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_device.h>
  37
  38 #include <linux/io.h>
  39 #include <asm/irq.h>
  40 #include <asm/prom.h>
  41 #include <asm/setup.h>
  42
  43 #include <linux/serial_core.h>
  44 #include <linux/sunserialcore.h>
  45
  46 #include "sunsab.h"
  47
  48 struct uart_sunsab_port {
  49         struct uart_port                port;           /* Generic UART port    */
  50         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
  51         unsigned long                   irqflags;       /* IRQ state flags      */
  52         int                             dsr;            /* Current DSR state    */
  53         unsigned int                    cec_timeout;    /* Chip poll timeout... */
  54         unsigned int                    tec_timeout;    /* likewise             */
  55         unsigned char                   interrupt_mask0;/* ISR0 masking         */
  56         unsigned char                   interrupt_mask1;/* ISR1 masking         */
  57         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
  58         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
  59         unsigned int                    gis_shift;
  60         int                             type;           /* SAB82532 version     */
  61
  62         /* Setting configuration bits while the transmitter is active
  63          * can cause garbage characters to get emitted by the chip.
  64          * Therefore, we cache such writes here and do the real register
  65          * write the next time the transmitter becomes idle.
  66          */
  67         unsigned int                    cached_ebrg;
  68         unsigned char                   cached_mode;
  69         unsigned char                   cached_pvr;
  70         unsigned char                   cached_dafo;
  71 };
  72
  73 /*
  74  * This assumes you have a 29.4912 MHz clock for your UART.
  75  */
  76 #define SAB_BASE_BAUD ( 29491200 / 16 )
  77
  78 static char *sab82532_version[16] = {
  79         "V1.0", "V2.0", "V3.2", "V(0x03)",
  80         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
  81         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
  82         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
  83 };
  84
  85 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
  86 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
  87
  88 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
  89 #define SAB82532_XMIT_FIFO_SIZE 32
  90
  91 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
  92 {
  93         int timeout = up->tec_timeout;
  94
  95         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
  96                 udelay(1);
  97 }
  98
  99 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
 100 {
 101         int timeout = up->cec_timeout;
 102
 103         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
 104                 udelay(1);
 105 }
 106
 107 static struct tty_port *
 108 receive_chars(struct uart_sunsab_port *up,
 109               union sab82532_irq_status *stat)
 110 {
 111         struct tty_port *port = NULL;
 112         unsigned char buf[32];
 113         int saw_console_brk = 0;
 114         int free_fifo = 0;
 115         int count = 0;
 116         int i;
 117
 118         if (up->port.state != NULL)             /* Unopened serial console */
 119                 port = &up->port.state->port;
 120
 121         /* Read number of BYTES (Character + Status) available. */
 122         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
 123                 count = SAB82532_RECV_FIFO_SIZE;
 124                 free_fifo++;
 125         }
 126
 127         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
 128                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
 129                 free_fifo++;
 130         }
 131
 132         /* Issue a FIFO read command in case we where idle. */
 133         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
 134                 sunsab_cec_wait(up);
 135                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
 136                 return port;
 137         }
 138
 139         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 140                 free_fifo++;
 141
 142         /* Read the FIFO. */
 143         for (i = 0; i < count; i++)
 144                 buf[i] = readb(&up->regs->r.rfifo[i]);
 145
 146         /* Issue Receive Message Complete command. */
 147         if (free_fifo) {
 148                 sunsab_cec_wait(up);
 149                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
 150         }
 151
 152         /* Count may be zero for BRK, so we check for it here */
 153         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
 154             (up->port.line == up->port.cons->index))
 155                 saw_console_brk = 1;
 156
 157         if (count == 0) {
 158                 if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 159                         stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 160                                              SAB82532_ISR0_FERR);
 161                         up->port.icount.brk++;
 162                         uart_handle_break(&up->port);
 163                 }
 164         }
 165
 166         for (i = 0; i < count; i++) {
 167                 unsigned char ch = buf[i], flag;
 168
 169                 flag = TTY_NORMAL;
 170                 up->port.icount.rx++;
 171
 172                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
 173                                                 SAB82532_ISR0_FERR |
 174                                                 SAB82532_ISR0_RFO)) ||
 175                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
 176                         /*
 177                          * For statistics only
 178                          */
 179                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 180                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
 181                                                      SAB82532_ISR0_FERR);
 182                                 up->port.icount.brk++;
 183                                 /*
 184                                  * We do the SysRQ and SAK checking
 185                                  * here because otherwise the break
 186                                  * may get masked by ignore_status_mask
 187                                  * or read_status_mask.
 188                                  */
 189                                 if (uart_handle_break(&up->port))
 190                                         continue;
 191                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 192                                 up->port.icount.parity++;
 193                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 194                                 up->port.icount.frame++;
 195                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 196                                 up->port.icount.overrun++;
 197
 198                         /*
 199                          * Mask off conditions which should be ingored.
 200                          */
 201                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
 202                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
 203
 204                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
 205                                 flag = TTY_BREAK;
 206                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
 207                                 flag = TTY_PARITY;
 208                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
 209                                 flag = TTY_FRAME;
 210                 }
 211
 212                 if (uart_handle_sysrq_char(&up->port, ch) || !port)
 213                         continue;
 214
 215                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
 216                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
 217                         tty_insert_flip_char(port, ch, flag);
 218                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
 219                         tty_insert_flip_char(port, 0, TTY_OVERRUN);
 220         }
 221
 222         if (saw_console_brk)
 223                 sun_do_break();
 224
 225         return port;
 226 }
 227
 228 static void sunsab_stop_tx(struct uart_port *);
 229 static void sunsab_tx_idle(struct uart_sunsab_port *);
 230
 231 static void transmit_chars(struct uart_sunsab_port *up,
 232                            union sab82532_irq_status *stat)
 233 {
 234         struct circ_buf *xmit = &up->port.state->xmit;
 235         int i;
 236
 237         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
 238                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
 239                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 240                 set_bit(SAB82532_ALLS, &up->irqflags);
 241         }
 242
 243 #if 0 /* [email protected] says this check causes problems */
 244         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 245                 return;
 246 #endif
 247
 248         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 249                 return;
 250
 251         set_bit(SAB82532_XPR, &up->irqflags);
 252         sunsab_tx_idle(up);
 253
 254         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 255                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 256                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
 257                 return;
 258         }
 259
 260         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 261         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 262         clear_bit(SAB82532_ALLS, &up->irqflags);
 263
 264         /* Stuff 32 bytes into Transmit FIFO. */
 265         clear_bit(SAB82532_XPR, &up->irqflags);
 266         for (i = 0; i < up->port.fifosize; i++) {
 267                 writeb(xmit->buf[xmit->tail],
 268                        &up->regs->w.xfifo[i]);
 269                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 270                 up->port.icount.tx++;
 271                 if (uart_circ_empty(xmit))
 272                         break;
 273         }
 274
 275         /* Issue a Transmit Frame command. */
 276         sunsab_cec_wait(up);
 277         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 278
 279         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 280                 uart_write_wakeup(&up->port);
 281
 282         if (uart_circ_empty(xmit))
 283                 sunsab_stop_tx(&up->port);
 284 }
 285
 286 static void check_status(struct uart_sunsab_port *up,
 287                          union sab82532_irq_status *stat)
 288 {
 289         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
 290                 uart_handle_dcd_change(&up->port,
 291                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
 292
 293         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
 294                 uart_handle_cts_change(&up->port,
 295                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
 296
 297         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
 298                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
 299                 up->port.icount.dsr++;
 300         }
 301
 302         wake_up_interruptible(&up->port.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         spin_lock_irqsave(&up->port.lock, 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         spin_unlock_irqrestore(&up->port.lock, 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                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 457                 up->port.icount.tx++;
 458                 if (uart_circ_empty(xmit))
 459                         break;
 460         }
 461
 462         /* Issue a Transmit Frame command.  */
 463         sunsab_cec_wait(up);
 464         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 465 }
 466
 467 /* port->lock is not held.  */
 468 static void sunsab_send_xchar(struct uart_port *port, char ch)
 469 {
 470         struct uart_sunsab_port *up =
 471                 container_of(port, struct uart_sunsab_port, port);
 472         unsigned long flags;
 473
 474         if (ch == __DISABLED_CHAR)
 475                 return;
 476
 477         spin_lock_irqsave(&up->port.lock, flags);
 478
 479         sunsab_tec_wait(up);
 480         writeb(ch, &up->regs->w.tic);
 481
 482         spin_unlock_irqrestore(&up->port.lock, flags);
 483 }
 484
 485 /* port->lock held by caller.  */
 486 static void sunsab_stop_rx(struct uart_port *port)
 487 {
 488         struct uart_sunsab_port *up =
 489                 container_of(port, struct uart_sunsab_port, port);
 490
 491         up->interrupt_mask0 |= SAB82532_IMR0_TCD;
 492         writeb(up->interrupt_mask1, &up->regs->w.imr0);
 493 }
 494
 495 /* port->lock is not held.  */
 496 static void sunsab_break_ctl(struct uart_port *port, int break_state)
 497 {
 498         struct uart_sunsab_port *up =
 499                 container_of(port, struct uart_sunsab_port, port);
 500         unsigned long flags;
 501         unsigned char val;
 502
 503         spin_lock_irqsave(&up->port.lock, flags);
 504
 505         val = up->cached_dafo;
 506         if (break_state)
 507                 val |= SAB82532_DAFO_XBRK;
 508         else
 509                 val &= ~SAB82532_DAFO_XBRK;
 510         up->cached_dafo = val;
 511
 512         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 513         if (test_bit(SAB82532_XPR, &up->irqflags))
 514                 sunsab_tx_idle(up);
 515
 516         spin_unlock_irqrestore(&up->port.lock, flags);
 517 }
 518
 519 /* port->lock is not held.  */
 520 static int sunsab_startup(struct uart_port *port)
 521 {
 522         struct uart_sunsab_port *up =
 523                 container_of(port, struct uart_sunsab_port, port);
 524         unsigned long flags;
 525         unsigned char tmp;
 526         int err = request_irq(up->port.irq, sunsab_interrupt,
 527                               IRQF_SHARED, "sab", up);
 528         if (err)
 529                 return err;
 530
 531         spin_lock_irqsave(&up->port.lock, flags);
 532
 533         /*
 534          * Wait for any commands or immediate characters
 535          */
 536         sunsab_cec_wait(up);
 537         sunsab_tec_wait(up);
 538
 539         /*
 540          * Clear the FIFO buffers.
 541          */
 542         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
 543         sunsab_cec_wait(up);
 544         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
 545
 546         /*
 547          * Clear the interrupt registers.
 548          */
 549         (void) readb(&up->regs->r.isr0);
 550         (void) readb(&up->regs->r.isr1);
 551
 552         /*
 553          * Now, initialize the UART
 554          */
 555         writeb(0, &up->regs->w.ccr0);                           /* power-down */
 556         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
 557                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
 558         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
 559         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
 560                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
 561         writeb(0, &up->regs->w.ccr3);
 562         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
 563         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
 564                            SAB82532_MODE_RAC);
 565         writeb(up->cached_mode, &up->regs->w.mode);
 566         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
 567
 568         tmp = readb(&up->regs->rw.ccr0);
 569         tmp |= SAB82532_CCR0_PU;        /* power-up */
 570         writeb(tmp, &up->regs->rw.ccr0);
 571
 572         /*
 573          * Finally, enable interrupts
 574          */
 575         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 576                                SAB82532_IMR0_PLLA);
 577         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 578         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 579                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 580                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 581                                SAB82532_IMR1_XPR);
 582         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 583         set_bit(SAB82532_ALLS, &up->irqflags);
 584         set_bit(SAB82532_XPR, &up->irqflags);
 585
 586         spin_unlock_irqrestore(&up->port.lock, flags);
 587
 588         return 0;
 589 }
 590
 591 /* port->lock is not held.  */
 592 static void sunsab_shutdown(struct uart_port *port)
 593 {
 594         struct uart_sunsab_port *up =
 595                 container_of(port, struct uart_sunsab_port, port);
 596         unsigned long flags;
 597
 598         spin_lock_irqsave(&up->port.lock, flags);
 599
 600         /* Disable Interrupts */
 601         up->interrupt_mask0 = 0xff;
 602         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 603         up->interrupt_mask1 = 0xff;
 604         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 605
 606         /* Disable break condition */
 607         up->cached_dafo = readb(&up->regs->rw.dafo);
 608         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
 609         writeb(up->cached_dafo, &up->regs->rw.dafo);
 610
 611         /* Disable Receiver */
 612         up->cached_mode &= ~SAB82532_MODE_RAC;
 613         writeb(up->cached_mode, &up->regs->rw.mode);
 614
 615         /*
 616          * XXX FIXME
 617          *
 618          * If the chip is powered down here the system hangs/crashes during
 619          * reboot or shutdown.  This needs to be investigated further,
 620          * similar behaviour occurs in 2.4 when the driver is configured
 621          * as a module only.  One hint may be that data is sometimes
 622          * transmitted at 9600 baud during shutdown (regardless of the
 623          * speed the chip was configured for when the port was open).
 624          */
 625 #if 0
 626         /* Power Down */
 627         tmp = readb(&up->regs->rw.ccr0);
 628         tmp &= ~SAB82532_CCR0_PU;
 629         writeb(tmp, &up->regs->rw.ccr0);
 630 #endif
 631
 632         spin_unlock_irqrestore(&up->port.lock, flags);
 633         free_irq(up->port.irq, up);
 634 }
 635
 636 /*
 637  * This is used to figure out the divisor speeds.
 638  *
 639  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
 640  *
 641  * with               0 <= N < 64 and 0 <= M < 16
 642  */
 643
 644 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
 645 {
 646         int     n, m;
 647
 648         if (baud == 0) {
 649                 *n_ret = 0;
 650                 *m_ret = 0;
 651                 return;
 652         }
 653
 654         /*
 655          * We scale numbers by 10 so that we get better accuracy
 656          * without having to use floating point.  Here we increment m
 657          * until n is within the valid range.
 658          */
 659         n = (SAB_BASE_BAUD * 10) / baud;
 660         m = 0;
 661         while (n >= 640) {
 662                 n = n / 2;
 663                 m++;
 664         }
 665         n = (n+5) / 10;
 666         /*
 667          * We try very hard to avoid speeds with M == 0 since they may
 668          * not work correctly for XTAL frequences above 10 MHz.
 669          */
 670         if ((m == 0) && ((n & 1) == 0)) {
 671                 n = n / 2;
 672                 m++;
 673         }
 674         *n_ret = n - 1;
 675         *m_ret = m;
 676 }
 677
 678 /* Internal routine, port->lock is held and local interrupts are disabled.  */
 679 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
 680                                   unsigned int iflag, unsigned int baud,
 681                                   unsigned int quot)
 682 {
 683         unsigned char dafo;
 684         int n, m;
 685
 686         /* Byte size and parity */
 687         switch (cflag & CSIZE) {
 688               case CS5: dafo = SAB82532_DAFO_CHL5; break;
 689               case CS6: dafo = SAB82532_DAFO_CHL6; break;
 690               case CS7: dafo = SAB82532_DAFO_CHL7; break;
 691               case CS8: dafo = SAB82532_DAFO_CHL8; break;
 692               /* Never happens, but GCC is too dumb to figure it out */
 693               default:  dafo = SAB82532_DAFO_CHL5; break;
 694         }
 695
 696         if (cflag & CSTOPB)
 697                 dafo |= SAB82532_DAFO_STOP;
 698
 699         if (cflag & PARENB)
 700                 dafo |= SAB82532_DAFO_PARE;
 701
 702         if (cflag & PARODD) {
 703                 dafo |= SAB82532_DAFO_PAR_ODD;
 704         } else {
 705                 dafo |= SAB82532_DAFO_PAR_EVEN;
 706         }
 707         up->cached_dafo = dafo;
 708
 709         calc_ebrg(baud, &n, &m);
 710
 711         up->cached_ebrg = n | (m << 6);
 712
 713         up->tec_timeout = (10 * 1000000) / baud;
 714         up->cec_timeout = up->tec_timeout >> 2;
 715
 716         /* CTS flow control flags */
 717         /* We encode read_status_mask and ignore_status_mask like so:
 718          *
 719          * ---------------------
 720          * | ... | ISR1 | ISR0 |
 721          * ---------------------
 722          *  ..    15   8 7    0
 723          */
 724
 725         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 726                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 727                                      SAB82532_ISR0_CDSC);
 728         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 729                                       SAB82532_ISR1_ALLS |
 730                                       SAB82532_ISR1_XPR) << 8;
 731         if (iflag & INPCK)
 732                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 733                                               SAB82532_ISR0_FERR);
 734         if (iflag & (IGNBRK | BRKINT | PARMRK))
 735                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 736
 737         /*
 738          * Characteres to ignore
 739          */
 740         up->port.ignore_status_mask = 0;
 741         if (iflag & IGNPAR)
 742                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 743                                                 SAB82532_ISR0_FERR);
 744         if (iflag & IGNBRK) {
 745                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 746                 /*
 747                  * If we're ignoring parity and break indicators,
 748                  * ignore overruns too (for real raw support).
 749                  */
 750                 if (iflag & IGNPAR)
 751                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 752         }
 753
 754         /*
 755          * ignore all characters if CREAD is not set
 756          */
 757         if ((cflag & CREAD) == 0)
 758                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 759                                                 SAB82532_ISR0_TCD);
 760
 761         uart_update_timeout(&up->port, cflag,
 762                             (up->port.uartclk / (16 * quot)));
 763
 764         /* Now schedule a register update when the chip's
 765          * transmitter is idle.
 766          */
 767         up->cached_mode |= SAB82532_MODE_RAC;
 768         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 769         if (test_bit(SAB82532_XPR, &up->irqflags))
 770                 sunsab_tx_idle(up);
 771 }
 772
 773 /* port->lock is not held.  */
 774 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 775                                const struct ktermios *old)
 776 {
 777         struct uart_sunsab_port *up =
 778                 container_of(port, struct uart_sunsab_port, port);
 779         unsigned long flags;
 780         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 781         unsigned int quot = uart_get_divisor(port, baud);
 782
 783         spin_lock_irqsave(&up->port.lock, flags);
 784         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 785         spin_unlock_irqrestore(&up->port.lock, flags);
 786 }
 787
 788 static const char *sunsab_type(struct uart_port *port)
 789 {
 790         struct uart_sunsab_port *up = (void *)port;
 791         static char buf[36];
 792
 793         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 794         return buf;
 795 }
 796
 797 static void sunsab_release_port(struct uart_port *port)
 798 {
 799 }
 800
 801 static int sunsab_request_port(struct uart_port *port)
 802 {
 803         return 0;
 804 }
 805
 806 static void sunsab_config_port(struct uart_port *port, int flags)
 807 {
 808 }
 809
 810 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 811 {
 812         return -EINVAL;
 813 }
 814
 815 static const struct uart_ops sunsab_pops = {
 816         .tx_empty       = sunsab_tx_empty,
 817         .set_mctrl      = sunsab_set_mctrl,
 818         .get_mctrl      = sunsab_get_mctrl,
 819         .stop_tx        = sunsab_stop_tx,
 820         .start_tx       = sunsab_start_tx,
 821         .send_xchar     = sunsab_send_xchar,
 822         .stop_rx        = sunsab_stop_rx,
 823         .break_ctl      = sunsab_break_ctl,
 824         .startup        = sunsab_startup,
 825         .shutdown       = sunsab_shutdown,
 826         .set_termios    = sunsab_set_termios,
 827         .type           = sunsab_type,
 828         .release_port   = sunsab_release_port,
 829         .request_port   = sunsab_request_port,
 830         .config_port    = sunsab_config_port,
 831         .verify_port    = sunsab_verify_port,
 832 };
 833
 834 static struct uart_driver sunsab_reg = {
 835         .owner                  = THIS_MODULE,
 836         .driver_name            = "sunsab",
 837         .dev_name               = "ttyS",
 838         .major                  = TTY_MAJOR,
 839 };
 840
 841 static struct uart_sunsab_port *sunsab_ports;
 842
 843 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 844
 845 static void sunsab_console_putchar(struct uart_port *port, unsigned char c)
 846 {
 847         struct uart_sunsab_port *up =
 848                 container_of(port, struct uart_sunsab_port, port);
 849
 850         sunsab_tec_wait(up);
 851         writeb(c, &up->regs->w.tic);
 852 }
 853
 854 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 855 {
 856         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 857         unsigned long flags;
 858         int locked = 1;
 859
 860         if (up->port.sysrq || oops_in_progress)
 861                 locked = spin_trylock_irqsave(&up->port.lock, flags);
 862         else
 863                 spin_lock_irqsave(&up->port.lock, flags);
 864
 865         uart_console_write(&up->port, s, n, sunsab_console_putchar);
 866         sunsab_tec_wait(up);
 867
 868         if (locked)
 869                 spin_unlock_irqrestore(&up->port.lock, flags);
 870 }
 871
 872 static int sunsab_console_setup(struct console *con, char *options)
 873 {
 874         struct uart_sunsab_port *up = &sunsab_ports[con->index];
 875         unsigned long flags;
 876         unsigned int baud, quot;
 877
 878         /*
 879          * The console framework calls us for each and every port
 880          * registered. Defer the console setup until the requested
 881          * port has been properly discovered. A bit of a hack,
 882          * though...
 883          */
 884         if (up->port.type != PORT_SUNSAB)
 885                 return -EINVAL;
 886
 887         printk("Console: ttyS%d (SAB82532)\n",
 888                (sunsab_reg.minor - 64) + con->index);
 889
 890         sunserial_console_termios(con, up->port.dev->of_node);
 891
 892         switch (con->cflag & CBAUD) {
 893         case B150: baud = 150; break;
 894         case B300: baud = 300; break;
 895         case B600: baud = 600; break;
 896         case B1200: baud = 1200; break;
 897         case B2400: baud = 2400; break;
 898         case B4800: baud = 4800; break;
 899         default: case B9600: baud = 9600; break;
 900         case B19200: baud = 19200; break;
 901         case B38400: baud = 38400; break;
 902         case B57600: baud = 57600; break;
 903         case B115200: baud = 115200; break;
 904         case B230400: baud = 230400; break;
 905         case B460800: baud = 460800; break;
 906         }
 907
 908         /*
 909          * Temporary fix.
 910          */
 911         spin_lock_init(&up->port.lock);
 912
 913         /*
 914          * Initialize the hardware
 915          */
 916         sunsab_startup(&up->port);
 917
 918         spin_lock_irqsave(&up->port.lock, flags);
 919
 920         /*
 921          * Finally, enable interrupts
 922          */
 923         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 924                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 925         writeb(up->interrupt_mask0, &up->regs->w.imr0);
 926         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 927                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 928                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 929                                 SAB82532_IMR1_XPR;
 930         writeb(up->interrupt_mask1, &up->regs->w.imr1);
 931
 932         quot = uart_get_divisor(&up->port, baud);
 933         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 934         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 935
 936         spin_unlock_irqrestore(&up->port.lock, flags);
 937
 938         return 0;
 939 }
 940
 941 static struct console sunsab_console = {
 942         .name   =       "ttyS",
 943         .write  =       sunsab_console_write,
 944         .device =       uart_console_device,
 945         .setup  =       sunsab_console_setup,
 946         .flags  =       CON_PRINTBUFFER,
 947         .index  =       -1,
 948         .data   =       &sunsab_reg,
 949 };
 950
 951 static inline struct console *SUNSAB_CONSOLE(void)
 952 {
 953         return &sunsab_console;
 954 }
 955 #else
 956 #define SUNSAB_CONSOLE()        (NULL)
 957 #define sunsab_console_init()   do { } while (0)
 958 #endif
 959
 960 static int sunsab_init_one(struct uart_sunsab_port *up,
 961                                      struct platform_device *op,
 962                                      unsigned long offset,
 963                                      int line)
 964 {
 965         up->port.line = line;
 966         up->port.dev = &op->dev;
 967
 968         up->port.mapbase = op->resource[0].start + offset;
 969         up->port.membase = of_ioremap(&op->resource[0], offset,
 970                                       sizeof(union sab82532_async_regs),
 971                                       "sab");
 972         if (!up->port.membase)
 973                 return -ENOMEM;
 974         up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
 975
 976         up->port.irq = op->archdata.irqs[0];
 977
 978         up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
 979         up->port.iotype = UPIO_MEM;
 980         up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSAB_CONSOLE);
 981
 982         writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
 983
 984         up->port.ops = &sunsab_pops;
 985         up->port.type = PORT_SUNSAB;
 986         up->port.uartclk = SAB_BASE_BAUD;
 987
 988         up->type = readb(&up->regs->r.vstr) & 0x0f;
 989         writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
 990         writeb(0xff, &up->regs->w.pim);
 991         if ((up->port.line & 0x1) == 0) {
 992                 up->pvr_dsr_bit = (1 << 0);
 993                 up->pvr_dtr_bit = (1 << 1);
 994                 up->gis_shift = 2;
 995         } else {
 996                 up->pvr_dsr_bit = (1 << 3);
 997                 up->pvr_dtr_bit = (1 << 2);
 998                 up->gis_shift = 0;
 999         }
1000         up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1001         writeb(up->cached_pvr, &up->regs->w.pvr);
1002         up->cached_mode = readb(&up->regs->rw.mode);
1003         up->cached_mode |= SAB82532_MODE_FRTS;
1004         writeb(up->cached_mode, &up->regs->rw.mode);
1005         up->cached_mode |= SAB82532_MODE_RTS;
1006         writeb(up->cached_mode, &up->regs->rw.mode);
1007
1008         up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1009         up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1010
1011         return 0;
1012 }
1013
1014 static int sab_probe(struct platform_device *op)
1015 {
1016         static int inst;
1017         struct uart_sunsab_port *up;
1018         int err;
1019
1020         up = &sunsab_ports[inst * 2];
1021
1022         err = sunsab_init_one(&up[0], op,
1023                               0,
1024                               (inst * 2) + 0);
1025         if (err)
1026                 goto out;
1027
1028         err = sunsab_init_one(&up[1], op,
1029                               sizeof(union sab82532_async_regs),
1030                               (inst * 2) + 1);
1031         if (err)
1032                 goto out1;
1033
1034         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1035                                 &sunsab_reg, up[0].port.line,
1036                                 false);
1037
1038         sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1039                                 &sunsab_reg, up[1].port.line,
1040                                 false);
1041
1042         err = uart_add_one_port(&sunsab_reg, &up[0].port);
1043         if (err)
1044                 goto out2;
1045
1046         err = uart_add_one_port(&sunsab_reg, &up[1].port);
1047         if (err)
1048                 goto out3;
1049
1050         platform_set_drvdata(op, &up[0]);
1051
1052         inst++;
1053
1054         return 0;
1055
1056 out3:
1057         uart_remove_one_port(&sunsab_reg, &up[0].port);
1058 out2:
1059         of_iounmap(&op->resource[0],
1060                    up[1].port.membase,
1061                    sizeof(union sab82532_async_regs));
1062 out1:
1063         of_iounmap(&op->resource[0],
1064                    up[0].port.membase,
1065                    sizeof(union sab82532_async_regs));
1066 out:
1067         return err;
1068 }
1069
1070 static int sab_remove(struct platform_device *op)
1071 {
1072         struct uart_sunsab_port *up = platform_get_drvdata(op);
1073
1074         uart_remove_one_port(&sunsab_reg, &up[1].port);
1075         uart_remove_one_port(&sunsab_reg, &up[0].port);
1076         of_iounmap(&op->resource[0],
1077                    up[1].port.membase,
1078                    sizeof(union sab82532_async_regs));
1079         of_iounmap(&op->resource[0],
1080                    up[0].port.membase,
1081                    sizeof(union sab82532_async_regs));
1082
1083         return 0;
1084 }
1085
1086 static const struct of_device_id sab_match[] = {
1087         {
1088                 .name = "se",
1089         },
1090         {
1091                 .name = "serial",
1092                 .compatible = "sab82532",
1093         },
1094         {},
1095 };
1096 MODULE_DEVICE_TABLE(of, sab_match);
1097
1098 static struct platform_driver sab_driver = {
1099         .driver = {
1100                 .name = "sab",
1101                 .of_match_table = sab_match,
1102         },
1103         .probe          = sab_probe,
1104         .remove         = sab_remove,
1105 };
1106
1107 static int __init sunsab_init(void)
1108 {
1109         struct device_node *dp;
1110         int err;
1111         int num_channels = 0;
1112
1113         for_each_node_by_name(dp, "se")
1114                 num_channels += 2;
1115         for_each_node_by_name(dp, "serial") {
1116                 if (of_device_is_compatible(dp, "sab82532"))
1117                         num_channels += 2;
1118         }
1119
1120         if (num_channels) {
1121                 sunsab_ports = kcalloc(num_channels,
1122                                        sizeof(struct uart_sunsab_port),
1123                                        GFP_KERNEL);
1124                 if (!sunsab_ports)
1125                         return -ENOMEM;
1126
1127                 err = sunserial_register_minors(&sunsab_reg, num_channels);
1128                 if (err) {
1129                         kfree(sunsab_ports);
1130                         sunsab_ports = NULL;
1131
1132                         return err;
1133                 }
1134         }
1135
1136         return platform_driver_register(&sab_driver);
1137 }
1138
1139 static void __exit sunsab_exit(void)
1140 {
1141         platform_driver_unregister(&sab_driver);
1142         if (sunsab_reg.nr) {
1143                 sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1144         }
1145
1146         kfree(sunsab_ports);
1147         sunsab_ports = NULL;
1148 }
1149
1150 module_init(sunsab_init);
1151 module_exit(sunsab_exit);
1152
1153 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1154 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1155 MODULE_LICENSE("GPL");