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  ([email protected])
   5  * Copyright (C) 2002, 2006  David S. Miller ([email protected])
   6  *
   7  * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
   8  *   Maxim Krasnyanskiy <[email protected]>
   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 <[email protected]>, 2001-Oct-12
  14  *
  15  * Ported to new 2.5.x UART layer.
  16  *   David S. Miller <[email protected]>
  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.h>
  37 #include <linux/platform_device.h>
  38
  39 #include <linux/io.h>
  40 #include <asm/irq.h>
  41 #include <asm/prom.h>
  42 #include <asm/setup.h>
  43
  44 #include <linux/serial_core.h>
  45 #include <linux/sunserialcore.h>
  46
  47 #include "sunsab.h"
  48
  49 struct uart_sunsab_port {
  50         struct uart_port                port;           /* Generic UART port    */
  51         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
  52         unsigned long                   irqflags;       /* IRQ state flags      */
  53         int                             dsr;            /* Current DSR state    */
  54         unsigned int                    cec_timeout;    /* Chip poll timeout... */
  55         unsigned int                    tec_timeout;    /* likewise             */
  56         unsigned char                   interrupt_mask0;/* ISR0 masking         */
  57         unsigned char                   interrupt_mask1;/* ISR1 masking         */
  58         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
  59         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
  60         unsigned int                    gis_shift;
  61         int                             type;           /* SAB82532 version     */
  62
  63         /* Setting configuration bits while the transmitter is active
  64          * can cause garbage characters to get emitted by the chip.
  65          * Therefore, we cache such writes here and do the real register
  66          * write the next time the transmitter becomes idle.
  67          */
  68         unsigned int                    cached_ebrg;
  69         unsigned char                   cached_mode;
  70         unsigned char                   cached_pvr;
  71         unsigned char                   cached_dafo;
  72 };
  73
  74 /*
  75  * This assumes you have a 29.4912 MHz clock for your UART.
  76  */
  77 #define SAB_BASE_BAUD ( 29491200 / 16 )
  78
  79 static char *sab82532_version[16] = {
  80         "V1.0", "V2.0", "V3.2", "V(0x03)",
  81         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
  82         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
  83         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
  84 };
  85
  86 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
  87 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
  88
  89 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
  90 #define SAB82532_XMIT_FIFO_SIZE 32
  91
  92 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
  93 {
  94         int timeout = up->tec_timeout;
  95
  96         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
  97                 udelay(1);
  98 }
  99
 100 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
 101 {
 102         int timeout = up->cec_timeout;
 103
 104         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
 105                 udelay(1);
 106 }
 107
 108 static struct tty_port *
 109 receive_chars(struct uart_sunsab_port *up,
 110               union sab82532_irq_status *stat)
 111 {
 112         struct tty_port *port = NULL;
 113         unsigned char buf[32];
 114         int saw_console_brk = 0;
 115         int free_fifo = 0;
 116         int count = 0;
 117         int i;
 118
 119         if (up->port.state != NULL)             /* Unopened serial console */
 120                 port = &up->port.state->port;
 121
 122         /* Read number of BYTES (Character + Status) available. */
 123         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
 124                 count = SAB82532_RECV_FIFO_SIZE;
 125                 free_fifo++;
 126         }
 127
 128         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
 129                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
 130                 free_fifo++;
 131         }
 132
 133         /* Issue a FIFO read command in case we where idle. */
 134         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
 135                 sunsab_cec_wait(up);
 136                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
 137                 return port;
 138         }
 139
 140         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 141                 free_fifo++;
 142
 143         /* Read the FIFO. */
 144         for (i = 0; i < count; i++)
 145                 buf[i] = readb(&up->regs->r.rfifo[i]);
 146
 147         /* Issue Receive Message Complete command. */
 148         if (free_fifo) {
 149                 sunsab_cec_wait(up);
 150                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
 151         }
 152
 153         /* Count may be zero for BRK, so we check for it here */
 154         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
 155             (up->port.line == up->port.cons->index))
 156                 saw_console_brk = 1;
 157
 158         if (count == 0) {
 159                 if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 160                         stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 161                                              SAB82532_ISR0_FERR);
 162                         up->port.icount.brk++;
 163                         uart_handle_break(&up->port);
 164                 }
 165         }
 166
 167         for (i = 0; i < count; i++) {
 168                 unsigned char ch = buf[i], flag;
 169
 170                 flag = TTY_NORMAL;
 171                 up->port.icount.rx++;
 172
 173                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
 174                                                 SAB82532_ISR0_FERR |
 175                                                 SAB82532_ISR0_RFO)) ||
 176                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 177                         /*
 178                          * For statistics only
 179                          */
 180                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 181                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 182                                                      SAB82532_ISR0_FERR);
 183                                 up->port.icount.brk++;
 184                                 /*
 185                                  * We do the SysRQ and SAK checking
 186                                  * here because otherwise the break
 187                                  * may get masked by ignore_status_mask
 188                                  * or read_status_mask.
 189                                  */
 190                                 if (uart_handle_break(&up->port))
 191                                         continue;
 192                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 193                                 up->port.icount.parity++;
 194                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 195                                 up->port.icount.frame++;
 196                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 197                                 up->port.icount.overrun++;
 198
 199                         /*
 200                          * Mask off conditions which should be ingored.
 201                          */
 202                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
 203                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
 204
 205                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 206                                 flag = TTY_BREAK;
 207                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 208                                 flag = TTY_PARITY;
 209                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 210                                 flag = TTY_FRAME;
 211                 }
 212
 213                 if (uart_handle_sysrq_char(&up->port, ch) || !port)
 214                         continue;
 215
 216                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
 217                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
 218                         tty_insert_flip_char(port, ch, flag);
 219                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 220                         tty_insert_flip_char(port, 0, TTY_OVERRUN);
 221         }
 222
 223         if (saw_console_brk)
 224                 sun_do_break();
 225
 226         return port;
 227 }
 228
 229 static void sunsab_stop_tx(struct uart_port *);
 230 static void sunsab_tx_idle(struct uart_sunsab_port *);
 231
 232 static void transmit_chars(struct uart_sunsab_port *up,
 233                            union sab82532_irq_status *stat)
 234 {
 235         struct circ_buf *xmit = &up->port.state->xmit;
 236         int i;
 237
 238         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
 239                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
 240                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 241                 set_bit(SAB82532_ALLS, &up->irqflags);
 242         }
 243
 244 #if 0 /* [email protected] says this check causes problems */
 245         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 246                 return;
 247 #endif
 248
 249         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 250                 return;
 251
 252         set_bit(SAB82532_XPR, &up->irqflags);
 253         sunsab_tx_idle(up);
 254
 255         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 256                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 257                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 258                 return;
 259         }
 260
 261         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 262         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 263         clear_bit(SAB82532_ALLS, &up->irqflags);
 264
 265         /* Stuff 32 bytes into Transmit FIFO. */
 266         clear_bit(SAB82532_XPR, &up->irqflags);
 267         for (i = 0; i < up->port.fifosize; i++) {
 268                 writeb(xmit->buf[xmit->tail],
 269                        &up->regs->w.xfifo[i]);
 270                 uart_xmit_advance(&up->port, 1);
 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.state->port.delta_msr_wait);
 303 }
 304
 305 static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
 306 {
 307         struct uart_sunsab_port *up = dev_id;
 308         struct tty_port *port = NULL;
 309         union sab82532_irq_status status;
 310         unsigned long flags;
 311         unsigned char gis;
 312
 313         uart_port_lock_irqsave(&up->port, &flags);
 314
 315         status.stat = 0;
 316         gis = readb(&up->regs->r.gis) >> up->gis_shift;
 317         if (gis & 1)
 318                 status.sreg.isr0 = readb(&up->regs->r.isr0);
 319         if (gis & 2)
 320                 status.sreg.isr1 = readb(&up->regs->r.isr1);
 321
 322         if (status.stat) {
 323                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 324                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
 325                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
 326                         port = receive_chars(up, &status);
 327                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
 328                     (status.sreg.isr1 & SAB82532_ISR1_CSC))
 329                         check_status(up, &status);
 330                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
 331                         transmit_chars(up, &status);
 332         }
 333
 334         uart_port_unlock_irqrestore(&up->port, flags);
 335
 336         if (port)
 337                 tty_flip_buffer_push(port);
 338
 339         return IRQ_HANDLED;
 340 }
 341
 342 /* port->lock is not held.  */
 343 static unsigned int sunsab_tx_empty(struct uart_port *port)
 344 {
 345         struct uart_sunsab_port *up =
 346                 container_of(port, struct uart_sunsab_port, port);
 347         int ret;
 348
 349         /* Do not need a lock for a state test like this.  */
 350         if (test_bit(SAB82532_ALLS, &up->irqflags))
 351                 ret = TIOCSER_TEMT;
 352         else
 353                 ret = 0;
 354
 355         return ret;
 356 }
 357
 358 /* port->lock held by caller.  */
 359 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
 360 {
 361         struct uart_sunsab_port *up =
 362                 container_of(port, struct uart_sunsab_port, port);
 363
 364         if (mctrl & TIOCM_RTS) {
 365                 up->cached_mode &= ~SAB82532_MODE_FRTS;
 366                 up->cached_mode |= SAB82532_MODE_RTS;
 367         } else {
 368                 up->cached_mode |= (SAB82532_MODE_FRTS |
 369                                     SAB82532_MODE_RTS);
 370         }
 371         if (mctrl & TIOCM_DTR) {
 372                 up->cached_pvr &= ~(up->pvr_dtr_bit);
 373         } else {
 374                 up->cached_pvr |= up->pvr_dtr_bit;
 375         }
 376
 377         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 378         if (test_bit(SAB82532_XPR, &up->irqflags))
 379                 sunsab_tx_idle(up);
 380 }
 381
 382 /* port->lock is held by caller and interrupts are disabled.  */
 383 static unsigned int sunsab_get_mctrl(struct uart_port *port)
 384 {
 385         struct uart_sunsab_port *up =
 386                 container_of(port, 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 =
 408                 container_of(port, struct uart_sunsab_port, port);
 409
 410         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 411         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 412 }
 413
 414 /* port->lock held by caller.  */
 415 static void sunsab_tx_idle(struct uart_sunsab_port *up)
 416 {
 417         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
 418                 u8 tmp;
 419
 420                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
 421                 writeb(up->cached_mode, &up->regs->rw.mode);
 422                 writeb(up->cached_pvr, &up->regs->rw.pvr);
 423                 writeb(up->cached_dafo, &up->regs->w.dafo);
 424
 425                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
 426                 tmp = readb(&up->regs->rw.ccr2);
 427                 tmp &= ~0xc0;
 428                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
 429                 writeb(tmp, &up->regs->rw.ccr2);
 430         }
 431 }
 432
 433 /* port->lock held by caller.  */
 434 static void sunsab_start_tx(struct uart_port *port)
 435 {
 436         struct uart_sunsab_port *up =
 437                 container_of(port, struct uart_sunsab_port, port);
 438         struct circ_buf *xmit = &up->port.state->xmit;
 439         int i;
 440
 441         if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 442                 return;
 443
 444         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 445         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 446
 447         if (!test_bit(SAB82532_XPR, &up->irqflags))
 448                 return;
 449
 450         clear_bit(SAB82532_ALLS, &up->irqflags);
 451         clear_bit(SAB82532_XPR, &up->irqflags);
 452
 453         for (i = 0; i < up->port.fifosize; i++) {
 454                 writeb(xmit->buf[xmit->tail],
 455                        &up->regs->w.xfifo[i]);
 456                 uart_xmit_advance(&up->port, 1);
 457                 if (uart_circ_empty(xmit))
 458                         break;
 459         }
 460
 461         /* Issue a Transmit Frame command.  */
 462         sunsab_cec_wait(up);
 463         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 464 }
 465
 466 /* port->lock is not held.  */
 467 static void sunsab_send_xchar(struct uart_port *port, char ch)
 468 {
 469         struct uart_sunsab_port *up =
 470                 container_of(port, struct uart_sunsab_port, port);
 471         unsigned long flags;
 472
 473         if (ch == __DISABLED_CHAR)
 474                 return;
 475
 476         uart_port_lock_irqsave(&up->port, &flags);
 477
 478         sunsab_tec_wait(up);
 479         writeb(ch, &up->regs->w.tic);
 480
 481         uart_port_unlock_irqrestore(&up->port, flags);
 482 }
 483
 484 /* port->lock held by caller.  */
 485 static void sunsab_stop_rx(struct uart_port *port)
 486 {
 487         struct uart_sunsab_port *up =
 488                 container_of(port, struct uart_sunsab_port, port);
 489
 490         up->interrupt_mask0 |= SAB82532_IMR0_TCD;
 491         writeb(up->interrupt_mask1, &up->regs->w.imr0);
 492 }
 493
 494 /* port->lock is not held.  */
 495 static void sunsab_break_ctl(struct uart_port *port, int break_state)
 496 {
 497         struct uart_sunsab_port *up =
 498                 container_of(port, struct uart_sunsab_port, port);
 499         unsigned long flags;
 500         unsigned char val;
 501
 502         uart_port_lock_irqsave(&up->port, &flags);
 503
 504         val = up->cached_dafo;
 505         if (break_state)
 506                 val |= SAB82532_DAFO_XBRK;
 507         else
 508                 val &= ~SAB82532_DAFO_XBRK;
 509         up->cached_dafo = val;
 510
 511         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 512         if (test_bit(SAB82532_XPR, &up->irqflags))
 513                 sunsab_tx_idle(up);
 514
 515         uart_port_unlock_irqrestore(&up->port, flags);
 516 }
 517
 518 /* port->lock is not held.  */
 519 static int sunsab_startup(struct uart_port *port)
 520 {
 521         struct uart_sunsab_port *up =
 522                 container_of(port, struct uart_sunsab_port, port);
 523         unsigned long flags;
 524         unsigned char tmp;
 525         int err = request_irq(up->port.irq, sunsab_interrupt,
 526                               IRQF_SHARED, "sab", up);
 527         if (err)
 528                 return err;
 529
 530         uart_port_lock_irqsave(&up->port, &flags);
 531
 532         /*
 533          * Wait for any commands or immediate characters
 534          */
 535         sunsab_cec_wait(up);
 536         sunsab_tec_wait(up);
 537
 538         /*
 539          * Clear the FIFO buffers.
 540          */
 541         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
 542         sunsab_cec_wait(up);
 543         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
 544
 545         /*
 546          * Clear the interrupt registers.
 547          */
 548         (void) readb(&up->regs->r.isr0);
 549         (void) readb(&up->regs->r.isr1);
 550
 551         /*
 552          * Now, initialize the UART
 553          */
 554         writeb(0, &up->regs->w.ccr0);                           /* power-down */
 555         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
 556                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
 557         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
 558         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
 559                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
 560         writeb(0, &up->regs->w.ccr3);
 561         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
 562         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
 563                            SAB82532_MODE_RAC);
 564         writeb(up->cached_mode, &up->regs->w.mode);
 565         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
 566
 567         tmp = readb(&up->regs->rw.ccr0);
 568         tmp |= SAB82532_CCR0_PU;        /* power-up */
 569         writeb(tmp, &up->regs->rw.ccr0);
 570
 571         /*
 572          * Finally, enable interrupts
 573          */
 574         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 575                                SAB82532_IMR0_PLLA);
 576         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 577         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 578                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 579                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 580                                SAB82532_IMR1_XPR);
 581         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 582         set_bit(SAB82532_ALLS, &up->irqflags);
 583         set_bit(SAB82532_XPR, &up->irqflags);
 584
 585         uart_port_unlock_irqrestore(&up->port, flags);
 586
 587         return 0;
 588 }
 589
 590 /* port->lock is not held.  */
 591 static void sunsab_shutdown(struct uart_port *port)
 592 {
 593         struct uart_sunsab_port *up =
 594                 container_of(port, struct uart_sunsab_port, port);
 595         unsigned long flags;
 596
 597         uart_port_lock_irqsave(&up->port, &flags);
 598
 599         /* Disable Interrupts */
 600         up->interrupt_mask0 = 0xff;
 601         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 602         up->interrupt_mask1 = 0xff;
 603         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 604
 605         /* Disable break condition */
 606         up->cached_dafo = readb(&up->regs->rw.dafo);
 607         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
 608         writeb(up->cached_dafo, &up->regs->rw.dafo);
 609
 610         /* Disable Receiver */
 611         up->cached_mode &= ~SAB82532_MODE_RAC;
 612         writeb(up->cached_mode, &up->regs->rw.mode);
 613
 614         /*
 615          * XXX FIXME
 616          *
 617          * If the chip is powered down here the system hangs/crashes during
 618          * reboot or shutdown.  This needs to be investigated further,
 619          * similar behaviour occurs in 2.4 when the driver is configured
 620          * as a module only.  One hint may be that data is sometimes
 621          * transmitted at 9600 baud during shutdown (regardless of the
 622          * speed the chip was configured for when the port was open).
 623          */
 624 #if 0
 625         /* Power Down */
 626         tmp = readb(&up->regs->rw.ccr0);
 627         tmp &= ~SAB82532_CCR0_PU;
 628         writeb(tmp, &up->regs->rw.ccr0);
 629 #endif
 630
 631         uart_port_unlock_irqrestore(&up->port, flags);
 632         free_irq(up->port.irq, up);
 633 }
 634
 635 /*
 636  * This is used to figure out the divisor speeds.
 637  *
 638  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
 639  *
 640  * with               0 <= N < 64 and 0 <= M < 16
 641  */
 642
 643 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
 644 {
 645         int     n, m;
 646
 647         if (baud == 0) {
 648                 *n_ret = 0;
 649                 *m_ret = 0;
 650                 return;
 651         }
 652
 653         /*
 654          * We scale numbers by 10 so that we get better accuracy
 655          * without having to use floating point.  Here we increment m
 656          * until n is within the valid range.
 657          */
 658         n = (SAB_BASE_BAUD * 10) / baud;
 659         m = 0;
 660         while (n >= 640) {
 661                 n = n / 2;
 662                 m++;
 663         }
 664         n = (n+5) / 10;
 665         /*
 666          * We try very hard to avoid speeds with M == 0 since they may
 667          * not work correctly for XTAL frequences above 10 MHz.
 668          */
 669         if ((m == 0) && ((n & 1) == 0)) {
 670                 n = n / 2;
 671                 m++;
 672         }
 673         *n_ret = n - 1;
 674         *m_ret = m;
 675 }
 676
 677 /* Internal routine, port->lock is held and local interrupts are disabled.  */
 678 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
 679                                   unsigned int iflag, unsigned int baud,
 680                                   unsigned int quot)
 681 {
 682         unsigned char dafo;
 683         int n, m;
 684
 685         /* Byte size and parity */
 686         switch (cflag & CSIZE) {
 687               case CS5: dafo = SAB82532_DAFO_CHL5; break;
 688               case CS6: dafo = SAB82532_DAFO_CHL6; break;
 689               case CS7: dafo = SAB82532_DAFO_CHL7; break;
 690               case CS8: dafo = SAB82532_DAFO_CHL8; break;
 691               /* Never happens, but GCC is too dumb to figure it out */
 692               default:  dafo = SAB82532_DAFO_CHL5; break;
 693         }
 694
 695         if (cflag & CSTOPB)
 696                 dafo |= SAB82532_DAFO_STOP;
 697
 698         if (cflag & PARENB)
 699                 dafo |= SAB82532_DAFO_PARE;
 700
 701         if (cflag & PARODD) {
 702                 dafo |= SAB82532_DAFO_PAR_ODD;
 703         } else {
 704                 dafo |= SAB82532_DAFO_PAR_EVEN;
 705         }
 706         up->cached_dafo = dafo;
 707
 708         calc_ebrg(baud, &n, &m);
 709
 710         up->cached_ebrg = n | (m << 6);
 711
 712         up->tec_timeout = (10 * 1000000) / baud;
 713         up->cec_timeout = up->tec_timeout >> 2;
 714
 715         /* CTS flow control flags */
 716         /* We encode read_status_mask and ignore_status_mask like so:
 717          *
 718          * ---------------------
 719          * | ... | ISR1 | ISR0 |
 720          * ---------------------
 721          *  ..    15   8 7    0
 722          */
 723
 724         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 725                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 726                                      SAB82532_ISR0_CDSC);
 727         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 728                                       SAB82532_ISR1_ALLS |
 729                                       SAB82532_ISR1_XPR) << 8;
 730         if (iflag & INPCK)
 731                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 732                                               SAB82532_ISR0_FERR);
 733         if (iflag & (IGNBRK | BRKINT | PARMRK))
 734                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 735
 736         /*
 737          * Characteres to ignore
 738          */
 739         up->port.ignore_status_mask = 0;
 740         if (iflag & IGNPAR)
 741                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 742                                                 SAB82532_ISR0_FERR);
 743         if (iflag & IGNBRK) {
 744                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 745                 /*
 746                  * If we're ignoring parity and break indicators,
 747                  * ignore overruns too (for real raw support).
 748                  */
 749                 if (iflag & IGNPAR)
 750                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 751         }
 752
 753         /*
 754          * ignore all characters if CREAD is not set
 755          */
 756         if ((cflag & CREAD) == 0)
 757                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 758                                                 SAB82532_ISR0_TCD);
 759
 760         uart_update_timeout(&up->port, cflag,
 761                             (up->port.uartclk / (16 * quot)));
 762
 763         /* Now schedule a register update when the chip's
 764          * transmitter is idle.
 765          */
 766         up->cached_mode |= SAB82532_MODE_RAC;
 767         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 768         if (test_bit(SAB82532_XPR, &up->irqflags))
 769                 sunsab_tx_idle(up);
 770 }
 771
 772 /* port->lock is not held.  */
 773 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 774                                const struct ktermios *old)
 775 {
 776         struct uart_sunsab_port *up =
 777                 container_of(port, struct uart_sunsab_port, port);
 778         unsigned long flags;
 779         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 780         unsigned int quot = uart_get_divisor(port, baud);
 781
 782         uart_port_lock_irqsave(&up->port, &flags);
 783         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 784         uart_port_unlock_irqrestore(&up->port, flags);
 785 }
 786
 787 static const char *sunsab_type(struct uart_port *port)
 788 {
 789         struct uart_sunsab_port *up = (void *)port;
 790         static char buf[36];
 791
 792         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 793         return buf;
 794 }
 795
 796 static void sunsab_release_port(struct uart_port *port)
 797 {
 798 }
 799
 800 static int sunsab_request_port(struct uart_port *port)
 801 {
 802         return 0;
 803 }
 804
 805 static void sunsab_config_port(struct uart_port *port, int flags)
 806 {
 807 }
 808
 809 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 810 {
 811         return -EINVAL;
 812 }
 813
 814 static const struct uart_ops sunsab_pops = {
 815         .tx_empty       = sunsab_tx_empty,
 816         .set_mctrl      = sunsab_set_mctrl,
 817         .get_mctrl      = sunsab_get_mctrl,
 818         .stop_tx        = sunsab_stop_tx,
 819         .start_tx       = sunsab_start_tx,
 820         .send_xchar     = sunsab_send_xchar,
 821         .stop_rx        = sunsab_stop_rx,
 822         .break_ctl      = sunsab_break_ctl,
 823         .startup        = sunsab_startup,
 824         .shutdown       = sunsab_shutdown,
 825         .set_termios    = sunsab_set_termios,
 826         .type           = sunsab_type,
 827         .release_port   = sunsab_release_port,
 828         .request_port   = sunsab_request_port,
 829         .config_port    = sunsab_config_port,
 830         .verify_port    = sunsab_verify_port,
 831 };
 832
 833 static struct uart_driver sunsab_reg = {
 834         .owner                  = THIS_MODULE,
 835         .driver_name            = "sunsab",
 836         .dev_name               = "ttyS",
 837         .major                  = TTY_MAJOR,
 838 };
 839
 840 static struct uart_sunsab_port *sunsab_ports;
 841
 842 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 843
 844 static void sunsab_console_putchar(struct uart_port *port, unsigned char c)
 845 {
 846         struct uart_sunsab_port *up =
 847                 container_of(port, struct uart_sunsab_port, port);
 848
 849         sunsab_tec_wait(up);
 850         writeb(c, &up->regs->w.tic);
 851 }
 852
 853 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 854 {
 855         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 856         unsigned long flags;
 857         int locked = 1;
 858
 859         if (up->port.sysrq || oops_in_progress)
 860                 locked = uart_port_trylock_irqsave(&up->port, &flags);
 861         else
 862                 uart_port_lock_irqsave(&up->port, &flags);
 863
 864         uart_console_write(&up->port, s, n, sunsab_console_putchar);
 865         sunsab_tec_wait(up);
 866
 867         if (locked)
 868                 uart_port_unlock_irqrestore(&up->port, flags);
 869 }
 870
 871 static int sunsab_console_setup(struct console *con, char *options)
 872 {
 873         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 874         unsigned long flags;
 875         unsigned int baud, quot;
 876
 877         /*
 878          * The console framework calls us for each and every port
 879          * registered. Defer the console setup until the requested
 880          * port has been properly discovered. A bit of a hack,
 881          * though...
 882          */
 883         if (up->port.type != PORT_SUNSAB)
 884                 return -EINVAL;
 885
 886         printk("Console: ttyS%d (SAB82532)\n",
 887                (sunsab_reg.minor - 64) + con->index);
 888
 889         sunserial_console_termios(con, up->port.dev->of_node);
 890
 891         switch (con->cflag & CBAUD) {
 892         case B150: baud = 150; break;
 893         case B300: baud = 300; break;
 894         case B600: baud = 600; break;
 895         case B1200: baud = 1200; break;
 896         case B2400: baud = 2400; break;
 897         case B4800: baud = 4800; break;
 898         default: case B9600: baud = 9600; break;
 899         case B19200: baud = 19200; break;
 900         case B38400: baud = 38400; break;
 901         case B57600: baud = 57600; break;
 902         case B115200: baud = 115200; break;
 903         case B230400: baud = 230400; break;
 904         case B460800: baud = 460800; break;
 905         }
 906
 907         /*
 908          * Temporary fix.
 909          */
 910         spin_lock_init(&up->port.lock);
 911
 912         /*
 913          * Initialize the hardware
 914          */
 915         sunsab_startup(&up->port);
 916
 917         uart_port_lock_irqsave(&up->port, &flags);
 918
 919         /*
 920          * Finally, enable interrupts
 921          */
 922         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 923                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 924         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 925         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 926                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 927                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 928                                 SAB82532_IMR1_XPR;
 929         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 930
 931         quot = uart_get_divisor(&up->port, baud);
 932         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 933         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 934
 935         uart_port_unlock_irqrestore(&up->port, flags);
 936
 937         return 0;
 938 }
 939
 940 static struct console sunsab_console = {
 941         .name   =       "ttyS",
 942         .write  =       sunsab_console_write,
 943         .device =       uart_console_device,
 944         .setup  =       sunsab_console_setup,
 945         .flags  =       CON_PRINTBUFFER,
 946         .index  =       -1,
 947         .data   =       &sunsab_reg,
 948 };
 949
 950 static inline struct console *SUNSAB_CONSOLE(void)
 951 {
 952         return &sunsab_console;
 953 }
 954 #else
 955 #define SUNSAB_CONSOLE()        (NULL)
 956 #define sunsab_console_init()   do { } while (0)
 957 #endif
 958
 959 static int sunsab_init_one(struct uart_sunsab_port *up,
 960                                      struct platform_device *op,
 961                                      unsigned long offset,
 962                                      int line)
 963 {
 964         up->port.line = line;
 965         up->port.dev = &op->dev;
 966
 967         up->port.mapbase = op->resource[0].start + offset;
 968         up->port.membase = of_ioremap(&op->resource[0], offset,
 969                                       sizeof(union sab82532_async_regs),
 970                                       "sab");
 971         if (!up->port.membase)
 972                 return -ENOMEM;
 973         up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
 974
 975         up->port.irq = op->archdata.irqs[0];
 976
 977         up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
 978         up->port.iotype = UPIO_MEM;
 979         up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSAB_CONSOLE);
 980
 981         writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
 982
 983         up->port.ops = &sunsab_pops;
 984         up->port.type = PORT_SUNSAB;
 985         up->port.uartclk = SAB_BASE_BAUD;
 986
 987         up->type = readb(&up->regs->r.vstr) & 0x0f;
 988         writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
 989         writeb(0xff, &up->regs->w.pim);
 990         if ((up->port.line & 0x1) == 0) {
 991                 up->pvr_dsr_bit = (1 << 0);
 992                 up->pvr_dtr_bit = (1 << 1);
 993                 up->gis_shift = 2;
 994         } else {
 995                 up->pvr_dsr_bit = (1 << 3);
 996                 up->pvr_dtr_bit = (1 << 2);
 997                 up->gis_shift = 0;
 998         }
 999         up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1000         writeb(up->cached_pvr, &up->regs->w.pvr);
1001         up->cached_mode = readb(&up->regs->rw.mode);
1002         up->cached_mode |= SAB82532_MODE_FRTS;
1003         writeb(up->cached_mode, &up->regs->rw.mode);
1004         up->cached_mode |= SAB82532_MODE_RTS;
1005         writeb(up->cached_mode, &up->regs->rw.mode);
1006
1007         up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1008         up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1009
1010         return 0;
1011 }
1012
1013 static int sab_probe(struct platform_device *op)
1014 {
1015         static int inst;
1016         struct uart_sunsab_port *up;
1017         int err;
1018
1019         up = &sunsab_ports[inst * 2];
1020
1021         err = sunsab_init_one(&up[0], op,
1022                               0,
1023                               (inst * 2) + 0);
1024         if (err)
1025                 goto out;
1026
1027         err = sunsab_init_one(&up[1], op,
1028                               sizeof(union sab82532_async_regs),
1029                               (inst * 2) + 1);
1030         if (err)
1031                 goto out1;
1032
1033         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1034                                 &sunsab_reg, up[0].port.line,
1035                                 false);
1036
1037         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1038                                 &sunsab_reg, up[1].port.line,
1039                                 false);
1040
1041         err = uart_add_one_port(&sunsab_reg, &up[0].port);
1042         if (err)
1043                 goto out2;
1044
1045         err = uart_add_one_port(&sunsab_reg, &up[1].port);
1046         if (err)
1047                 goto out3;
1048
1049         platform_set_drvdata(op, &up[0]);
1050
1051         inst++;
1052
1053         return 0;
1054
1055 out3:
1056         uart_remove_one_port(&sunsab_reg, &up[0].port);
1057 out2:
1058         of_iounmap(&op->resource[0],
1059                    up[1].port.membase,
1060                    sizeof(union sab82532_async_regs));
1061 out1:
1062         of_iounmap(&op->resource[0],
1063                    up[0].port.membase,
1064                    sizeof(union sab82532_async_regs));
1065 out:
1066         return err;
1067 }
1068
1069 static int sab_remove(struct platform_device *op)
1070 {
1071         struct uart_sunsab_port *up = platform_get_drvdata(op);
1072
1073         uart_remove_one_port(&sunsab_reg, &up[1].port);
1074         uart_remove_one_port(&sunsab_reg, &up[0].port);
1075         of_iounmap(&op->resource[0],
1076                    up[1].port.membase,
1077                    sizeof(union sab82532_async_regs));
1078         of_iounmap(&op->resource[0],
1079                    up[0].port.membase,
1080                    sizeof(union sab82532_async_regs));
1081
1082         return 0;
1083 }
1084
1085 static const struct of_device_id sab_match[] = {
1086         {
1087                 .name = "se",
1088         },
1089         {
1090                 .name = "serial",
1091                 .compatible = "sab82532",
1092         },
1093         {},
1094 };
1095 MODULE_DEVICE_TABLE(of, sab_match);
1096
1097 static struct platform_driver sab_driver = {
1098         .driver = {
1099                 .name = "sab",
1100                 .of_match_table = sab_match,
1101         },
1102         .probe          = sab_probe,
1103         .remove         = sab_remove,
1104 };
1105
1106 static int __init sunsab_init(void)
1107 {
1108         struct device_node *dp;
1109         int err;
1110         int num_channels = 0;
1111
1112         for_each_node_by_name(dp, "se")
1113                 num_channels += 2;
1114         for_each_node_by_name(dp, "serial") {
1115                 if (of_device_is_compatible(dp, "sab82532"))
1116                         num_channels += 2;
1117         }
1118
1119         if (num_channels) {
1120                 sunsab_ports = kcalloc(num_channels,
1121                                        sizeof(struct uart_sunsab_port),
1122                                        GFP_KERNEL);
1123                 if (!sunsab_ports)
1124                         return -ENOMEM;
1125
1126                 err = sunserial_register_minors(&sunsab_reg, num_channels);
1127                 if (err) {
1128                         kfree(sunsab_ports);
1129                         sunsab_ports = NULL;
1130
1131                         return err;
1132                 }
1133         }
1134
1135         err = platform_driver_register(&sab_driver);
1136         if (err) {
1137                 kfree(sunsab_ports);
1138                 sunsab_ports = NULL;
1139         }
1140
1141         return err;
1142 }
1143
1144 static void __exit sunsab_exit(void)
1145 {
1146         platform_driver_unregister(&sab_driver);
1147         if (sunsab_reg.nr) {
1148                 sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1149         }
1150
1151         kfree(sunsab_ports);
1152         sunsab_ports = NULL;
1153 }
1154
1155 module_init(sunsab_init);
1156 module_exit(sunsab_exit);
1157
1158 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1159 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1160 MODULE_LICENSE("GPL");