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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  David S. Miller (davem@redhat.com)
   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@redhat.com>
  16  */
  17
  18 #include <linux/config.h>
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/errno.h>
  23 #include <linux/tty.h>
  24 #include <linux/tty_flip.h>
  25 #include <linux/major.h>
  26 #include <linux/string.h>
  27 #include <linux/ptrace.h>
  28 #include <linux/ioport.h>
  29 #include <linux/circ_buf.h>
  30 #include <linux/serial.h>
  31 #include <linux/sysrq.h>
  32 #include <linux/console.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/slab.h>
  35 #include <linux/delay.h>
  36 #include <linux/init.h>
  37
  38 #include <asm/io.h>
  39 #include <asm/irq.h>
  40 #include <asm/oplib.h>
  41 #include <asm/ebus.h>
  42
  43 #if defined(CONFIG_SERIAL_SUNZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  44 #define SUPPORT_SYSRQ
  45 #endif
  46
  47 #include <linux/serial_core.h>
  48
  49 #include "suncore.h"
  50 #include "sunsab.h"
  51
  52 struct uart_sunsab_port {
  53         struct uart_port                port;           /* Generic UART port    */
  54         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
  55         unsigned long                   irqflags;       /* IRQ state flags      */
  56         int                             dsr;            /* Current DSR state    */
  57         unsigned int                    cec_timeout;    /* Chip poll timeout... */
  58         unsigned int                    tec_timeout;    /* likewise             */
  59         unsigned char                   interrupt_mask0;/* ISR0 masking         */
  60         unsigned char                   interrupt_mask1;/* ISR1 masking         */
  61         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
  62         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
  63         int                             type;           /* SAB82532 version     */
  64
  65         /* Setting configuration bits while the transmitter is active
  66          * can cause garbage characters to get emitted by the chip.
  67          * Therefore, we cache such writes here and do the real register
  68          * write the next time the transmitter becomes idle.
  69          */
  70         unsigned int                    cached_ebrg;
  71         unsigned char                   cached_mode;
  72         unsigned char                   cached_pvr;
  73         unsigned char                   cached_dafo;
  74 };
  75
  76 /*
  77  * This assumes you have a 29.4912 MHz clock for your UART.
  78  */
  79 #define SAB_BASE_BAUD ( 29491200 / 16 )
  80
  81 static char *sab82532_version[16] = {
  82         "V1.0", "V2.0", "V3.2", "V(0x03)",
  83         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
  84         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
  85         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
  86 };
  87
  88 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
  89 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
  90
  91 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
  92 #define SAB82532_XMIT_FIFO_SIZE 32
  93
  94 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
  95 {
  96         int timeout = up->tec_timeout;
  97
  98         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
  99                 udelay(1);
 100 }
 101
 102 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
 103 {
 104         int timeout = up->cec_timeout;
 105
 106         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
 107                 udelay(1);
 108 }
 109
 110 static struct tty_struct *
 111 receive_chars(struct uart_sunsab_port *up,
 112               union sab82532_irq_status *stat,
 113               struct pt_regs *regs)
 114 {
 115         struct tty_struct *tty = NULL;
 116         unsigned char buf[32];
 117         int saw_console_brk = 0;
 118         int free_fifo = 0;
 119         int count = 0;
 120         int i;
 121
 122         if (up->port.info != NULL)              /* Unopened serial console */
 123                 tty = up->port.info->tty;
 124
 125         /* Read number of BYTES (Character + Status) available. */
 126         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
 127                 count = SAB82532_RECV_FIFO_SIZE;
 128                 free_fifo++;
 129         }
 130
 131         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
 132                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
 133                 free_fifo++;
 134         }
 135
 136         /* Issue a FIFO read command in case we where idle. */
 137         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
 138                 sunsab_cec_wait(up);
 139                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
 140                 return tty;
 141         }
 142
 143         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 144                 free_fifo++;
 145
 146         /* Read the FIFO. */
 147         for (i = 0; i < count; i++)
 148                 buf[i] = readb(&up->regs->r.rfifo[i]);
 149
 150         /* Issue Receive Message Complete command. */
 151         if (free_fifo) {
 152                 sunsab_cec_wait(up);
 153                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
 154         }
 155
 156         /* Count may be zero for BRK, so we check for it here */
 157         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
 158             (up->port.line == up->port.cons->index))
 159                 saw_console_brk = 1;
 160
 161         for (i = 0; i < count; i++) {
 162                 unsigned char ch = buf[i], flag;
 163
 164                 if (tty == NULL) {
 165                         uart_handle_sysrq_char(&up->port, ch, regs);
 166                         continue;
 167                 }
 168
 169                 flag = TTY_NORMAL;
 170                 up->port.icount.rx++;
 171
 172                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
 173                                                 SAB82532_ISR0_FERR |
 174                                                 SAB82532_ISR0_RFO)) ||
 175                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 176                         /*
 177                          * For statistics only
 178                          */
 179                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 180                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 181                                                      SAB82532_ISR0_FERR);
 182                                 up->port.icount.brk++;
 183                                 /*
 184                                  * We do the SysRQ and SAK checking
 185                                  * here because otherwise the break
 186                                  * may get masked by ignore_status_mask
 187                                  * or read_status_mask.
 188                                  */
 189                                 if (uart_handle_break(&up->port))
 190                                         continue;
 191                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 192                                 up->port.icount.parity++;
 193                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 194                                 up->port.icount.frame++;
 195                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 196                                 up->port.icount.overrun++;
 197
 198                         /*
 199                          * Mask off conditions which should be ingored.
 200                          */
 201                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
 202                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
 203
 204                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 205                                 flag = TTY_BREAK;
 206                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 207                                 flag = TTY_PARITY;
 208                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 209                                 flag = TTY_FRAME;
 210                 }
 211
 212                 if (uart_handle_sysrq_char(&up->port, ch, regs))
 213                         continue;
 214
 215                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
 216                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
 217                         tty_insert_flip_char(tty, ch, flag);
 218                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 219                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 220         }
 221
 222         if (saw_console_brk)
 223                 sun_do_break();
 224
 225         return tty;
 226 }
 227
 228 static void sunsab_stop_tx(struct uart_port *);
 229 static void sunsab_tx_idle(struct uart_sunsab_port *);
 230
 231 static void transmit_chars(struct uart_sunsab_port *up,
 232                            union sab82532_irq_status *stat)
 233 {
 234         struct circ_buf *xmit = &up->port.info->xmit;
 235         int i;
 236
 237         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
 238                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
 239                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 240                 set_bit(SAB82532_ALLS, &up->irqflags);
 241         }
 242
 243 #if 0 /* bde@nwlink.com says this check causes problems */
 244         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 245                 return;
 246 #endif
 247
 248         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 249                 return;
 250
 251         set_bit(SAB82532_XPR, &up->irqflags);
 252         sunsab_tx_idle(up);
 253
 254         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 255                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 256                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 257                 return;
 258         }
 259
 260         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 261         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 262         clear_bit(SAB82532_ALLS, &up->irqflags);
 263
 264         /* Stuff 32 bytes into Transmit FIFO. */
 265         clear_bit(SAB82532_XPR, &up->irqflags);
 266         for (i = 0; i < up->port.fifosize; i++) {
 267                 writeb(xmit->buf[xmit->tail],
 268                        &up->regs->w.xfifo[i]);
 269                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 270                 up->port.icount.tx++;
 271                 if (uart_circ_empty(xmit))
 272                         break;
 273         }
 274
 275         /* Issue a Transmit Frame command. */
 276         sunsab_cec_wait(up);
 277         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 278
 279         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 280                 uart_write_wakeup(&up->port);
 281
 282         if (uart_circ_empty(xmit))
 283                 sunsab_stop_tx(&up->port);
 284 }
 285
 286 static void check_status(struct uart_sunsab_port *up,
 287                          union sab82532_irq_status *stat)
 288 {
 289         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
 290                 uart_handle_dcd_change(&up->port,
 291                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
 292
 293         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
 294                 uart_handle_cts_change(&up->port,
 295                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
 296
 297         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
 298                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
 299                 up->port.icount.dsr++;
 300         }
 301
 302         wake_up_interruptible(&up->port.info->delta_msr_wait);
 303 }
 304
 305 static irqreturn_t sunsab_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 306 {
 307         struct uart_sunsab_port *up = dev_id;
 308         struct tty_struct *tty;
 309         union sab82532_irq_status status;
 310         unsigned long flags;
 311
 312         spin_lock_irqsave(&up->port.lock, flags);
 313
 314         status.stat = 0;
 315         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA0)
 316                 status.sreg.isr0 = readb(&up->regs->r.isr0);
 317         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA1)
 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, regs);
 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(&up->port.lock);
 334
 335         if (tty)
 336                 tty_flip_buffer_push(tty);
 337
 338         up++;
 339
 340         spin_lock(&up->port.lock);
 341
 342         status.stat = 0;
 343         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB0)
 344                 status.sreg.isr0 = readb(&up->regs->r.isr0);
 345         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB1)
 346                 status.sreg.isr1 = readb(&up->regs->r.isr1);
 347
 348         tty = NULL;
 349         if (status.stat) {
 350                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 351                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
 352                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
 353
 354                         tty = receive_chars(up, &status, regs);
 355                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
 356                     (status.sreg.isr1 & (SAB82532_ISR1_BRK | SAB82532_ISR1_CSC)))
 357                         check_status(up, &status);
 358                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
 359                         transmit_chars(up, &status);
 360         }
 361
 362         spin_unlock_irqrestore(&up->port.lock, flags);
 363
 364         if (tty)
 365                 tty_flip_buffer_push(tty);
 366
 367         return IRQ_HANDLED;
 368 }
 369
 370 /* port->lock is not held.  */
 371 static unsigned int sunsab_tx_empty(struct uart_port *port)
 372 {
 373         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 374         int ret;
 375
 376         /* Do not need a lock for a state test like this.  */
 377         if (test_bit(SAB82532_ALLS, &up->irqflags))
 378                 ret = TIOCSER_TEMT;
 379         else
 380                 ret = 0;
 381
 382         return ret;
 383 }
 384
 385 /* port->lock held by caller.  */
 386 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
 387 {
 388         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 389
 390         if (mctrl & TIOCM_RTS) {
 391                 up->cached_mode &= ~SAB82532_MODE_FRTS;
 392                 up->cached_mode |= SAB82532_MODE_RTS;
 393         } else {
 394                 up->cached_mode |= (SAB82532_MODE_FRTS |
 395                                     SAB82532_MODE_RTS);
 396         }
 397         if (mctrl & TIOCM_DTR) {
 398                 up->cached_pvr &= ~(up->pvr_dtr_bit);
 399         } else {
 400                 up->cached_pvr |= up->pvr_dtr_bit;
 401         }
 402
 403         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 404         if (test_bit(SAB82532_XPR, &up->irqflags))
 405                 sunsab_tx_idle(up);
 406 }
 407
 408 /* port->lock is held by caller and interrupts are disabled.  */
 409 static unsigned int sunsab_get_mctrl(struct uart_port *port)
 410 {
 411         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 412         unsigned char val;
 413         unsigned int result;
 414
 415         result = 0;
 416
 417         val = readb(&up->regs->r.pvr);
 418         result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
 419
 420         val = readb(&up->regs->r.vstr);
 421         result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
 422
 423         val = readb(&up->regs->r.star);
 424         result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
 425
 426         return result;
 427 }
 428
 429 /* port->lock held by caller.  */
 430 static void sunsab_stop_tx(struct uart_port *port)
 431 {
 432         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 433
 434         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 435         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 436 }
 437
 438 /* port->lock held by caller.  */
 439 static void sunsab_tx_idle(struct uart_sunsab_port *up)
 440 {
 441         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
 442                 u8 tmp;
 443
 444                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
 445                 writeb(up->cached_mode, &up->regs->rw.mode);
 446                 writeb(up->cached_pvr, &up->regs->rw.pvr);
 447                 writeb(up->cached_dafo, &up->regs->w.dafo);
 448
 449                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
 450                 tmp = readb(&up->regs->rw.ccr2);
 451                 tmp &= ~0xc0;
 452                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
 453                 writeb(tmp, &up->regs->rw.ccr2);
 454         }
 455 }
 456
 457 /* port->lock held by caller.  */
 458 static void sunsab_start_tx(struct uart_port *port)
 459 {
 460         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 461         struct circ_buf *xmit = &up->port.info->xmit;
 462         int i;
 463
 464         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 465         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 466
 467         if (!test_bit(SAB82532_XPR, &up->irqflags))
 468                 return;
 469
 470         clear_bit(SAB82532_ALLS, &up->irqflags);
 471         clear_bit(SAB82532_XPR, &up->irqflags);
 472
 473         for (i = 0; i < up->port.fifosize; i++) {
 474                 writeb(xmit->buf[xmit->tail],
 475                        &up->regs->w.xfifo[i]);
 476                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 477                 up->port.icount.tx++;
 478                 if (uart_circ_empty(xmit))
 479                         break;
 480         }
 481
 482         /* Issue a Transmit Frame command.  */
 483         sunsab_cec_wait(up);
 484         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 485 }
 486
 487 /* port->lock is not held.  */
 488 static void sunsab_send_xchar(struct uart_port *port, char ch)
 489 {
 490         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 491         unsigned long flags;
 492
 493         spin_lock_irqsave(&up->port.lock, flags);
 494
 495         sunsab_tec_wait(up);
 496         writeb(ch, &up->regs->w.tic);
 497
 498         spin_unlock_irqrestore(&up->port.lock, flags);
 499 }
 500
 501 /* port->lock held by caller.  */
 502 static void sunsab_stop_rx(struct uart_port *port)
 503 {
 504         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 505
 506         up->interrupt_mask0 |= SAB82532_ISR0_TCD;
 507         writeb(up->interrupt_mask1, &up->regs->w.imr0);
 508 }
 509
 510 /* port->lock held by caller.  */
 511 static void sunsab_enable_ms(struct uart_port *port)
 512 {
 513         /* For now we always receive these interrupts.  */
 514 }
 515
 516 /* port->lock is not held.  */
 517 static void sunsab_break_ctl(struct uart_port *port, int break_state)
 518 {
 519         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 520         unsigned long flags;
 521         unsigned char val;
 522
 523         spin_lock_irqsave(&up->port.lock, flags);
 524
 525         val = up->cached_dafo;
 526         if (break_state)
 527                 val |= SAB82532_DAFO_XBRK;
 528         else
 529                 val &= ~SAB82532_DAFO_XBRK;
 530         up->cached_dafo = val;
 531
 532         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 533         if (test_bit(SAB82532_XPR, &up->irqflags))
 534                 sunsab_tx_idle(up);
 535
 536         spin_unlock_irqrestore(&up->port.lock, flags);
 537 }
 538
 539 /* port->lock is not held.  */
 540 static int sunsab_startup(struct uart_port *port)
 541 {
 542         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 543         unsigned long flags;
 544         unsigned char tmp;
 545
 546         spin_lock_irqsave(&up->port.lock, flags);
 547
 548         /*
 549          * Wait for any commands or immediate characters
 550          */
 551         sunsab_cec_wait(up);
 552         sunsab_tec_wait(up);
 553
 554         /*
 555          * Clear the FIFO buffers.
 556          */
 557         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
 558         sunsab_cec_wait(up);
 559         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
 560
 561         /*
 562          * Clear the interrupt registers.
 563          */
 564         (void) readb(&up->regs->r.isr0);
 565         (void) readb(&up->regs->r.isr1);
 566
 567         /*
 568          * Now, initialize the UART
 569          */
 570         writeb(0, &up->regs->w.ccr0);                           /* power-down */
 571         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
 572                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
 573         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
 574         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
 575                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
 576         writeb(0, &up->regs->w.ccr3);
 577         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
 578         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
 579                            SAB82532_MODE_RAC);
 580         writeb(up->cached_mode, &up->regs->w.mode);
 581         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
 582
 583         tmp = readb(&up->regs->rw.ccr0);
 584         tmp |= SAB82532_CCR0_PU;        /* power-up */
 585         writeb(tmp, &up->regs->rw.ccr0);
 586
 587         /*
 588          * Finally, enable interrupts
 589          */
 590         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 591                                SAB82532_IMR0_PLLA);
 592         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 593         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 594                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 595                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 596                                SAB82532_IMR1_XPR);
 597         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 598         set_bit(SAB82532_ALLS, &up->irqflags);
 599         set_bit(SAB82532_XPR, &up->irqflags);
 600
 601         spin_unlock_irqrestore(&up->port.lock, flags);
 602
 603         return 0;
 604 }
 605
 606 /* port->lock is not held.  */
 607 static void sunsab_shutdown(struct uart_port *port)
 608 {
 609         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 610         unsigned long flags;
 611
 612         spin_lock_irqsave(&up->port.lock, flags);
 613
 614         /* Disable Interrupts */
 615         up->interrupt_mask0 = 0xff;
 616         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 617         up->interrupt_mask1 = 0xff;
 618         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 619
 620         /* Disable break condition */
 621         up->cached_dafo = readb(&up->regs->rw.dafo);
 622         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
 623         writeb(up->cached_dafo, &up->regs->rw.dafo);
 624
 625         /* Disable Receiver */
 626         up->cached_mode &= ~SAB82532_MODE_RAC;
 627         writeb(up->cached_mode, &up->regs->rw.mode);
 628
 629         /*
 630          * XXX FIXME
 631          *
 632          * If the chip is powered down here the system hangs/crashes during
 633          * reboot or shutdown.  This needs to be investigated further,
 634          * similar behaviour occurs in 2.4 when the driver is configured
 635          * as a module only.  One hint may be that data is sometimes
 636          * transmitted at 9600 baud during shutdown (regardless of the
 637          * speed the chip was configured for when the port was open).
 638          */
 639 #if 0
 640         /* Power Down */
 641         tmp = readb(&up->regs->rw.ccr0);
 642         tmp &= ~SAB82532_CCR0_PU;
 643         writeb(tmp, &up->regs->rw.ccr0);
 644 #endif
 645
 646         spin_unlock_irqrestore(&up->port.lock, flags);
 647 }
 648
 649 /*
 650  * This is used to figure out the divisor speeds.
 651  *
 652  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
 653  *
 654  * with               0 <= N < 64 and 0 <= M < 16
 655  */
 656
 657 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
 658 {
 659         int     n, m;
 660
 661         if (baud == 0) {
 662                 *n_ret = 0;
 663                 *m_ret = 0;
 664                 return;
 665         }
 666
 667         /*
 668          * We scale numbers by 10 so that we get better accuracy
 669          * without having to use floating point.  Here we increment m
 670          * until n is within the valid range.
 671          */
 672         n = (SAB_BASE_BAUD * 10) / baud;
 673         m = 0;
 674         while (n >= 640) {
 675                 n = n / 2;
 676                 m++;
 677         }
 678         n = (n+5) / 10;
 679         /*
 680          * We try very hard to avoid speeds with M == 0 since they may
 681          * not work correctly for XTAL frequences above 10 MHz.
 682          */
 683         if ((m == 0) && ((n & 1) == 0)) {
 684                 n = n / 2;
 685                 m++;
 686         }
 687         *n_ret = n - 1;
 688         *m_ret = m;
 689 }
 690
 691 /* Internal routine, port->lock is held and local interrupts are disabled.  */
 692 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
 693                                   unsigned int iflag, unsigned int baud,
 694                                   unsigned int quot)
 695 {
 696         unsigned char dafo;
 697         int bits, n, m;
 698
 699         /* Byte size and parity */
 700         switch (cflag & CSIZE) {
 701               case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 702               case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
 703               case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
 704               case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
 705               /* Never happens, but GCC is too dumb to figure it out */
 706               default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 707         }
 708
 709         if (cflag & CSTOPB) {
 710                 dafo |= SAB82532_DAFO_STOP;
 711                 bits++;
 712         }
 713
 714         if (cflag & PARENB) {
 715                 dafo |= SAB82532_DAFO_PARE;
 716                 bits++;
 717         }
 718
 719         if (cflag & PARODD) {
 720                 dafo |= SAB82532_DAFO_PAR_ODD;
 721         } else {
 722                 dafo |= SAB82532_DAFO_PAR_EVEN;
 723         }
 724         up->cached_dafo = dafo;
 725
 726         calc_ebrg(baud, &n, &m);
 727
 728         up->cached_ebrg = n | (m << 6);
 729
 730         up->tec_timeout = (10 * 1000000) / baud;
 731         up->cec_timeout = up->tec_timeout >> 2;
 732
 733         /* CTS flow control flags */
 734         /* We encode read_status_mask and ignore_status_mask like so:
 735          *
 736          * ---------------------
 737          * | ... | ISR1 | ISR0 |
 738          * ---------------------
 739          *  ..    15   8 7    0
 740          */
 741
 742         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 743                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 744                                      SAB82532_ISR0_CDSC);
 745         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 746                                       SAB82532_ISR1_ALLS |
 747                                       SAB82532_ISR1_XPR) << 8;
 748         if (iflag & INPCK)
 749                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 750                                               SAB82532_ISR0_FERR);
 751         if (iflag & (BRKINT | PARMRK))
 752                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 753
 754         /*
 755          * Characteres to ignore
 756          */
 757         up->port.ignore_status_mask = 0;
 758         if (iflag & IGNPAR)
 759                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 760                                                 SAB82532_ISR0_FERR);
 761         if (iflag & IGNBRK) {
 762                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 763                 /*
 764                  * If we're ignoring parity and break indicators,
 765                  * ignore overruns too (for real raw support).
 766                  */
 767                 if (iflag & IGNPAR)
 768                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 769         }
 770
 771         /*
 772          * ignore all characters if CREAD is not set
 773          */
 774         if ((cflag & CREAD) == 0)
 775                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 776                                                 SAB82532_ISR0_TCD);
 777
 778         uart_update_timeout(&up->port, cflag,
 779                             (up->port.uartclk / (16 * quot)));
 780
 781         /* Now schedule a register update when the chip's
 782          * transmitter is idle.
 783          */
 784         up->cached_mode |= SAB82532_MODE_RAC;
 785         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 786         if (test_bit(SAB82532_XPR, &up->irqflags))
 787                 sunsab_tx_idle(up);
 788 }
 789
 790 /* port->lock is not held.  */
 791 static void sunsab_set_termios(struct uart_port *port, struct termios *termios,
 792                                struct termios *old)
 793 {
 794         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 795         unsigned long flags;
 796         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 797         unsigned int quot = uart_get_divisor(port, baud);
 798
 799         spin_lock_irqsave(&up->port.lock, flags);
 800         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 801         spin_unlock_irqrestore(&up->port.lock, flags);
 802 }
 803
 804 static const char *sunsab_type(struct uart_port *port)
 805 {
 806         struct uart_sunsab_port *up = (void *)port;
 807         static char buf[36];
 808
 809         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 810         return buf;
 811 }
 812
 813 static void sunsab_release_port(struct uart_port *port)
 814 {
 815 }
 816
 817 static int sunsab_request_port(struct uart_port *port)
 818 {
 819         return 0;
 820 }
 821
 822 static void sunsab_config_port(struct uart_port *port, int flags)
 823 {
 824 }
 825
 826 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 827 {
 828         return -EINVAL;
 829 }
 830
 831 static struct uart_ops sunsab_pops = {
 832         .tx_empty       = sunsab_tx_empty,
 833         .set_mctrl      = sunsab_set_mctrl,
 834         .get_mctrl      = sunsab_get_mctrl,
 835         .stop_tx        = sunsab_stop_tx,
 836         .start_tx       = sunsab_start_tx,
 837         .send_xchar     = sunsab_send_xchar,
 838         .stop_rx        = sunsab_stop_rx,
 839         .enable_ms      = sunsab_enable_ms,
 840         .break_ctl      = sunsab_break_ctl,
 841         .startup        = sunsab_startup,
 842         .shutdown       = sunsab_shutdown,
 843         .set_termios    = sunsab_set_termios,
 844         .type           = sunsab_type,
 845         .release_port   = sunsab_release_port,
 846         .request_port   = sunsab_request_port,
 847         .config_port    = sunsab_config_port,
 848         .verify_port    = sunsab_verify_port,
 849 };
 850
 851 static struct uart_driver sunsab_reg = {
 852         .owner                  = THIS_MODULE,
 853         .driver_name            = "serial",
 854         .dev_name               = "ttyS",
 855         .major                  = TTY_MAJOR,
 856 };
 857
 858 static struct uart_sunsab_port *sunsab_ports;
 859 static int num_channels;
 860
 861 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 862
 863 static void sunsab_console_putchar(struct uart_port *port, int c)
 864 {
 865         struct uart_sunsab_port *up = (struct uart_sunsab_port *)port;
 866         unsigned long flags;
 867
 868         spin_lock_irqsave(&up->port.lock, flags);
 869
 870         sunsab_tec_wait(up);
 871         writeb(c, &up->regs->w.tic);
 872
 873         spin_unlock_irqrestore(&up->port.lock, flags);
 874 }
 875
 876 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 877 {
 878         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 879
 880         uart_console_write(&up->port, s, n, sunsab_console_putchar);
 881         sunsab_tec_wait(up);
 882 }
 883
 884 static int sunsab_console_setup(struct console *con, char *options)
 885 {
 886         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 887         unsigned long flags;
 888         unsigned int baud, quot;
 889
 890         printk("Console: ttyS%d (SAB82532)\n",
 891                (sunsab_reg.minor - 64) + con->index);
 892
 893         sunserial_console_termios(con);
 894
 895         switch (con->cflag & CBAUD) {
 896         case B150: baud = 150; break;
 897         case B300: baud = 300; break;
 898         case B600: baud = 600; break;
 899         case B1200: baud = 1200; break;
 900         case B2400: baud = 2400; break;
 901         case B4800: baud = 4800; break;
 902         default: case B9600: baud = 9600; break;
 903         case B19200: baud = 19200; break;
 904         case B38400: baud = 38400; break;
 905         case B57600: baud = 57600; break;
 906         case B115200: baud = 115200; break;
 907         case B230400: baud = 230400; break;
 908         case B460800: baud = 460800; break;
 909         };
 910
 911         /*
 912          * Temporary fix.
 913          */
 914         spin_lock_init(&up->port.lock);
 915
 916         /*
 917          * Initialize the hardware
 918          */
 919         sunsab_startup(&up->port);
 920
 921         spin_lock_irqsave(&up->port.lock, flags);
 922
 923         /*
 924          * Finally, enable interrupts
 925          */
 926         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 927                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 928         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 929         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 930                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 931                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 932                                 SAB82532_IMR1_XPR;
 933         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 934
 935         quot = uart_get_divisor(&up->port, baud);
 936         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 937         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 938
 939         spin_unlock_irqrestore(&up->port.lock, flags);
 940
 941         return 0;
 942 }
 943
 944 static struct console sunsab_console = {
 945         .name   =       "ttyS",
 946         .write  =       sunsab_console_write,
 947         .device =       uart_console_device,
 948         .setup  =       sunsab_console_setup,
 949         .flags  =       CON_PRINTBUFFER,
 950         .index  =       -1,
 951         .data   =       &sunsab_reg,
 952 };
 953
 954 static inline struct console *SUNSAB_CONSOLE(void)
 955 {
 956         int i;
 957
 958         if (con_is_present())
 959                 return NULL;
 960
 961         for (i = 0; i < num_channels; i++) {
 962                 int this_minor = sunsab_reg.minor + i;
 963
 964                 if ((this_minor - 64) == (serial_console - 1))
 965                         break;
 966         }
 967         if (i == num_channels)
 968                 return NULL;
 969
 970         sunsab_console.index = i;
 971
 972         return &sunsab_console;
 973 }
 974 #else
 975 #define SUNSAB_CONSOLE()        (NULL)
 976 #define sunsab_console_init()   do { } while (0)
 977 #endif
 978
 979 static void __init for_each_sab_edev(void (*callback)(struct linux_ebus_device *, void *), void *arg)
 980 {
 981         struct linux_ebus *ebus;
 982         struct linux_ebus_device *edev = NULL;
 983
 984         for_each_ebus(ebus) {
 985                 for_each_ebusdev(edev, ebus) {
 986                         if (!strcmp(edev->prom_node->name, "se")) {
 987                                 callback(edev, arg);
 988                                 continue;
 989                         } else if (!strcmp(edev->prom_node->name, "serial")) {
 990                                 char *compat;
 991                                 int clen;
 992
 993                                 /* On RIO this can be an SE, check it.  We could
 994                                  * just check ebus->is_rio, but this is more portable.
 995                                  */
 996                                 compat = of_get_property(edev->prom_node,
 997                                                          "compatible", &clen);
 998                                 if (compat && clen > 0) {
 999                                         if (strncmp(compat, "sab82532", 8) == 0) {
1000                                                 callback(edev, arg);
1001                                                 continue;
1002                                         }
1003                                 }
1004                         }
1005                 }
1006         }
1007 }
1008
1009 static void __init sab_count_callback(struct linux_ebus_device *edev, void *arg)
1010 {
1011         int *count_p = arg;
1012
1013         (*count_p)++;
1014 }
1015
1016 static void __init sab_attach_callback(struct linux_ebus_device *edev, void *arg)
1017 {
1018         int *instance_p = arg;
1019         struct uart_sunsab_port *up;
1020         unsigned long regs, offset;
1021         int i;
1022
1023         /* Note: ports are located in reverse order */
1024         regs = edev->resource[0].start;
1025         offset = sizeof(union sab82532_async_regs);
1026         for (i = 0; i < 2; i++) {
1027                 up = &sunsab_ports[(*instance_p * 2) + 1 - i];
1028
1029                 memset(up, 0, sizeof(*up));
1030                 up->regs = ioremap(regs + offset, sizeof(union sab82532_async_regs));
1031                 up->port.irq = edev->irqs[0];
1032                 up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
1033                 up->port.mapbase = (unsigned long)up->regs;
1034                 up->port.iotype = UPIO_MEM;
1035
1036                 writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
1037
1038                 offset -= sizeof(union sab82532_async_regs);
1039         }
1040
1041         (*instance_p)++;
1042 }
1043
1044 static int __init probe_for_sabs(void)
1045 {
1046         int this_sab = 0;
1047
1048         /* Find device instances.  */
1049         for_each_sab_edev(&sab_count_callback, &this_sab);
1050         if (!this_sab)
1051                 return -ENODEV;
1052
1053         /* Allocate tables.  */
1054         sunsab_ports = kmalloc(sizeof(struct uart_sunsab_port) * this_sab * 2,
1055                                GFP_KERNEL);
1056         if (!sunsab_ports)
1057                 return -ENOMEM;
1058
1059         num_channels = this_sab * 2;
1060
1061         this_sab = 0;
1062         for_each_sab_edev(&sab_attach_callback, &this_sab);
1063         return 0;
1064 }
1065
1066 static void __init sunsab_init_hw(void)
1067 {
1068         int i;
1069
1070         for (i = 0; i < num_channels; i++) {
1071                 struct uart_sunsab_port *up = &sunsab_ports[i];
1072
1073                 up->port.line = i;
1074                 up->port.ops = &sunsab_pops;
1075                 up->port.type = PORT_SUNSAB;
1076                 up->port.uartclk = SAB_BASE_BAUD;
1077
1078                 up->type = readb(&up->regs->r.vstr) & 0x0f;
1079                 writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
1080                 writeb(0xff, &up->regs->w.pim);
1081                 if (up->port.line == 0) {
1082                         up->pvr_dsr_bit = (1 << 0);
1083                         up->pvr_dtr_bit = (1 << 1);
1084                 } else {
1085                         up->pvr_dsr_bit = (1 << 3);
1086                         up->pvr_dtr_bit = (1 << 2);
1087                 }
1088                 up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1089                 writeb(up->cached_pvr, &up->regs->w.pvr);
1090                 up->cached_mode = readb(&up->regs->rw.mode);
1091                 up->cached_mode |= SAB82532_MODE_FRTS;
1092                 writeb(up->cached_mode, &up->regs->rw.mode);
1093                 up->cached_mode |= SAB82532_MODE_RTS;
1094                 writeb(up->cached_mode, &up->regs->rw.mode);
1095
1096                 up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1097                 up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1098
1099                 if (!(up->port.line & 0x01)) {
1100                         if (request_irq(up->port.irq, sunsab_interrupt,
1101                                         SA_SHIRQ, "serial(sab82532)", up)) {
1102                                 printk("sunsab%d: can't get IRQ %x\n",
1103                                        i, up->port.irq);
1104                                 continue;
1105                         }
1106                 }
1107         }
1108 }
1109
1110 static int __init sunsab_init(void)
1111 {
1112         int ret = probe_for_sabs();
1113         int i;
1114
1115         if (ret < 0)
1116                 return ret;
1117
1118         sunsab_init_hw();
1119
1120         sunsab_reg.minor = sunserial_current_minor;
1121         sunsab_reg.nr = num_channels;
1122
1123         ret = uart_register_driver(&sunsab_reg);
1124         if (ret < 0) {
1125                 int i;
1126
1127                 for (i = 0; i < num_channels; i++) {
1128                         struct uart_sunsab_port *up = &sunsab_ports[i];
1129
1130                         if (!(up->port.line & 0x01))
1131                                 free_irq(up->port.irq, up);
1132                         iounmap(up->regs);
1133                 }
1134                 kfree(sunsab_ports);
1135                 sunsab_ports = NULL;
1136
1137                 return ret;
1138         }
1139
1140         sunsab_reg.tty_driver->name_base = sunsab_reg.minor - 64;
1141
1142         sunsab_reg.cons = SUNSAB_CONSOLE();
1143
1144         sunserial_current_minor += num_channels;
1145
1146         for (i = 0; i < num_channels; i++) {
1147                 struct uart_sunsab_port *up = &sunsab_ports[i];
1148
1149                 uart_add_one_port(&sunsab_reg, &up->port);
1150         }
1151
1152         return 0;
1153 }
1154
1155 static void __exit sunsab_exit(void)
1156 {
1157         int i;
1158
1159         for (i = 0; i < num_channels; i++) {
1160                 struct uart_sunsab_port *up = &sunsab_ports[i];
1161
1162                 uart_remove_one_port(&sunsab_reg, &up->port);
1163
1164                 if (!(up->port.line & 0x01))
1165                         free_irq(up->port.irq, up);
1166                 iounmap(up->regs);
1167         }
1168
1169         sunserial_current_minor -= num_channels;
1170         uart_unregister_driver(&sunsab_reg);
1171
1172         kfree(sunsab_ports);
1173         sunsab_ports = NULL;
1174 }
1175
1176 module_init(sunsab_init);
1177 module_exit(sunsab_exit);
1178
1179 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1180 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1181 MODULE_LICENSE("GPL");