drivers/serial/bfin_5xx.c

   1 /*
   2  * Blackfin On-Chip Serial Driver
   3  *
   4  * Copyright 2006-2008 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 <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 static struct bfin_serial_port bfin_serial_ports[BFIN_UART_NR_PORTS];
  46 static int nr_active_ports = ARRAY_SIZE(bfin_serial_resource);
  47
  48 /*
  49  * Setup for console. Argument comes from the menuconfig
  50  */
  51 #define DMA_RX_XCOUNT           512
  52 #define DMA_RX_YCOUNT           (PAGE_SIZE / DMA_RX_XCOUNT)
  53
  54 #define DMA_RX_FLUSH_JIFFIES    (HZ / 50)
  55 #define CTS_CHECK_JIFFIES       (HZ / 50)
  56
  57 #ifdef CONFIG_SERIAL_BFIN_DMA
  58 static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
  59 #else
  60 static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
  61 #endif
  62
  63 static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
  64
  65 /*
  66  * interrupts are disabled on entry
  67  */
  68 static void bfin_serial_stop_tx(struct uart_port *port)
  69 {
  70         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
  71         struct circ_buf *xmit = &uart->port.info->xmit;
  72
  73         while (!(UART_GET_LSR(uart) & TEMT))
  74                 cpu_relax();
  75
  76 #ifdef CONFIG_SERIAL_BFIN_DMA
  77         disable_dma(uart->tx_dma_channel);
  78         xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
  79         uart->port.icount.tx += uart->tx_count;
  80         uart->tx_count = 0;
  81         uart->tx_done = 1;
  82 #else
  83 #ifdef CONFIG_BF54x
  84         /* Clear TFI bit */
  85         UART_PUT_LSR(uart, TFI);
  86 #endif
  87         UART_CLEAR_IER(uart, ETBEI);
  88 #endif
  89 }
  90
  91 /*
  92  * port is locked and interrupts are disabled
  93  */
  94 static void bfin_serial_start_tx(struct uart_port *port)
  95 {
  96         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
  97
  98 #ifdef CONFIG_SERIAL_BFIN_DMA
  99         if (uart->tx_done)
 100                 bfin_serial_dma_tx_chars(uart);
 101 #else
 102         UART_SET_IER(uart, ETBEI);
 103         bfin_serial_tx_chars(uart);
 104 #endif
 105 }
 106
 107 /*
 108  * Interrupts are enabled
 109  */
 110 static void bfin_serial_stop_rx(struct uart_port *port)
 111 {
 112         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 113 #ifdef CONFIG_KGDB_UART
 114         if (uart->port.line != CONFIG_KGDB_UART_PORT)
 115 #endif
 116         UART_CLEAR_IER(uart, ERBFI);
 117 }
 118
 119 /*
 120  * Set the modem control timer to fire immediately.
 121  */
 122 static void bfin_serial_enable_ms(struct uart_port *port)
 123 {
 124 }
 125
 126 #ifdef CONFIG_KGDB_UART
 127 static int kgdb_entry_state;
 128
 129 void kgdb_put_debug_char(int chr)
 130 {
 131         struct bfin_serial_port *uart;
 132
 133         if (CONFIG_KGDB_UART_PORT < 0
 134                 || CONFIG_KGDB_UART_PORT >= BFIN_UART_NR_PORTS)
 135                 uart = &bfin_serial_ports[0];
 136         else
 137                 uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
 138
 139         while (!(UART_GET_LSR(uart) & THRE)) {
 140                 SSYNC();
 141         }
 142
 143         UART_CLEAR_DLAB(uart);
 144         UART_PUT_CHAR(uart, (unsigned char)chr);
 145         SSYNC();
 146 }
 147
 148 int kgdb_get_debug_char(void)
 149 {
 150         struct bfin_serial_port *uart;
 151         unsigned char chr;
 152
 153         if (CONFIG_KGDB_UART_PORT < 0
 154                 || CONFIG_KGDB_UART_PORT >= BFIN_UART_NR_PORTS)
 155                 uart = &bfin_serial_ports[0];
 156         else
 157                 uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
 158
 159         while(!(UART_GET_LSR(uart) & DR)) {
 160                 SSYNC();
 161         }
 162         UART_CLEAR_DLAB(uart);
 163         chr = UART_GET_CHAR(uart);
 164         SSYNC();
 165
 166         return chr;
 167 }
 168 #endif
 169
 170 #if ANOMALY_05000363 && defined(CONFIG_SERIAL_BFIN_PIO)
 171 # define UART_GET_ANOMALY_THRESHOLD(uart)    ((uart)->anomaly_threshold)
 172 # define UART_SET_ANOMALY_THRESHOLD(uart, v) ((uart)->anomaly_threshold = (v))
 173 #else
 174 # define UART_GET_ANOMALY_THRESHOLD(uart)    0
 175 # define UART_SET_ANOMALY_THRESHOLD(uart, v)
 176 #endif
 177
 178 #ifdef CONFIG_SERIAL_BFIN_PIO
 179 static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
 180 {
 181         struct tty_struct *tty = uart->port.info->port.tty;
 182         unsigned int status, ch, flg;
 183         static struct timeval anomaly_start = { .tv_sec = 0 };
 184
 185         status = UART_GET_LSR(uart);
 186         UART_CLEAR_LSR(uart);
 187
 188         ch = UART_GET_CHAR(uart);
 189         uart->port.icount.rx++;
 190
 191 #ifdef CONFIG_KGDB_UART
 192         if (uart->port.line == CONFIG_KGDB_UART_PORT) {
 193                 struct pt_regs *regs = get_irq_regs();
 194                 if (uart->port.cons->index == CONFIG_KGDB_UART_PORT && ch == 0x1) { /* Ctrl + A */
 195                         kgdb_breakkey_pressed(regs);
 196                         return;
 197                 } else if (kgdb_entry_state == 0 && ch == '$') {/* connection from KGDB */
 198                         kgdb_entry_state = 1;
 199                 } else if (kgdb_entry_state == 1 && ch == 'q') {
 200                         kgdb_entry_state = 0;
 201                         kgdb_breakkey_pressed(regs);
 202                         return;
 203                 } else if (ch == 0x3) {/* Ctrl + C */
 204                         kgdb_entry_state = 0;
 205                         kgdb_breakkey_pressed(regs);
 206                         return;
 207                 } else {
 208                         kgdb_entry_state = 0;
 209                 }
 210         }
 211 #endif
 212
 213         if (ANOMALY_05000363) {
 214                 /* The BF533 (and BF561) family of processors have a nice anomaly
 215                  * where they continuously generate characters for a "single" break.
 216                  * We have to basically ignore this flood until the "next" valid
 217                  * character comes across.  Due to the nature of the flood, it is
 218                  * not possible to reliably catch bytes that are sent too quickly
 219                  * after this break.  So application code talking to the Blackfin
 220                  * which sends a break signal must allow at least 1.5 character
 221                  * times after the end of the break for things to stabilize.  This
 222                  * timeout was picked as it must absolutely be larger than 1
 223                  * character time +/- some percent.  So 1.5 sounds good.  All other
 224                  * Blackfin families operate properly.  Woo.
 225                  */
 226                 if (anomaly_start.tv_sec) {
 227                         struct timeval curr;
 228                         suseconds_t usecs;
 229
 230                         if ((~ch & (~ch + 1)) & 0xff)
 231                                 goto known_good_char;
 232
 233                         do_gettimeofday(&curr);
 234                         if (curr.tv_sec - anomaly_start.tv_sec > 1)
 235                                 goto known_good_char;
 236
 237                         usecs = 0;
 238                         if (curr.tv_sec != anomaly_start.tv_sec)
 239                                 usecs += USEC_PER_SEC;
 240                         usecs += curr.tv_usec - anomaly_start.tv_usec;
 241
 242                         if (usecs > UART_GET_ANOMALY_THRESHOLD(uart))
 243                                 goto known_good_char;
 244
 245                         if (ch)
 246                                 anomaly_start.tv_sec = 0;
 247                         else
 248                                 anomaly_start = curr;
 249
 250                         return;
 251
 252  known_good_char:
 253                         anomaly_start.tv_sec = 0;
 254                 }
 255         }
 256
 257         if (status & BI) {
 258                 if (ANOMALY_05000363)
 259                         if (bfin_revid() < 5)
 260                                 do_gettimeofday(&anomaly_start);
 261                 uart->port.icount.brk++;
 262                 if (uart_handle_break(&uart->port))
 263                         goto ignore_char;
 264                 status &= ~(PE | FE);
 265         }
 266         if (status & PE)
 267                 uart->port.icount.parity++;
 268         if (status & OE)
 269                 uart->port.icount.overrun++;
 270         if (status & FE)
 271                 uart->port.icount.frame++;
 272
 273         status &= uart->port.read_status_mask;
 274
 275         if (status & BI)
 276                 flg = TTY_BREAK;
 277         else if (status & PE)
 278                 flg = TTY_PARITY;
 279         else if (status & FE)
 280                 flg = TTY_FRAME;
 281         else
 282                 flg = TTY_NORMAL;
 283
 284         if (uart_handle_sysrq_char(&uart->port, ch))
 285                 goto ignore_char;
 286
 287         uart_insert_char(&uart->port, status, OE, ch, flg);
 288
 289  ignore_char:
 290         tty_flip_buffer_push(tty);
 291 }
 292
 293 static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
 294 {
 295         struct circ_buf *xmit = &uart->port.info->xmit;
 296
 297         /*
 298          * Check the modem control lines before
 299          * transmitting anything.
 300          */
 301         bfin_serial_mctrl_check(uart);
 302
 303         if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
 304                 bfin_serial_stop_tx(&uart->port);
 305                 return;
 306         }
 307
 308         if (uart->port.x_char) {
 309                 UART_PUT_CHAR(uart, uart->port.x_char);
 310                 uart->port.icount.tx++;
 311                 uart->port.x_char = 0;
 312         }
 313
 314         while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
 315                 UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
 316                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 317                 uart->port.icount.tx++;
 318                 SSYNC();
 319         }
 320
 321         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 322                 uart_write_wakeup(&uart->port);
 323 }
 324
 325 static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
 326 {
 327         struct bfin_serial_port *uart = dev_id;
 328
 329         spin_lock(&uart->port.lock);
 330         while (UART_GET_LSR(uart) & DR)
 331                 bfin_serial_rx_chars(uart);
 332         spin_unlock(&uart->port.lock);
 333
 334         return IRQ_HANDLED;
 335 }
 336
 337 static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
 338 {
 339         struct bfin_serial_port *uart = dev_id;
 340
 341         spin_lock(&uart->port.lock);
 342         if (UART_GET_LSR(uart) & THRE)
 343                 bfin_serial_tx_chars(uart);
 344         spin_unlock(&uart->port.lock);
 345
 346         return IRQ_HANDLED;
 347 }
 348 #endif
 349
 350 #ifdef CONFIG_SERIAL_BFIN_DMA
 351 static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
 352 {
 353         struct circ_buf *xmit = &uart->port.info->xmit;
 354
 355         uart->tx_done = 0;
 356
 357         /*
 358          * Check the modem control lines before
 359          * transmitting anything.
 360          */
 361         bfin_serial_mctrl_check(uart);
 362
 363         if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
 364                 uart->tx_count = 0;
 365                 uart->tx_done = 1;
 366                 return;
 367         }
 368
 369         if (uart->port.x_char) {
 370                 UART_PUT_CHAR(uart, uart->port.x_char);
 371                 uart->port.icount.tx++;
 372                 uart->port.x_char = 0;
 373         }
 374
 375         uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
 376         if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
 377                 uart->tx_count = UART_XMIT_SIZE - xmit->tail;
 378         blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
 379                                         (unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
 380         set_dma_config(uart->tx_dma_channel,
 381                 set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
 382                         INTR_ON_BUF,
 383                         DIMENSION_LINEAR,
 384                         DATA_SIZE_8,
 385                         DMA_SYNC_RESTART));
 386         set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
 387         set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
 388         set_dma_x_modify(uart->tx_dma_channel, 1);
 389         enable_dma(uart->tx_dma_channel);
 390
 391         UART_SET_IER(uart, ETBEI);
 392 }
 393
 394 static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
 395 {
 396         struct tty_struct *tty = uart->port.info->port.tty;
 397         int i, flg, status;
 398
 399         status = UART_GET_LSR(uart);
 400         UART_CLEAR_LSR(uart);
 401
 402         uart->port.icount.rx +=
 403                 CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
 404                 UART_XMIT_SIZE);
 405
 406         if (status & BI) {
 407                 uart->port.icount.brk++;
 408                 if (uart_handle_break(&uart->port))
 409                         goto dma_ignore_char;
 410                 status &= ~(PE | FE);
 411         }
 412         if (status & PE)
 413                 uart->port.icount.parity++;
 414         if (status & OE)
 415                 uart->port.icount.overrun++;
 416         if (status & FE)
 417                 uart->port.icount.frame++;
 418
 419         status &= uart->port.read_status_mask;
 420
 421         if (status & BI)
 422                 flg = TTY_BREAK;
 423         else if (status & PE)
 424                 flg = TTY_PARITY;
 425         else if (status & FE)
 426                 flg = TTY_FRAME;
 427         else
 428                 flg = TTY_NORMAL;
 429
 430         for (i = uart->rx_dma_buf.tail; i != uart->rx_dma_buf.head; i++) {
 431                 if (i >= UART_XMIT_SIZE)
 432                         i = 0;
 433                 if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
 434                         uart_insert_char(&uart->port, status, OE,
 435                                 uart->rx_dma_buf.buf[i], flg);
 436         }
 437
 438  dma_ignore_char:
 439         tty_flip_buffer_push(tty);
 440 }
 441
 442 void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
 443 {
 444         int x_pos, pos;
 445
 446         uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
 447         x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
 448         uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
 449         if (uart->rx_dma_nrows == DMA_RX_YCOUNT)
 450                 uart->rx_dma_nrows = 0;
 451         x_pos = DMA_RX_XCOUNT - x_pos;
 452         if (x_pos == DMA_RX_XCOUNT)
 453                 x_pos = 0;
 454
 455         pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
 456         if (pos != uart->rx_dma_buf.tail) {
 457                 uart->rx_dma_buf.head = pos;
 458                 bfin_serial_dma_rx_chars(uart);
 459                 uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
 460         }
 461
 462         mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
 463 }
 464
 465 static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
 466 {
 467         struct bfin_serial_port *uart = dev_id;
 468         struct circ_buf *xmit = &uart->port.info->xmit;
 469
 470         spin_lock(&uart->port.lock);
 471         if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
 472                 disable_dma(uart->tx_dma_channel);
 473                 clear_dma_irqstat(uart->tx_dma_channel);
 474                 UART_CLEAR_IER(uart, ETBEI);
 475                 xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
 476                 uart->port.icount.tx += uart->tx_count;
 477
 478                 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 479                         uart_write_wakeup(&uart->port);
 480
 481                 bfin_serial_dma_tx_chars(uart);
 482         }
 483
 484         spin_unlock(&uart->port.lock);
 485         return IRQ_HANDLED;
 486 }
 487
 488 static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
 489 {
 490         struct bfin_serial_port *uart = dev_id;
 491         unsigned short irqstat;
 492
 493         spin_lock(&uart->port.lock);
 494         irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
 495         clear_dma_irqstat(uart->rx_dma_channel);
 496         spin_unlock(&uart->port.lock);
 497
 498         mod_timer(&(uart->rx_dma_timer), jiffies);
 499
 500         return IRQ_HANDLED;
 501 }
 502 #endif
 503
 504 /*
 505  * Return TIOCSER_TEMT when transmitter is not busy.
 506  */
 507 static unsigned int bfin_serial_tx_empty(struct uart_port *port)
 508 {
 509         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 510         unsigned short lsr;
 511
 512         lsr = UART_GET_LSR(uart);
 513         if (lsr & TEMT)
 514                 return TIOCSER_TEMT;
 515         else
 516                 return 0;
 517 }
 518
 519 static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
 520 {
 521 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 522         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 523         if (uart->cts_pin < 0)
 524                 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 525
 526         if (UART_GET_CTS(uart))
 527                 return TIOCM_DSR | TIOCM_CAR;
 528         else
 529 #endif
 530                 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 531 }
 532
 533 static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
 534 {
 535 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 536         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 537         if (uart->rts_pin < 0)
 538                 return;
 539
 540         if (mctrl & TIOCM_RTS)
 541                 UART_CLEAR_RTS(uart);
 542         else
 543                 UART_SET_RTS(uart);
 544 #endif
 545 }
 546
 547 /*
 548  * Handle any change of modem status signal since we were last called.
 549  */
 550 static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
 551 {
 552 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 553         unsigned int status;
 554         struct uart_info *info = uart->port.info;
 555         struct tty_struct *tty = info->port.tty;
 556
 557         status = bfin_serial_get_mctrl(&uart->port);
 558         uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
 559         if (!(status & TIOCM_CTS)) {
 560                 tty->hw_stopped = 1;
 561                 uart->cts_timer.data = (unsigned long)(uart);
 562                 uart->cts_timer.function = (void *)bfin_serial_mctrl_check;
 563                 uart->cts_timer.expires = jiffies + CTS_CHECK_JIFFIES;
 564                 add_timer(&(uart->cts_timer));
 565         } else {
 566                 tty->hw_stopped = 0;
 567         }
 568 #endif
 569 }
 570
 571 /*
 572  * Interrupts are always disabled.
 573  */
 574 static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
 575 {
 576         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 577         u16 lcr = UART_GET_LCR(uart);
 578         if (break_state)
 579                 lcr |= SB;
 580         else
 581                 lcr &= ~SB;
 582         UART_PUT_LCR(uart, lcr);
 583         SSYNC();
 584 }
 585
 586 static int bfin_serial_startup(struct uart_port *port)
 587 {
 588         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 589
 590 #ifdef CONFIG_SERIAL_BFIN_DMA
 591         dma_addr_t dma_handle;
 592
 593         if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
 594                 printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
 595                 return -EBUSY;
 596         }
 597
 598         if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
 599                 printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
 600                 free_dma(uart->rx_dma_channel);
 601                 return -EBUSY;
 602         }
 603
 604         set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
 605         set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);
 606
 607         uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
 608         uart->rx_dma_buf.head = 0;
 609         uart->rx_dma_buf.tail = 0;
 610         uart->rx_dma_nrows = 0;
 611
 612         set_dma_config(uart->rx_dma_channel,
 613                 set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
 614                                 INTR_ON_ROW, DIMENSION_2D,
 615                                 DATA_SIZE_8,
 616                                 DMA_SYNC_RESTART));
 617         set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
 618         set_dma_x_modify(uart->rx_dma_channel, 1);
 619         set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
 620         set_dma_y_modify(uart->rx_dma_channel, 1);
 621         set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
 622         enable_dma(uart->rx_dma_channel);
 623
 624         uart->rx_dma_timer.data = (unsigned long)(uart);
 625         uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
 626         uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
 627         add_timer(&(uart->rx_dma_timer));
 628 #else
 629         if (request_irq(uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED,
 630              "BFIN_UART_RX", uart)) {
 631 # ifdef CONFIG_KGDB_UART
 632                 if (uart->port.line != CONFIG_KGDB_UART_PORT) {
 633 # endif
 634                 printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
 635                 return -EBUSY;
 636 # ifdef CONFIG_KGDB_UART
 637                 }
 638 # endif
 639         }
 640
 641         if (request_irq
 642             (uart->port.irq+1, bfin_serial_tx_int, IRQF_DISABLED,
 643              "BFIN_UART_TX", uart)) {
 644                 printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
 645                 free_irq(uart->port.irq, uart);
 646                 return -EBUSY;
 647         }
 648 #endif
 649         UART_SET_IER(uart, ERBFI);
 650         return 0;
 651 }
 652
 653 static void bfin_serial_shutdown(struct uart_port *port)
 654 {
 655         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 656
 657 #ifdef CONFIG_SERIAL_BFIN_DMA
 658         disable_dma(uart->tx_dma_channel);
 659         free_dma(uart->tx_dma_channel);
 660         disable_dma(uart->rx_dma_channel);
 661         free_dma(uart->rx_dma_channel);
 662         del_timer(&(uart->rx_dma_timer));
 663         dma_free_coherent(NULL, PAGE_SIZE, uart->rx_dma_buf.buf, 0);
 664 #else
 665 #ifdef  CONFIG_KGDB_UART
 666         if (uart->port.line != CONFIG_KGDB_UART_PORT)
 667 #endif
 668         free_irq(uart->port.irq, uart);
 669         free_irq(uart->port.irq+1, uart);
 670 #endif
 671 }
 672
 673 static void
 674 bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
 675                    struct ktermios *old)
 676 {
 677         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 678         unsigned long flags;
 679         unsigned int baud, quot;
 680         unsigned short val, ier, lcr = 0;
 681
 682         switch (termios->c_cflag & CSIZE) {
 683         case CS8:
 684                 lcr = WLS(8);
 685                 break;
 686         case CS7:
 687                 lcr = WLS(7);
 688                 break;
 689         case CS6:
 690                 lcr = WLS(6);
 691                 break;
 692         case CS5:
 693                 lcr = WLS(5);
 694                 break;
 695         default:
 696                 printk(KERN_ERR "%s: word lengh not supported\n",
 697                         __func__);
 698         }
 699
 700         if (termios->c_cflag & CSTOPB)
 701                 lcr |= STB;
 702         if (termios->c_cflag & PARENB)
 703                 lcr |= PEN;
 704         if (!(termios->c_cflag & PARODD))
 705                 lcr |= EPS;
 706         if (termios->c_cflag & CMSPAR)
 707                 lcr |= STP;
 708
 709         port->read_status_mask = OE;
 710         if (termios->c_iflag & INPCK)
 711                 port->read_status_mask |= (FE | PE);
 712         if (termios->c_iflag & (BRKINT | PARMRK))
 713                 port->read_status_mask |= BI;
 714
 715         /*
 716          * Characters to ignore
 717          */
 718         port->ignore_status_mask = 0;
 719         if (termios->c_iflag & IGNPAR)
 720                 port->ignore_status_mask |= FE | PE;
 721         if (termios->c_iflag & IGNBRK) {
 722                 port->ignore_status_mask |= BI;
 723                 /*
 724                  * If we're ignoring parity and break indicators,
 725                  * ignore overruns too (for real raw support).
 726                  */
 727                 if (termios->c_iflag & IGNPAR)
 728                         port->ignore_status_mask |= OE;
 729         }
 730
 731         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
 732         quot = uart_get_divisor(port, baud);
 733         spin_lock_irqsave(&uart->port.lock, flags);
 734
 735         UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
 736
 737         /* Disable UART */
 738         ier = UART_GET_IER(uart);
 739         UART_DISABLE_INTS(uart);
 740
 741         /* Set DLAB in LCR to Access DLL and DLH */
 742         UART_SET_DLAB(uart);
 743
 744         UART_PUT_DLL(uart, quot & 0xFF);
 745         UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
 746         SSYNC();
 747
 748         /* Clear DLAB in LCR to Access THR RBR IER */
 749         UART_CLEAR_DLAB(uart);
 750
 751         UART_PUT_LCR(uart, lcr);
 752
 753         /* Enable UART */
 754         UART_ENABLE_INTS(uart, ier);
 755
 756         val = UART_GET_GCTL(uart);
 757         val |= UCEN;
 758         UART_PUT_GCTL(uart, val);
 759
 760         spin_unlock_irqrestore(&uart->port.lock, flags);
 761 }
 762
 763 static const char *bfin_serial_type(struct uart_port *port)
 764 {
 765         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 766
 767         return uart->port.type == PORT_BFIN ? "BFIN-UART" : NULL;
 768 }
 769
 770 /*
 771  * Release the memory region(s) being used by 'port'.
 772  */
 773 static void bfin_serial_release_port(struct uart_port *port)
 774 {
 775 }
 776
 777 /*
 778  * Request the memory region(s) being used by 'port'.
 779  */
 780 static int bfin_serial_request_port(struct uart_port *port)
 781 {
 782         return 0;
 783 }
 784
 785 /*
 786  * Configure/autoconfigure the port.
 787  */
 788 static void bfin_serial_config_port(struct uart_port *port, int flags)
 789 {
 790         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 791
 792         if (flags & UART_CONFIG_TYPE &&
 793             bfin_serial_request_port(&uart->port) == 0)
 794                 uart->port.type = PORT_BFIN;
 795 }
 796
 797 /*
 798  * Verify the new serial_struct (for TIOCSSERIAL).
 799  * The only change we allow are to the flags and type, and
 800  * even then only between PORT_BFIN and PORT_UNKNOWN
 801  */
 802 static int
 803 bfin_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
 804 {
 805         return 0;
 806 }
 807
 808 /*
 809  * Enable the IrDA function if tty->ldisc.num is N_IRDA.
 810  * In other cases, disable IrDA function.
 811  */
 812 static void bfin_serial_set_ldisc(struct uart_port *port)
 813 {
 814         int line = port->line;
 815         unsigned short val;
 816
 817         if (line >= port->info->port.tty->driver->num)
 818                 return;
 819
 820         switch (port->info->port.tty->termios->c_line) {
 821         case N_IRDA:
 822                 val = UART_GET_GCTL(&bfin_serial_ports[line]);
 823                 val |= (IREN | RPOLC);
 824                 UART_PUT_GCTL(&bfin_serial_ports[line], val);
 825                 break;
 826         default:
 827                 val = UART_GET_GCTL(&bfin_serial_ports[line]);
 828                 val &= ~(IREN | RPOLC);
 829                 UART_PUT_GCTL(&bfin_serial_ports[line], val);
 830         }
 831 }
 832
 833 static struct uart_ops bfin_serial_pops = {
 834         .tx_empty       = bfin_serial_tx_empty,
 835         .set_mctrl      = bfin_serial_set_mctrl,
 836         .get_mctrl      = bfin_serial_get_mctrl,
 837         .stop_tx        = bfin_serial_stop_tx,
 838         .start_tx       = bfin_serial_start_tx,
 839         .stop_rx        = bfin_serial_stop_rx,
 840         .enable_ms      = bfin_serial_enable_ms,
 841         .break_ctl      = bfin_serial_break_ctl,
 842         .startup        = bfin_serial_startup,
 843         .shutdown       = bfin_serial_shutdown,
 844         .set_termios    = bfin_serial_set_termios,
 845         .set_ldisc      = bfin_serial_set_ldisc,
 846         .type           = bfin_serial_type,
 847         .release_port   = bfin_serial_release_port,
 848         .request_port   = bfin_serial_request_port,
 849         .config_port    = bfin_serial_config_port,
 850         .verify_port    = bfin_serial_verify_port,
 851 };
 852
 853 static void __init bfin_serial_init_ports(void)
 854 {
 855         static int first = 1;
 856         int i;
 857
 858         if (!first)
 859                 return;
 860         first = 0;
 861
 862         for (i = 0; i < nr_active_ports; i++) {
 863                 bfin_serial_ports[i].port.uartclk   = get_sclk();
 864                 bfin_serial_ports[i].port.ops       = &bfin_serial_pops;
 865                 bfin_serial_ports[i].port.line      = i;
 866                 bfin_serial_ports[i].port.iotype    = UPIO_MEM;
 867                 bfin_serial_ports[i].port.membase   =
 868                         (void __iomem *)bfin_serial_resource[i].uart_base_addr;
 869                 bfin_serial_ports[i].port.mapbase   =
 870                         bfin_serial_resource[i].uart_base_addr;
 871                 bfin_serial_ports[i].port.irq       =
 872                         bfin_serial_resource[i].uart_irq;
 873                 bfin_serial_ports[i].port.flags     = UPF_BOOT_AUTOCONF;
 874 #ifdef CONFIG_SERIAL_BFIN_DMA
 875                 bfin_serial_ports[i].tx_done        = 1;
 876                 bfin_serial_ports[i].tx_count       = 0;
 877                 bfin_serial_ports[i].tx_dma_channel =
 878                         bfin_serial_resource[i].uart_tx_dma_channel;
 879                 bfin_serial_ports[i].rx_dma_channel =
 880                         bfin_serial_resource[i].uart_rx_dma_channel;
 881                 init_timer(&(bfin_serial_ports[i].rx_dma_timer));
 882 #endif
 883 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
 884                 init_timer(&(bfin_serial_ports[i].cts_timer));
 885                 bfin_serial_ports[i].cts_pin        =
 886                         bfin_serial_resource[i].uart_cts_pin;
 887                 bfin_serial_ports[i].rts_pin        =
 888                         bfin_serial_resource[i].uart_rts_pin;
 889 #endif
 890                 bfin_serial_hw_init(&bfin_serial_ports[i]);
 891         }
 892
 893 }
 894
 895 #ifdef CONFIG_SERIAL_BFIN_CONSOLE
 896 /*
 897  * If the port was already initialised (eg, by a boot loader),
 898  * try to determine the current setup.
 899  */
 900 static void __init
 901 bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
 902                            int *parity, int *bits)
 903 {
 904         unsigned short status;
 905
 906         status = UART_GET_IER(uart) & (ERBFI | ETBEI);
 907         if (status == (ERBFI | ETBEI)) {
 908                 /* ok, the port was enabled */
 909                 u16 lcr, dlh, dll;
 910
 911                 lcr = UART_GET_LCR(uart);
 912
 913                 *parity = 'n';
 914                 if (lcr & PEN) {
 915                         if (lcr & EPS)
 916                                 *parity = 'e';
 917                         else
 918                                 *parity = 'o';
 919                 }
 920                 switch (lcr & 0x03) {
 921                         case 0: *bits = 5; break;
 922                         case 1: *bits = 6; break;
 923                         case 2: *bits = 7; break;
 924                         case 3: *bits = 8; break;
 925                 }
 926                 /* Set DLAB in LCR to Access DLL and DLH */
 927                 UART_SET_DLAB(uart);
 928
 929                 dll = UART_GET_DLL(uart);
 930                 dlh = UART_GET_DLH(uart);
 931
 932                 /* Clear DLAB in LCR to Access THR RBR IER */
 933                 UART_CLEAR_DLAB(uart);
 934
 935                 *baud = get_sclk() / (16*(dll | dlh << 8));
 936         }
 937         pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __func__, *baud, *parity, *bits);
 938 }
 939 #endif
 940
 941 #if defined(CONFIG_SERIAL_BFIN_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
 942 static struct uart_driver bfin_serial_reg;
 943
 944 static int __init
 945 bfin_serial_console_setup(struct console *co, char *options)
 946 {
 947         struct bfin_serial_port *uart;
 948 # ifdef CONFIG_SERIAL_BFIN_CONSOLE
 949         int baud = 57600;
 950         int bits = 8;
 951         int parity = 'n';
 952 #  ifdef CONFIG_SERIAL_BFIN_CTSRTS
 953         int flow = 'r';
 954 #  else
 955         int flow = 'n';
 956 #  endif
 957 # endif
 958
 959         /*
 960          * Check whether an invalid uart number has been specified, and
 961          * if so, search for the first available port that does have
 962          * console support.
 963          */
 964         if (co->index == -1 || co->index >= nr_active_ports)
 965                 co->index = 0;
 966         uart = &bfin_serial_ports[co->index];
 967
 968 # ifdef CONFIG_SERIAL_BFIN_CONSOLE
 969         if (options)
 970                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 971         else
 972                 bfin_serial_console_get_options(uart, &baud, &parity, &bits);
 973
 974         return uart_set_options(&uart->port, co, baud, parity, bits, flow);
 975 # else
 976         return 0;
 977 # endif
 978 }
 979 #endif /* defined (CONFIG_SERIAL_BFIN_CONSOLE) ||
 980                                  defined (CONFIG_EARLY_PRINTK) */
 981
 982 #ifdef CONFIG_SERIAL_BFIN_CONSOLE
 983 static void bfin_serial_console_putchar(struct uart_port *port, int ch)
 984 {
 985         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
 986         while (!(UART_GET_LSR(uart) & THRE))
 987                 barrier();
 988         UART_PUT_CHAR(uart, ch);
 989         SSYNC();
 990 }
 991
 992 /*
 993  * Interrupts are disabled on entering
 994  */
 995 static void
 996 bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
 997 {
 998         struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
 999         int flags = 0;
1000
1001         spin_lock_irqsave(&uart->port.lock, flags);
1002         uart_console_write(&uart->port, s, count, bfin_serial_console_putchar);
1003         spin_unlock_irqrestore(&uart->port.lock, flags);
1004
1005 }
1006
1007 static struct console bfin_serial_console = {
1008         .name           = BFIN_SERIAL_NAME,
1009         .write          = bfin_serial_console_write,
1010         .device         = uart_console_device,
1011         .setup          = bfin_serial_console_setup,
1012         .flags          = CON_PRINTBUFFER,
1013         .index          = -1,
1014         .data           = &bfin_serial_reg,
1015 };
1016
1017 static int __init bfin_serial_rs_console_init(void)
1018 {
1019         bfin_serial_init_ports();
1020         register_console(&bfin_serial_console);
1021 #ifdef CONFIG_KGDB_UART
1022         kgdb_entry_state = 0;
1023         init_kgdb_uart();
1024 #endif
1025         return 0;
1026 }
1027 console_initcall(bfin_serial_rs_console_init);
1028
1029 #define BFIN_SERIAL_CONSOLE     &bfin_serial_console
1030 #else
1031 #define BFIN_SERIAL_CONSOLE     NULL
1032 #endif /* CONFIG_SERIAL_BFIN_CONSOLE */
1033
1034
1035 #ifdef CONFIG_EARLY_PRINTK
1036 static __init void early_serial_putc(struct uart_port *port, int ch)
1037 {
1038         unsigned timeout = 0xffff;
1039         struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
1040
1041         while ((!(UART_GET_LSR(uart) & THRE)) && --timeout)
1042                 cpu_relax();
1043         UART_PUT_CHAR(uart, ch);
1044 }
1045
1046 static __init void early_serial_write(struct console *con, const char *s,
1047                                         unsigned int n)
1048 {
1049         struct bfin_serial_port *uart = &bfin_serial_ports[con->index];
1050         unsigned int i;
1051
1052         for (i = 0; i < n; i++, s++) {
1053                 if (*s == '\n')
1054                         early_serial_putc(&uart->port, '\r');
1055                 early_serial_putc(&uart->port, *s);
1056         }
1057 }
1058
1059 static struct __initdata console bfin_early_serial_console = {
1060         .name = "early_BFuart",
1061         .write = early_serial_write,
1062         .device = uart_console_device,
1063         .flags = CON_PRINTBUFFER,
1064         .setup = bfin_serial_console_setup,
1065         .index = -1,
1066         .data  = &bfin_serial_reg,
1067 };
1068
1069 struct console __init *bfin_earlyserial_init(unsigned int port,
1070                                                 unsigned int cflag)
1071 {
1072         struct bfin_serial_port *uart;
1073         struct ktermios t;
1074
1075         if (port == -1 || port >= nr_active_ports)
1076                 port = 0;
1077         bfin_serial_init_ports();
1078         bfin_early_serial_console.index = port;
1079         uart = &bfin_serial_ports[port];
1080         t.c_cflag = cflag;
1081         t.c_iflag = 0;
1082         t.c_oflag = 0;
1083         t.c_lflag = ICANON;
1084         t.c_line = port;
1085         bfin_serial_set_termios(&uart->port, &t, &t);
1086         return &bfin_early_serial_console;
1087 }
1088
1089 #endif /* CONFIG_SERIAL_BFIN_CONSOLE */
1090
1091 static struct uart_driver bfin_serial_reg = {
1092         .owner                  = THIS_MODULE,
1093         .driver_name            = "bfin-uart",
1094         .dev_name               = BFIN_SERIAL_NAME,
1095         .major                  = BFIN_SERIAL_MAJOR,
1096         .minor                  = BFIN_SERIAL_MINOR,
1097         .nr                     = BFIN_UART_NR_PORTS,
1098         .cons                   = BFIN_SERIAL_CONSOLE,
1099 };
1100
1101 static int bfin_serial_suspend(struct platform_device *dev, pm_message_t state)
1102 {
1103         int i;
1104
1105         for (i = 0; i < nr_active_ports; i++) {
1106                 if (bfin_serial_ports[i].port.dev != &dev->dev)
1107                         continue;
1108                 uart_suspend_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
1109         }
1110
1111         return 0;
1112 }
1113
1114 static int bfin_serial_resume(struct platform_device *dev)
1115 {
1116         int i;
1117
1118         for (i = 0; i < nr_active_ports; i++) {
1119                 if (bfin_serial_ports[i].port.dev != &dev->dev)
1120                         continue;
1121                 uart_resume_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
1122         }
1123
1124         return 0;
1125 }
1126
1127 static int bfin_serial_probe(struct platform_device *dev)
1128 {
1129         struct resource *res = dev->resource;
1130         int i;
1131
1132         for (i = 0; i < dev->num_resources; i++, res++)
1133                 if (res->flags & IORESOURCE_MEM)
1134                         break;
1135
1136         if (i < dev->num_resources) {
1137                 for (i = 0; i < nr_active_ports; i++, res++) {
1138                         if (bfin_serial_ports[i].port.mapbase != res->start)
1139                                 continue;
1140                         bfin_serial_ports[i].port.dev = &dev->dev;
1141                         uart_add_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
1142                 }
1143         }
1144
1145         return 0;
1146 }
1147
1148 static int bfin_serial_remove(struct platform_device *dev)
1149 {
1150         int i;
1151
1152         for (i = 0; i < nr_active_ports; i++) {
1153                 if (bfin_serial_ports[i].port.dev != &dev->dev)
1154                         continue;
1155                 uart_remove_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
1156                 bfin_serial_ports[i].port.dev = NULL;
1157 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
1158                 gpio_free(bfin_serial_ports[i].cts_pin);
1159                 gpio_free(bfin_serial_ports[i].rts_pin);
1160 #endif
1161         }
1162
1163         return 0;
1164 }
1165
1166 static struct platform_driver bfin_serial_driver = {
1167         .probe          = bfin_serial_probe,
1168         .remove         = bfin_serial_remove,
1169         .suspend        = bfin_serial_suspend,
1170         .resume         = bfin_serial_resume,
1171         .driver         = {
1172                 .name   = "bfin-uart",
1173                 .owner  = THIS_MODULE,
1174         },
1175 };
1176
1177 static int __init bfin_serial_init(void)
1178 {
1179         int ret;
1180 #ifdef CONFIG_KGDB_UART
1181         struct bfin_serial_port *uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
1182         struct ktermios t;
1183 #endif
1184
1185         pr_info("Serial: Blackfin serial driver\n");
1186
1187         bfin_serial_init_ports();
1188
1189         ret = uart_register_driver(&bfin_serial_reg);
1190         if (ret == 0) {
1191                 ret = platform_driver_register(&bfin_serial_driver);
1192                 if (ret) {
1193                         pr_debug("uart register failed\n");
1194                         uart_unregister_driver(&bfin_serial_reg);
1195                 }
1196         }
1197 #ifdef CONFIG_KGDB_UART
1198         if (uart->port.cons->index != CONFIG_KGDB_UART_PORT) {
1199                 request_irq(uart->port.irq, bfin_serial_rx_int,
1200                         IRQF_DISABLED, "BFIN_UART_RX", uart);
1201                 pr_info("Request irq for kgdb uart port\n");
1202                 UART_SET_IER(uart, ERBFI);
1203                 SSYNC();
1204                 t.c_cflag = CS8|B57600;
1205                 t.c_iflag = 0;
1206                 t.c_oflag = 0;
1207                 t.c_lflag = ICANON;
1208                 t.c_line = CONFIG_KGDB_UART_PORT;
1209                 bfin_serial_set_termios(&uart->port, &t, &t);
1210         }
1211 #endif
1212         return ret;
1213 }
1214
1215 static void __exit bfin_serial_exit(void)
1216 {
1217         platform_driver_unregister(&bfin_serial_driver);
1218         uart_unregister_driver(&bfin_serial_reg);
1219 }
1220
1221 module_init(bfin_serial_init);
1222 module_exit(bfin_serial_exit);
1223
1224 MODULE_AUTHOR("Aubrey.Li <aubrey.li@analog.com>");
1225 MODULE_DESCRIPTION("Blackfin generic serial port driver");
1226 MODULE_LICENSE("GPL");
1227 MODULE_ALIAS_CHARDEV_MAJOR(BFIN_SERIAL_MAJOR);
1228 MODULE_ALIAS("platform:bfin-uart");