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v5.4
   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
  52struct 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
  82static 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
  95static __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
 103static __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
 111static struct tty_port *
 112receive_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
 232static void sunsab_stop_tx(struct uart_port *);
 233static void sunsab_tx_idle(struct uart_sunsab_port *);
 234
 235static 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
 290static 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
 309static 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.  */
 347static 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.  */
 363static 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.  */
 387static 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.  */
 409static 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.  */
 419static 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.  */
 438static 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.  */
 472static 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.  */
 490static 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.  */
 500static 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.  */
 524static 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.  */
 596static 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
 648static 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.  */
 683static 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.  */
 782static 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
 796static 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
 805static void sunsab_release_port(struct uart_port *port)
 806{
 807}
 808
 809static int sunsab_request_port(struct uart_port *port)
 810{
 811	return 0;
 812}
 813
 814static void sunsab_config_port(struct uart_port *port, int flags)
 815{
 816}
 817
 818static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 819{
 820	return -EINVAL;
 821}
 822
 823static 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
 842static struct uart_driver sunsab_reg = {
 843	.owner			= THIS_MODULE,
 844	.driver_name		= "sunsab",
 845	.dev_name		= "ttyS",
 846	.major			= TTY_MAJOR,
 847};
 848
 849static struct uart_sunsab_port *sunsab_ports;
 850
 851#ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 852
 853static 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
 862static 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
 880static 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
 949static 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
 959static 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
 968static 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
1021static 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
1063out3:
1064	uart_remove_one_port(&sunsab_reg, &up[0].port);
1065out2:
1066	of_iounmap(&op->resource[0],
1067		   up[1].port.membase,
1068		   sizeof(union sab82532_async_regs));
1069out1:
1070	of_iounmap(&op->resource[0],
1071		   up[0].port.membase,
1072		   sizeof(union sab82532_async_regs));
1073out:
1074	return err;
1075}
1076
1077static 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
1093static const struct of_device_id sab_match[] = {
1094	{
1095		.name = "se",
1096	},
1097	{
1098		.name = "serial",
1099		.compatible = "sab82532",
1100	},
1101	{},
1102};
1103MODULE_DEVICE_TABLE(of, sab_match);
1104
1105static 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
1114static 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	return platform_driver_register(&sab_driver);
1144}
1145
1146static void __exit sunsab_exit(void)
1147{
1148	platform_driver_unregister(&sab_driver);
1149	if (sunsab_reg.nr) {
1150		sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1151	}
1152
1153	kfree(sunsab_ports);
1154	sunsab_ports = NULL;
1155}
1156
1157module_init(sunsab_init);
1158module_exit(sunsab_exit);
1159
1160MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1161MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1162MODULE_LICENSE("GPL");
v5.9
   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#include <linux/serial_core.h>
  44#include <linux/sunserialcore.h>
  45
  46#include "sunsab.h"
  47
  48struct 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
  78static 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
  91static __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
  99static __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
 107static struct tty_port *
 108receive_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
 228static void sunsab_stop_tx(struct uart_port *);
 229static void sunsab_tx_idle(struct uart_sunsab_port *);
 230
 231static 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 /* bde@nwlink.com says this check causes problems */
 244	if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
 245		return;
 246#endif
 247
 248	if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
 249		return;
 250
 251	set_bit(SAB82532_XPR, &up->irqflags);
 252	sunsab_tx_idle(up);
 253
 254	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 255		up->interrupt_mask1 |= SAB82532_IMR1_XPR;
 256		writeb(up->interrupt_mask1, &up->regs->w.imr1);
 257		return;
 258	}
 259
 260	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 261	writeb(up->interrupt_mask1, &up->regs->w.imr1);
 262	clear_bit(SAB82532_ALLS, &up->irqflags);
 263
 264	/* Stuff 32 bytes into Transmit FIFO. */
 265	clear_bit(SAB82532_XPR, &up->irqflags);
 266	for (i = 0; i < up->port.fifosize; i++) {
 267		writeb(xmit->buf[xmit->tail],
 268		       &up->regs->w.xfifo[i]);
 269		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 270		up->port.icount.tx++;
 271		if (uart_circ_empty(xmit))
 272			break;
 273	}
 274
 275	/* Issue a Transmit Frame command. */
 276	sunsab_cec_wait(up);
 277	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
 278
 279	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 280		uart_write_wakeup(&up->port);
 281
 282	if (uart_circ_empty(xmit))
 283		sunsab_stop_tx(&up->port);
 284}
 285
 286static 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
 305static 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.  */
 343static 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.  */
 359static 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.  */
 383static 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.  */
 405static 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.  */
 415static 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.  */
 434static 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.  */
 468static 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.  */
 486static 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.  */
 496static 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.  */
 520static 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.  */
 592static 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
 644static 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.  */
 679static 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 bits, n, m;
 685
 686	/* Byte size and parity */
 687	switch (cflag & CSIZE) {
 688	      case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 689	      case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
 690	      case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
 691	      case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
 692	      /* Never happens, but GCC is too dumb to figure it out */
 693	      default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
 694	}
 695
 696	if (cflag & CSTOPB) {
 697		dafo |= SAB82532_DAFO_STOP;
 698		bits++;
 699	}
 700
 701	if (cflag & PARENB) {
 702		dafo |= SAB82532_DAFO_PARE;
 703		bits++;
 704	}
 705
 706	if (cflag & PARODD) {
 707		dafo |= SAB82532_DAFO_PAR_ODD;
 708	} else {
 709		dafo |= SAB82532_DAFO_PAR_EVEN;
 710	}
 711	up->cached_dafo = dafo;
 712
 713	calc_ebrg(baud, &n, &m);
 714
 715	up->cached_ebrg = n | (m << 6);
 716
 717	up->tec_timeout = (10 * 1000000) / baud;
 718	up->cec_timeout = up->tec_timeout >> 2;
 719
 720	/* CTS flow control flags */
 721	/* We encode read_status_mask and ignore_status_mask like so:
 722	 *
 723	 * ---------------------
 724	 * | ... | ISR1 | ISR0 |
 725	 * ---------------------
 726	 *  ..    15   8 7    0
 727	 */
 728
 729	up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
 730				     SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
 731				     SAB82532_ISR0_CDSC);
 732	up->port.read_status_mask |= (SAB82532_ISR1_CSC |
 733				      SAB82532_ISR1_ALLS |
 734				      SAB82532_ISR1_XPR) << 8;
 735	if (iflag & INPCK)
 736		up->port.read_status_mask |= (SAB82532_ISR0_PERR |
 737					      SAB82532_ISR0_FERR);
 738	if (iflag & (IGNBRK | BRKINT | PARMRK))
 739		up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
 740
 741	/*
 742	 * Characteres to ignore
 743	 */
 744	up->port.ignore_status_mask = 0;
 745	if (iflag & IGNPAR)
 746		up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
 747						SAB82532_ISR0_FERR);
 748	if (iflag & IGNBRK) {
 749		up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
 750		/*
 751		 * If we're ignoring parity and break indicators,
 752		 * ignore overruns too (for real raw support).
 753		 */
 754		if (iflag & IGNPAR)
 755			up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
 756	}
 757
 758	/*
 759	 * ignore all characters if CREAD is not set
 760	 */
 761	if ((cflag & CREAD) == 0)
 762		up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
 763						SAB82532_ISR0_TCD);
 764
 765	uart_update_timeout(&up->port, cflag,
 766			    (up->port.uartclk / (16 * quot)));
 767
 768	/* Now schedule a register update when the chip's
 769	 * transmitter is idle.
 770	 */
 771	up->cached_mode |= SAB82532_MODE_RAC;
 772	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
 773	if (test_bit(SAB82532_XPR, &up->irqflags))
 774		sunsab_tx_idle(up);
 775}
 776
 777/* port->lock is not held.  */
 778static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
 779			       struct ktermios *old)
 780{
 781	struct uart_sunsab_port *up =
 782		container_of(port, struct uart_sunsab_port, port);
 783	unsigned long flags;
 784	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 785	unsigned int quot = uart_get_divisor(port, baud);
 786
 787	spin_lock_irqsave(&up->port.lock, flags);
 788	sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
 789	spin_unlock_irqrestore(&up->port.lock, flags);
 790}
 791
 792static const char *sunsab_type(struct uart_port *port)
 793{
 794	struct uart_sunsab_port *up = (void *)port;
 795	static char buf[36];
 796	
 797	sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
 798	return buf;
 799}
 800
 801static void sunsab_release_port(struct uart_port *port)
 802{
 803}
 804
 805static int sunsab_request_port(struct uart_port *port)
 806{
 807	return 0;
 808}
 809
 810static void sunsab_config_port(struct uart_port *port, int flags)
 811{
 812}
 813
 814static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
 815{
 816	return -EINVAL;
 817}
 818
 819static const struct uart_ops sunsab_pops = {
 820	.tx_empty	= sunsab_tx_empty,
 821	.set_mctrl	= sunsab_set_mctrl,
 822	.get_mctrl	= sunsab_get_mctrl,
 823	.stop_tx	= sunsab_stop_tx,
 824	.start_tx	= sunsab_start_tx,
 825	.send_xchar	= sunsab_send_xchar,
 826	.stop_rx	= sunsab_stop_rx,
 827	.break_ctl	= sunsab_break_ctl,
 828	.startup	= sunsab_startup,
 829	.shutdown	= sunsab_shutdown,
 830	.set_termios	= sunsab_set_termios,
 831	.type		= sunsab_type,
 832	.release_port	= sunsab_release_port,
 833	.request_port	= sunsab_request_port,
 834	.config_port	= sunsab_config_port,
 835	.verify_port	= sunsab_verify_port,
 836};
 837
 838static struct uart_driver sunsab_reg = {
 839	.owner			= THIS_MODULE,
 840	.driver_name		= "sunsab",
 841	.dev_name		= "ttyS",
 842	.major			= TTY_MAJOR,
 843};
 844
 845static struct uart_sunsab_port *sunsab_ports;
 846
 847#ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
 848
 849static void sunsab_console_putchar(struct uart_port *port, int c)
 850{
 851	struct uart_sunsab_port *up =
 852		container_of(port, struct uart_sunsab_port, port);
 853
 854	sunsab_tec_wait(up);
 855	writeb(c, &up->regs->w.tic);
 856}
 857
 858static void sunsab_console_write(struct console *con, const char *s, unsigned n)
 859{
 860	struct uart_sunsab_port *up = &sunsab_ports[con->index];
 861	unsigned long flags;
 862	int locked = 1;
 863
 864	if (up->port.sysrq || oops_in_progress)
 865		locked = spin_trylock_irqsave(&up->port.lock, flags);
 866	else
 867		spin_lock_irqsave(&up->port.lock, flags);
 868
 869	uart_console_write(&up->port, s, n, sunsab_console_putchar);
 870	sunsab_tec_wait(up);
 871
 872	if (locked)
 873		spin_unlock_irqrestore(&up->port.lock, flags);
 874}
 875
 876static int sunsab_console_setup(struct console *con, char *options)
 877{
 878	struct uart_sunsab_port *up = &sunsab_ports[con->index];
 879	unsigned long flags;
 880	unsigned int baud, quot;
 881
 882	/*
 883	 * The console framework calls us for each and every port
 884	 * registered. Defer the console setup until the requested
 885	 * port has been properly discovered. A bit of a hack,
 886	 * though...
 887	 */
 888	if (up->port.type != PORT_SUNSAB)
 889		return -EINVAL;
 890
 891	printk("Console: ttyS%d (SAB82532)\n",
 892	       (sunsab_reg.minor - 64) + con->index);
 893
 894	sunserial_console_termios(con, up->port.dev->of_node);
 895
 896	switch (con->cflag & CBAUD) {
 897	case B150: baud = 150; break;
 898	case B300: baud = 300; break;
 899	case B600: baud = 600; break;
 900	case B1200: baud = 1200; break;
 901	case B2400: baud = 2400; break;
 902	case B4800: baud = 4800; break;
 903	default: case B9600: baud = 9600; break;
 904	case B19200: baud = 19200; break;
 905	case B38400: baud = 38400; break;
 906	case B57600: baud = 57600; break;
 907	case B115200: baud = 115200; break;
 908	case B230400: baud = 230400; break;
 909	case B460800: baud = 460800; break;
 910	}
 911
 912	/*
 913	 * Temporary fix.
 914	 */
 915	spin_lock_init(&up->port.lock);
 916
 917	/*
 918	 * Initialize the hardware
 919	 */
 920	sunsab_startup(&up->port);
 921
 922	spin_lock_irqsave(&up->port.lock, flags);
 923
 924	/*
 925	 * Finally, enable interrupts
 926	 */
 927	up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
 928				SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
 929	writeb(up->interrupt_mask0, &up->regs->w.imr0);
 930	up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
 931				SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
 932				SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
 933				SAB82532_IMR1_XPR;
 934	writeb(up->interrupt_mask1, &up->regs->w.imr1);
 935
 936	quot = uart_get_divisor(&up->port, baud);
 937	sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
 938	sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
 939
 940	spin_unlock_irqrestore(&up->port.lock, flags);
 941	
 942	return 0;
 943}
 944
 945static struct console sunsab_console = {
 946	.name	=	"ttyS",
 947	.write	=	sunsab_console_write,
 948	.device	=	uart_console_device,
 949	.setup	=	sunsab_console_setup,
 950	.flags	=	CON_PRINTBUFFER,
 951	.index	=	-1,
 952	.data	=	&sunsab_reg,
 953};
 954
 955static inline struct console *SUNSAB_CONSOLE(void)
 956{
 957	return &sunsab_console;
 958}
 959#else
 960#define SUNSAB_CONSOLE()	(NULL)
 961#define sunsab_console_init()	do { } while (0)
 962#endif
 963
 964static int sunsab_init_one(struct uart_sunsab_port *up,
 965				     struct platform_device *op,
 966				     unsigned long offset,
 967				     int line)
 968{
 969	up->port.line = line;
 970	up->port.dev = &op->dev;
 971
 972	up->port.mapbase = op->resource[0].start + offset;
 973	up->port.membase = of_ioremap(&op->resource[0], offset,
 974				      sizeof(union sab82532_async_regs),
 975				      "sab");
 976	if (!up->port.membase)
 977		return -ENOMEM;
 978	up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
 979
 980	up->port.irq = op->archdata.irqs[0];
 981
 982	up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
 983	up->port.iotype = UPIO_MEM;
 984	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSAB_CONSOLE);
 985
 986	writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
 987
 988	up->port.ops = &sunsab_pops;
 989	up->port.type = PORT_SUNSAB;
 990	up->port.uartclk = SAB_BASE_BAUD;
 991
 992	up->type = readb(&up->regs->r.vstr) & 0x0f;
 993	writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
 994	writeb(0xff, &up->regs->w.pim);
 995	if ((up->port.line & 0x1) == 0) {
 996		up->pvr_dsr_bit = (1 << 0);
 997		up->pvr_dtr_bit = (1 << 1);
 998		up->gis_shift = 2;
 999	} else {
1000		up->pvr_dsr_bit = (1 << 3);
1001		up->pvr_dtr_bit = (1 << 2);
1002		up->gis_shift = 0;
1003	}
1004	up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1005	writeb(up->cached_pvr, &up->regs->w.pvr);
1006	up->cached_mode = readb(&up->regs->rw.mode);
1007	up->cached_mode |= SAB82532_MODE_FRTS;
1008	writeb(up->cached_mode, &up->regs->rw.mode);
1009	up->cached_mode |= SAB82532_MODE_RTS;
1010	writeb(up->cached_mode, &up->regs->rw.mode);
1011
1012	up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1013	up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1014
1015	return 0;
1016}
1017
1018static int sab_probe(struct platform_device *op)
1019{
1020	static int inst;
1021	struct uart_sunsab_port *up;
1022	int err;
1023
1024	up = &sunsab_ports[inst * 2];
1025
1026	err = sunsab_init_one(&up[0], op,
1027			      0,
1028			      (inst * 2) + 0);
1029	if (err)
1030		goto out;
1031
1032	err = sunsab_init_one(&up[1], op,
1033			      sizeof(union sab82532_async_regs),
1034			      (inst * 2) + 1);
1035	if (err)
1036		goto out1;
1037
1038	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1039				&sunsab_reg, up[0].port.line,
1040				false);
1041
1042	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1043				&sunsab_reg, up[1].port.line,
1044				false);
1045
1046	err = uart_add_one_port(&sunsab_reg, &up[0].port);
1047	if (err)
1048		goto out2;
1049
1050	err = uart_add_one_port(&sunsab_reg, &up[1].port);
1051	if (err)
1052		goto out3;
1053
1054	platform_set_drvdata(op, &up[0]);
1055
1056	inst++;
1057
1058	return 0;
1059
1060out3:
1061	uart_remove_one_port(&sunsab_reg, &up[0].port);
1062out2:
1063	of_iounmap(&op->resource[0],
1064		   up[1].port.membase,
1065		   sizeof(union sab82532_async_regs));
1066out1:
1067	of_iounmap(&op->resource[0],
1068		   up[0].port.membase,
1069		   sizeof(union sab82532_async_regs));
1070out:
1071	return err;
1072}
1073
1074static int sab_remove(struct platform_device *op)
1075{
1076	struct uart_sunsab_port *up = platform_get_drvdata(op);
1077
1078	uart_remove_one_port(&sunsab_reg, &up[1].port);
1079	uart_remove_one_port(&sunsab_reg, &up[0].port);
1080	of_iounmap(&op->resource[0],
1081		   up[1].port.membase,
1082		   sizeof(union sab82532_async_regs));
1083	of_iounmap(&op->resource[0],
1084		   up[0].port.membase,
1085		   sizeof(union sab82532_async_regs));
1086
1087	return 0;
1088}
1089
1090static const struct of_device_id sab_match[] = {
1091	{
1092		.name = "se",
1093	},
1094	{
1095		.name = "serial",
1096		.compatible = "sab82532",
1097	},
1098	{},
1099};
1100MODULE_DEVICE_TABLE(of, sab_match);
1101
1102static struct platform_driver sab_driver = {
1103	.driver = {
1104		.name = "sab",
1105		.of_match_table = sab_match,
1106	},
1107	.probe		= sab_probe,
1108	.remove		= sab_remove,
1109};
1110
1111static int __init sunsab_init(void)
1112{
1113	struct device_node *dp;
1114	int err;
1115	int num_channels = 0;
1116
1117	for_each_node_by_name(dp, "se")
1118		num_channels += 2;
1119	for_each_node_by_name(dp, "serial") {
1120		if (of_device_is_compatible(dp, "sab82532"))
1121			num_channels += 2;
1122	}
1123
1124	if (num_channels) {
1125		sunsab_ports = kcalloc(num_channels,
1126				       sizeof(struct uart_sunsab_port),
1127				       GFP_KERNEL);
1128		if (!sunsab_ports)
1129			return -ENOMEM;
1130
1131		err = sunserial_register_minors(&sunsab_reg, num_channels);
1132		if (err) {
1133			kfree(sunsab_ports);
1134			sunsab_ports = NULL;
1135
1136			return err;
1137		}
1138	}
1139
1140	return platform_driver_register(&sab_driver);
1141}
1142
1143static void __exit sunsab_exit(void)
1144{
1145	platform_driver_unregister(&sab_driver);
1146	if (sunsab_reg.nr) {
1147		sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1148	}
1149
1150	kfree(sunsab_ports);
1151	sunsab_ports = NULL;
1152}
1153
1154module_init(sunsab_init);
1155module_exit(sunsab_exit);
1156
1157MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1158MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1159MODULE_LICENSE("GPL");