drivers/serial/bfin_5xx.c

   1 /*
   2  * Blackfin On-Chip Serial Driver
   3  *
   4  * Copyright 2006-2007 Analog Devices Inc.
   5  *
   6  * Enter bugs at http://blackfin.uclinux.org/
   7  *
   8  * Licensed under the GPL-2 or later.
   9  */
  10
  11 #if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  12 #define SUPPORT_SYSRQ
  13 #endif
  14
  15 #include <linux/module.h>
  16 #include <linux/ioport.h>
  17 #include <linux/init.h>
  18 #include <linux/console.h>
  19 #include <linux/sysrq.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/tty.h>
  22 #include <linux/tty_flip.h>
  23 #include <linux/serial_core.h>
  24
  25 #ifdef CONFIG_KGDB_UART
  26 #include <linux/kgdb.h>
  27 #include <asm/irq_regs.h>
  28 #endif
  29
  30 #include <asm/gpio.h>
  31 #include <asm/mach/bfin_serial_5xx.h>
  32
  33 #ifdef CONFIG_SERIAL_BFIN_DMA
  34 #include <linux/dma-mapping.h>
  35 #include <asm/io.h>
  36 #include <asm/irq.h>
  37 #include <asm/cacheflush.h>
  38 #endif
  39
  40 /* UART name and device definitions */
  41 #define BFIN_SERIAL_NAME        "ttyBF"
  42 #define BFIN_SERIAL_MAJOR       204
  43 #define BFIN_SERIAL_MINOR       64
  44
  45 /*
  46  * Setup for console. Argument comes from the menuconfig
  47  */
  48 #define DMA_RX_XCOUNT           512
  49 #define DMA_RX_YCOUNT           (PAGE_SIZE / DMA_RX_XCOUNT)
  50
  51 #define DMA_RX_FLUSH_JIFFIES    (HZ / 50)
  52
  53 #ifdef CONFIG_SERIAL_BFIN_DMA
  54 static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
  55 #else
  56 static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
  57 #endif
  58
  59 static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
  60
  61 /*
  62  * interrupts are disabled on entry
  63  */
  64 static void bfin_serial_stop_tx(struct uart_port *port)
  65 {
  66         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
  67         struct circ_buf *xmit = &uart->port.info->xmit;
  68
  69         while (!(UART_GET_LSR(uart) & TEMT))
  70                 cpu_relax();
  71
  72 #ifdef CONFIG_SERIAL_BFIN_DMA
  73         disable_dma(uart->tx_dma_channel);
  74         xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
  75         uart->port.icount.tx += uart->tx_count;
  76         uart->tx_count = 0;
  77         uart->tx_done = 1;
  78 #else
  79 #ifdef CONFIG_BF54x
  80         /* Clear TFI bit */
  81         UART_PUT_LSR(uart, TFI);
  82 #endif
  83         UART_CLEAR_IER(uart, ETBEI);
  84 #endif
  85 }
  86
  87 /*
  88  * port is locked and interrupts are disabled
  89  */
  90 static void bfin_serial_start_tx(struct uart_port *port)
  91 {
  92         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
  93
  94 #ifdef CONFIG_SERIAL_BFIN_DMA
  95         if (uart->tx_done)
  96                 bfin_serial_dma_tx_chars(uart);
  97 #else
  98         UART_SET_IER(uart, ETBEI);
  99         bfin_serial_tx_chars(uart);
 100 #endif
 101 }
 102
 103 /*
 104  * Interrupts are enabled
 105  */
 106 static void bfin_serial_stop_rx(struct uart_port *port)
 107 {
 108         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 109 #ifdef CONFIG_KGDB_UART
 110         if (uart->port.line != CONFIG_KGDB_UART_PORT)
 111 #endif
 112         UART_CLEAR_IER(uart, ERBFI);
 113 }
 114
 115 /*
 116  * Set the modem control timer to fire immediately.
 117  */
 118 static void bfin_serial_enable_ms(struct uart_port *port)
 119 {
 120 }
 121
 122 #ifdef CONFIG_KGDB_UART
 123 static int kgdb_entry_state;
 124
 125 void kgdb_put_debug_char(int chr)
 126 {
 127         struct bfin_serial_port *uart;
 128
 129         if (CONFIG_KGDB_UART_PORT < 0
 130                 || CONFIG_KGDB_UART_PORT >= BFIN_UART_NR_PORTS)
 131                 uart = &bfin_serial_ports[0];
 132         else
 133                 uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
 134
 135         while (!(UART_GET_LSR(uart) & THRE)) {
 136                 SSYNC();
 137         }
 138
 139         UART_CLEAR_DLAB(uart);
 140         UART_PUT_CHAR(uart, (unsigned char)chr);
 141         SSYNC();
 142 }
 143
 144 int kgdb_get_debug_char(void)
 145 {
 146         struct bfin_serial_port *uart;
 147         unsigned char chr;
 148
 149         if (CONFIG_KGDB_UART_PORT < 0
 150                 || CONFIG_KGDB_UART_PORT >= BFIN_UART_NR_PORTS)
 151                 uart = &bfin_serial_ports[0];
 152         else
 153                 uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
 154
 155         while(!(UART_GET_LSR(uart) & DR)) {
 156                 SSYNC();
 157         }
 158         UART_CLEAR_DLAB(uart);
 159         chr = UART_GET_CHAR(uart);
 160         SSYNC();
 161
 162         return chr;
 163 }
 164 #endif
 165
 166 #if ANOMALY_05000363 && defined(CONFIG_SERIAL_BFIN_PIO)
 167 # define UART_GET_ANOMALY_THRESHOLD(uart)    ((uart)->anomaly_threshold)
 168 # define UART_SET_ANOMALY_THRESHOLD(uart, v) ((uart)->anomaly_threshold = (v))
 169 #else
 170 # define UART_GET_ANOMALY_THRESHOLD(uart)    0
 171 # define UART_SET_ANOMALY_THRESHOLD(uart, v)
 172 #endif
 173
 174 #ifdef CONFIG_SERIAL_BFIN_PIO
 175 static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
 176 {
 177         struct tty_struct *tty = uart->port.info->tty;
 178         unsigned int status, ch, flg;
 179         static struct timeval anomaly_start = { .tv_sec = 0 };
 180
 181         status = UART_GET_LSR(uart);
 182         UART_CLEAR_LSR(uart);
 183
 184         ch = UART_GET_CHAR(uart);
 185         uart->port.icount.rx++;
 186
 187 #ifdef CONFIG_KGDB_UART
 188         if (uart->port.line == CONFIG_KGDB_UART_PORT) {
 189                 struct pt_regs *regs = get_irq_regs();
 190                 if (uart->port.cons->index == CONFIG_KGDB_UART_PORT && ch == 0x1) { /* Ctrl + A */
 191                         kgdb_breakkey_pressed(regs);
 192                         return;
 193                 } else if (kgdb_entry_state == 0 && ch == '$') {/* connection from KGDB */
 194                         kgdb_entry_state = 1;
 195                 } else if (kgdb_entry_state == 1 && ch == 'q') {
 196                         kgdb_entry_state = 0;
 197                         kgdb_breakkey_pressed(regs);
 198                         return;
 199                 } else if (ch == 0x3) {/* Ctrl + C */
 200                         kgdb_entry_state = 0;
 201                         kgdb_breakkey_pressed(regs);
 202                         return;
 203                 } else {
 204                         kgdb_entry_state = 0;
 205                 }
 206         }
 207 #endif
 208
 209         if (ANOMALY_05000363) {
 210                 /* The BF533 (and BF561) family of processors have a nice anomaly
 211                  * where they continuously generate characters for a "single" break.
 212                  * We have to basically ignore this flood until the "next" valid
 213                  * character comes across.  Due to the nature of the flood, it is
 214                  * not possible to reliably catch bytes that are sent too quickly
 215                  * after this break.  So application code talking to the Blackfin
 216                  * which sends a break signal must allow at least 1.5 character
 217                  * times after the end of the break for things to stabilize.  This
 218                  * timeout was picked as it must absolutely be larger than 1
 219                  * character time +/- some percent.  So 1.5 sounds good.  All other
 220                  * Blackfin families operate properly.  Woo.
 221                  */
 222                 if (anomaly_start.tv_sec) {
 223                         struct timeval curr;
 224                         suseconds_t usecs;
 225
 226                         if ((~ch & (~ch + 1)) & 0xff)
 227                                 goto known_good_char;
 228
 229                         do_gettimeofday(&curr);
 230                         if (curr.tv_sec - anomaly_start.tv_sec > 1)
 231                                 goto known_good_char;
 232
 233                         usecs = 0;
 234                         if (curr.tv_sec != anomaly_start.tv_sec)
 235                                 usecs += USEC_PER_SEC;
 236                         usecs += curr.tv_usec - anomaly_start.tv_usec;
 237
 238                         if (usecs > UART_GET_ANOMALY_THRESHOLD(uart))
 239                                 goto known_good_char;
 240
 241                         if (ch)
 242                                 anomaly_start.tv_sec = 0;
 243                         else
 244                                 anomaly_start = curr;
 245
 246                         return;
 247
 248  known_good_char:
 249                         anomaly_start.tv_sec = 0;
 250                 }
 251         }
 252
 253         if (status & BI) {
 254                 if (ANOMALY_05000363)
 255                         if (bfin_revid() < 5)
 256                                 do_gettimeofday(&anomaly_start);
 257                 uart->port.icount.brk++;
 258                 if (uart_handle_break(&uart->port))
 259                         goto ignore_char;
 260                 status &= ~(PE | FE);
 261         }
 262         if (status & PE)
 263                 uart->port.icount.parity++;
 264         if (status & OE)
 265                 uart->port.icount.overrun++;
 266         if (status & FE)
 267                 uart->port.icount.frame++;
 268
 269         status &= uart->port.read_status_mask;
 270
 271         if (status & BI)
 272                 flg = TTY_BREAK;
 273         else if (status & PE)
 274                 flg = TTY_PARITY;
 275         else if (status & FE)
 276                 flg = TTY_FRAME;
 277         else
 278                 flg = TTY_NORMAL;
 279
 280         if (uart_handle_sysrq_char(&uart->port, ch))
 281                 goto ignore_char;
 282
 283         uart_insert_char(&uart->port, status, OE, ch, flg);
 284
 285  ignore_char:
 286         tty_flip_buffer_push(tty);
 287 }
 288
 289 static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
 290 {
 291         struct circ_buf *xmit = &uart->port.info->xmit;
 292
 293         if (uart->port.x_char) {
 294                 UART_PUT_CHAR(uart, uart->port.x_char);
 295                 uart->port.icount.tx++;
 296                 uart->port.x_char = 0;
 297         }
 298         /*
 299          * Check the modem control lines before
 300          * transmitting anything.
 301          */
 302         bfin_serial_mctrl_check(uart);
 303
 304         if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
 305                 bfin_serial_stop_tx(&uart->port);
 306                 return;
 307         }
 308
 309         while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
 310                 UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
 311                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 312                 uart->port.icount.tx++;
 313                 SSYNC();
 314         }
 315
 316         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 317                 uart_write_wakeup(&uart->port);
 318
 319         if (uart_circ_empty(xmit))
 320                 bfin_serial_stop_tx(&uart->port);
 321 }
 322
 323 static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
 324 {
 325         struct bfin_serial_port *uart = dev_id;
 326
 327         spin_lock(&uart->port.lock);
 328         while (UART_GET_LSR(uart) & DR)
 329                 bfin_serial_rx_chars(uart);
 330         spin_unlock(&uart->port.lock);
 331
 332         return IRQ_HANDLED;
 333 }
 334
 335 static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
 336 {
 337         struct bfin_serial_port *uart = dev_id;
 338
 339         spin_lock(&uart->port.lock);
 340         if (UART_GET_LSR(uart) & THRE)
 341                 bfin_serial_tx_chars(uart);
 342         spin_unlock(&uart->port.lock);
 343
 344         return IRQ_HANDLED;
 345 }
 346 #endif
 347
 348 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 349 static void bfin_serial_do_work(struct work_struct *work)
 350 {
 351         struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
 352
 353         bfin_serial_mctrl_check(uart);
 354 }
 355 #endif
 356
 357 #ifdef CONFIG_SERIAL_BFIN_DMA
 358 static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
 359 {
 360         struct circ_buf *xmit = &uart->port.info->xmit;
 361
 362         uart->tx_done = 0;
 363
 364         if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
 365                 uart->tx_count = 0;
 366                 uart->tx_done = 1;
 367                 return;
 368         }
 369
 370         if (uart->port.x_char) {
 371                 UART_PUT_CHAR(uart, uart->port.x_char);
 372                 uart->port.icount.tx++;
 373                 uart->port.x_char = 0;
 374         }
 375
 376         /*
 377          * Check the modem control lines before
 378          * transmitting anything.
 379          */
 380         bfin_serial_mctrl_check(uart);
 381
 382         uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
 383         if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
 384                 uart->tx_count = UART_XMIT_SIZE - xmit->tail;
 385         blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
 386                                         (unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
 387         set_dma_config(uart->tx_dma_channel,
 388                 set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
 389                         INTR_ON_BUF,
 390                         DIMENSION_LINEAR,
 391                         DATA_SIZE_8,
 392                         DMA_SYNC_RESTART));
 393         set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
 394         set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
 395         set_dma_x_modify(uart->tx_dma_channel, 1);
 396         enable_dma(uart->tx_dma_channel);
 397
 398         UART_SET_IER(uart, ETBEI);
 399 }
 400
 401 static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
 402 {
 403         struct tty_struct *tty = uart->port.info->tty;
 404         int i, flg, status;
 405
 406         status = UART_GET_LSR(uart);
 407         UART_CLEAR_LSR(uart);
 408
 409         uart->port.icount.rx +=
 410                 CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
 411                 UART_XMIT_SIZE);
 412
 413         if (status & BI) {
 414                 uart->port.icount.brk++;
 415                 if (uart_handle_break(&uart->port))
 416                         goto dma_ignore_char;
 417                 status &= ~(PE | FE);
 418         }
 419         if (status & PE)
 420                 uart->port.icount.parity++;
 421         if (status & OE)
 422                 uart->port.icount.overrun++;
 423         if (status & FE)
 424                 uart->port.icount.frame++;
 425
 426         status &= uart->port.read_status_mask;
 427
 428         if (status & BI)
 429                 flg = TTY_BREAK;
 430         else if (status & PE)
 431                 flg = TTY_PARITY;
 432         else if (status & FE)
 433                 flg = TTY_FRAME;
 434         else
 435                 flg = TTY_NORMAL;
 436
 437         for (i = uart->rx_dma_buf.tail; i != uart->rx_dma_buf.head; i++) {
 438                 if (i >= UART_XMIT_SIZE)
 439                         i = 0;
 440                 if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
 441                         uart_insert_char(&uart->port, status, OE,
 442                                 uart->rx_dma_buf.buf[i], flg);
 443         }
 444
 445  dma_ignore_char:
 446         tty_flip_buffer_push(tty);
 447 }
 448
 449 void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
 450 {
 451         int x_pos, pos;
 452
 453         uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
 454         x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
 455         uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
 456         if (uart->rx_dma_nrows == DMA_RX_YCOUNT)
 457                 uart->rx_dma_nrows = 0;
 458         x_pos = DMA_RX_XCOUNT - x_pos;
 459         if (x_pos == DMA_RX_XCOUNT)
 460                 x_pos = 0;
 461
 462         pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
 463         if (pos != uart->rx_dma_buf.tail) {
 464                 uart->rx_dma_buf.head = pos;
 465                 bfin_serial_dma_rx_chars(uart);
 466                 uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
 467         }
 468
 469         mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
 470 }
 471
 472 static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
 473 {
 474         struct bfin_serial_port *uart = dev_id;
 475         struct circ_buf *xmit = &uart->port.info->xmit;
 476
 477         spin_lock(&uart->port.lock);
 478         if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
 479                 disable_dma(uart->tx_dma_channel);
 480                 clear_dma_irqstat(uart->tx_dma_channel);
 481                 UART_CLEAR_IER(uart, ETBEI);
 482                 xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
 483                 uart->port.icount.tx += uart->tx_count;
 484
 485                 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 486                         uart_write_wakeup(&uart->port);
 487
 488                 bfin_serial_dma_tx_chars(uart);
 489         }
 490
 491         spin_unlock(&uart->port.lock);
 492         return IRQ_HANDLED;
 493 }
 494
 495 static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
 496 {
 497         struct bfin_serial_port *uart = dev_id;
 498         unsigned short irqstat;
 499
 500         spin_lock(&uart->port.lock);
 501         irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
 502         clear_dma_irqstat(uart->rx_dma_channel);
 503         spin_unlock(&uart->port.lock);
 504
 505         mod_timer(&(uart->rx_dma_timer), jiffies);
 506
 507         return IRQ_HANDLED;
 508 }
 509 #endif
 510
 511 /*
 512  * Return TIOCSER_TEMT when transmitter is not busy.
 513  */
 514 static unsigned int bfin_serial_tx_empty(struct uart_port *port)
 515 {
 516         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 517         unsigned short lsr;
 518
 519         lsr = UART_GET_LSR(uart);
 520         if (lsr & TEMT)
 521                 return TIOCSER_TEMT;
 522         else
 523                 return 0;
 524 }
 525
 526 static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
 527 {
 528 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 529         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 530         if (uart->cts_pin < 0)
 531                 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 532
 533         if (UART_GET_CTS(uart))
 534                 return TIOCM_DSR | TIOCM_CAR;
 535         else
 536 #endif
 537                 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 538 }
 539
 540 static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 541 {
 542 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 543         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 544         if (uart->rts_pin < 0)
 545                 return;
 546
 547         if (mctrl & TIOCM_RTS)
 548                 UART_CLEAR_RTS(uart);
 549         else
 550                 UART_SET_RTS(uart);
 551 #endif
 552 }
 553
 554 /*
 555  * Handle any change of modem status signal since we were last called.
 556  */
 557 static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
 558 {
 559 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 560         unsigned int status;
 561         struct uart_info *info = uart->port.info;
 562         struct tty_struct *tty = info->tty;
 563
 564         status = bfin_serial_get_mctrl(&uart->port);
 565         uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
 566         if (!(status & TIOCM_CTS)) {
 567                 tty->hw_stopped = 1;
 568                 schedule_work(&uart->cts_workqueue);
 569         } else {
 570                 tty->hw_stopped = 0;
 571         }
 572 #endif
 573 }
 574
 575 /*
 576  * Interrupts are always disabled.
 577  */
 578 static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
 579 {
 580         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 581         u16 lcr = UART_GET_LCR(uart);
 582         if (break_state)
 583                 lcr |= SB;
 584         else
 585                 lcr &= ~SB;
 586         UART_PUT_LCR(uart, lcr);
 587         SSYNC();
 588 }
 589
 590 static int bfin_serial_startup(struct uart_port *port)
 591 {
 592         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 593
 594 #ifdef CONFIG_SERIAL_BFIN_DMA
 595         dma_addr_t dma_handle;
 596
 597         if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
 598                 printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
 599                 return -EBUSY;
 600         }
 601
 602         if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
 603                 printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
 604                 free_dma(uart->rx_dma_channel);
 605                 return -EBUSY;
 606         }
 607
 608         set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
 609         set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);
 610
 611         uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
 612         uart->rx_dma_buf.head = 0;
 613         uart->rx_dma_buf.tail = 0;
 614         uart->rx_dma_nrows = 0;
 615
 616         set_dma_config(uart->rx_dma_channel,
 617                 set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
 618                                 INTR_ON_ROW, DIMENSION_2D,
 619                                 DATA_SIZE_8,
 620                                 DMA_SYNC_RESTART));
 621         set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
 622         set_dma_x_modify(uart->rx_dma_channel, 1);
 623         set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
 624         set_dma_y_modify(uart->rx_dma_channel, 1);
 625         set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
 626         enable_dma(uart->rx_dma_channel);
 627
 628         uart->rx_dma_timer.data = (unsigned long)(uart);
 629         uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
 630         uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
 631         add_timer(&(uart->rx_dma_timer));
 632 #else
 633         if (request_irq(uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED,
 634              "BFIN_UART_RX", uart)) {
 635 # ifdef CONFIG_KGDB_UART
 636                 if (uart->port.line != CONFIG_KGDB_UART_PORT) {
 637 # endif
 638                 printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
 639                 return -EBUSY;
 640 # ifdef CONFIG_KGDB_UART
 641                 }
 642 # endif
 643         }
 644
 645         if (request_irq
 646             (uart->port.irq+1, bfin_serial_tx_int, IRQF_DISABLED,
 647              "BFIN_UART_TX", uart)) {
 648                 printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
 649                 free_irq(uart->port.irq, uart);
 650                 return -EBUSY;
 651         }
 652 #endif
 653         UART_SET_IER(uart, ERBFI);
 654         return 0;
 655 }
 656
 657 static void bfin_serial_shutdown(struct uart_port *port)
 658 {
 659         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 660
 661 #ifdef CONFIG_SERIAL_BFIN_DMA
 662         disable_dma(uart->tx_dma_channel);
 663         free_dma(uart->tx_dma_channel);
 664         disable_dma(uart->rx_dma_channel);
 665         free_dma(uart->rx_dma_channel);
 666         del_timer(&(uart->rx_dma_timer));
 667         dma_free_coherent(NULL, PAGE_SIZE, uart->rx_dma_buf.buf, 0);
 668 #else
 669 #ifdef  CONFIG_KGDB_UART
 670         if (uart->port.line != CONFIG_KGDB_UART_PORT)
 671 #endif
 672         free_irq(uart->port.irq, uart);
 673         free_irq(uart->port.irq+1, uart);
 674 #endif
 675 }
 676
 677 static void
 678 bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
 679                    struct ktermios *old)
 680 {
 681         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 682         unsigned long flags;
 683         unsigned int baud, quot;
 684         unsigned short val, ier, lcr = 0;
 685
 686         switch (termios->c_cflag & CSIZE) {
 687         case CS8:
 688                 lcr = WLS(8);
 689                 break;
 690         case CS7:
 691                 lcr = WLS(7);
 692                 break;
 693         case CS6:
 694                 lcr = WLS(6);
 695                 break;
 696         case CS5:
 697                 lcr = WLS(5);
 698                 break;
 699         default:
 700                 printk(KERN_ERR "%s: word lengh not supported\n",
 701                         __func__);
 702         }
 703
 704         if (termios->c_cflag & CSTOPB)
 705                 lcr |= STB;
 706         if (termios->c_cflag & PARENB)
 707                 lcr |= PEN;
 708         if (!(termios->c_cflag & PARODD))
 709                 lcr |= EPS;
 710         if (termios->c_cflag & CMSPAR)
 711                 lcr |= STP;
 712
 713         port->read_status_mask = OE;
 714         if (termios->c_iflag & INPCK)
 715                 port->read_status_mask |= (FE | PE);
 716         if (termios->c_iflag & (BRKINT | PARMRK))
 717                 port->read_status_mask |= BI;
 718
 719         /*
 720          * Characters to ignore
 721          */
 722         port->ignore_status_mask = 0;
 723         if (termios->c_iflag & IGNPAR)
 724                 port->ignore_status_mask |= FE | PE;
 725         if (termios->c_iflag & IGNBRK) {
 726                 port->ignore_status_mask |= BI;
 727                 /*
 728                  * If we're ignoring parity and break indicators,
 729                  * ignore overruns too (for real raw support).
 730                  */
 731                 if (termios->c_iflag & IGNPAR)
 732                         port->ignore_status_mask |= OE;
 733         }
 734
 735         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
 736         quot = uart_get_divisor(port, baud);
 737         spin_lock_irqsave(&uart->port.lock, flags);
 738
 739         UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
 740
 741         /* Disable UART */
 742         ier = UART_GET_IER(uart);
 743         UART_DISABLE_INTS(uart);
 744
 745         /* Set DLAB in LCR to Access DLL and DLH */
 746         UART_SET_DLAB(uart);
 747
 748         UART_PUT_DLL(uart, quot & 0xFF);
 749         UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
 750         SSYNC();
 751
 752         /* Clear DLAB in LCR to Access THR RBR IER */
 753         UART_CLEAR_DLAB(uart);
 754
 755         UART_PUT_LCR(uart, lcr);
 756
 757         /* Enable UART */
 758         UART_ENABLE_INTS(uart, ier);
 759
 760         val = UART_GET_GCTL(uart);
 761         val |= UCEN;
 762         UART_PUT_GCTL(uart, val);
 763
 764         spin_unlock_irqrestore(&uart->port.lock, flags);
 765 }
 766
 767 static const char *bfin_serial_type(struct uart_port *port)
 768 {
 769         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 770
 771         return uart->port.type == PORT_BFIN ? "BFIN-UART" : NULL;
 772 }
 773
 774 /*
 775  * Release the memory region(s) being used by 'port'.
 776  */
 777 static void bfin_serial_release_port(struct uart_port *port)
 778 {
 779 }
 780
 781 /*
 782  * Request the memory region(s) being used by 'port'.
 783  */
 784 static int bfin_serial_request_port(struct uart_port *port)
 785 {
 786         return 0;
 787 }
 788
 789 /*
 790  * Configure/autoconfigure the port.
 791  */
 792 static void bfin_serial_config_port(struct uart_port *port, int flags)
 793 {
 794         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 795
 796         if (flags & UART_CONFIG_TYPE &&
 797             bfin_serial_request_port(&uart->port) == 0)
 798                 uart->port.type = PORT_BFIN;
 799 }
 800
 801 /*
 802  * Verify the new serial_struct (for TIOCSSERIAL).
 803  * The only change we allow are to the flags and type, and
 804  * even then only between PORT_BFIN and PORT_UNKNOWN
 805  */
 806 static int
 807 bfin_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
 808 {
 809         return 0;
 810 }
 811
 812 /*
 813  * Enable the IrDA function if tty->ldisc.num is N_IRDA.
 814  * In other cases, disable IrDA function.
 815  */
 816 static void bfin_serial_set_ldisc(struct uart_port *port)
 817 {
 818         int line = port->line;
 819         unsigned short val;
 820
 821         if (line >= port->info->tty->driver->num)
 822                 return;
 823
 824         switch (port->info->tty->ldisc.num) {
 825         case N_IRDA:
 826                 val = UART_GET_GCTL(&bfin_serial_ports[line]);
 827                 val |= (IREN | RPOLC);
 828                 UART_PUT_GCTL(&bfin_serial_ports[line], val);
 829                 break;
 830         default:
 831                 val = UART_GET_GCTL(&bfin_serial_ports[line]);
 832                 val &= ~(IREN | RPOLC);
 833                 UART_PUT_GCTL(&bfin_serial_ports[line], val);
 834         }
 835 }
 836
 837 static struct uart_ops bfin_serial_pops = {
 838         .tx_empty       = bfin_serial_tx_empty,
 839         .set_mctrl      = bfin_serial_set_mctrl,
 840         .get_mctrl      = bfin_serial_get_mctrl,
 841         .stop_tx        = bfin_serial_stop_tx,
 842         .start_tx       = bfin_serial_start_tx,
 843         .stop_rx        = bfin_serial_stop_rx,
 844         .enable_ms      = bfin_serial_enable_ms,
 845         .break_ctl      = bfin_serial_break_ctl,
 846         .startup        = bfin_serial_startup,
 847         .shutdown       = bfin_serial_shutdown,
 848         .set_termios    = bfin_serial_set_termios,
 849         .set_ldisc      = bfin_serial_set_ldisc,
 850         .type           = bfin_serial_type,
 851         .release_port   = bfin_serial_release_port,
 852         .request_port   = bfin_serial_request_port,
 853         .config_port    = bfin_serial_config_port,
 854         .verify_port    = bfin_serial_verify_port,
 855 };
 856
 857 static void __init bfin_serial_init_ports(void)
 858 {
 859         static int first = 1;
 860         int i;
 861
 862         if (!first)
 863                 return;
 864         first = 0;
 865
 866         for (i = 0; i < nr_ports; i++) {
 867                 bfin_serial_ports[i].port.uartclk   = get_sclk();
 868                 bfin_serial_ports[i].port.ops       = &bfin_serial_pops;
 869                 bfin_serial_ports[i].port.line      = i;
 870                 bfin_serial_ports[i].port.iotype    = UPIO_MEM;
 871                 bfin_serial_ports[i].port.membase   =
 872                         (void __iomem *)bfin_serial_resource[i].uart_base_addr;
 873                 bfin_serial_ports[i].port.mapbase   =
 874                         bfin_serial_resource[i].uart_base_addr;
 875                 bfin_serial_ports[i].port.irq       =
 876                         bfin_serial_resource[i].uart_irq;
 877                 bfin_serial_ports[i].port.flags     = UPF_BOOT_AUTOCONF;
 878 #ifdef CONFIG_SERIAL_BFIN_DMA
 879                 bfin_serial_ports[i].tx_done        = 1;
 880                 bfin_serial_ports[i].tx_count       = 0;
 881                 bfin_serial_ports[i].tx_dma_channel =
 882                         bfin_serial_resource[i].uart_tx_dma_channel;
 883                 bfin_serial_ports[i].rx_dma_channel =
 884                         bfin_serial_resource[i].uart_rx_dma_channel;
 885                 init_timer(&(bfin_serial_ports[i].rx_dma_timer));
 886 #endif
 887 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 888                 INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
 889                 bfin_serial_ports[i].cts_pin        =
 890                         bfin_serial_resource[i].uart_cts_pin;
 891                 bfin_serial_ports[i].rts_pin        =
 892                         bfin_serial_resource[i].uart_rts_pin;
 893 #endif
 894                 bfin_serial_hw_init(&bfin_serial_ports[i]);
 895         }
 896
 897 }
 898
 899 #ifdef CONFIG_SERIAL_BFIN_CONSOLE
 900 /*
 901  * If the port was already initialised (eg, by a boot loader),
 902  * try to determine the current setup.
 903  */
 904 static void __init
 905 bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
 906                            int *parity, int *bits)
 907 {
 908         unsigned short status;
 909
 910         status = UART_GET_IER(uart) & (ERBFI | ETBEI);
 911         if (status == (ERBFI | ETBEI)) {
 912                 /* ok, the port was enabled */
 913                 u16 lcr, dlh, dll;
 914
 915                 lcr = UART_GET_LCR(uart);
 916
 917                 *parity = 'n';
 918                 if (lcr & PEN) {
 919                         if (lcr & EPS)
 920                                 *parity = 'e';
 921                         else
 922                                 *parity = 'o';
 923                 }
 924                 switch (lcr & 0x03) {
 925                         case 0: *bits = 5; break;
 926                         case 1: *bits = 6; break;
 927                         case 2: *bits = 7; break;
 928                         case 3: *bits = 8; break;
 929                 }
 930                 /* Set DLAB in LCR to Access DLL and DLH */
 931                 UART_SET_DLAB(uart);
 932
 933                 dll = UART_GET_DLL(uart);
 934                 dlh = UART_GET_DLH(uart);
 935
 936                 /* Clear DLAB in LCR to Access THR RBR IER */
 937                 UART_CLEAR_DLAB(uart);
 938
 939                 *baud = get_sclk() / (16*(dll | dlh << 8));
 940         }
 941         pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __func__, *baud, *parity, *bits);
 942 }
 943 #endif
 944
 945 #if defined(CONFIG_SERIAL_BFIN_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
 946 static struct uart_driver bfin_serial_reg;
 947
 948 static int __init
 949 bfin_serial_console_setup(struct console *co, char *options)
 950 {
 951         struct bfin_serial_port *uart;
 952 # ifdef CONFIG_SERIAL_BFIN_CONSOLE
 953         int baud = 57600;
 954         int bits = 8;
 955         int parity = 'n';
 956 #  ifdef CONFIG_SERIAL_BFIN_CTSRTS
 957         int flow = 'r';
 958 #  else
 959         int flow = 'n';
 960 #  endif
 961 # endif
 962
 963         /*
 964          * Check whether an invalid uart number has been specified, and
 965          * if so, search for the first available port that does have
 966          * console support.
 967          */
 968         if (co->index == -1 || co->index >= nr_ports)
 969                 co->index = 0;
 970         uart = &bfin_serial_ports[co->index];
 971
 972 # ifdef CONFIG_SERIAL_BFIN_CONSOLE
 973         if (options)
 974                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 975         else
 976                 bfin_serial_console_get_options(uart, &baud, &parity, &bits);
 977
 978         return uart_set_options(&uart->port, co, baud, parity, bits, flow);
 979 # else
 980         return 0;
 981 # endif
 982 }
 983 #endif /* defined (CONFIG_SERIAL_BFIN_CONSOLE) ||
 984                                  defined (CONFIG_EARLY_PRINTK) */
 985
 986 #ifdef CONFIG_SERIAL_BFIN_CONSOLE
 987 static void bfin_serial_console_putchar(struct uart_port *port, int ch)
 988 {
 989         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 990         while (!(UART_GET_LSR(uart) & THRE))
 991                 barrier();
 992         UART_PUT_CHAR(uart, ch);
 993         SSYNC();
 994 }
 995
 996 /*
 997  * Interrupts are disabled on entering
 998  */
 999 static void
1000 bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
1001 {
1002         struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
1003         int flags = 0;
1004
1005         spin_lock_irqsave(&uart->port.lock, flags);
1006         uart_console_write(&uart->port, s, count, bfin_serial_console_putchar);
1007         spin_unlock_irqrestore(&uart->port.lock, flags);
1008
1009 }
1010
1011 static struct console bfin_serial_console = {
1012         .name           = BFIN_SERIAL_NAME,
1013         .write          = bfin_serial_console_write,
1014         .device         = uart_console_device,
1015         .setup          = bfin_serial_console_setup,
1016         .flags          = CON_PRINTBUFFER,
1017         .index          = -1,
1018         .data           = &bfin_serial_reg,
1019 };
1020
1021 static int __init bfin_serial_rs_console_init(void)
1022 {
1023         bfin_serial_init_ports();
1024         register_console(&bfin_serial_console);
1025 #ifdef CONFIG_KGDB_UART
1026         kgdb_entry_state = 0;
1027         init_kgdb_uart();
1028 #endif
1029         return 0;
1030 }
1031 console_initcall(bfin_serial_rs_console_init);
1032
1033 #define BFIN_SERIAL_CONSOLE     &bfin_serial_console
1034 #else
1035 #define BFIN_SERIAL_CONSOLE     NULL
1036 #endif /* CONFIG_SERIAL_BFIN_CONSOLE */
1037
1038
1039 #ifdef CONFIG_EARLY_PRINTK
1040 static __init void early_serial_putc(struct uart_port *port, int ch)
1041 {
1042         unsigned timeout = 0xffff;
1043         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
1044
1045         while ((!(UART_GET_LSR(uart) & THRE)) && --timeout)
1046                 cpu_relax();
1047         UART_PUT_CHAR(uart, ch);
1048 }
1049
1050 static __init void early_serial_write(struct console *con, const char *s,
1051                                         unsigned int n)
1052 {
1053         struct bfin_serial_port *uart = &bfin_serial_ports[con->index];
1054         unsigned int i;
1055
1056         for (i = 0; i < n; i++, s++) {
1057                 if (*s == '\n')
1058                         early_serial_putc(&uart->port, '\r');
1059                 early_serial_putc(&uart->port, *s);
1060         }
1061 }
1062
1063 static struct __init console bfin_early_serial_console = {
1064         .name = "early_BFuart",
1065         .write = early_serial_write,
1066         .device = uart_console_device,
1067         .flags = CON_PRINTBUFFER,
1068         .setup = bfin_serial_console_setup,
1069         .index = -1,
1070         .data  = &bfin_serial_reg,
1071 };
1072
1073 struct console __init *bfin_earlyserial_init(unsigned int port,
1074                                                 unsigned int cflag)
1075 {
1076         struct bfin_serial_port *uart;
1077         struct ktermios t;
1078
1079         if (port == -1 || port >= nr_ports)
1080                 port = 0;
1081         bfin_serial_init_ports();
1082         bfin_early_serial_console.index = port;
1083         uart = &bfin_serial_ports[port];
1084         t.c_cflag = cflag;
1085         t.c_iflag = 0;
1086         t.c_oflag = 0;
1087         t.c_lflag = ICANON;
1088         t.c_line = port;
1089         bfin_serial_set_termios(&uart->port, &t, &t);
1090         return &bfin_early_serial_console;
1091 }
1092
1093 #endif /* CONFIG_SERIAL_BFIN_CONSOLE */
1094
1095 static struct uart_driver bfin_serial_reg = {
1096         .owner                  = THIS_MODULE,
1097         .driver_name            = "bfin-uart",
1098         .dev_name               = BFIN_SERIAL_NAME,
1099         .major                  = BFIN_SERIAL_MAJOR,
1100         .minor                  = BFIN_SERIAL_MINOR,
1101         .nr                     = BFIN_UART_NR_PORTS,
1102         .cons                   = BFIN_SERIAL_CONSOLE,
1103 };
1104
1105 static int bfin_serial_suspend(struct platform_device *dev, pm_message_t state)
1106 {
1107         struct bfin_serial_port *uart = platform_get_drvdata(dev);
1108
1109         if (uart)
1110                 uart_suspend_port(&bfin_serial_reg, &uart->port);
1111
1112         return 0;
1113 }
1114
1115 static int bfin_serial_resume(struct platform_device *dev)
1116 {
1117         struct bfin_serial_port *uart = platform_get_drvdata(dev);
1118
1119         if (uart)
1120                 uart_resume_port(&bfin_serial_reg, &uart->port);
1121
1122         return 0;
1123 }
1124
1125 static int bfin_serial_probe(struct platform_device *dev)
1126 {
1127         struct resource *res = dev->resource;
1128         int i;
1129
1130         for (i = 0; i < dev->num_resources; i++, res++)
1131                 if (res->flags & IORESOURCE_MEM)
1132                         break;
1133
1134         if (i < dev->num_resources) {
1135                 for (i = 0; i < nr_ports; i++, res++) {
1136                         if (bfin_serial_ports[i].port.mapbase != res->start)
1137                                 continue;
1138                         bfin_serial_ports[i].port.dev = &dev->dev;
1139                         uart_add_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
1140                         platform_set_drvdata(dev, &bfin_serial_ports[i]);
1141                 }
1142         }
1143
1144         return 0;
1145 }
1146
1147 static int bfin_serial_remove(struct platform_device *pdev)
1148 {
1149         struct bfin_serial_port *uart = platform_get_drvdata(pdev);
1150
1151
1152 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
1153         gpio_free(uart->cts_pin);
1154         gpio_free(uart->rts_pin);
1155 #endif
1156
1157         platform_set_drvdata(pdev, NULL);
1158
1159         if (uart)
1160                 uart_remove_one_port(&bfin_serial_reg, &uart->port);
1161
1162         return 0;
1163 }
1164
1165 static struct platform_driver bfin_serial_driver = {
1166         .probe          = bfin_serial_probe,
1167         .remove         = bfin_serial_remove,
1168         .suspend        = bfin_serial_suspend,
1169         .resume         = bfin_serial_resume,
1170         .driver         = {
1171                 .name   = "bfin-uart",
1172                 .owner  = THIS_MODULE,
1173         },
1174 };
1175
1176 static int __init bfin_serial_init(void)
1177 {
1178         int ret;
1179 #ifdef CONFIG_KGDB_UART
1180         struct bfin_serial_port *uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
1181         struct ktermios t;
1182 #endif
1183
1184         pr_info("Serial: Blackfin serial driver\n");
1185
1186         bfin_serial_init_ports();
1187
1188         ret = uart_register_driver(&bfin_serial_reg);
1189         if (ret == 0) {
1190                 ret = platform_driver_register(&bfin_serial_driver);
1191                 if (ret) {
1192                         pr_debug("uart register failed\n");
1193                         uart_unregister_driver(&bfin_serial_reg);
1194                 }
1195         }
1196 #ifdef CONFIG_KGDB_UART
1197         if (uart->port.cons->index != CONFIG_KGDB_UART_PORT) {
1198                 request_irq(uart->port.irq, bfin_serial_rx_int,
1199                         IRQF_DISABLED, "BFIN_UART_RX", uart);
1200                 pr_info("Request irq for kgdb uart port\n");
1201                 UART_SET_IER(uart, ERBFI);
1202                 SSYNC();
1203                 t.c_cflag = CS8|B57600;
1204                 t.c_iflag = 0;
1205                 t.c_oflag = 0;
1206                 t.c_lflag = ICANON;
1207                 t.c_line = CONFIG_KGDB_UART_PORT;
1208                 bfin_serial_set_termios(&uart->port, &t, &t);
1209         }
1210 #endif
1211         return ret;
1212 }
1213
1214 static void __exit bfin_serial_exit(void)
1215 {
1216         platform_driver_unregister(&bfin_serial_driver);
1217         uart_unregister_driver(&bfin_serial_reg);
1218 }
1219
1220 module_init(bfin_serial_init);
1221 module_exit(bfin_serial_exit);
1222
1223 MODULE_AUTHOR("Aubrey.Li <aubrey.li@analog.com>");
1224 MODULE_DESCRIPTION("Blackfin generic serial port driver");
1225 MODULE_LICENSE("GPL");
1226 MODULE_ALIAS_CHARDEV_MAJOR(BFIN_SERIAL_MAJOR);
1227 MODULE_ALIAS("platform:bfin-uart");