB_UART_FIRMWARE_CREDITS) 468 chars += GB_UART_FIRMWARE_CREDITS - gb_tty->credits; 469 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 470 471 return chars; 472 } 473 474 static int gb_tty_break_ctl(struct tty_struct *tty, int state) 475 { 476 struct gb_tty *gb_tty = tty->driver_data; 477 478 return send_break(gb_tty, state ? 1 : 0); 479 } 480 481 static void gb_tty_set_termios(struct tty_struct *tty, 482 const struct ktermios *termios_old) 483 { 484 struct gb_uart_set_line_coding_request newline; 485 struct gb_tty *gb_tty = tty->driver_data; 486 struct ktermios *termios = &tty->termios; 487 u8 newctrl = gb_tty->ctrlout; 488 489 newline.rate = cpu_to_le32(tty_get_baud_rate(tty)); 490 newline.format = termios->c_cflag & CSTOPB ? 491 GB_SERIAL_2_STOP_BITS : GB_SERIAL_1_STOP_BITS; 492 newline.parity = termios->c_cflag & PARENB ? 493 (termios->c_cflag & PARODD ? 1 : 2) + 494 (termios->c_cflag & CMSPAR ? 2 : 0) : 0; 495 496 newline.data_bits = tty_get_char_size(termios->c_cflag); 497 498 /* FIXME: needs to clear unsupported bits in the termios */ 499 gb_tty->clocal = ((termios->c_cflag & CLOCAL) != 0); 500 501 if (C_BAUD(tty) == B0) { 502 newline.rate = gb_tty->line_coding.rate; 503 newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 504 } else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) { 505 newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 506 } 507 508 if (newctrl != gb_tty->ctrlout) { 509 gb_tty->ctrlout = newctrl; 510 send_control(gb_tty, newctrl); 511 } 512 513 if (C_CRTSCTS(tty) && C_BAUD(tty) != B0) 514 newline.flow_control = GB_SERIAL_AUTO_RTSCTS_EN; 515 else 516 newline.flow_control = 0; 517 518 if (memcmp(&gb_tty->line_coding, &newline, sizeof(newline))) { 519 memcpy(&gb_tty->line_coding, &newline, sizeof(newline)); 520 send_line_coding(gb_tty); 521 } 522 } 523 524 static int gb_tty_tiocmget(struct tty_struct *tty) 525 { 526 struct gb_tty *gb_tty = tty->driver_data; 527 528 return (gb_tty->ctrlout & GB_UART_CTRL_DTR ? TIOCM_DTR : 0) | 529 (gb_tty->ctrlout & GB_UART_CTRL_RTS ? TIOCM_RTS : 0) | 530 (gb_tty->ctrlin & GB_UART_CTRL_DSR ? TIOCM_DSR : 0) | 531 (gb_tty->ctrlin & GB_UART_CTRL_RI ? TIOCM_RI : 0) | 532 (gb_tty->ctrlin & GB_UART_CTRL_DCD ? TIOCM_CD : 0) | 533 TIOCM_CTS; 534 } 535 536 static int gb_tty_tiocmset(struct tty_struct *tty, unsigned int set, 537 unsigned int clear) 538 { 539 struct gb_tty *gb_tty = tty->driver_data; 540 u8 newctrl = gb_tty->ctrlout; 541 542 set = (set & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) | 543 (set & TIOCM_RTS ? GB_UART_CTRL_RTS : 0); 544 clear = (clear & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) | 545 (clear & TIOCM_RTS ? GB_UART_CTRL_RTS : 0); 546 547 newctrl = (newctrl & ~clear) | set; 548 if (gb_tty->ctrlout == newctrl) 549 return 0; 550 551 gb_tty->ctrlout = newctrl; 552 return send_control(gb_tty, newctrl); 553 } 554 555 static void gb_tty_throttle(struct tty_struct *tty) 556 { 557 struct gb_tty *gb_tty = tty->driver_data; 558 unsigned char stop_char; 559 int retval; 560 561 if (I_IXOFF(tty)) { 562 stop_char = STOP_CHAR(tty); 563 retval = gb_tty_write(tty, &stop_char, 1); 564 if (retval <= 0) 565 return; 566 } 567 568 if (tty->termios.c_cflag & CRTSCTS) { 569 gb_tty->ctrlout &= ~GB_UART_CTRL_RTS; 570 retval = send_control(gb_tty, gb_tty->ctrlout); 571 } 572 } 573 574 static void gb_tty_unthrottle(struct tty_struct *tty) 575 { 576 struct gb_tty *gb_tty = tty->driver_data; 577 unsigned char start_char; 578 int retval; 579 580 if (I_IXOFF(tty)) { 581 start_char = START_CHAR(tty); 582 retval = gb_tty_write(tty, &start_char, 1); 583 if (retval <= 0) 584 return; 585 } 586 587 if (tty->termios.c_cflag & CRTSCTS) { 588 gb_tty->ctrlout |= GB_UART_CTRL_RTS; 589 retval = send_control(gb_tty, gb_tty->ctrlout); 590 } 591 } 592 593 static int get_serial_info(struct tty_struct *tty, 594 struct serial_struct *ss) 595 { 596 struct gb_tty *gb_tty = tty->driver_data; 597 598 ss->line = gb_tty->minor; 599 ss->close_delay = jiffies_to_msecs(gb_tty->port.close_delay) / 10; 600 ss->closing_wait = 601 gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? 602 ASYNC_CLOSING_WAIT_NONE : 603 jiffies_to_msecs(gb_tty->port.closing_wait) / 10; 604 605 return 0; 606 } 607 608 static int set_serial_info(struct tty_struct *tty, 609 struct serial_struct *ss) 610 { 611 struct gb_tty *gb_tty = tty->driver_data; 612 unsigned int closing_wait; 613 unsigned int close_delay; 614 int retval = 0; 615 616 close_delay = msecs_to_jiffies(ss->close_delay * 10); 617 closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 618 ASYNC_CLOSING_WAIT_NONE : 619 msecs_to_jiffies(ss->closing_wait * 10); 620 621 mutex_lock(&gb_tty->port.mutex); 622 if (!capable(CAP_SYS_ADMIN)) { 623 if ((close_delay != gb_tty->port.close_delay) || 624 (closing_wait != gb_tty->port.closing_wait)) 625 retval = -EPERM; 626 } else { 627 gb_tty->port.close_delay = close_delay; 628 gb_tty->port.closing_wait = closing_wait; 629 } 630 mutex_unlock(&gb_tty->port.mutex); 631 return retval; 632 } 633 634 static int wait_serial_change(struct gb_tty *gb_tty, unsigned long arg) 635 { 636 int retval = 0; 637 DECLARE_WAITQUEUE(wait, current); 638 struct async_icount old; 639 struct async_icount new; 640 641 if (!(arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD))) 642 return -EINVAL; 643 644 do { 645 spin_lock_irq(&gb_tty->read_lock); 646 old = gb_tty->oldcount; 647 new = gb_tty->iocount; 648 gb_tty->oldcount = new; 649 spin_unlock_irq(&gb_tty->read_lock); 650 651 if ((arg & TIOCM_DSR) && (old.dsr != new.dsr)) 652 break; 653 if ((arg & TIOCM_CD) && (old.dcd != new.dcd)) 654 break; 655 if ((arg & TIOCM_RI) && (old.rng != new.rng)) 656 break; 657 658 add_wait_queue(&gb_tty->wioctl, &wait); 659 set_current_state(TASK_INTERRUPTIBLE); 660 schedule(); 661 remove_wait_queue(&gb_tty->wioctl, &wait); 662 if (gb_tty->disconnected) { 663 if (arg & TIOCM_CD) 664 break; 665 retval = -ENODEV; 666 } else if (signal_pending(current)) { 667 retval = -ERESTARTSYS; 668 } 669 } while (!retval); 670 671 return retval; 672 } 673 674 static int gb_tty_get_icount(struct tty_struct *tty, 675 struct serial_icounter_struct *icount) 676 { 677 struct gb_tty *gb_tty = tty->driver_data; 678 679 icount->dsr = gb_tty->iocount.dsr; 680 icount->rng = gb_tty->iocount.rng; 681 icount->dcd = gb_tty->iocount.dcd; 682 icount->frame = gb_tty->iocount.frame; 683 icount->overrun = gb_tty->iocount.overrun; 684 icount->parity = gb_tty->iocount.parity; 685 icount->brk = gb_tty->iocount.brk; 686 687 return 0; 688 } 689 690 static int gb_tty_ioctl(struct tty_struct *tty, unsigned int cmd, 691 unsigned long arg) 692 { 693 struct gb_tty *gb_tty = tty->driver_data; 694 695 switch (cmd) { 696 case TIOCMIWAIT: 697 return wait_serial_change(gb_tty, arg); 698 } 699 700 return -ENOIOCTLCMD; 701 } 702 703 static void gb_tty_dtr_rts(struct tty_port *port, bool active) 704 { 705 struct gb_tty *gb_tty; 706 u8 newctrl; 707 708 gb_tty = container_of(port, struct gb_tty, port); 709 newctrl = gb_tty->ctrlout; 710 711 if (active) 712 newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 713 else 714 newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS); 715 716 gb_tty->ctrlout = newctrl; 717 send_control(gb_tty, newctrl); 718 } 719 720 static int gb_tty_port_activate(struct tty_port *port, 721 struct tty_struct *tty) 722 { 723 struct gb_tty *gb_tty; 724 725 gb_tty = container_of(port, struct gb_tty, port); 726 727 return gbphy_runtime_get_sync(gb_tty->gbphy_dev); 728 } 729 730 static void gb_tty_port_shutdown(struct tty_port *port) 731 { 732 struct gb_tty *gb_tty; 733 unsigned long flags; 734 int ret; 735 736 gb_tty = container_of(port, struct gb_tty, port); 737 738 gb_tty->close_pending = true; 739 740 cancel_work_sync(&gb_tty->tx_work); 741 742 spin_lock_irqsave(&gb_tty->write_lock, flags); 743 kfifo_reset_out(&gb_tty->write_fifo); 744 spin_unlock_irqrestore(&gb_tty->write_lock, flags); 745 746 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS) 747 goto out; 748 749 ret = gb_uart_flush(gb_tty, GB_SERIAL_FLAG_FLUSH_TRANSMITTER); 750 if (ret) { 751 dev_err(&gb_tty->gbphy_dev->dev, 752 "error flushing transmitter: %d\n", ret); 753 } 754 755 gb_uart_wait_for_all_credits(gb_tty); 756 757 out: 758 gb_tty->close_pending = false; 759 760 gbphy_runtime_put_autosuspend(gb_tty->gbphy_dev); 761 } 762 763 static void gb_tty_port_destruct(struct tty_port *port) 764 { 765 struct gb_tty *gb_tty = container_of(port, struct gb_tty, port); 766 767 if (gb_tty->minor != GB_NUM_MINORS) 768 release_minor(gb_tty); 769 kfifo_free(&gb_tty->write_fifo); 770 kfree(gb_tty->buffer); 771 kfree(gb_tty); 772 } 773 774 static const struct tty_operations gb_ops = { 775 .install = gb_tty_install, 776 .open = gb_tty_open, 777 .close = gb_tty_close, 778 .cleanup = gb_tty_cleanup, 779 .hangup = gb_tty_hangup, 780 .write = gb_tty_write, 781 .write_room = gb_tty_write_room, 782 .ioctl = gb_tty_ioctl, 783 .throttle = gb_tty_throttle, 784 .unthrottle = gb_tty_unthrottle, 785 .chars_in_buffer = gb_tty_chars_in_buffer, 786 .break_ctl = gb_tty_break_ctl, 787 .set_termios = gb_tty_set_termios, 788 .tiocmget = gb_tty_tiocmget, 789 .tiocmset = gb_tty_tiocmset, 790 .get_icount = gb_tty_get_icount, 791 .set_serial = set_serial_info, 792 .get_serial = get_serial_info, 793 }; 794 795 static const struct tty_port_operations gb_port_ops = { 796 .dtr_rts = gb_tty_dtr_rts, 797 .activate = gb_tty_port_activate, 798 .shutdown = gb_tty_port_shutdown, 799 .destruct = gb_tty_port_destruct, 800 }; 801 802 static int gb_uart_probe(struct gbphy_device *gbphy_dev, 803 const struct gbphy_device_id *id) 804 { 805 struct gb_connection *connection; 806 size_t max_payload; 807 struct gb_tty *gb_tty; 808 struct device *tty_dev; 809 int retval; 810 int minor; 811 812 connection = gb_connection_create(gbphy_dev->bundle, 813 le16_to_cpu(gbphy_dev->cport_desc->id), 814 gb_uart_request_handler); 815 if (IS_ERR(connection)) 816 return PTR_ERR(connection); 817 818 max_payload = gb_operation_get_payload_size_max(connection); 819 if (max_payload < sizeof(struct gb_uart_send_data_request)) { 820 retval = -EINVAL; 821 goto exit_connection_destroy; 822 } 823 824 gb_tty = kzalloc(sizeof(*gb_tty), GFP_KERNEL); 825 if (!gb_tty) { 826 retval = -ENOMEM; 827 goto exit_connection_destroy; 828 } 829 830 tty_port_init(&gb_tty->port); 831 gb_tty->port.ops = &gb_port_ops; 832 gb_tty->minor = GB_NUM_MINORS; 833 834 gb_tty->buffer_payload_max = max_payload - 835 sizeof(struct gb_uart_send_data_request); 836 837 gb_tty->buffer = kzalloc(gb_tty->buffer_payload_max, GFP_KERNEL); 838 if (!gb_tty->buffer) { 839 retval = -ENOMEM; 840 goto exit_put_port; 841 } 842 843 INIT_WORK(&gb_tty->tx_work, gb_uart_tx_write_work); 844 845 retval = kfifo_alloc(&gb_tty->write_fifo, GB_UART_WRITE_FIFO_SIZE, 846 GFP_KERNEL); 847 if (retval) 848 goto exit_put_port; 849 850 gb_tty->credits = GB_UART_FIRMWARE_CREDITS; 851 init_completion(&gb_tty->credits_complete); 852 853 minor = alloc_minor(gb_tty); 854 if (minor < 0) { 855 if (minor == -ENOSPC) { 856 dev_err(&gbphy_dev->dev, 857 "no more free minor numbers\n"); 858 retval = -ENODEV; 859 } else { 860 retval = minor; 861 } 862 goto exit_put_port; 863 } 864 865 gb_tty->minor = minor; 866 spin_lock_init(&gb_tty->write_lock); 867 spin_lock_init(&gb_tty->read_lock); 868 init_waitqueue_head(&gb_tty->wioctl); 869 mutex_init(&gb_tty->mutex); 870 871 gb_tty->connection = connection; 872 gb_tty->gbphy_dev = gbphy_dev; 873 gb_connection_set_data(connection, gb_tty); 874 gb_gbphy_set_data(gbphy_dev, gb_tty); 875 876 retval = gb_connection_enable_tx(connection); 877 if (retval) 878 goto exit_put_port; 879 880 send_control(gb_tty, gb_tty->ctrlout); 881 882 /* initialize the uart to be 9600n81 */ 883 gb_tty->line_coding.rate = cpu_to_le32(9600); 884 gb_tty->line_coding.format = GB_SERIAL_1_STOP_BITS; 885 gb_tty->line_coding.parity = GB_SERIAL_NO_PARITY; 886 gb_tty->line_coding.data_bits = 8; 887 send_line_coding(gb_tty); 888 889 retval = gb_connection_enable(connection); 890 if (retval) 891 goto exit_connection_disable; 892 893 tty_dev = tty_port_register_device(&gb_tty->port, gb_tty_driver, minor, 894 &gbphy_dev->dev); 895 if (IS_ERR(tty_dev)) { 896 retval = PTR_ERR(tty_dev); 897 goto exit_connection_disable; 898 } 899 900 gbphy_runtime_put_autosuspend(gbphy_dev); 901 return 0; 902 903 exit_connection_disable: 904 gb_connection_disable(connection); 905 exit_put_port: 906 tty_port_put(&gb_tty->port); 907 exit_connection_destroy: 908 gb_connection_destroy(connection); 909 910 return retval; 911 } 912 913 static void gb_uart_remove(struct gbphy_device *gbphy_dev) 914 { 915 struct gb_tty *gb_tty = gb_gbphy_get_data(gbphy_dev); 916 struct gb_connection *connection = gb_tty->connection; 917 struct tty_struct *tty; 918 int ret; 919 920 ret = gbphy_runtime_get_sync(gbphy_dev); 921 if (ret) 922 gbphy_runtime_get_noresume(gbphy_dev); 923 924 mutex_lock(&gb_tty->mutex); 925 gb_tty->disconnected = true; 926 927 wake_up_all(&gb_tty->wioctl); 928 mutex_unlock(&gb_tty->mutex); 929 930 tty = tty_port_tty_get(&gb_tty->port); 931 if (tty) { 932 tty_vhangup(tty); 933 tty_kref_put(tty); 934 } 935 936 gb_connection_disable_rx(connection); 937 tty_unregister_device(gb_tty_driver, gb_tty->minor); 938 939 gb_connection_disable(connection); 940 gb_connection_destroy(connection); 941 942 tty_port_put(&gb_tty->port); 943 } 944 945 static int gb_tty_init(void) 946 { 947 int retval = 0; 948 949 gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, 0); 950 if (IS_ERR(gb_tty_driver)) { 951 pr_err("Can not allocate tty driver\n"); 952 retval = -ENOMEM; 953 goto fail_unregister_dev; 954 } 955 956 gb_tty_driver->driver_name = "gb"; 957 gb_tty_driver->name = GB_NAME; 958 gb_tty_driver->major = 0; 959 gb_tty_driver->minor_start = 0; 960 gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; 961 gb_tty_driver->subtype = SERIAL_TYPE_NORMAL; 962 gb_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; 963 gb_tty_driver->init_termios = tty_std_termios; 964 gb_tty_driver->init_termios.c_cflag = B9600 | CS8 | 965 CREAD | HUPCL | CLOCAL; 966 tty_set_operations(gb_tty_driver, &gb_ops); 967 968 retval = tty_register_driver(gb_tty_driver); 969 if (retval) { 970 pr_err("Can not register tty driver: %d\n", retval); 971 goto fail_put_gb_tty; 972 } 973 974 return 0; 975 976 fail_put_gb_tty: 977 tty_driver_kref_put(gb_tty_driver); 978 fail_unregister_dev: 979 return retval; 980 } 981 982 static void gb_tty_exit(void) 983 { 984 tty_unregister_driver(gb_tty_driver); 985 tty_driver_kref_put(gb_tty_driver); 986 idr_destroy(&tty_minors); 987 } 988 989 static const struct gbphy_device_id gb_uart_id_table[] = { 990 { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_UART) }, 991 { }, 992 }; 993 MODULE_DEVICE_TABLE(gbphy, gb_uart_id_table); 994 995 static struct gbphy_driver uart_driver = { 996 .name = "uart", 997 .probe = gb_uart_probe, 998 .remove = gb_uart_remove, 999 .id_table = gb_uart_id_table, 1000 }; 1001 1002 static int gb_uart_driver_init(void) 1003 { 1004 int ret; 1005 1006 ret = gb_tty_init(); 1007 if (ret) 1008 return ret; 1009 1010 ret = gb_gbphy_register(&uart_driver); 1011 if (ret) { 1012 gb_tty_exit(); 1013 return ret; 1014 } 1015 1016 return 0; 1017 } 1018 module_init(gb_uart_driver_init); 1019 1020 static void gb_uart_driver_exit(void) 1021 { 1022 gb_gbphy_deregister(&uart_driver); 1023 gb_tty_exit(); 1024 } 1025 1026 module_exit(gb_uart_driver_exit); 1027 MODULE_LICENSE("GPL v2"); 1028