drivers/tty/serial/sunsab.c

   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 #include <linux/of_device.h>
  36
  37 #include <asm/io.h>
  38 #include <asm/irq.h>
  39 #include <asm/prom.h>
  40 #include <asm/setup.h>
  41
  42 #if defined(CONFIG_SERIAL_SUNSAB_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  43 #define SUPPORT_SYSRQ
  44 #endif
  45
  46 #include <linux/serial_core.h>
  47 #include <linux/sunserialcore.h>
  48
  49 #include "sunsab.h"
  50
  51 struct uart_sunsab_port {
  52         struct uart_port                port;           /* Generic UART port    */
  53         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
  54         unsigned long                   irqflags;       /* IRQ state flags      */
  55         int                             dsr;            /* Current DSR state    */
  56         unsigned int                    cec_timeout;    /* Chip poll timeout... */
  57         unsigned int                    tec_timeout;    /* likewise             */
  58         unsigned char                   interrupt_mask0;/* ISR0 masking         */
  59         unsigned char                   interrupt_mask1;/* ISR1 masking         */
  60         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
  61         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
  62         unsigned int                    gis_shift;
  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_port *
 111 receive_chars(struct uart_sunsab_port *up,
 112               union sab82532_irq_status *stat)
 113 {
 114         struct tty_port *port = NULL;
 115         unsigned char buf[32];
 116         int saw_console_brk = 0;
 117         int free_fifo = 0;
 118         int count = 0;
 119         int i;
 120
 121         if (up->port.state != NULL)             /* Unopened serial console */
 122                 port = &up->port.state->port;
 123
 124         /* Read number of BYTES (Character + Status) available. */
 125         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
 126                 count = SAB82532_RECV_FIFO_SIZE;
 127                 free_fifo++;
 128         }
 129
 130         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
 131                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
 132                 free_fifo++;
 133         }
 134
 135         /* Issue a FIFO read command in case we where idle. */
 136         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
 137                 sunsab_cec_wait(up);
 138                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
 139                 return port;
 140         }
 141
 142         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 143                 free_fifo++;
 144
 145         /* Read the FIFO. */
 146         for (i = 0; i < count; i++)
 147                 buf[i] = readb(&up->regs->r.rfifo[i]);
 148
 149         /* Issue Receive Message Complete command. */
 150         if (free_fifo) {
 151                 sunsab_cec_wait(up);
 152                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
 153         }
 154
 155         /* Count may be zero for BRK, so we check for it here */
 156         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
 157             (up->port.line == up->port.cons->index))
 158                 saw_console_brk = 1;
 159
 160         if (count == 0) {
 161                 if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 162                         stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 163                                              SAB82532_ISR0_FERR);
 164                         up->port.icount.brk++;
 165                         uart_handle_break(&up->port);
 166                 }
 167         }
 168
 169         for (i = 0; i < count; i++) {
 170                 unsigned char ch = buf[i], flag;
 171
 172                 flag = TTY_NORMAL;
 173                 up->port.icount.rx++;
 174
 175                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
 176                                                 SAB82532_ISR0_FERR |
 177                                                 SAB82532_ISR0_RFO)) ||
 178                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 179                         /*
 180                          * For statistics only
 181                          */
 182                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 183                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 184                                                      SAB82532_ISR0_FERR);
 185                                 up->port.icount.brk++;
 186                                 /*
 187                                  * We do the SysRQ and SAK checking
 188                                  * here because otherwise the break
 189                                  * may get masked by ignore_status_mask
 190                                  * or read_status_mask.
 191                                  */
 192                                 if (uart_handle_break(&up->port))
 193                                         continue;
 194                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 195                                 up->port.icount.parity++;
 196                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 197                                 up->port.icount.frame++;
 198                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 199                                 up->port.icount.overrun++;
 200
 201                         /*
 202                          * Mask off conditions which should be ingored.
 203                          */
 204                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
 205                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
 206
 207                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 208                                 flag = TTY_BREAK;
 209                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 210                                 flag = TTY_PARITY;
 211                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 212                                 flag = TTY_FRAME;
 213                 }
 214
 215                 if (uart_handle_sysrq_char(&up->port, ch) || !port)
 216                         continue;
 217
 218                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
 219                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
 220                         tty_insert_flip_char(port, ch, flag);
 221                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 222                         tty_insert_flip_char(port, 0, TTY_OVERRUN);
 223         }
 224
 225         if (saw_console_brk)
 226                 sun_do_break();
 227
 228         return port;
 229 }
 230
 231 static void sunsab_stop_tx(struct uart_port *);
 232 static void sunsab_tx_idle(struct uart_sunsab_port *);
 233
 234 static void transmit_chars(struct uart_sunsab_port *up,
 235                            union sab82532_irq_status *stat)
 236 {
 237         struct circ_buf *xmit = &up->port.state->xmit;
 238         int i;
 239
 240         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
 241                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
 242                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 243                 set_bit(SAB82532_ALLS, &up->irqflags);
 244         }
 245
 246 #if 0 /* bde@nwlink.com says this check causes problems */
 247         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 248                 return;
 249 #endif
 250
 251         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 252                 return;
 253
 254         set_bit(SAB82532_XPR, &up->irqflags);
 255         sunsab_tx_idle(up);
 256
 257         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 258                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 259                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 260                 return;
 261         }
 262
 263         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 264         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 265         clear_bit(SAB82532_ALLS, &up->irqflags);
 266
 267         /* Stuff 32 bytes into Transmit FIFO. */
 268         clear_bit(SAB82532_XPR, &up->irqflags);
 269         for (i = 0; i < up->port.fifosize; i++) {
 270                 writeb(xmit->buf[xmit->tail],
 271                        &up->regs->w.xfifo[i]);
 272                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 273                 up->port.icount.tx++;
 274                 if (uart_circ_empty(xmit))
 275                         break;
 276         }
 277
 278         /* Issue a Transmit Frame command. */
 279         sunsab_cec_wait(up);
 280         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 281
 282         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 283                 uart_write_wakeup(&up->port);
 284
 285         if (uart_circ_empty(xmit))
 286                 sunsab_stop_tx(&up->port);
 287 }
 288
 289 static void check_status(struct uart_sunsab_port *up,
 290                          union sab82532_irq_status *stat)
 291 {
 292         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
 293                 uart_handle_dcd_change(&up->port,
 294                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
 295
 296         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
 297                 uart_handle_cts_change(&up->port,
 298                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
 299
 300         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
 301                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
 302                 up->port.icount.dsr++;
 303         }
 304
 305         wake_up_interruptible(&up->port.state->port.delta_msr_wait);
 306 }
 307
 308 static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
 309 {
 310         struct uart_sunsab_port *up = dev_id;
 311         struct tty_port *port = NULL;
 312         union sab82532_irq_status status;
 313         unsigned long flags;
 314         unsigned char gis;
 315
 316         spin_lock_irqsave(&up->port.lock, flags);
 317
 318         status.stat = 0;
 319         gis = readb(&up->regs->r.gis) >> up->gis_shift;
 320         if (gis & 1)
 321                 status.sreg.isr0 = readb(&up->regs->r.isr0);
 322         if (gis & 2)
 323                 status.sreg.isr1 = readb(&up->regs->r.isr1);
 324
 325         if (status.stat) {
 326                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 327                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
 328                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
 329                         port = receive_chars(up, &status);
 330                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
 331                     (status.sreg.isr1 & SAB82532_ISR1_CSC))
 332                         check_status(up, &status);
 333                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
 334                         transmit_chars(up, &status);
 335         }
 336
 337         spin_unlock_irqrestore(&up->port.lock, flags);
 338
 339         if (port)
 340                 tty_flip_buffer_push(port);
 341
 342         return IRQ_HANDLED;
 343 }
 344
 345 /* port->lock is not held.  */
 346 static unsigned int sunsab_tx_empty(struct uart_port *port)
 347 {
 348         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 349         int ret;
 350
 351         /* Do not need a lock for a state test like this.  */
 352         if (test_bit(SAB82532_ALLS, &up->irqflags))
 353                 ret = TIOCSER_TEMT;
 354         else
 355                 ret = 0;
 356
 357         return ret;
 358 }
 359
 360 /* port->lock held by caller.  */
 361 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
 362 {
 363         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 364
 365         if (mctrl & TIOCM_RTS) {
 366                 up->cached_mode &= ~SAB82532_MODE_FRTS;
 367                 up->cached_mode |= SAB82532_MODE_RTS;
 368         } else {
 369                 up->cached_mode |= (SAB82532_MODE_FRTS |
 370                                     SAB82532_MODE_RTS);
 371         }
 372         if (mctrl & TIOCM_DTR) {
 373                 up->cached_pvr &= ~(up->pvr_dtr_bit);
 374         } else {
 375                 up->cached_pvr |= up->pvr_dtr_bit;
 376         }
 377
 378         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 379         if (test_bit(SAB82532_XPR, &up->irqflags))
 380                 sunsab_tx_idle(up);
 381 }
 382
 383 /* port->lock is held by caller and interrupts are disabled.  */
 384 static unsigned int sunsab_get_mctrl(struct uart_port *port)
 385 {
 386         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 387         unsigned char val;
 388         unsigned int result;
 389
 390         result = 0;
 391
 392         val = readb(&up->regs->r.pvr);
 393         result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
 394
 395         val = readb(&up->regs->r.vstr);
 396         result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
 397
 398         val = readb(&up->regs->r.star);
 399         result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
 400
 401         return result;
 402 }
 403
 404 /* port->lock held by caller.  */
 405 static void sunsab_stop_tx(struct uart_port *port)
 406 {
 407         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 408
 409         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 410         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 411 }
 412
 413 /* port->lock held by caller.  */
 414 static void sunsab_tx_idle(struct uart_sunsab_port *up)
 415 {
 416         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
 417                 u8 tmp;
 418
 419                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
 420                 writeb(up->cached_mode, &up->regs->rw.mode);
 421                 writeb(up->cached_pvr, &up->regs->rw.pvr);
 422                 writeb(up->cached_dafo, &up->regs->w.dafo);
 423
 424                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
 425                 tmp = readb(&up->regs->rw.ccr2);
 426                 tmp &= ~0xc0;
 427                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
 428                 writeb(tmp, &up->regs->rw.ccr2);
 429         }
 430 }
 431
 432 /* port->lock held by caller.  */
 433 static void sunsab_start_tx(struct uart_port *port)
 434 {
 435         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 436         struct circ_buf *xmit = &up->port.state->xmit;
 437         int i;
 438
 439         if (uart_circ_empty(xmit))
 440                 return;
 441
 442         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 443         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 444
 445         if (!test_bit(SAB82532_XPR, &up->irqflags))
 446                 return;
 447
 448         clear_bit(SAB82532_ALLS, &up->irqflags);
 449         clear_bit(SAB82532_XPR, &up->irqflags);
 450
 451         for (i = 0; i < up->port.fifosize; i++) {
 452                 writeb(xmit->buf[xmit->tail],
 453                        &up->regs->w.xfifo[i]);
 454                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 455                 up->port.icount.tx++;
 456                 if (uart_circ_empty(xmit))
 457                         break;
 458         }
 459
 460         /* Issue a Transmit Frame command.  */
 461         sunsab_cec_wait(up);
 462         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 463 }
 464
 465 /* port->lock is not held.  */
 466 static void sunsab_send_xchar(struct uart_port *port, char ch)
 467 {
 468         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 469         unsigned long flags;
 470
 471         spin_lock_irqsave(&up->port.lock, flags);
 472
 473         sunsab_tec_wait(up);
 474         writeb(ch, &up->regs->w.tic);
 475
 476         spin_unlock_irqrestore(&up->port.lock, flags);
 477 }
 478
 479 /* port->lock held by caller.  */
 480 static void sunsab_stop_rx(struct uart_port *port)
 481 {
 482         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 483
 484         up->interrupt_mask0 |= SAB82532_IMR0_TCD;
 485         writeb(up->interrupt_mask1, &up->regs->w.imr0);
 486 }
 487
 488 /* port->lock is not held.  */
 489 static void sunsab_break_ctl(struct uart_port *port, int break_state)
 490 {
 491         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 492         unsigned long flags;
 493         unsigned char val;
 494
 495         spin_lock_irqsave(&up->port.lock, flags);
 496
 497         val = up->cached_dafo;
 498         if (break_state)
 499                 val |= SAB82532_DAFO_XBRK;
 500         else
 501                 val &= ~SAB82532_DAFO_XBRK;
 502         up->cached_dafo = val;
 503
 504         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 505         if (test_bit(SAB82532_XPR, &up->irqflags))
 506                 sunsab_tx_idle(up);
 507
 508         spin_unlock_irqrestore(&up->port.lock, flags);
 509 }
 510
 511 /* port->lock is not held.  */
 512 static int sunsab_startup(struct uart_port *port)
 513 {
 514         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 515         unsigned long flags;
 516         unsigned char tmp;
 517         int err = request_irq(up->port.irq, sunsab_interrupt,
 518                               IRQF_SHARED, "sab", up);
 519         if (err)
 520                 return err;
 521
 522         spin_lock_irqsave(&up->port.lock, flags);
 523
 524         /*
 525          * Wait for any commands or immediate characters
 526          */
 527         sunsab_cec_wait(up);
 528         sunsab_tec_wait(up);
 529
 530         /*
 531          * Clear the FIFO buffers.
 532          */
 533         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
 534         sunsab_cec_wait(up);
 535         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
 536
 537         /*
 538          * Clear the interrupt registers.
 539          */
 540         (void) readb(&up->regs->r.isr0);
 541         (void) readb(&up->regs->r.isr1);
 542
 543         /*
 544          * Now, initialize the UART
 545          */
 546         writeb(0, &up->regs->w.ccr0);                           /* power-down */
 547         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
 548                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
 549         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
 550         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
 551                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
 552         writeb(0, &up->regs->w.ccr3);
 553         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
 554         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
 555                            SAB82532_MODE_RAC);
 556         writeb(up->cached_mode, &up->regs->w.mode);
 557         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
 558
 559         tmp = readb(&up->regs->rw.ccr0);
 560         tmp |= SAB82532_CCR0_PU;        /* power-up */
 561         writeb(tmp, &up->regs->rw.ccr0);
 562
 563         /*
 564          * Finally, enable interrupts
 565          */
 566         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 567                                SAB82532_IMR0_PLLA);
 568         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 569         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 570                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 571                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 572                                SAB82532_IMR1_XPR);
 573         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 574         set_bit(SAB82532_ALLS, &up->irqflags);
 575         set_bit(SAB82532_XPR, &up->irqflags);
 576
 577         spin_unlock_irqrestore(&up->port.lock, flags);
 578
 579         return 0;
 580 }
 581
 582 /* port->lock is not held.  */
 583 static void sunsab_shutdown(struct uart_port *port)
 584 {
 585         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 586         unsigned long flags;
 587
 588         spin_lock_irqsave(&up->port.lock, flags);
 589
 590         /* Disable Interrupts */
 591         up->interrupt_mask0 = 0xff;
 592         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 593         up->interrupt_mask1 = 0xff;
 594         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 595
 596         /* Disable break condition */
 597         up->cached_dafo = readb(&up->regs->rw.dafo);
 598         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
 599         writeb(up->cached_dafo, &up->regs->rw.dafo);
 600
 601         /* Disable Receiver */
 602         up->cached_mode &= ~SAB82532_MODE_RAC;
 603         writeb(up->cached_mode, &up->regs->rw.mode);
 604
 605         /*
 606          * XXX FIXME
 607          *
 608          * If the chip is powered down here the system hangs/crashes during
 609          * reboot or shutdown.  This needs to be investigated further,
 610          * similar behaviour occurs in 2.4 when the driver is configured
 611          * as a module only.  One hint may be that data is sometimes
 612          * transmitted at 9600 baud during shutdown (regardless of the
 613          * speed the chip was configured for when the port was open).
 614          */
 615 #if 0
 616         /* Power Down */
 617         tmp = readb(&up->regs->rw.ccr0);
 618         tmp &= ~SAB82532_CCR0_PU;
 619         writeb(tmp, &up->regs->rw.ccr0);
 620 #endif
 621
 622         spin_unlock_irqrestore(&up->port.lock, flags);
 623         free_irq(up->port.irq, up);
 624 }
 625
 626 /*
 627  * This is used to figure out the divisor speeds.
 628  *
 629  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
 630  *
 631  * with               0 <= N < 64 and 0 <= M < 16
 632  */
 633
 634 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
 635 {
 636         int     n, m;
 637
 638         if (baud == 0) {
 639                 *n_ret = 0;
 640                 *m_ret = 0;
 641                 return;
 642         }
 643
 644         /*
 645          * We scale numbers by 10 so that we get better accuracy
 646          * without having to use floating point.  Here we increment m
 647          * until n is within the valid range.
 648          */
 649         n = (SAB_BASE_BAUD * 10) / baud;
 650         m = 0;
 651         while (n >= 640) {
 652                 n = n / 2;
 653                 m++;
 654         }
 655         n = (n+5) / 10;
 656         /*
 657          * We try very hard to avoid speeds with M == 0 since they may
 658          * not work correctly for XTAL frequences above 10 MHz.
 659          */
 660         if ((m == 0) && ((n & 1) == 0)) {
 661                 n = n / 2;
 662                 m++;
 663         }
 664         *n_ret = n - 1;
 665         *m_ret = m;
 666 }
 667
 668 /* Internal routine, port->lock is held and local interrupts are disabled.  */
 669 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
 670                                   unsigned int iflag, unsigned int baud,
 671                                   unsigned int quot)
 672 {
 673         unsigned char dafo;
 674         int bits, n, m;
 675
 676         /* Byte size and parity */
 677         switch (cflag & CSIZE) {
 678               case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 679               case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
 680               case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
 681               case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
 682               /* Never happens, but GCC is too dumb to figure it out */
 683               default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 684         }
 685
 686         if (cflag & CSTOPB) {
 687                 dafo |= SAB82532_DAFO_STOP;
 688                 bits++;
 689         }
 690
 691         if (cflag & PARENB) {
 692                 dafo |= SAB82532_DAFO_PARE;
 693                 bits++;
 694         }
 695
 696         if (cflag & PARODD) {
 697                 dafo |= SAB82532_DAFO_PAR_ODD;
 698         } else {
 699                 dafo |= SAB82532_DAFO_PAR_EVEN;
 700         }
 701         up->cached_dafo = dafo;
 702
 703         calc_ebrg(baud, &n, &m);
 704
 705         up->cached_ebrg = n | (m << 6);
 706
 707         up->tec_timeout = (10 * 1000000) / baud;
 708         up->cec_timeout = up->tec_timeout >> 2;
 709
 710         /* CTS flow control flags */
 711         /* We encode read_status_mask and ignore_status_mask like so:
 712          *
 713          * ---------------------
 714          * | ... | ISR1 | ISR0 |
 715          * ---------------------
 716          *  ..    15   8 7    0
 717          */
 718
 719         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 720                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 721                                      SAB82532_ISR0_CDSC);
 722         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 723                                       SAB82532_ISR1_ALLS |
 724                                       SAB82532_ISR1_XPR) << 8;
 725         if (iflag & INPCK)
 726                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 727                                               SAB82532_ISR0_FERR);
 728         if (iflag & (IGNBRK | BRKINT | PARMRK))
 729                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 730
 731         /*
 732          * Characteres to ignore
 733          */
 734         up->port.ignore_status_mask = 0;
 735         if (iflag & IGNPAR)
 736                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 737                                                 SAB82532_ISR0_FERR);
 738         if (iflag & IGNBRK) {
 739                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 740                 /*
 741                  * If we're ignoring parity and break indicators,
 742                  * ignore overruns too (for real raw support).
 743                  */
 744                 if (iflag & IGNPAR)
 745                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 746         }
 747
 748         /*
 749          * ignore all characters if CREAD is not set
 750          */
 751         if ((cflag & CREAD) == 0)
 752                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 753                                                 SAB82532_ISR0_TCD);
 754
 755         uart_update_timeout(&up->port, cflag,
 756                             (up->port.uartclk / (16 * quot)));
 757
 758         /* Now schedule a register update when the chip's
 759          * transmitter is idle.
 760          */
 761         up->cached_mode |= SAB82532_MODE_RAC;
 762         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 763         if (test_bit(SAB82532_XPR, &up->irqflags))
 764                 sunsab_tx_idle(up);
 765 }
 766
 767 /* port->lock is not held.  */
 768 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 769                                struct ktermios *old)
 770 {
 771         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
 772         unsigned long flags;
 773         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 774         unsigned int quot = uart_get_divisor(port, baud);
 775
 776         spin_lock_irqsave(&up->port.lock, flags);
 777         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 778         spin_unlock_irqrestore(&up->port.lock, flags);
 779 }
 780
 781 static const char *sunsab_type(struct uart_port *port)
 782 {
 783         struct uart_sunsab_port *up = (void *)port;
 784         static char buf[36];
 785
 786         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 787         return buf;
 788 }
 789
 790 static void sunsab_release_port(struct uart_port *port)
 791 {
 792 }
 793
 794 static int sunsab_request_port(struct uart_port *port)
 795 {
 796         return 0;
 797 }
 798
 799 static void sunsab_config_port(struct uart_port *port, int flags)
 800 {
 801 }
 802
 803 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 804 {
 805         return -EINVAL;
 806 }
 807
 808 static struct uart_ops sunsab_pops = {
 809         .tx_empty       = sunsab_tx_empty,
 810         .set_mctrl      = sunsab_set_mctrl,
 811         .get_mctrl      = sunsab_get_mctrl,
 812         .stop_tx        = sunsab_stop_tx,
 813         .start_tx       = sunsab_start_tx,
 814         .send_xchar     = sunsab_send_xchar,
 815         .stop_rx        = sunsab_stop_rx,
 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         if (up->port.sysrq || oops_in_progress)
 853                 locked = spin_trylock_irqsave(&up->port.lock, flags);
 854         else
 855                 spin_lock_irqsave(&up->port.lock, flags);
 856
 857         uart_console_write(&up->port, s, n, sunsab_console_putchar);
 858         sunsab_tec_wait(up);
 859
 860         if (locked)
 861                 spin_unlock_irqrestore(&up->port.lock, flags);
 862 }
 863
 864 static int sunsab_console_setup(struct console *con, char *options)
 865 {
 866         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 867         unsigned long flags;
 868         unsigned int baud, quot;
 869
 870         /*
 871          * The console framework calls us for each and every port
 872          * registered. Defer the console setup until the requested
 873          * port has been properly discovered. A bit of a hack,
 874          * though...
 875          */
 876         if (up->port.type != PORT_SUNSAB)
 877                 return -1;
 878
 879         printk("Console: ttyS%d (SAB82532)\n",
 880                (sunsab_reg.minor - 64) + con->index);
 881
 882         sunserial_console_termios(con, up->port.dev->of_node);
 883
 884         switch (con->cflag & CBAUD) {
 885         case B150: baud = 150; break;
 886         case B300: baud = 300; break;
 887         case B600: baud = 600; break;
 888         case B1200: baud = 1200; break;
 889         case B2400: baud = 2400; break;
 890         case B4800: baud = 4800; break;
 891         default: case B9600: baud = 9600; break;
 892         case B19200: baud = 19200; break;
 893         case B38400: baud = 38400; break;
 894         case B57600: baud = 57600; break;
 895         case B115200: baud = 115200; break;
 896         case B230400: baud = 230400; break;
 897         case B460800: baud = 460800; break;
 898         }
 899
 900         /*
 901          * Temporary fix.
 902          */
 903         spin_lock_init(&up->port.lock);
 904
 905         /*
 906          * Initialize the hardware
 907          */
 908         sunsab_startup(&up->port);
 909
 910         spin_lock_irqsave(&up->port.lock, flags);
 911
 912         /*
 913          * Finally, enable interrupts
 914          */
 915         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 916                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 917         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 918         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 919                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 920                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 921                                 SAB82532_IMR1_XPR;
 922         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 923
 924         quot = uart_get_divisor(&up->port, baud);
 925         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 926         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 927
 928         spin_unlock_irqrestore(&up->port.lock, flags);
 929
 930         return 0;
 931 }
 932
 933 static struct console sunsab_console = {
 934         .name   =       "ttyS",
 935         .write  =       sunsab_console_write,
 936         .device =       uart_console_device,
 937         .setup  =       sunsab_console_setup,
 938         .flags  =       CON_PRINTBUFFER,
 939         .index  =       -1,
 940         .data   =       &sunsab_reg,
 941 };
 942
 943 static inline struct console *SUNSAB_CONSOLE(void)
 944 {
 945         return &sunsab_console;
 946 }
 947 #else
 948 #define SUNSAB_CONSOLE()        (NULL)
 949 #define sunsab_console_init()   do { } while (0)
 950 #endif
 951
 952 static int sunsab_init_one(struct uart_sunsab_port *up,
 953                                      struct platform_device *op,
 954                                      unsigned long offset,
 955                                      int line)
 956 {
 957         up->port.line = line;
 958         up->port.dev = &op->dev;
 959
 960         up->port.mapbase = op->resource[0].start + offset;
 961         up->port.membase = of_ioremap(&op->resource[0], offset,
 962                                       sizeof(union sab82532_async_regs),
 963                                       "sab");
 964         if (!up->port.membase)
 965                 return -ENOMEM;
 966         up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
 967
 968         up->port.irq = op->archdata.irqs[0];
 969
 970         up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
 971         up->port.iotype = UPIO_MEM;
 972
 973         writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
 974
 975         up->port.ops = &sunsab_pops;
 976         up->port.type = PORT_SUNSAB;
 977         up->port.uartclk = SAB_BASE_BAUD;
 978
 979         up->type = readb(&up->regs->r.vstr) & 0x0f;
 980         writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
 981         writeb(0xff, &up->regs->w.pim);
 982         if ((up->port.line & 0x1) == 0) {
 983                 up->pvr_dsr_bit = (1 << 0);
 984                 up->pvr_dtr_bit = (1 << 1);
 985                 up->gis_shift = 2;
 986         } else {
 987                 up->pvr_dsr_bit = (1 << 3);
 988                 up->pvr_dtr_bit = (1 << 2);
 989                 up->gis_shift = 0;
 990         }
 991         up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
 992         writeb(up->cached_pvr, &up->regs->w.pvr);
 993         up->cached_mode = readb(&up->regs->rw.mode);
 994         up->cached_mode |= SAB82532_MODE_FRTS;
 995         writeb(up->cached_mode, &up->regs->rw.mode);
 996         up->cached_mode |= SAB82532_MODE_RTS;
 997         writeb(up->cached_mode, &up->regs->rw.mode);
 998
 999         up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1000         up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1001
1002         return 0;
1003 }
1004
1005 static int sab_probe(struct platform_device *op)
1006 {
1007         static int inst;
1008         struct uart_sunsab_port *up;
1009         int err;
1010
1011         up = &sunsab_ports[inst * 2];
1012
1013         err = sunsab_init_one(&up[0], op,
1014                               0,
1015                               (inst * 2) + 0);
1016         if (err)
1017                 goto out;
1018
1019         err = sunsab_init_one(&up[1], op,
1020                               sizeof(union sab82532_async_regs),
1021                               (inst * 2) + 1);
1022         if (err)
1023                 goto out1;
1024
1025         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1026                                 &sunsab_reg, up[0].port.line,
1027                                 false);
1028
1029         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1030                                 &sunsab_reg, up[1].port.line,
1031                                 false);
1032
1033         err = uart_add_one_port(&sunsab_reg, &up[0].port);
1034         if (err)
1035                 goto out2;
1036
1037         err = uart_add_one_port(&sunsab_reg, &up[1].port);
1038         if (err)
1039                 goto out3;
1040
1041         platform_set_drvdata(op, &up[0]);
1042
1043         inst++;
1044
1045         return 0;
1046
1047 out3:
1048         uart_remove_one_port(&sunsab_reg, &up[0].port);
1049 out2:
1050         of_iounmap(&op->resource[0],
1051                    up[1].port.membase,
1052                    sizeof(union sab82532_async_regs));
1053 out1:
1054         of_iounmap(&op->resource[0],
1055                    up[0].port.membase,
1056                    sizeof(union sab82532_async_regs));
1057 out:
1058         return err;
1059 }
1060
1061 static int sab_remove(struct platform_device *op)
1062 {
1063         struct uart_sunsab_port *up = platform_get_drvdata(op);
1064
1065         uart_remove_one_port(&sunsab_reg, &up[1].port);
1066         uart_remove_one_port(&sunsab_reg, &up[0].port);
1067         of_iounmap(&op->resource[0],
1068                    up[1].port.membase,
1069                    sizeof(union sab82532_async_regs));
1070         of_iounmap(&op->resource[0],
1071                    up[0].port.membase,
1072                    sizeof(union sab82532_async_regs));
1073
1074         return 0;
1075 }
1076
1077 static const struct of_device_id sab_match[] = {
1078         {
1079                 .name = "se",
1080         },
1081         {
1082                 .name = "serial",
1083                 .compatible = "sab82532",
1084         },
1085         {},
1086 };
1087 MODULE_DEVICE_TABLE(of, sab_match);
1088
1089 static struct platform_driver sab_driver = {
1090         .driver = {
1091                 .name = "sab",
1092                 .owner = THIS_MODULE,
1093                 .of_match_table = sab_match,
1094         },
1095         .probe          = sab_probe,
1096         .remove         = sab_remove,
1097 };
1098
1099 static int __init sunsab_init(void)
1100 {
1101         struct device_node *dp;
1102         int err;
1103         int num_channels = 0;
1104
1105         for_each_node_by_name(dp, "se")
1106                 num_channels += 2;
1107         for_each_node_by_name(dp, "serial") {
1108                 if (of_device_is_compatible(dp, "sab82532"))
1109                         num_channels += 2;
1110         }
1111
1112         if (num_channels) {
1113                 sunsab_ports = kzalloc(sizeof(struct uart_sunsab_port) *
1114                                        num_channels, GFP_KERNEL);
1115                 if (!sunsab_ports)
1116                         return -ENOMEM;
1117
1118                 err = sunserial_register_minors(&sunsab_reg, num_channels);
1119                 if (err) {
1120                         kfree(sunsab_ports);
1121                         sunsab_ports = NULL;
1122
1123                         return err;
1124                 }
1125         }
1126
1127         return platform_driver_register(&sab_driver);
1128 }
1129
1130 static void __exit sunsab_exit(void)
1131 {
1132         platform_driver_unregister(&sab_driver);
1133         if (sunsab_reg.nr) {
1134                 sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1135         }
1136
1137         kfree(sunsab_ports);
1138         sunsab_ports = NULL;
1139 }
1140
1141 module_init(sunsab_init);
1142 module_exit(sunsab_exit);
1143
1144 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1145 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1146 MODULE_LICENSE("GPL");