drivers/tty/serial/sunsab.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
   3  *
   4  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
   5  * Copyright (C) 2002, 2006  David S. Miller (davem@davemloft.net)
   6  *
   7  * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
   8  *   Maxim Krasnyanskiy <maxk@qualcomm.com>
   9  *
  10  * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
  11  * rates to be programmed into the UART.  Also eliminated a lot of
  12  * duplicated code in the console setup.
  13  *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
  14  *
  15  * Ported to new 2.5.x UART layer.
  16  *   David S. Miller <davem@davemloft.net>
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/errno.h>
  22 #include <linux/tty.h>
  23 #include <linux/tty_flip.h>
  24 #include <linux/major.h>
  25 #include <linux/string.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/ioport.h>
  28 #include <linux/circ_buf.h>
  29 #include <linux/serial.h>
  30 #include <linux/sysrq.h>
  31 #include <linux/console.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/slab.h>
  34 #include <linux/delay.h>
  35 #include <linux/init.h>
  36 #include <linux/of_device.h>
  37
  38 #include <asm/io.h>
  39 #include <asm/irq.h>
  40 #include <asm/prom.h>
  41 #include <asm/setup.h>
  42
  43 #if defined(CONFIG_SERIAL_SUNSAB_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  44 #define SUPPORT_SYSRQ
  45 #endif
  46
  47 #include <linux/serial_core.h>
  48 #include <linux/sunserialcore.h>
  49
  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         unsigned int                    gis_shift;
  64         int                             type;           /* SAB82532 version     */
  65
  66         /* Setting configuration bits while the transmitter is active
  67          * can cause garbage characters to get emitted by the chip.
  68          * Therefore, we cache such writes here and do the real register
  69          * write the next time the transmitter becomes idle.
  70          */
  71         unsigned int                    cached_ebrg;
  72         unsigned char                   cached_mode;
  73         unsigned char                   cached_pvr;
  74         unsigned char                   cached_dafo;
  75 };
  76
  77 /*
  78  * This assumes you have a 29.4912 MHz clock for your UART.
  79  */
  80 #define SAB_BASE_BAUD ( 29491200 / 16 )
  81
  82 static char *sab82532_version[16] = {
  83         "V1.0", "V2.0", "V3.2", "V(0x03)",
  84         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
  85         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
  86         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
  87 };
  88
  89 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
  90 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
  91
  92 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
  93 #define SAB82532_XMIT_FIFO_SIZE 32
  94
  95 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
  96 {
  97         int timeout = up->tec_timeout;
  98
  99         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
 100                 udelay(1);
 101 }
 102
 103 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
 104 {
 105         int timeout = up->cec_timeout;
 106
 107         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
 108                 udelay(1);
 109 }
 110
 111 static struct tty_port *
 112 receive_chars(struct uart_sunsab_port *up,
 113               union sab82532_irq_status *stat)
 114 {
 115         struct tty_port *port = 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.state != NULL)             /* Unopened serial console */
 123                 port = &up->port.state->port;
 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 port;
 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         if (count == 0) {
 162                 if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 163                         stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 164                                              SAB82532_ISR0_FERR);
 165                         up->port.icount.brk++;
 166                         uart_handle_break(&up->port);
 167                 }
 168         }
 169
 170         for (i = 0; i < count; i++) {
 171                 unsigned char ch = buf[i], flag;
 172
 173                 flag = TTY_NORMAL;
 174                 up->port.icount.rx++;
 175
 176                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
 177                                                 SAB82532_ISR0_FERR |
 178                                                 SAB82532_ISR0_RFO)) ||
 179                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 180                         /*
 181                          * For statistics only
 182                          */
 183                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 184                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 185                                                      SAB82532_ISR0_FERR);
 186                                 up->port.icount.brk++;
 187                                 /*
 188                                  * We do the SysRQ and SAK checking
 189                                  * here because otherwise the break
 190                                  * may get masked by ignore_status_mask
 191                                  * or read_status_mask.
 192                                  */
 193                                 if (uart_handle_break(&up->port))
 194                                         continue;
 195                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 196                                 up->port.icount.parity++;
 197                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 198                                 up->port.icount.frame++;
 199                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 200                                 up->port.icount.overrun++;
 201
 202                         /*
 203                          * Mask off conditions which should be ingored.
 204                          */
 205                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
 206                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
 207
 208                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 209                                 flag = TTY_BREAK;
 210                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 211                                 flag = TTY_PARITY;
 212                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 213                                 flag = TTY_FRAME;
 214                 }
 215
 216                 if (uart_handle_sysrq_char(&up->port, ch) || !port)
 217                         continue;
 218
 219                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
 220                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
 221                         tty_insert_flip_char(port, ch, flag);
 222                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 223                         tty_insert_flip_char(port, 0, TTY_OVERRUN);
 224         }
 225
 226         if (saw_console_brk)
 227                 sun_do_break();
 228
 229         return port;
 230 }
 231
 232 static void sunsab_stop_tx(struct uart_port *);
 233 static void sunsab_tx_idle(struct uart_sunsab_port *);
 234
 235 static void transmit_chars(struct uart_sunsab_port *up,
 236                            union sab82532_irq_status *stat)
 237 {
 238         struct circ_buf *xmit = &up->port.state->xmit;
 239         int i;
 240
 241         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
 242                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
 243                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 244                 set_bit(SAB82532_ALLS, &up->irqflags);
 245         }
 246
 247 #if 0 /* bde@nwlink.com says this check causes problems */
 248         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 249                 return;
 250 #endif
 251
 252         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 253                 return;
 254
 255         set_bit(SAB82532_XPR, &up->irqflags);
 256         sunsab_tx_idle(up);
 257
 258         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 259                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 260                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 261                 return;
 262         }
 263
 264         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 265         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 266         clear_bit(SAB82532_ALLS, &up->irqflags);
 267
 268         /* Stuff 32 bytes into Transmit FIFO. */
 269         clear_bit(SAB82532_XPR, &up->irqflags);
 270         for (i = 0; i < up->port.fifosize; i++) {
 271                 writeb(xmit->buf[xmit->tail],
 272                        &up->regs->w.xfifo[i]);
 273                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 274                 up->port.icount.tx++;
 275                 if (uart_circ_empty(xmit))
 276                         break;
 277         }
 278
 279         /* Issue a Transmit Frame command. */
 280         sunsab_cec_wait(up);
 281         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 282
 283         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 284                 uart_write_wakeup(&up->port);
 285
 286         if (uart_circ_empty(xmit))
 287                 sunsab_stop_tx(&up->port);
 288 }
 289
 290 static void check_status(struct uart_sunsab_port *up,
 291                          union sab82532_irq_status *stat)
 292 {
 293         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
 294                 uart_handle_dcd_change(&up->port,
 295                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
 296
 297         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
 298                 uart_handle_cts_change(&up->port,
 299                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
 300
 301         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
 302                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
 303                 up->port.icount.dsr++;
 304         }
 305
 306         wake_up_interruptible(&up->port.state->port.delta_msr_wait);
 307 }
 308
 309 static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
 310 {
 311         struct uart_sunsab_port *up = dev_id;
 312         struct tty_port *port = NULL;
 313         union sab82532_irq_status status;
 314         unsigned long flags;
 315         unsigned char gis;
 316
 317         spin_lock_irqsave(&up->port.lock, flags);
 318
 319         status.stat = 0;
 320         gis = readb(&up->regs->r.gis) >> up->gis_shift;
 321         if (gis & 1)
 322                 status.sreg.isr0 = readb(&up->regs->r.isr0);
 323         if (gis & 2)
 324                 status.sreg.isr1 = readb(&up->regs->r.isr1);
 325
 326         if (status.stat) {
 327                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 328                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
 329                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
 330                         port = receive_chars(up, &status);
 331                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
 332                     (status.sreg.isr1 & SAB82532_ISR1_CSC))
 333                         check_status(up, &status);
 334                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
 335                         transmit_chars(up, &status);
 336         }
 337
 338         spin_unlock_irqrestore(&up->port.lock, flags);
 339
 340         if (port)
 341                 tty_flip_buffer_push(port);
 342
 343         return IRQ_HANDLED;
 344 }
 345
 346 /* port->lock is not held.  */
 347 static unsigned int sunsab_tx_empty(struct uart_port *port)
 348 {
 349         struct uart_sunsab_port *up =
 350                 container_of(port, struct uart_sunsab_port, port);
 351         int ret;
 352
 353         /* Do not need a lock for a state test like this.  */
 354         if (test_bit(SAB82532_ALLS, &up->irqflags))
 355                 ret = TIOCSER_TEMT;
 356         else
 357                 ret = 0;
 358
 359         return ret;
 360 }
 361
 362 /* port->lock held by caller.  */
 363 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
 364 {
 365         struct uart_sunsab_port *up =
 366                 container_of(port, struct uart_sunsab_port, port);
 367
 368         if (mctrl & TIOCM_RTS) {
 369                 up->cached_mode &= ~SAB82532_MODE_FRTS;
 370                 up->cached_mode |= SAB82532_MODE_RTS;
 371         } else {
 372                 up->cached_mode |= (SAB82532_MODE_FRTS |
 373                                     SAB82532_MODE_RTS);
 374         }
 375         if (mctrl & TIOCM_DTR) {
 376                 up->cached_pvr &= ~(up->pvr_dtr_bit);
 377         } else {
 378                 up->cached_pvr |= up->pvr_dtr_bit;
 379         }
 380
 381         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 382         if (test_bit(SAB82532_XPR, &up->irqflags))
 383                 sunsab_tx_idle(up);
 384 }
 385
 386 /* port->lock is held by caller and interrupts are disabled.  */
 387 static unsigned int sunsab_get_mctrl(struct uart_port *port)
 388 {
 389         struct uart_sunsab_port *up =
 390                 container_of(port, struct uart_sunsab_port, port);
 391         unsigned char val;
 392         unsigned int result;
 393
 394         result = 0;
 395
 396         val = readb(&up->regs->r.pvr);
 397         result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
 398
 399         val = readb(&up->regs->r.vstr);
 400         result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
 401
 402         val = readb(&up->regs->r.star);
 403         result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
 404
 405         return result;
 406 }
 407
 408 /* port->lock held by caller.  */
 409 static void sunsab_stop_tx(struct uart_port *port)
 410 {
 411         struct uart_sunsab_port *up =
 412                 container_of(port, struct uart_sunsab_port, port);
 413
 414         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 415         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 416 }
 417
 418 /* port->lock held by caller.  */
 419 static void sunsab_tx_idle(struct uart_sunsab_port *up)
 420 {
 421         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
 422                 u8 tmp;
 423
 424                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
 425                 writeb(up->cached_mode, &up->regs->rw.mode);
 426                 writeb(up->cached_pvr, &up->regs->rw.pvr);
 427                 writeb(up->cached_dafo, &up->regs->w.dafo);
 428
 429                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
 430                 tmp = readb(&up->regs->rw.ccr2);
 431                 tmp &= ~0xc0;
 432                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
 433                 writeb(tmp, &up->regs->rw.ccr2);
 434         }
 435 }
 436
 437 /* port->lock held by caller.  */
 438 static void sunsab_start_tx(struct uart_port *port)
 439 {
 440         struct uart_sunsab_port *up =
 441                 container_of(port, struct uart_sunsab_port, port);
 442         struct circ_buf *xmit = &up->port.state->xmit;
 443         int i;
 444
 445         if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 446                 return;
 447
 448         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 449         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 450
 451         if (!test_bit(SAB82532_XPR, &up->irqflags))
 452                 return;
 453
 454         clear_bit(SAB82532_ALLS, &up->irqflags);
 455         clear_bit(SAB82532_XPR, &up->irqflags);
 456
 457         for (i = 0; i < up->port.fifosize; i++) {
 458                 writeb(xmit->buf[xmit->tail],
 459                        &up->regs->w.xfifo[i]);
 460                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 461                 up->port.icount.tx++;
 462                 if (uart_circ_empty(xmit))
 463                         break;
 464         }
 465
 466         /* Issue a Transmit Frame command.  */
 467         sunsab_cec_wait(up);
 468         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 469 }
 470
 471 /* port->lock is not held.  */
 472 static void sunsab_send_xchar(struct uart_port *port, char ch)
 473 {
 474         struct uart_sunsab_port *up =
 475                 container_of(port, struct uart_sunsab_port, port);
 476         unsigned long flags;
 477
 478         if (ch == __DISABLED_CHAR)
 479                 return;
 480
 481         spin_lock_irqsave(&up->port.lock, flags);
 482
 483         sunsab_tec_wait(up);
 484         writeb(ch, &up->regs->w.tic);
 485
 486         spin_unlock_irqrestore(&up->port.lock, flags);
 487 }
 488
 489 /* port->lock held by caller.  */
 490 static void sunsab_stop_rx(struct uart_port *port)
 491 {
 492         struct uart_sunsab_port *up =
 493                 container_of(port, struct uart_sunsab_port, port);
 494
 495         up->interrupt_mask0 |= SAB82532_IMR0_TCD;
 496         writeb(up->interrupt_mask1, &up->regs->w.imr0);
 497 }
 498
 499 /* port->lock is not held.  */
 500 static void sunsab_break_ctl(struct uart_port *port, int break_state)
 501 {
 502         struct uart_sunsab_port *up =
 503                 container_of(port, struct uart_sunsab_port, port);
 504         unsigned long flags;
 505         unsigned char val;
 506
 507         spin_lock_irqsave(&up->port.lock, flags);
 508
 509         val = up->cached_dafo;
 510         if (break_state)
 511                 val |= SAB82532_DAFO_XBRK;
 512         else
 513                 val &= ~SAB82532_DAFO_XBRK;
 514         up->cached_dafo = val;
 515
 516         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 517         if (test_bit(SAB82532_XPR, &up->irqflags))
 518                 sunsab_tx_idle(up);
 519
 520         spin_unlock_irqrestore(&up->port.lock, flags);
 521 }
 522
 523 /* port->lock is not held.  */
 524 static int sunsab_startup(struct uart_port *port)
 525 {
 526         struct uart_sunsab_port *up =
 527                 container_of(port, struct uart_sunsab_port, port);
 528         unsigned long flags;
 529         unsigned char tmp;
 530         int err = request_irq(up->port.irq, sunsab_interrupt,
 531                               IRQF_SHARED, "sab", up);
 532         if (err)
 533                 return err;
 534
 535         spin_lock_irqsave(&up->port.lock, flags);
 536
 537         /*
 538          * Wait for any commands or immediate characters
 539          */
 540         sunsab_cec_wait(up);
 541         sunsab_tec_wait(up);
 542
 543         /*
 544          * Clear the FIFO buffers.
 545          */
 546         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
 547         sunsab_cec_wait(up);
 548         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
 549
 550         /*
 551          * Clear the interrupt registers.
 552          */
 553         (void) readb(&up->regs->r.isr0);
 554         (void) readb(&up->regs->r.isr1);
 555
 556         /*
 557          * Now, initialize the UART
 558          */
 559         writeb(0, &up->regs->w.ccr0);                           /* power-down */
 560         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
 561                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
 562         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
 563         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
 564                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
 565         writeb(0, &up->regs->w.ccr3);
 566         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
 567         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
 568                            SAB82532_MODE_RAC);
 569         writeb(up->cached_mode, &up->regs->w.mode);
 570         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
 571
 572         tmp = readb(&up->regs->rw.ccr0);
 573         tmp |= SAB82532_CCR0_PU;        /* power-up */
 574         writeb(tmp, &up->regs->rw.ccr0);
 575
 576         /*
 577          * Finally, enable interrupts
 578          */
 579         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 580                                SAB82532_IMR0_PLLA);
 581         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 582         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 583                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 584                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 585                                SAB82532_IMR1_XPR);
 586         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 587         set_bit(SAB82532_ALLS, &up->irqflags);
 588         set_bit(SAB82532_XPR, &up->irqflags);
 589
 590         spin_unlock_irqrestore(&up->port.lock, flags);
 591
 592         return 0;
 593 }
 594
 595 /* port->lock is not held.  */
 596 static void sunsab_shutdown(struct uart_port *port)
 597 {
 598         struct uart_sunsab_port *up =
 599                 container_of(port, struct uart_sunsab_port, port);
 600         unsigned long flags;
 601
 602         spin_lock_irqsave(&up->port.lock, flags);
 603
 604         /* Disable Interrupts */
 605         up->interrupt_mask0 = 0xff;
 606         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 607         up->interrupt_mask1 = 0xff;
 608         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 609
 610         /* Disable break condition */
 611         up->cached_dafo = readb(&up->regs->rw.dafo);
 612         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
 613         writeb(up->cached_dafo, &up->regs->rw.dafo);
 614
 615         /* Disable Receiver */
 616         up->cached_mode &= ~SAB82532_MODE_RAC;
 617         writeb(up->cached_mode, &up->regs->rw.mode);
 618
 619         /*
 620          * XXX FIXME
 621          *
 622          * If the chip is powered down here the system hangs/crashes during
 623          * reboot or shutdown.  This needs to be investigated further,
 624          * similar behaviour occurs in 2.4 when the driver is configured
 625          * as a module only.  One hint may be that data is sometimes
 626          * transmitted at 9600 baud during shutdown (regardless of the
 627          * speed the chip was configured for when the port was open).
 628          */
 629 #if 0
 630         /* Power Down */
 631         tmp = readb(&up->regs->rw.ccr0);
 632         tmp &= ~SAB82532_CCR0_PU;
 633         writeb(tmp, &up->regs->rw.ccr0);
 634 #endif
 635
 636         spin_unlock_irqrestore(&up->port.lock, flags);
 637         free_irq(up->port.irq, up);
 638 }
 639
 640 /*
 641  * This is used to figure out the divisor speeds.
 642  *
 643  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
 644  *
 645  * with               0 <= N < 64 and 0 <= M < 16
 646  */
 647
 648 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
 649 {
 650         int     n, m;
 651
 652         if (baud == 0) {
 653                 *n_ret = 0;
 654                 *m_ret = 0;
 655                 return;
 656         }
 657
 658         /*
 659          * We scale numbers by 10 so that we get better accuracy
 660          * without having to use floating point.  Here we increment m
 661          * until n is within the valid range.
 662          */
 663         n = (SAB_BASE_BAUD * 10) / baud;
 664         m = 0;
 665         while (n >= 640) {
 666                 n = n / 2;
 667                 m++;
 668         }
 669         n = (n+5) / 10;
 670         /*
 671          * We try very hard to avoid speeds with M == 0 since they may
 672          * not work correctly for XTAL frequences above 10 MHz.
 673          */
 674         if ((m == 0) && ((n & 1) == 0)) {
 675                 n = n / 2;
 676                 m++;
 677         }
 678         *n_ret = n - 1;
 679         *m_ret = m;
 680 }
 681
 682 /* Internal routine, port->lock is held and local interrupts are disabled.  */
 683 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
 684                                   unsigned int iflag, unsigned int baud,
 685                                   unsigned int quot)
 686 {
 687         unsigned char dafo;
 688         int bits, n, m;
 689
 690         /* Byte size and parity */
 691         switch (cflag & CSIZE) {
 692               case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 693               case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
 694               case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
 695               case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
 696               /* Never happens, but GCC is too dumb to figure it out */
 697               default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 698         }
 699
 700         if (cflag & CSTOPB) {
 701                 dafo |= SAB82532_DAFO_STOP;
 702                 bits++;
 703         }
 704
 705         if (cflag & PARENB) {
 706                 dafo |= SAB82532_DAFO_PARE;
 707                 bits++;
 708         }
 709
 710         if (cflag & PARODD) {
 711                 dafo |= SAB82532_DAFO_PAR_ODD;
 712         } else {
 713                 dafo |= SAB82532_DAFO_PAR_EVEN;
 714         }
 715         up->cached_dafo = dafo;
 716
 717         calc_ebrg(baud, &n, &m);
 718
 719         up->cached_ebrg = n | (m << 6);
 720
 721         up->tec_timeout = (10 * 1000000) / baud;
 722         up->cec_timeout = up->tec_timeout >> 2;
 723
 724         /* CTS flow control flags */
 725         /* We encode read_status_mask and ignore_status_mask like so:
 726          *
 727          * ---------------------
 728          * | ... | ISR1 | ISR0 |
 729          * ---------------------
 730          *  ..    15   8 7    0
 731          */
 732
 733         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 734                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 735                                      SAB82532_ISR0_CDSC);
 736         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 737                                       SAB82532_ISR1_ALLS |
 738                                       SAB82532_ISR1_XPR) << 8;
 739         if (iflag & INPCK)
 740                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 741                                               SAB82532_ISR0_FERR);
 742         if (iflag & (IGNBRK | BRKINT | PARMRK))
 743                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 744
 745         /*
 746          * Characteres to ignore
 747          */
 748         up->port.ignore_status_mask = 0;
 749         if (iflag & IGNPAR)
 750                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 751                                                 SAB82532_ISR0_FERR);
 752         if (iflag & IGNBRK) {
 753                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 754                 /*
 755                  * If we're ignoring parity and break indicators,
 756                  * ignore overruns too (for real raw support).
 757                  */
 758                 if (iflag & IGNPAR)
 759                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 760         }
 761
 762         /*
 763          * ignore all characters if CREAD is not set
 764          */
 765         if ((cflag & CREAD) == 0)
 766                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 767                                                 SAB82532_ISR0_TCD);
 768
 769         uart_update_timeout(&up->port, cflag,
 770                             (up->port.uartclk / (16 * quot)));
 771
 772         /* Now schedule a register update when the chip's
 773          * transmitter is idle.
 774          */
 775         up->cached_mode |= SAB82532_MODE_RAC;
 776         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 777         if (test_bit(SAB82532_XPR, &up->irqflags))
 778                 sunsab_tx_idle(up);
 779 }
 780
 781 /* port->lock is not held.  */
 782 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 783                                struct ktermios *old)
 784 {
 785         struct uart_sunsab_port *up =
 786                 container_of(port, struct uart_sunsab_port, port);
 787         unsigned long flags;
 788         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 789         unsigned int quot = uart_get_divisor(port, baud);
 790
 791         spin_lock_irqsave(&up->port.lock, flags);
 792         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 793         spin_unlock_irqrestore(&up->port.lock, flags);
 794 }
 795
 796 static const char *sunsab_type(struct uart_port *port)
 797 {
 798         struct uart_sunsab_port *up = (void *)port;
 799         static char buf[36];
 800
 801         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 802         return buf;
 803 }
 804
 805 static void sunsab_release_port(struct uart_port *port)
 806 {
 807 }
 808
 809 static int sunsab_request_port(struct uart_port *port)
 810 {
 811         return 0;
 812 }
 813
 814 static void sunsab_config_port(struct uart_port *port, int flags)
 815 {
 816 }
 817
 818 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 819 {
 820         return -EINVAL;
 821 }
 822
 823 static const struct uart_ops sunsab_pops = {
 824         .tx_empty       = sunsab_tx_empty,
 825         .set_mctrl      = sunsab_set_mctrl,
 826         .get_mctrl      = sunsab_get_mctrl,
 827         .stop_tx        = sunsab_stop_tx,
 828         .start_tx       = sunsab_start_tx,
 829         .send_xchar     = sunsab_send_xchar,
 830         .stop_rx        = sunsab_stop_rx,
 831         .break_ctl      = sunsab_break_ctl,
 832         .startup        = sunsab_startup,
 833         .shutdown       = sunsab_shutdown,
 834         .set_termios    = sunsab_set_termios,
 835         .type           = sunsab_type,
 836         .release_port   = sunsab_release_port,
 837         .request_port   = sunsab_request_port,
 838         .config_port    = sunsab_config_port,
 839         .verify_port    = sunsab_verify_port,
 840 };
 841
 842 static struct uart_driver sunsab_reg = {
 843         .owner                  = THIS_MODULE,
 844         .driver_name            = "sunsab",
 845         .dev_name               = "ttyS",
 846         .major                  = TTY_MAJOR,
 847 };
 848
 849 static struct uart_sunsab_port *sunsab_ports;
 850
 851 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 852
 853 static void sunsab_console_putchar(struct uart_port *port, int c)
 854 {
 855         struct uart_sunsab_port *up =
 856                 container_of(port, struct uart_sunsab_port, port);
 857
 858         sunsab_tec_wait(up);
 859         writeb(c, &up->regs->w.tic);
 860 }
 861
 862 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 863 {
 864         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 865         unsigned long flags;
 866         int locked = 1;
 867
 868         if (up->port.sysrq || oops_in_progress)
 869                 locked = spin_trylock_irqsave(&up->port.lock, flags);
 870         else
 871                 spin_lock_irqsave(&up->port.lock, flags);
 872
 873         uart_console_write(&up->port, s, n, sunsab_console_putchar);
 874         sunsab_tec_wait(up);
 875
 876         if (locked)
 877                 spin_unlock_irqrestore(&up->port.lock, flags);
 878 }
 879
 880 static int sunsab_console_setup(struct console *con, char *options)
 881 {
 882         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 883         unsigned long flags;
 884         unsigned int baud, quot;
 885
 886         /*
 887          * The console framework calls us for each and every port
 888          * registered. Defer the console setup until the requested
 889          * port has been properly discovered. A bit of a hack,
 890          * though...
 891          */
 892         if (up->port.type != PORT_SUNSAB)
 893                 return -1;
 894
 895         printk("Console: ttyS%d (SAB82532)\n",
 896                (sunsab_reg.minor - 64) + con->index);
 897
 898         sunserial_console_termios(con, up->port.dev->of_node);
 899
 900         switch (con->cflag & CBAUD) {
 901         case B150: baud = 150; break;
 902         case B300: baud = 300; break;
 903         case B600: baud = 600; break;
 904         case B1200: baud = 1200; break;
 905         case B2400: baud = 2400; break;
 906         case B4800: baud = 4800; break;
 907         default: case B9600: baud = 9600; break;
 908         case B19200: baud = 19200; break;
 909         case B38400: baud = 38400; break;
 910         case B57600: baud = 57600; break;
 911         case B115200: baud = 115200; break;
 912         case B230400: baud = 230400; break;
 913         case B460800: baud = 460800; break;
 914         }
 915
 916         /*
 917          * Temporary fix.
 918          */
 919         spin_lock_init(&up->port.lock);
 920
 921         /*
 922          * Initialize the hardware
 923          */
 924         sunsab_startup(&up->port);
 925
 926         spin_lock_irqsave(&up->port.lock, flags);
 927
 928         /*
 929          * Finally, enable interrupts
 930          */
 931         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 932                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 933         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 934         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 935                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 936                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 937                                 SAB82532_IMR1_XPR;
 938         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 939
 940         quot = uart_get_divisor(&up->port, baud);
 941         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 942         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 943
 944         spin_unlock_irqrestore(&up->port.lock, flags);
 945
 946         return 0;
 947 }
 948
 949 static struct console sunsab_console = {
 950         .name   =       "ttyS",
 951         .write  =       sunsab_console_write,
 952         .device =       uart_console_device,
 953         .setup  =       sunsab_console_setup,
 954         .flags  =       CON_PRINTBUFFER,
 955         .index  =       -1,
 956         .data   =       &sunsab_reg,
 957 };
 958
 959 static inline struct console *SUNSAB_CONSOLE(void)
 960 {
 961         return &sunsab_console;
 962 }
 963 #else
 964 #define SUNSAB_CONSOLE()        (NULL)
 965 #define sunsab_console_init()   do { } while (0)
 966 #endif
 967
 968 static int sunsab_init_one(struct uart_sunsab_port *up,
 969                                      struct platform_device *op,
 970                                      unsigned long offset,
 971                                      int line)
 972 {
 973         up->port.line = line;
 974         up->port.dev = &op->dev;
 975
 976         up->port.mapbase = op->resource[0].start + offset;
 977         up->port.membase = of_ioremap(&op->resource[0], offset,
 978                                       sizeof(union sab82532_async_regs),
 979                                       "sab");
 980         if (!up->port.membase)
 981                 return -ENOMEM;
 982         up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
 983
 984         up->port.irq = op->archdata.irqs[0];
 985
 986         up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
 987         up->port.iotype = UPIO_MEM;
 988
 989         writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
 990
 991         up->port.ops = &sunsab_pops;
 992         up->port.type = PORT_SUNSAB;
 993         up->port.uartclk = SAB_BASE_BAUD;
 994
 995         up->type = readb(&up->regs->r.vstr) & 0x0f;
 996         writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
 997         writeb(0xff, &up->regs->w.pim);
 998         if ((up->port.line & 0x1) == 0) {
 999                 up->pvr_dsr_bit = (1 << 0);
1000                 up->pvr_dtr_bit = (1 << 1);
1001                 up->gis_shift = 2;
1002         } else {
1003                 up->pvr_dsr_bit = (1 << 3);
1004                 up->pvr_dtr_bit = (1 << 2);
1005                 up->gis_shift = 0;
1006         }
1007         up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1008         writeb(up->cached_pvr, &up->regs->w.pvr);
1009         up->cached_mode = readb(&up->regs->rw.mode);
1010         up->cached_mode |= SAB82532_MODE_FRTS;
1011         writeb(up->cached_mode, &up->regs->rw.mode);
1012         up->cached_mode |= SAB82532_MODE_RTS;
1013         writeb(up->cached_mode, &up->regs->rw.mode);
1014
1015         up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1016         up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1017
1018         return 0;
1019 }
1020
1021 static int sab_probe(struct platform_device *op)
1022 {
1023         static int inst;
1024         struct uart_sunsab_port *up;
1025         int err;
1026
1027         up = &sunsab_ports[inst * 2];
1028
1029         err = sunsab_init_one(&up[0], op,
1030                               0,
1031                               (inst * 2) + 0);
1032         if (err)
1033                 goto out;
1034
1035         err = sunsab_init_one(&up[1], op,
1036                               sizeof(union sab82532_async_regs),
1037                               (inst * 2) + 1);
1038         if (err)
1039                 goto out1;
1040
1041         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1042                                 &sunsab_reg, up[0].port.line,
1043                                 false);
1044
1045         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1046                                 &sunsab_reg, up[1].port.line,
1047                                 false);
1048
1049         err = uart_add_one_port(&sunsab_reg, &up[0].port);
1050         if (err)
1051                 goto out2;
1052
1053         err = uart_add_one_port(&sunsab_reg, &up[1].port);
1054         if (err)
1055                 goto out3;
1056
1057         platform_set_drvdata(op, &up[0]);
1058
1059         inst++;
1060
1061         return 0;
1062
1063 out3:
1064         uart_remove_one_port(&sunsab_reg, &up[0].port);
1065 out2:
1066         of_iounmap(&op->resource[0],
1067                    up[1].port.membase,
1068                    sizeof(union sab82532_async_regs));
1069 out1:
1070         of_iounmap(&op->resource[0],
1071                    up[0].port.membase,
1072                    sizeof(union sab82532_async_regs));
1073 out:
1074         return err;
1075 }
1076
1077 static int sab_remove(struct platform_device *op)
1078 {
1079         struct uart_sunsab_port *up = platform_get_drvdata(op);
1080
1081         uart_remove_one_port(&sunsab_reg, &up[1].port);
1082         uart_remove_one_port(&sunsab_reg, &up[0].port);
1083         of_iounmap(&op->resource[0],
1084                    up[1].port.membase,
1085                    sizeof(union sab82532_async_regs));
1086         of_iounmap(&op->resource[0],
1087                    up[0].port.membase,
1088                    sizeof(union sab82532_async_regs));
1089
1090         return 0;
1091 }
1092
1093 static const struct of_device_id sab_match[] = {
1094         {
1095                 .name = "se",
1096         },
1097         {
1098                 .name = "serial",
1099                 .compatible = "sab82532",
1100         },
1101         {},
1102 };
1103 MODULE_DEVICE_TABLE(of, sab_match);
1104
1105 static struct platform_driver sab_driver = {
1106         .driver = {
1107                 .name = "sab",
1108                 .of_match_table = sab_match,
1109         },
1110         .probe          = sab_probe,
1111         .remove         = sab_remove,
1112 };
1113
1114 static int __init sunsab_init(void)
1115 {
1116         struct device_node *dp;
1117         int err;
1118         int num_channels = 0;
1119
1120         for_each_node_by_name(dp, "se")
1121                 num_channels += 2;
1122         for_each_node_by_name(dp, "serial") {
1123                 if (of_device_is_compatible(dp, "sab82532"))
1124                         num_channels += 2;
1125         }
1126
1127         if (num_channels) {
1128                 sunsab_ports = kcalloc(num_channels,
1129                                        sizeof(struct uart_sunsab_port),
1130                                        GFP_KERNEL);
1131                 if (!sunsab_ports)
1132                         return -ENOMEM;
1133
1134                 err = sunserial_register_minors(&sunsab_reg, num_channels);
1135                 if (err) {
1136                         kfree(sunsab_ports);
1137                         sunsab_ports = NULL;
1138
1139                         return err;
1140                 }
1141         }
1142
1143         err = platform_driver_register(&sab_driver);
1144         if (err) {
1145                 kfree(sunsab_ports);
1146                 sunsab_ports = NULL;
1147         }
1148
1149         return err;
1150 }
1151
1152 static void __exit sunsab_exit(void)
1153 {
1154         platform_driver_unregister(&sab_driver);
1155         if (sunsab_reg.nr) {
1156                 sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1157         }
1158
1159         kfree(sunsab_ports);
1160         sunsab_ports = NULL;
1161 }
1162
1163 module_init(sunsab_init);
1164 module_exit(sunsab_exit);
1165
1166 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1167 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1168 MODULE_LICENSE("GPL");