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   1 /* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
   2  *
   3  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
   4  * Copyright (C) 2002, 2006  David S. Miller (davem@davemloft.net)
   5  *
   6  * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
   7  *   Maxim Krasnyanskiy <maxk@qualcomm.com>
   8  *
   9  * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
  10  * rates to be programmed into the UART.  Also eliminated a lot of
  11  * duplicated code in the console setup.
  12  *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
  13  *
  14  * Ported to new 2.5.x UART layer.
  15  *   David S. Miller <davem@davemloft.net>
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/kernel.h>
  20 #include <linux/errno.h>
  21 #include <linux/tty.h>
  22 #include <linux/tty_flip.h>
  23 #include <linux/major.h>
  24 #include <linux/string.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/ioport.h>
  27 #include <linux/circ_buf.h>
  28 #include <linux/serial.h>
  29 #include <linux/sysrq.h>
  30 #include <linux/console.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/slab.h>
  33 #include <linux/delay.h>
  34 #include <linux/init.h>
  35
  36 #include <asm/io.h>
  37 #include <asm/irq.h>
  38 #include <asm/prom.h>
  39 #include <asm/of_device.h>
  40
  41 #if defined(CONFIG_SERIAL_SUNSAB_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  42 #define SUPPORT_SYSRQ
  43 #endif
  44
  45 #include <linux/serial_core.h>
  46
  47 #include "suncore.h"
  48 #include "sunsab.h"
  49
  50 struct uart_sunsab_port {
  51         struct uart_port                port;           /* Generic UART port    */
  52         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
  53         unsigned long                   irqflags;       /* IRQ state flags      */
  54         int                             dsr;            /* Current DSR state    */
  55         unsigned int                    cec_timeout;    /* Chip poll timeout... */
  56         unsigned int                    tec_timeout;    /* likewise             */
  57         unsigned char                   interrupt_mask0;/* ISR0 masking         */
  58         unsigned char                   interrupt_mask1;/* ISR1 masking         */
  59         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
  60         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
  61         unsigned int                    gis_shift;
  62         int                             type;           /* SAB82532 version     */
  63
  64         /* Setting configuration bits while the transmitter is active
  65          * can cause garbage characters to get emitted by the chip.
  66          * Therefore, we cache such writes here and do the real register
  67          * write the next time the transmitter becomes idle.
  68          */
  69         unsigned int                    cached_ebrg;
  70         unsigned char                   cached_mode;
  71         unsigned char                   cached_pvr;
  72         unsigned char                   cached_dafo;
  73 };
  74
  75 /*
  76  * This assumes you have a 29.4912 MHz clock for your UART.
  77  */
  78 #define SAB_BASE_BAUD ( 29491200 / 16 )
  79
  80 static char *sab82532_version[16] = {
  81         "V1.0", "V2.0", "V3.2", "V(0x03)",
  82         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
  83         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
  84         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
  85 };
  86
  87 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
  88 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
  89
  90 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
  91 #define SAB82532_XMIT_FIFO_SIZE 32
  92
  93 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
  94 {
  95         int timeout = up->tec_timeout;
  96
  97         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
  98                 udelay(1);
  99 }
 100
 101 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
 102 {
 103         int timeout = up->cec_timeout;
 104
 105         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
 106                 udelay(1);
 107 }
 108
 109 static struct tty_struct *
 110 receive_chars(struct uart_sunsab_port *up,
 111               union sab82532_irq_status *stat)
 112 {
 113         struct tty_struct *tty = NULL;
 114         unsigned char buf[32];
 115         int saw_console_brk = 0;
 116         int free_fifo = 0;
 117         int count = 0;
 118         int i;
 119
 120         if (up->port.info != NULL)              /* Unopened serial console */
 121                 tty = up->port.info->tty;
 122
 123         /* Read number of BYTES (Character + Status) available. */
 124         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
 125                 count = SAB82532_RECV_FIFO_SIZE;
 126                 free_fifo++;
 127         }
 128
 129         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
 130                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
 131                 free_fifo++;
 132         }
 133
 134         /* Issue a FIFO read command in case we where idle. */
 135         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
 136                 sunsab_cec_wait(up);
 137                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
 138                 return tty;
 139         }
 140
 141         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 142                 free_fifo++;
 143
 144         /* Read the FIFO. */
 145         for (i = 0; i < count; i++)
 146                 buf[i] = readb(&up->regs->r.rfifo[i]);
 147
 148         /* Issue Receive Message Complete command. */
 149         if (free_fifo) {
 150                 sunsab_cec_wait(up);
 151                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
 152         }
 153
 154         /* Count may be zero for BRK, so we check for it here */
 155         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
 156             (up->port.line == up->port.cons->index))
 157                 saw_console_brk = 1;
 158
 159         for (i = 0; i < count; i++) {
 160                 unsigned char ch = buf[i], flag;
 161
 162                 if (tty == NULL) {
 163                         uart_handle_sysrq_char(&up->port, ch);
 164                         continue;
 165                 }
 166
 167                 flag = TTY_NORMAL;
 168                 up->port.icount.rx++;
 169
 170                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
 171                                                 SAB82532_ISR0_FERR |
 172                                                 SAB82532_ISR0_RFO)) ||
 173                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 174                         /*
 175                          * For statistics only
 176                          */
 177                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 178                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 179                                                      SAB82532_ISR0_FERR);
 180                                 up->port.icount.brk++;
 181                                 /*
 182                                  * We do the SysRQ and SAK checking
 183                                  * here because otherwise the break
 184                                  * may get masked by ignore_status_mask
 185                                  * or read_status_mask.
 186                                  */
 187                                 if (uart_handle_break(&up->port))
 188                                         continue;
 189                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 190                                 up->port.icount.parity++;
 191                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 192                                 up->port.icount.frame++;
 193                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 194                                 up->port.icount.overrun++;
 195
 196                         /*
 197                          * Mask off conditions which should be ingored.
 198                          */
 199                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
 200                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
 201
 202                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 203                                 flag = TTY_BREAK;
 204                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 205                                 flag = TTY_PARITY;
 206                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 207                                 flag = TTY_FRAME;
 208                 }
 209
 210                 if (uart_handle_sysrq_char(&up->port, ch))
 211                         continue;
 212
 213                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
 214                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
 215                         tty_insert_flip_char(tty, ch, flag);
 216                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 217                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 218         }
 219
 220         if (saw_console_brk)
 221                 sun_do_break();
 222
 223         return tty;
 224 }
 225
 226 static void sunsab_stop_tx(struct uart_port *);
 227 static void sunsab_tx_idle(struct uart_sunsab_port *);
 228
 229 static void transmit_chars(struct uart_sunsab_port *up,
 230                            union sab82532_irq_status *stat)
 231 {
 232         struct circ_buf *xmit = &up->port.info->xmit;
 233         int i;
 234
 235         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
 236                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
 237                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 238                 set_bit(SAB82532_ALLS, &up->irqflags);
 239         }
 240
 241 #if 0 /* bde@nwlink.com says this check causes problems */
 242         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 243                 return;
 244 #endif
 245
 246         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 247                 return;
 248
 249         set_bit(SAB82532_XPR, &up->irqflags);
 250         sunsab_tx_idle(up);
 251
 252         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 253                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 254                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 255                 return;
 256         }
 257
 258         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 259         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 260         clear_bit(SAB82532_ALLS, &up->irqflags);
 261
 262         /* Stuff 32 bytes into Transmit FIFO. */
 263         clear_bit(SAB82532_XPR, &up->irqflags);
 264         for (i = 0; i < up->port.fifosize; i++) {
 265                 writeb(xmit->buf[xmit->tail],
 266                        &up->regs->w.xfifo[i]);
 267                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 268                 up->port.icount.tx++;
 269                 if (uart_circ_empty(xmit))
 270                         break;
 271         }
 272
 273         /* Issue a Transmit Frame command. */
 274         sunsab_cec_wait(up);
 275         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 276
 277         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 278                 uart_write_wakeup(&up->port);
 279
 280         if (uart_circ_empty(xmit))
 281                 sunsab_stop_tx(&up->port);
 282 }
 283
 284 static void check_status(struct uart_sunsab_port *up,
 285                          union sab82532_irq_status *stat)
 286 {
 287         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
 288                 uart_handle_dcd_change(&up->port,
 289                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
 290
 291         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
 292                 uart_handle_cts_change(&up->port,
 293                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
 294
 295         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
 296                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
 297                 up->port.icount.dsr++;
 298         }
 299
 300         wake_up_interruptible(&up->port.info->delta_msr_wait);
 301 }
 302
 303 static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
 304 {
 305         struct uart_sunsab_port *up = dev_id;
 306         struct tty_struct *tty;
 307         union sab82532_irq_status status;
 308         unsigned long flags;
 309         unsigned char gis;
 310
 311         spin_lock_irqsave(&up->port.lock, flags);
 312
 313         status.stat = 0;
 314         gis = readb(&up->regs->r.gis) >> up->gis_shift;
 315         if (gis & 1)
 316                 status.sreg.isr0 = readb(&up->regs->r.isr0);
 317         if (gis & 2)
 318                 status.sreg.isr1 = readb(&up->regs->r.isr1);
 319
 320         tty = NULL;
 321         if (status.stat) {
 322                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 323                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
 324                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
 325                         tty = receive_chars(up, &status);
 326                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
 327                     (status.sreg.isr1 & SAB82532_ISR1_CSC))
 328                         check_status(up, &status);
 329                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
 330                         transmit_chars(up, &status);
 331         }
 332
 333         spin_unlock_irqrestore(&up->port.lock, flags);
 334
 335         if (tty)
 336                 tty_flip_buffer_push(tty);
 337
 338         return IRQ_HANDLED;
 339 }
 340
 341 /* port->lock is not held.  */
 342 static unsigned int sunsab_tx_empty(struct uart_port *port)
 343 {
 344         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 345         int ret;
 346
 347         /* Do not need a lock for a state test like this.  */
 348         if (test_bit(SAB82532_ALLS, &up->irqflags))
 349                 ret = TIOCSER_TEMT;
 350         else
 351                 ret = 0;
 352
 353         return ret;
 354 }
 355
 356 /* port->lock held by caller.  */
 357 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
 358 {
 359         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 360
 361         if (mctrl & TIOCM_RTS) {
 362                 up->cached_mode &= ~SAB82532_MODE_FRTS;
 363                 up->cached_mode |= SAB82532_MODE_RTS;
 364         } else {
 365                 up->cached_mode |= (SAB82532_MODE_FRTS |
 366                                     SAB82532_MODE_RTS);
 367         }
 368         if (mctrl & TIOCM_DTR) {
 369                 up->cached_pvr &= ~(up->pvr_dtr_bit);
 370         } else {
 371                 up->cached_pvr |= up->pvr_dtr_bit;
 372         }
 373
 374         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 375         if (test_bit(SAB82532_XPR, &up->irqflags))
 376                 sunsab_tx_idle(up);
 377 }
 378
 379 /* port->lock is held by caller and interrupts are disabled.  */
 380 static unsigned int sunsab_get_mctrl(struct uart_port *port)
 381 {
 382         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 383         unsigned char val;
 384         unsigned int result;
 385
 386         result = 0;
 387
 388         val = readb(&up->regs->r.pvr);
 389         result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
 390
 391         val = readb(&up->regs->r.vstr);
 392         result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
 393
 394         val = readb(&up->regs->r.star);
 395         result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
 396
 397         return result;
 398 }
 399
 400 /* port->lock held by caller.  */
 401 static void sunsab_stop_tx(struct uart_port *port)
 402 {
 403         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 404
 405         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 406         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 407 }
 408
 409 /* port->lock held by caller.  */
 410 static void sunsab_tx_idle(struct uart_sunsab_port *up)
 411 {
 412         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
 413                 u8 tmp;
 414
 415                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
 416                 writeb(up->cached_mode, &up->regs->rw.mode);
 417                 writeb(up->cached_pvr, &up->regs->rw.pvr);
 418                 writeb(up->cached_dafo, &up->regs->w.dafo);
 419
 420                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
 421                 tmp = readb(&up->regs->rw.ccr2);
 422                 tmp &= ~0xc0;
 423                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
 424                 writeb(tmp, &up->regs->rw.ccr2);
 425         }
 426 }
 427
 428 /* port->lock held by caller.  */
 429 static void sunsab_start_tx(struct uart_port *port)
 430 {
 431         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 432         struct circ_buf *xmit = &up->port.info->xmit;
 433         int i;
 434
 435         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 436         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 437
 438         if (!test_bit(SAB82532_XPR, &up->irqflags))
 439                 return;
 440
 441         clear_bit(SAB82532_ALLS, &up->irqflags);
 442         clear_bit(SAB82532_XPR, &up->irqflags);
 443
 444         for (i = 0; i < up->port.fifosize; i++) {
 445                 writeb(xmit->buf[xmit->tail],
 446                        &up->regs->w.xfifo[i]);
 447                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 448                 up->port.icount.tx++;
 449                 if (uart_circ_empty(xmit))
 450                         break;
 451         }
 452
 453         /* Issue a Transmit Frame command.  */
 454         sunsab_cec_wait(up);
 455         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 456 }
 457
 458 /* port->lock is not held.  */
 459 static void sunsab_send_xchar(struct uart_port *port, char ch)
 460 {
 461         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 462         unsigned long flags;
 463
 464         spin_lock_irqsave(&up->port.lock, flags);
 465
 466         sunsab_tec_wait(up);
 467         writeb(ch, &up->regs->w.tic);
 468
 469         spin_unlock_irqrestore(&up->port.lock, flags);
 470 }
 471
 472 /* port->lock held by caller.  */
 473 static void sunsab_stop_rx(struct uart_port *port)
 474 {
 475         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 476
 477         up->interrupt_mask0 |= SAB82532_ISR0_TCD;
 478         writeb(up->interrupt_mask1, &up->regs->w.imr0);
 479 }
 480
 481 /* port->lock held by caller.  */
 482 static void sunsab_enable_ms(struct uart_port *port)
 483 {
 484         /* For now we always receive these interrupts.  */
 485 }
 486
 487 /* port->lock is not held.  */
 488 static void sunsab_break_ctl(struct uart_port *port, int break_state)
 489 {
 490         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 491         unsigned long flags;
 492         unsigned char val;
 493
 494         spin_lock_irqsave(&up->port.lock, flags);
 495
 496         val = up->cached_dafo;
 497         if (break_state)
 498                 val |= SAB82532_DAFO_XBRK;
 499         else
 500                 val &= ~SAB82532_DAFO_XBRK;
 501         up->cached_dafo = val;
 502
 503         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 504         if (test_bit(SAB82532_XPR, &up->irqflags))
 505                 sunsab_tx_idle(up);
 506
 507         spin_unlock_irqrestore(&up->port.lock, flags);
 508 }
 509
 510 /* port->lock is not held.  */
 511 static int sunsab_startup(struct uart_port *port)
 512 {
 513         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 514         unsigned long flags;
 515         unsigned char tmp;
 516         int err = request_irq(up->port.irq, sunsab_interrupt,
 517                               IRQF_SHARED, "sab", up);
 518         if (err)
 519                 return err;
 520
 521         spin_lock_irqsave(&up->port.lock, flags);
 522
 523         /*
 524          * Wait for any commands or immediate characters
 525          */
 526         sunsab_cec_wait(up);
 527         sunsab_tec_wait(up);
 528
 529         /*
 530          * Clear the FIFO buffers.
 531          */
 532         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
 533         sunsab_cec_wait(up);
 534         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
 535
 536         /*
 537          * Clear the interrupt registers.
 538          */
 539         (void) readb(&up->regs->r.isr0);
 540         (void) readb(&up->regs->r.isr1);
 541
 542         /*
 543          * Now, initialize the UART
 544          */
 545         writeb(0, &up->regs->w.ccr0);                           /* power-down */
 546         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
 547                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
 548         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
 549         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
 550                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
 551         writeb(0, &up->regs->w.ccr3);
 552         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
 553         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
 554                            SAB82532_MODE_RAC);
 555         writeb(up->cached_mode, &up->regs->w.mode);
 556         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
 557
 558         tmp = readb(&up->regs->rw.ccr0);
 559         tmp |= SAB82532_CCR0_PU;        /* power-up */
 560         writeb(tmp, &up->regs->rw.ccr0);
 561
 562         /*
 563          * Finally, enable interrupts
 564          */
 565         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 566                                SAB82532_IMR0_PLLA);
 567         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 568         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 569                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 570                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 571                                SAB82532_IMR1_XPR);
 572         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 573         set_bit(SAB82532_ALLS, &up->irqflags);
 574         set_bit(SAB82532_XPR, &up->irqflags);
 575
 576         spin_unlock_irqrestore(&up->port.lock, flags);
 577
 578         return 0;
 579 }
 580
 581 /* port->lock is not held.  */
 582 static void sunsab_shutdown(struct uart_port *port)
 583 {
 584         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 585         unsigned long flags;
 586
 587         spin_lock_irqsave(&up->port.lock, flags);
 588
 589         /* Disable Interrupts */
 590         up->interrupt_mask0 = 0xff;
 591         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 592         up->interrupt_mask1 = 0xff;
 593         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 594
 595         /* Disable break condition */
 596         up->cached_dafo = readb(&up->regs->rw.dafo);
 597         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
 598         writeb(up->cached_dafo, &up->regs->rw.dafo);
 599
 600         /* Disable Receiver */
 601         up->cached_mode &= ~SAB82532_MODE_RAC;
 602         writeb(up->cached_mode, &up->regs->rw.mode);
 603
 604         /*
 605          * XXX FIXME
 606          *
 607          * If the chip is powered down here the system hangs/crashes during
 608          * reboot or shutdown.  This needs to be investigated further,
 609          * similar behaviour occurs in 2.4 when the driver is configured
 610          * as a module only.  One hint may be that data is sometimes
 611          * transmitted at 9600 baud during shutdown (regardless of the
 612          * speed the chip was configured for when the port was open).
 613          */
 614 #if 0
 615         /* Power Down */
 616         tmp = readb(&up->regs->rw.ccr0);
 617         tmp &= ~SAB82532_CCR0_PU;
 618         writeb(tmp, &up->regs->rw.ccr0);
 619 #endif
 620
 621         spin_unlock_irqrestore(&up->port.lock, flags);
 622         free_irq(up->port.irq, up);
 623 }
 624
 625 /*
 626  * This is used to figure out the divisor speeds.
 627  *
 628  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
 629  *
 630  * with               0 <= N < 64 and 0 <= M < 16
 631  */
 632
 633 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
 634 {
 635         int     n, m;
 636
 637         if (baud == 0) {
 638                 *n_ret = 0;
 639                 *m_ret = 0;
 640                 return;
 641         }
 642
 643         /*
 644          * We scale numbers by 10 so that we get better accuracy
 645          * without having to use floating point.  Here we increment m
 646          * until n is within the valid range.
 647          */
 648         n = (SAB_BASE_BAUD * 10) / baud;
 649         m = 0;
 650         while (n >= 640) {
 651                 n = n / 2;
 652                 m++;
 653         }
 654         n = (n+5) / 10;
 655         /*
 656          * We try very hard to avoid speeds with M == 0 since they may
 657          * not work correctly for XTAL frequences above 10 MHz.
 658          */
 659         if ((m == 0) && ((n & 1) == 0)) {
 660                 n = n / 2;
 661                 m++;
 662         }
 663         *n_ret = n - 1;
 664         *m_ret = m;
 665 }
 666
 667 /* Internal routine, port->lock is held and local interrupts are disabled.  */
 668 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
 669                                   unsigned int iflag, unsigned int baud,
 670                                   unsigned int quot)
 671 {
 672         unsigned char dafo;
 673         int bits, n, m;
 674
 675         /* Byte size and parity */
 676         switch (cflag & CSIZE) {
 677               case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 678               case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
 679               case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
 680               case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
 681               /* Never happens, but GCC is too dumb to figure it out */
 682               default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 683         }
 684
 685         if (cflag & CSTOPB) {
 686                 dafo |= SAB82532_DAFO_STOP;
 687                 bits++;
 688         }
 689
 690         if (cflag & PARENB) {
 691                 dafo |= SAB82532_DAFO_PARE;
 692                 bits++;
 693         }
 694
 695         if (cflag & PARODD) {
 696                 dafo |= SAB82532_DAFO_PAR_ODD;
 697         } else {
 698                 dafo |= SAB82532_DAFO_PAR_EVEN;
 699         }
 700         up->cached_dafo = dafo;
 701
 702         calc_ebrg(baud, &n, &m);
 703
 704         up->cached_ebrg = n | (m << 6);
 705
 706         up->tec_timeout = (10 * 1000000) / baud;
 707         up->cec_timeout = up->tec_timeout >> 2;
 708
 709         /* CTS flow control flags */
 710         /* We encode read_status_mask and ignore_status_mask like so:
 711          *
 712          * ---------------------
 713          * | ... | ISR1 | ISR0 |
 714          * ---------------------
 715          *  ..    15   8 7    0
 716          */
 717
 718         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 719                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 720                                      SAB82532_ISR0_CDSC);
 721         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 722                                       SAB82532_ISR1_ALLS |
 723                                       SAB82532_ISR1_XPR) << 8;
 724         if (iflag & INPCK)
 725                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 726                                               SAB82532_ISR0_FERR);
 727         if (iflag & (BRKINT | PARMRK))
 728                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 729
 730         /*
 731          * Characteres to ignore
 732          */
 733         up->port.ignore_status_mask = 0;
 734         if (iflag & IGNPAR)
 735                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 736                                                 SAB82532_ISR0_FERR);
 737         if (iflag & IGNBRK) {
 738                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 739                 /*
 740                  * If we're ignoring parity and break indicators,
 741                  * ignore overruns too (for real raw support).
 742                  */
 743                 if (iflag & IGNPAR)
 744                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 745         }
 746
 747         /*
 748          * ignore all characters if CREAD is not set
 749          */
 750         if ((cflag & CREAD) == 0)
 751                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 752                                                 SAB82532_ISR0_TCD);
 753
 754         uart_update_timeout(&up->port, cflag,
 755                             (up->port.uartclk / (16 * quot)));
 756
 757         /* Now schedule a register update when the chip's
 758          * transmitter is idle.
 759          */
 760         up->cached_mode |= SAB82532_MODE_RAC;
 761         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 762         if (test_bit(SAB82532_XPR, &up->irqflags))
 763                 sunsab_tx_idle(up);
 764 }
 765
 766 /* port->lock is not held.  */
 767 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 768                                struct ktermios *old)
 769 {
 770         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 771         unsigned long flags;
 772         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 773         unsigned int quot = uart_get_divisor(port, baud);
 774
 775         spin_lock_irqsave(&up->port.lock, flags);
 776         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 777         spin_unlock_irqrestore(&up->port.lock, flags);
 778 }
 779
 780 static const char *sunsab_type(struct uart_port *port)
 781 {
 782         struct uart_sunsab_port *up = (void *)port;
 783         static char buf[36];
 784
 785         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 786         return buf;
 787 }
 788
 789 static void sunsab_release_port(struct uart_port *port)
 790 {
 791 }
 792
 793 static int sunsab_request_port(struct uart_port *port)
 794 {
 795         return 0;
 796 }
 797
 798 static void sunsab_config_port(struct uart_port *port, int flags)
 799 {
 800 }
 801
 802 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 803 {
 804         return -EINVAL;
 805 }
 806
 807 static struct uart_ops sunsab_pops = {
 808         .tx_empty       = sunsab_tx_empty,
 809         .set_mctrl      = sunsab_set_mctrl,
 810         .get_mctrl      = sunsab_get_mctrl,
 811         .stop_tx        = sunsab_stop_tx,
 812         .start_tx       = sunsab_start_tx,
 813         .send_xchar     = sunsab_send_xchar,
 814         .stop_rx        = sunsab_stop_rx,
 815         .enable_ms      = sunsab_enable_ms,
 816         .break_ctl      = sunsab_break_ctl,
 817         .startup        = sunsab_startup,
 818         .shutdown       = sunsab_shutdown,
 819         .set_termios    = sunsab_set_termios,
 820         .type           = sunsab_type,
 821         .release_port   = sunsab_release_port,
 822         .request_port   = sunsab_request_port,
 823         .config_port    = sunsab_config_port,
 824         .verify_port    = sunsab_verify_port,
 825 };
 826
 827 static struct uart_driver sunsab_reg = {
 828         .owner                  = THIS_MODULE,
 829         .driver_name            = "sunsab",
 830         .dev_name               = "ttyS",
 831         .major                  = TTY_MAJOR,
 832 };
 833
 834 static struct uart_sunsab_port *sunsab_ports;
 835
 836 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 837
 838 static void sunsab_console_putchar(struct uart_port *port, int c)
 839 {
 840         struct uart_sunsab_port *up = (struct uart_sunsab_port *)port;
 841
 842         sunsab_tec_wait(up);
 843         writeb(c, &up->regs->w.tic);
 844 }
 845
 846 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 847 {
 848         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 849         unsigned long flags;
 850         int locked = 1;
 851
 852         local_irq_save(flags);
 853         if (up->port.sysrq) {
 854                 locked = 0;
 855         } else if (oops_in_progress) {
 856                 locked = spin_trylock(&up->port.lock);
 857         } else
 858                 spin_lock(&up->port.lock);
 859
 860         uart_console_write(&up->port, s, n, sunsab_console_putchar);
 861         sunsab_tec_wait(up);
 862
 863         if (locked)
 864                 spin_unlock(&up->port.lock);
 865         local_irq_restore(flags);
 866 }
 867
 868 static int sunsab_console_setup(struct console *con, char *options)
 869 {
 870         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 871         unsigned long flags;
 872         unsigned int baud, quot;
 873
 874         /*
 875          * The console framework calls us for each and every port
 876          * registered. Defer the console setup until the requested
 877          * port has been properly discovered. A bit of a hack,
 878          * though...
 879          */
 880         if (up->port.type != PORT_SUNSAB)
 881                 return -1;
 882
 883         printk("Console: ttyS%d (SAB82532)\n",
 884                (sunsab_reg.minor - 64) + con->index);
 885
 886         sunserial_console_termios(con);
 887
 888         switch (con->cflag & CBAUD) {
 889         case B150: baud = 150; break;
 890         case B300: baud = 300; break;
 891         case B600: baud = 600; break;
 892         case B1200: baud = 1200; break;
 893         case B2400: baud = 2400; break;
 894         case B4800: baud = 4800; break;
 895         default: case B9600: baud = 9600; break;
 896         case B19200: baud = 19200; break;
 897         case B38400: baud = 38400; break;
 898         case B57600: baud = 57600; break;
 899         case B115200: baud = 115200; break;
 900         case B230400: baud = 230400; break;
 901         case B460800: baud = 460800; break;
 902         };
 903
 904         /*
 905          * Temporary fix.
 906          */
 907         spin_lock_init(&up->port.lock);
 908
 909         /*
 910          * Initialize the hardware
 911          */
 912         sunsab_startup(&up->port);
 913
 914         spin_lock_irqsave(&up->port.lock, flags);
 915
 916         /*
 917          * Finally, enable interrupts
 918          */
 919         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 920                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 921         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 922         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 923                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 924                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 925                                 SAB82532_IMR1_XPR;
 926         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 927
 928         quot = uart_get_divisor(&up->port, baud);
 929         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 930         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 931
 932         spin_unlock_irqrestore(&up->port.lock, flags);
 933
 934         return 0;
 935 }
 936
 937 static struct console sunsab_console = {
 938         .name   =       "ttyS",
 939         .write  =       sunsab_console_write,
 940         .device =       uart_console_device,
 941         .setup  =       sunsab_console_setup,
 942         .flags  =       CON_PRINTBUFFER,
 943         .index  =       -1,
 944         .data   =       &sunsab_reg,
 945 };
 946
 947 static inline struct console *SUNSAB_CONSOLE(void)
 948 {
 949         return &sunsab_console;
 950 }
 951 #else
 952 #define SUNSAB_CONSOLE()        (NULL)
 953 #define sunsab_console_init()   do { } while (0)
 954 #endif
 955
 956 static int __devinit sunsab_init_one(struct uart_sunsab_port *up,
 957                                      struct of_device *op,
 958                                      unsigned long offset,
 959                                      int line)
 960 {
 961         up->port.line = line;
 962         up->port.dev = &op->dev;
 963
 964         up->port.mapbase = op->resource[0].start + offset;
 965         up->port.membase = of_ioremap(&op->resource[0], offset,
 966                                       sizeof(union sab82532_async_regs),
 967                                       "sab");
 968         if (!up->port.membase)
 969                 return -ENOMEM;
 970         up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
 971
 972         up->port.irq = op->irqs[0];
 973
 974         up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
 975         up->port.iotype = UPIO_MEM;
 976
 977         writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
 978
 979         up->port.ops = &sunsab_pops;
 980         up->port.type = PORT_SUNSAB;
 981         up->port.uartclk = SAB_BASE_BAUD;
 982
 983         up->type = readb(&up->regs->r.vstr) & 0x0f;
 984         writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
 985         writeb(0xff, &up->regs->w.pim);
 986         if ((up->port.line & 0x1) == 0) {
 987                 up->pvr_dsr_bit = (1 << 0);
 988                 up->pvr_dtr_bit = (1 << 1);
 989                 up->gis_shift = 2;
 990         } else {
 991                 up->pvr_dsr_bit = (1 << 3);
 992                 up->pvr_dtr_bit = (1 << 2);
 993                 up->gis_shift = 0;
 994         }
 995         up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
 996         writeb(up->cached_pvr, &up->regs->w.pvr);
 997         up->cached_mode = readb(&up->regs->rw.mode);
 998         up->cached_mode |= SAB82532_MODE_FRTS;
 999         writeb(up->cached_mode, &up->regs->rw.mode);
1000         up->cached_mode |= SAB82532_MODE_RTS;
1001         writeb(up->cached_mode, &up->regs->rw.mode);
1002
1003         up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1004         up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1005
1006         return 0;
1007 }
1008
1009 static int __devinit sab_probe(struct of_device *op, const struct of_device_id *match)
1010 {
1011         static int inst;
1012         struct uart_sunsab_port *up;
1013         int err;
1014
1015         up = &sunsab_ports[inst * 2];
1016
1017         err = sunsab_init_one(&up[0], op,
1018                               0,
1019                               (inst * 2) + 0);
1020         if (err)
1021                 goto out;
1022
1023         err = sunsab_init_one(&up[1], op,
1024                               sizeof(union sab82532_async_regs),
1025                               (inst * 2) + 1);
1026         if (err)
1027                 goto out1;
1028
1029         sunserial_console_match(SUNSAB_CONSOLE(), op->node,
1030                                 &sunsab_reg, up[0].port.line);
1031
1032         sunserial_console_match(SUNSAB_CONSOLE(), op->node,
1033                                 &sunsab_reg, up[1].port.line);
1034
1035         err = uart_add_one_port(&sunsab_reg, &up[0].port);
1036         if (err)
1037                 goto out2;
1038
1039         err = uart_add_one_port(&sunsab_reg, &up[1].port);
1040         if (err)
1041                 goto out3;
1042
1043         dev_set_drvdata(&op->dev, &up[0]);
1044
1045         inst++;
1046
1047         return 0;
1048
1049 out3:
1050         uart_remove_one_port(&sunsab_reg, &up[0].port);
1051 out2:
1052         of_iounmap(&op->resource[0],
1053                    up[1].port.membase,
1054                    sizeof(union sab82532_async_regs));
1055 out1:
1056         of_iounmap(&op->resource[0],
1057                    up[0].port.membase,
1058                    sizeof(union sab82532_async_regs));
1059 out:
1060         return err;
1061 }
1062
1063 static int __devexit sab_remove(struct of_device *op)
1064 {
1065         struct uart_sunsab_port *up = dev_get_drvdata(&op->dev);
1066
1067         uart_remove_one_port(&sunsab_reg, &up[1].port);
1068         uart_remove_one_port(&sunsab_reg, &up[0].port);
1069         of_iounmap(&op->resource[0],
1070                    up[1].port.membase,
1071                    sizeof(union sab82532_async_regs));
1072         of_iounmap(&op->resource[0],
1073                    up[0].port.membase,
1074                    sizeof(union sab82532_async_regs));
1075
1076         dev_set_drvdata(&op->dev, NULL);
1077
1078         return 0;
1079 }
1080
1081 static struct of_device_id sab_match[] = {
1082         {
1083                 .name = "se",
1084         },
1085         {
1086                 .name = "serial",
1087                 .compatible = "sab82532",
1088         },
1089         {},
1090 };
1091 MODULE_DEVICE_TABLE(of, sab_match);
1092
1093 static struct of_platform_driver sab_driver = {
1094         .name           = "sab",
1095         .match_table    = sab_match,
1096         .probe          = sab_probe,
1097         .remove         = __devexit_p(sab_remove),
1098 };
1099
1100 static int __init sunsab_init(void)
1101 {
1102         struct device_node *dp;
1103         int err;
1104         int num_channels = 0;
1105
1106         for_each_node_by_name(dp, "se")
1107                 num_channels += 2;
1108         for_each_node_by_name(dp, "serial") {
1109                 if (of_device_is_compatible(dp, "sab82532"))
1110                         num_channels += 2;
1111         }
1112
1113         if (num_channels) {
1114                 sunsab_ports = kzalloc(sizeof(struct uart_sunsab_port) *
1115                                        num_channels, GFP_KERNEL);
1116                 if (!sunsab_ports)
1117                         return -ENOMEM;
1118
1119                 sunsab_reg.cons = SUNSAB_CONSOLE();
1120                 err = sunserial_register_minors(&sunsab_reg, num_channels);
1121                 if (err) {
1122                         kfree(sunsab_ports);
1123                         sunsab_ports = NULL;
1124
1125                         return err;
1126                 }
1127         }
1128
1129         return of_register_driver(&sab_driver, &of_bus_type);
1130 }
1131
1132 static void __exit sunsab_exit(void)
1133 {
1134         of_unregister_driver(&sab_driver);
1135         if (sunsab_reg.nr) {
1136                 sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1137         }
1138
1139         kfree(sunsab_ports);
1140         sunsab_ports = NULL;
1141 }
1142
1143 module_init(sunsab_init);
1144 module_exit(sunsab_exit);
1145
1146 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1147 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1148 MODULE_LICENSE("GPL");