xref: /openbmc/linux/drivers/tty/serial/sunsab.c (revision 9cfc5c90)
1 /* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
2  *
3  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
4  * Copyright (C) 2002, 2006  David S. Miller (davem@davemloft.net)
5  *
6  * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
7  *   Maxim Krasnyanskiy <maxk@qualcomm.com>
8  *
9  * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
10  * rates to be programmed into the UART.  Also eliminated a lot of
11  * duplicated code in the console setup.
12  *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
13  *
14  * Ported to new 2.5.x UART layer.
15  *   David S. Miller <davem@davemloft.net>
16  */
17 
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/tty.h>
22 #include <linux/tty_flip.h>
23 #include <linux/major.h>
24 #include <linux/string.h>
25 #include <linux/ptrace.h>
26 #include <linux/ioport.h>
27 #include <linux/circ_buf.h>
28 #include <linux/serial.h>
29 #include <linux/sysrq.h>
30 #include <linux/console.h>
31 #include <linux/spinlock.h>
32 #include <linux/slab.h>
33 #include <linux/delay.h>
34 #include <linux/init.h>
35 #include <linux/of_device.h>
36 
37 #include <asm/io.h>
38 #include <asm/irq.h>
39 #include <asm/prom.h>
40 #include <asm/setup.h>
41 
42 #if defined(CONFIG_SERIAL_SUNSAB_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
43 #define SUPPORT_SYSRQ
44 #endif
45 
46 #include <linux/serial_core.h>
47 #include <linux/sunserialcore.h>
48 
49 #include "sunsab.h"
50 
51 struct uart_sunsab_port {
52 	struct uart_port		port;		/* Generic UART port	*/
53 	union sab82532_async_regs	__iomem *regs;	/* Chip registers	*/
54 	unsigned long			irqflags;	/* IRQ state flags	*/
55 	int				dsr;		/* Current DSR state	*/
56 	unsigned int			cec_timeout;	/* Chip poll timeout... */
57 	unsigned int			tec_timeout;	/* likewise		*/
58 	unsigned char			interrupt_mask0;/* ISR0 masking		*/
59 	unsigned char			interrupt_mask1;/* ISR1 masking		*/
60 	unsigned char			pvr_dtr_bit;	/* Which PVR bit is DTR */
61 	unsigned char			pvr_dsr_bit;	/* Which PVR bit is DSR */
62 	unsigned int			gis_shift;
63 	int				type;		/* SAB82532 version	*/
64 
65 	/* Setting configuration bits while the transmitter is active
66 	 * can cause garbage characters to get emitted by the chip.
67 	 * Therefore, we cache such writes here and do the real register
68 	 * write the next time the transmitter becomes idle.
69 	 */
70 	unsigned int			cached_ebrg;
71 	unsigned char			cached_mode;
72 	unsigned char			cached_pvr;
73 	unsigned char			cached_dafo;
74 };
75 
76 /*
77  * This assumes you have a 29.4912 MHz clock for your UART.
78  */
79 #define SAB_BASE_BAUD ( 29491200 / 16 )
80 
81 static char *sab82532_version[16] = {
82 	"V1.0", "V2.0", "V3.2", "V(0x03)",
83 	"V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
84 	"V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
85 	"V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
86 };
87 
88 #define SAB82532_MAX_TEC_TIMEOUT 200000	/* 1 character time (at 50 baud) */
89 #define SAB82532_MAX_CEC_TIMEOUT  50000	/* 2.5 TX CLKs (at 50 baud) */
90 
91 #define SAB82532_RECV_FIFO_SIZE	32      /* Standard async fifo sizes */
92 #define SAB82532_XMIT_FIFO_SIZE	32
93 
94 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
95 {
96 	int timeout = up->tec_timeout;
97 
98 	while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
99 		udelay(1);
100 }
101 
102 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
103 {
104 	int timeout = up->cec_timeout;
105 
106 	while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
107 		udelay(1);
108 }
109 
110 static struct tty_port *
111 receive_chars(struct uart_sunsab_port *up,
112 	      union sab82532_irq_status *stat)
113 {
114 	struct tty_port *port = NULL;
115 	unsigned char buf[32];
116 	int saw_console_brk = 0;
117 	int free_fifo = 0;
118 	int count = 0;
119 	int i;
120 
121 	if (up->port.state != NULL)		/* Unopened serial console */
122 		port = &up->port.state->port;
123 
124 	/* Read number of BYTES (Character + Status) available. */
125 	if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
126 		count = SAB82532_RECV_FIFO_SIZE;
127 		free_fifo++;
128 	}
129 
130 	if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
131 		count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
132 		free_fifo++;
133 	}
134 
135 	/* Issue a FIFO read command in case we where idle. */
136 	if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
137 		sunsab_cec_wait(up);
138 		writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
139 		return port;
140 	}
141 
142 	if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
143 		free_fifo++;
144 
145 	/* Read the FIFO. */
146 	for (i = 0; i < count; i++)
147 		buf[i] = readb(&up->regs->r.rfifo[i]);
148 
149 	/* Issue Receive Message Complete command. */
150 	if (free_fifo) {
151 		sunsab_cec_wait(up);
152 		writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
153 	}
154 
155 	/* Count may be zero for BRK, so we check for it here */
156 	if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
157 	    (up->port.line == up->port.cons->index))
158 		saw_console_brk = 1;
159 
160 	if (count == 0) {
161 		if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
162 			stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
163 					     SAB82532_ISR0_FERR);
164 			up->port.icount.brk++;
165 			uart_handle_break(&up->port);
166 		}
167 	}
168 
169 	for (i = 0; i < count; i++) {
170 		unsigned char ch = buf[i], flag;
171 
172 		flag = TTY_NORMAL;
173 		up->port.icount.rx++;
174 
175 		if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
176 						SAB82532_ISR0_FERR |
177 						SAB82532_ISR0_RFO)) ||
178 		    unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
179 			/*
180 			 * For statistics only
181 			 */
182 			if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
183 				stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
184 						     SAB82532_ISR0_FERR);
185 				up->port.icount.brk++;
186 				/*
187 				 * We do the SysRQ and SAK checking
188 				 * here because otherwise the break
189 				 * may get masked by ignore_status_mask
190 				 * or read_status_mask.
191 				 */
192 				if (uart_handle_break(&up->port))
193 					continue;
194 			} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
195 				up->port.icount.parity++;
196 			else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
197 				up->port.icount.frame++;
198 			if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
199 				up->port.icount.overrun++;
200 
201 			/*
202 			 * Mask off conditions which should be ingored.
203 			 */
204 			stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
205 			stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
206 
207 			if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
208 				flag = TTY_BREAK;
209 			} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
210 				flag = TTY_PARITY;
211 			else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
212 				flag = TTY_FRAME;
213 		}
214 
215 		if (uart_handle_sysrq_char(&up->port, ch) || !port)
216 			continue;
217 
218 		if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
219 		    (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
220 			tty_insert_flip_char(port, ch, flag);
221 		if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
222 			tty_insert_flip_char(port, 0, TTY_OVERRUN);
223 	}
224 
225 	if (saw_console_brk)
226 		sun_do_break();
227 
228 	return port;
229 }
230 
231 static void sunsab_stop_tx(struct uart_port *);
232 static void sunsab_tx_idle(struct uart_sunsab_port *);
233 
234 static void transmit_chars(struct uart_sunsab_port *up,
235 			   union sab82532_irq_status *stat)
236 {
237 	struct circ_buf *xmit = &up->port.state->xmit;
238 	int i;
239 
240 	if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
241 		up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
242 		writeb(up->interrupt_mask1, &up->regs->w.imr1);
243 		set_bit(SAB82532_ALLS, &up->irqflags);
244 	}
245 
246 #if 0 /* bde@nwlink.com says this check causes problems */
247 	if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
248 		return;
249 #endif
250 
251 	if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
252 		return;
253 
254 	set_bit(SAB82532_XPR, &up->irqflags);
255 	sunsab_tx_idle(up);
256 
257 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
258 		up->interrupt_mask1 |= SAB82532_IMR1_XPR;
259 		writeb(up->interrupt_mask1, &up->regs->w.imr1);
260 		return;
261 	}
262 
263 	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
264 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
265 	clear_bit(SAB82532_ALLS, &up->irqflags);
266 
267 	/* Stuff 32 bytes into Transmit FIFO. */
268 	clear_bit(SAB82532_XPR, &up->irqflags);
269 	for (i = 0; i < up->port.fifosize; i++) {
270 		writeb(xmit->buf[xmit->tail],
271 		       &up->regs->w.xfifo[i]);
272 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
273 		up->port.icount.tx++;
274 		if (uart_circ_empty(xmit))
275 			break;
276 	}
277 
278 	/* Issue a Transmit Frame command. */
279 	sunsab_cec_wait(up);
280 	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
281 
282 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
283 		uart_write_wakeup(&up->port);
284 
285 	if (uart_circ_empty(xmit))
286 		sunsab_stop_tx(&up->port);
287 }
288 
289 static void check_status(struct uart_sunsab_port *up,
290 			 union sab82532_irq_status *stat)
291 {
292 	if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
293 		uart_handle_dcd_change(&up->port,
294 				       !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
295 
296 	if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
297 		uart_handle_cts_change(&up->port,
298 				       (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
299 
300 	if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
301 		up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
302 		up->port.icount.dsr++;
303 	}
304 
305 	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
306 }
307 
308 static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
309 {
310 	struct uart_sunsab_port *up = dev_id;
311 	struct tty_port *port = NULL;
312 	union sab82532_irq_status status;
313 	unsigned long flags;
314 	unsigned char gis;
315 
316 	spin_lock_irqsave(&up->port.lock, flags);
317 
318 	status.stat = 0;
319 	gis = readb(&up->regs->r.gis) >> up->gis_shift;
320 	if (gis & 1)
321 		status.sreg.isr0 = readb(&up->regs->r.isr0);
322 	if (gis & 2)
323 		status.sreg.isr1 = readb(&up->regs->r.isr1);
324 
325 	if (status.stat) {
326 		if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
327 					 SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
328 		    (status.sreg.isr1 & SAB82532_ISR1_BRK))
329 			port = receive_chars(up, &status);
330 		if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
331 		    (status.sreg.isr1 & SAB82532_ISR1_CSC))
332 			check_status(up, &status);
333 		if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
334 			transmit_chars(up, &status);
335 	}
336 
337 	spin_unlock_irqrestore(&up->port.lock, flags);
338 
339 	if (port)
340 		tty_flip_buffer_push(port);
341 
342 	return IRQ_HANDLED;
343 }
344 
345 /* port->lock is not held.  */
346 static unsigned int sunsab_tx_empty(struct uart_port *port)
347 {
348 	struct uart_sunsab_port *up =
349 		container_of(port, struct uart_sunsab_port, port);
350 	int ret;
351 
352 	/* Do not need a lock for a state test like this.  */
353 	if (test_bit(SAB82532_ALLS, &up->irqflags))
354 		ret = TIOCSER_TEMT;
355 	else
356 		ret = 0;
357 
358 	return ret;
359 }
360 
361 /* port->lock held by caller.  */
362 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
363 {
364 	struct uart_sunsab_port *up =
365 		container_of(port, struct uart_sunsab_port, port);
366 
367 	if (mctrl & TIOCM_RTS) {
368 		up->cached_mode &= ~SAB82532_MODE_FRTS;
369 		up->cached_mode |= SAB82532_MODE_RTS;
370 	} else {
371 		up->cached_mode |= (SAB82532_MODE_FRTS |
372 				    SAB82532_MODE_RTS);
373 	}
374 	if (mctrl & TIOCM_DTR) {
375 		up->cached_pvr &= ~(up->pvr_dtr_bit);
376 	} else {
377 		up->cached_pvr |= up->pvr_dtr_bit;
378 	}
379 
380 	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
381 	if (test_bit(SAB82532_XPR, &up->irqflags))
382 		sunsab_tx_idle(up);
383 }
384 
385 /* port->lock is held by caller and interrupts are disabled.  */
386 static unsigned int sunsab_get_mctrl(struct uart_port *port)
387 {
388 	struct uart_sunsab_port *up =
389 		container_of(port, struct uart_sunsab_port, port);
390 	unsigned char val;
391 	unsigned int result;
392 
393 	result = 0;
394 
395 	val = readb(&up->regs->r.pvr);
396 	result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
397 
398 	val = readb(&up->regs->r.vstr);
399 	result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
400 
401 	val = readb(&up->regs->r.star);
402 	result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
403 
404 	return result;
405 }
406 
407 /* port->lock held by caller.  */
408 static void sunsab_stop_tx(struct uart_port *port)
409 {
410 	struct uart_sunsab_port *up =
411 		container_of(port, struct uart_sunsab_port, port);
412 
413 	up->interrupt_mask1 |= SAB82532_IMR1_XPR;
414 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
415 }
416 
417 /* port->lock held by caller.  */
418 static void sunsab_tx_idle(struct uart_sunsab_port *up)
419 {
420 	if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
421 		u8 tmp;
422 
423 		clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
424 		writeb(up->cached_mode, &up->regs->rw.mode);
425 		writeb(up->cached_pvr, &up->regs->rw.pvr);
426 		writeb(up->cached_dafo, &up->regs->w.dafo);
427 
428 		writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
429 		tmp = readb(&up->regs->rw.ccr2);
430 		tmp &= ~0xc0;
431 		tmp |= (up->cached_ebrg >> 2) & 0xc0;
432 		writeb(tmp, &up->regs->rw.ccr2);
433 	}
434 }
435 
436 /* port->lock held by caller.  */
437 static void sunsab_start_tx(struct uart_port *port)
438 {
439 	struct uart_sunsab_port *up =
440 		container_of(port, struct uart_sunsab_port, port);
441 	struct circ_buf *xmit = &up->port.state->xmit;
442 	int i;
443 
444 	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
445 		return;
446 
447 	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
448 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
449 
450 	if (!test_bit(SAB82532_XPR, &up->irqflags))
451 		return;
452 
453 	clear_bit(SAB82532_ALLS, &up->irqflags);
454 	clear_bit(SAB82532_XPR, &up->irqflags);
455 
456 	for (i = 0; i < up->port.fifosize; i++) {
457 		writeb(xmit->buf[xmit->tail],
458 		       &up->regs->w.xfifo[i]);
459 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
460 		up->port.icount.tx++;
461 		if (uart_circ_empty(xmit))
462 			break;
463 	}
464 
465 	/* Issue a Transmit Frame command.  */
466 	sunsab_cec_wait(up);
467 	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
468 }
469 
470 /* port->lock is not held.  */
471 static void sunsab_send_xchar(struct uart_port *port, char ch)
472 {
473 	struct uart_sunsab_port *up =
474 		container_of(port, struct uart_sunsab_port, port);
475 	unsigned long flags;
476 
477 	if (ch == __DISABLED_CHAR)
478 		return;
479 
480 	spin_lock_irqsave(&up->port.lock, flags);
481 
482 	sunsab_tec_wait(up);
483 	writeb(ch, &up->regs->w.tic);
484 
485 	spin_unlock_irqrestore(&up->port.lock, flags);
486 }
487 
488 /* port->lock held by caller.  */
489 static void sunsab_stop_rx(struct uart_port *port)
490 {
491 	struct uart_sunsab_port *up =
492 		container_of(port, struct uart_sunsab_port, port);
493 
494 	up->interrupt_mask0 |= SAB82532_IMR0_TCD;
495 	writeb(up->interrupt_mask1, &up->regs->w.imr0);
496 }
497 
498 /* port->lock is not held.  */
499 static void sunsab_break_ctl(struct uart_port *port, int break_state)
500 {
501 	struct uart_sunsab_port *up =
502 		container_of(port, struct uart_sunsab_port, port);
503 	unsigned long flags;
504 	unsigned char val;
505 
506 	spin_lock_irqsave(&up->port.lock, flags);
507 
508 	val = up->cached_dafo;
509 	if (break_state)
510 		val |= SAB82532_DAFO_XBRK;
511 	else
512 		val &= ~SAB82532_DAFO_XBRK;
513 	up->cached_dafo = val;
514 
515 	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
516 	if (test_bit(SAB82532_XPR, &up->irqflags))
517 		sunsab_tx_idle(up);
518 
519 	spin_unlock_irqrestore(&up->port.lock, flags);
520 }
521 
522 /* port->lock is not held.  */
523 static int sunsab_startup(struct uart_port *port)
524 {
525 	struct uart_sunsab_port *up =
526 		container_of(port, struct uart_sunsab_port, port);
527 	unsigned long flags;
528 	unsigned char tmp;
529 	int err = request_irq(up->port.irq, sunsab_interrupt,
530 			      IRQF_SHARED, "sab", up);
531 	if (err)
532 		return err;
533 
534 	spin_lock_irqsave(&up->port.lock, flags);
535 
536 	/*
537 	 * Wait for any commands or immediate characters
538 	 */
539 	sunsab_cec_wait(up);
540 	sunsab_tec_wait(up);
541 
542 	/*
543 	 * Clear the FIFO buffers.
544 	 */
545 	writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
546 	sunsab_cec_wait(up);
547 	writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
548 
549 	/*
550 	 * Clear the interrupt registers.
551 	 */
552 	(void) readb(&up->regs->r.isr0);
553 	(void) readb(&up->regs->r.isr1);
554 
555 	/*
556 	 * Now, initialize the UART
557 	 */
558 	writeb(0, &up->regs->w.ccr0);				/* power-down */
559 	writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
560 	       SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
561 	writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
562 	writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
563 	       SAB82532_CCR2_TOE, &up->regs->w.ccr2);
564 	writeb(0, &up->regs->w.ccr3);
565 	writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
566 	up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
567 			   SAB82532_MODE_RAC);
568 	writeb(up->cached_mode, &up->regs->w.mode);
569 	writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
570 
571 	tmp = readb(&up->regs->rw.ccr0);
572 	tmp |= SAB82532_CCR0_PU;	/* power-up */
573 	writeb(tmp, &up->regs->rw.ccr0);
574 
575 	/*
576 	 * Finally, enable interrupts
577 	 */
578 	up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
579 			       SAB82532_IMR0_PLLA);
580 	writeb(up->interrupt_mask0, &up->regs->w.imr0);
581 	up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
582 			       SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
583 			       SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
584 			       SAB82532_IMR1_XPR);
585 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
586 	set_bit(SAB82532_ALLS, &up->irqflags);
587 	set_bit(SAB82532_XPR, &up->irqflags);
588 
589 	spin_unlock_irqrestore(&up->port.lock, flags);
590 
591 	return 0;
592 }
593 
594 /* port->lock is not held.  */
595 static void sunsab_shutdown(struct uart_port *port)
596 {
597 	struct uart_sunsab_port *up =
598 		container_of(port, struct uart_sunsab_port, port);
599 	unsigned long flags;
600 
601 	spin_lock_irqsave(&up->port.lock, flags);
602 
603 	/* Disable Interrupts */
604 	up->interrupt_mask0 = 0xff;
605 	writeb(up->interrupt_mask0, &up->regs->w.imr0);
606 	up->interrupt_mask1 = 0xff;
607 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
608 
609 	/* Disable break condition */
610 	up->cached_dafo = readb(&up->regs->rw.dafo);
611 	up->cached_dafo &= ~SAB82532_DAFO_XBRK;
612 	writeb(up->cached_dafo, &up->regs->rw.dafo);
613 
614 	/* Disable Receiver */
615 	up->cached_mode &= ~SAB82532_MODE_RAC;
616 	writeb(up->cached_mode, &up->regs->rw.mode);
617 
618 	/*
619 	 * XXX FIXME
620 	 *
621 	 * If the chip is powered down here the system hangs/crashes during
622 	 * reboot or shutdown.  This needs to be investigated further,
623 	 * similar behaviour occurs in 2.4 when the driver is configured
624 	 * as a module only.  One hint may be that data is sometimes
625 	 * transmitted at 9600 baud during shutdown (regardless of the
626 	 * speed the chip was configured for when the port was open).
627 	 */
628 #if 0
629 	/* Power Down */
630 	tmp = readb(&up->regs->rw.ccr0);
631 	tmp &= ~SAB82532_CCR0_PU;
632 	writeb(tmp, &up->regs->rw.ccr0);
633 #endif
634 
635 	spin_unlock_irqrestore(&up->port.lock, flags);
636 	free_irq(up->port.irq, up);
637 }
638 
639 /*
640  * This is used to figure out the divisor speeds.
641  *
642  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
643  *
644  * with               0 <= N < 64 and 0 <= M < 16
645  */
646 
647 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
648 {
649 	int	n, m;
650 
651 	if (baud == 0) {
652 		*n_ret = 0;
653 		*m_ret = 0;
654 		return;
655 	}
656 
657 	/*
658 	 * We scale numbers by 10 so that we get better accuracy
659 	 * without having to use floating point.  Here we increment m
660 	 * until n is within the valid range.
661 	 */
662 	n = (SAB_BASE_BAUD * 10) / baud;
663 	m = 0;
664 	while (n >= 640) {
665 		n = n / 2;
666 		m++;
667 	}
668 	n = (n+5) / 10;
669 	/*
670 	 * We try very hard to avoid speeds with M == 0 since they may
671 	 * not work correctly for XTAL frequences above 10 MHz.
672 	 */
673 	if ((m == 0) && ((n & 1) == 0)) {
674 		n = n / 2;
675 		m++;
676 	}
677 	*n_ret = n - 1;
678 	*m_ret = m;
679 }
680 
681 /* Internal routine, port->lock is held and local interrupts are disabled.  */
682 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
683 				  unsigned int iflag, unsigned int baud,
684 				  unsigned int quot)
685 {
686 	unsigned char dafo;
687 	int bits, n, m;
688 
689 	/* Byte size and parity */
690 	switch (cflag & CSIZE) {
691 	      case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
692 	      case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
693 	      case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
694 	      case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
695 	      /* Never happens, but GCC is too dumb to figure it out */
696 	      default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
697 	}
698 
699 	if (cflag & CSTOPB) {
700 		dafo |= SAB82532_DAFO_STOP;
701 		bits++;
702 	}
703 
704 	if (cflag & PARENB) {
705 		dafo |= SAB82532_DAFO_PARE;
706 		bits++;
707 	}
708 
709 	if (cflag & PARODD) {
710 		dafo |= SAB82532_DAFO_PAR_ODD;
711 	} else {
712 		dafo |= SAB82532_DAFO_PAR_EVEN;
713 	}
714 	up->cached_dafo = dafo;
715 
716 	calc_ebrg(baud, &n, &m);
717 
718 	up->cached_ebrg = n | (m << 6);
719 
720 	up->tec_timeout = (10 * 1000000) / baud;
721 	up->cec_timeout = up->tec_timeout >> 2;
722 
723 	/* CTS flow control flags */
724 	/* We encode read_status_mask and ignore_status_mask like so:
725 	 *
726 	 * ---------------------
727 	 * | ... | ISR1 | ISR0 |
728 	 * ---------------------
729 	 *  ..    15   8 7    0
730 	 */
731 
732 	up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
733 				     SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
734 				     SAB82532_ISR0_CDSC);
735 	up->port.read_status_mask |= (SAB82532_ISR1_CSC |
736 				      SAB82532_ISR1_ALLS |
737 				      SAB82532_ISR1_XPR) << 8;
738 	if (iflag & INPCK)
739 		up->port.read_status_mask |= (SAB82532_ISR0_PERR |
740 					      SAB82532_ISR0_FERR);
741 	if (iflag & (IGNBRK | BRKINT | PARMRK))
742 		up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
743 
744 	/*
745 	 * Characteres to ignore
746 	 */
747 	up->port.ignore_status_mask = 0;
748 	if (iflag & IGNPAR)
749 		up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
750 						SAB82532_ISR0_FERR);
751 	if (iflag & IGNBRK) {
752 		up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
753 		/*
754 		 * If we're ignoring parity and break indicators,
755 		 * ignore overruns too (for real raw support).
756 		 */
757 		if (iflag & IGNPAR)
758 			up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
759 	}
760 
761 	/*
762 	 * ignore all characters if CREAD is not set
763 	 */
764 	if ((cflag & CREAD) == 0)
765 		up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
766 						SAB82532_ISR0_TCD);
767 
768 	uart_update_timeout(&up->port, cflag,
769 			    (up->port.uartclk / (16 * quot)));
770 
771 	/* Now schedule a register update when the chip's
772 	 * transmitter is idle.
773 	 */
774 	up->cached_mode |= SAB82532_MODE_RAC;
775 	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
776 	if (test_bit(SAB82532_XPR, &up->irqflags))
777 		sunsab_tx_idle(up);
778 }
779 
780 /* port->lock is not held.  */
781 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
782 			       struct ktermios *old)
783 {
784 	struct uart_sunsab_port *up =
785 		container_of(port, struct uart_sunsab_port, port);
786 	unsigned long flags;
787 	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
788 	unsigned int quot = uart_get_divisor(port, baud);
789 
790 	spin_lock_irqsave(&up->port.lock, flags);
791 	sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
792 	spin_unlock_irqrestore(&up->port.lock, flags);
793 }
794 
795 static const char *sunsab_type(struct uart_port *port)
796 {
797 	struct uart_sunsab_port *up = (void *)port;
798 	static char buf[36];
799 
800 	sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
801 	return buf;
802 }
803 
804 static void sunsab_release_port(struct uart_port *port)
805 {
806 }
807 
808 static int sunsab_request_port(struct uart_port *port)
809 {
810 	return 0;
811 }
812 
813 static void sunsab_config_port(struct uart_port *port, int flags)
814 {
815 }
816 
817 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
818 {
819 	return -EINVAL;
820 }
821 
822 static struct uart_ops sunsab_pops = {
823 	.tx_empty	= sunsab_tx_empty,
824 	.set_mctrl	= sunsab_set_mctrl,
825 	.get_mctrl	= sunsab_get_mctrl,
826 	.stop_tx	= sunsab_stop_tx,
827 	.start_tx	= sunsab_start_tx,
828 	.send_xchar	= sunsab_send_xchar,
829 	.stop_rx	= sunsab_stop_rx,
830 	.break_ctl	= sunsab_break_ctl,
831 	.startup	= sunsab_startup,
832 	.shutdown	= sunsab_shutdown,
833 	.set_termios	= sunsab_set_termios,
834 	.type		= sunsab_type,
835 	.release_port	= sunsab_release_port,
836 	.request_port	= sunsab_request_port,
837 	.config_port	= sunsab_config_port,
838 	.verify_port	= sunsab_verify_port,
839 };
840 
841 static struct uart_driver sunsab_reg = {
842 	.owner			= THIS_MODULE,
843 	.driver_name		= "sunsab",
844 	.dev_name		= "ttyS",
845 	.major			= TTY_MAJOR,
846 };
847 
848 static struct uart_sunsab_port *sunsab_ports;
849 
850 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
851 
852 static void sunsab_console_putchar(struct uart_port *port, int c)
853 {
854 	struct uart_sunsab_port *up =
855 		container_of(port, struct uart_sunsab_port, port);
856 
857 	sunsab_tec_wait(up);
858 	writeb(c, &up->regs->w.tic);
859 }
860 
861 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
862 {
863 	struct uart_sunsab_port *up = &sunsab_ports[con->index];
864 	unsigned long flags;
865 	int locked = 1;
866 
867 	if (up->port.sysrq || oops_in_progress)
868 		locked = spin_trylock_irqsave(&up->port.lock, flags);
869 	else
870 		spin_lock_irqsave(&up->port.lock, flags);
871 
872 	uart_console_write(&up->port, s, n, sunsab_console_putchar);
873 	sunsab_tec_wait(up);
874 
875 	if (locked)
876 		spin_unlock_irqrestore(&up->port.lock, flags);
877 }
878 
879 static int sunsab_console_setup(struct console *con, char *options)
880 {
881 	struct uart_sunsab_port *up = &sunsab_ports[con->index];
882 	unsigned long flags;
883 	unsigned int baud, quot;
884 
885 	/*
886 	 * The console framework calls us for each and every port
887 	 * registered. Defer the console setup until the requested
888 	 * port has been properly discovered. A bit of a hack,
889 	 * though...
890 	 */
891 	if (up->port.type != PORT_SUNSAB)
892 		return -1;
893 
894 	printk("Console: ttyS%d (SAB82532)\n",
895 	       (sunsab_reg.minor - 64) + con->index);
896 
897 	sunserial_console_termios(con, up->port.dev->of_node);
898 
899 	switch (con->cflag & CBAUD) {
900 	case B150: baud = 150; break;
901 	case B300: baud = 300; break;
902 	case B600: baud = 600; break;
903 	case B1200: baud = 1200; break;
904 	case B2400: baud = 2400; break;
905 	case B4800: baud = 4800; break;
906 	default: case B9600: baud = 9600; break;
907 	case B19200: baud = 19200; break;
908 	case B38400: baud = 38400; break;
909 	case B57600: baud = 57600; break;
910 	case B115200: baud = 115200; break;
911 	case B230400: baud = 230400; break;
912 	case B460800: baud = 460800; break;
913 	}
914 
915 	/*
916 	 * Temporary fix.
917 	 */
918 	spin_lock_init(&up->port.lock);
919 
920 	/*
921 	 * Initialize the hardware
922 	 */
923 	sunsab_startup(&up->port);
924 
925 	spin_lock_irqsave(&up->port.lock, flags);
926 
927 	/*
928 	 * Finally, enable interrupts
929 	 */
930 	up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
931 				SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
932 	writeb(up->interrupt_mask0, &up->regs->w.imr0);
933 	up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
934 				SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
935 				SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
936 				SAB82532_IMR1_XPR;
937 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
938 
939 	quot = uart_get_divisor(&up->port, baud);
940 	sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
941 	sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
942 
943 	spin_unlock_irqrestore(&up->port.lock, flags);
944 
945 	return 0;
946 }
947 
948 static struct console sunsab_console = {
949 	.name	=	"ttyS",
950 	.write	=	sunsab_console_write,
951 	.device	=	uart_console_device,
952 	.setup	=	sunsab_console_setup,
953 	.flags	=	CON_PRINTBUFFER,
954 	.index	=	-1,
955 	.data	=	&sunsab_reg,
956 };
957 
958 static inline struct console *SUNSAB_CONSOLE(void)
959 {
960 	return &sunsab_console;
961 }
962 #else
963 #define SUNSAB_CONSOLE()	(NULL)
964 #define sunsab_console_init()	do { } while (0)
965 #endif
966 
967 static int sunsab_init_one(struct uart_sunsab_port *up,
968 				     struct platform_device *op,
969 				     unsigned long offset,
970 				     int line)
971 {
972 	up->port.line = line;
973 	up->port.dev = &op->dev;
974 
975 	up->port.mapbase = op->resource[0].start + offset;
976 	up->port.membase = of_ioremap(&op->resource[0], offset,
977 				      sizeof(union sab82532_async_regs),
978 				      "sab");
979 	if (!up->port.membase)
980 		return -ENOMEM;
981 	up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
982 
983 	up->port.irq = op->archdata.irqs[0];
984 
985 	up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
986 	up->port.iotype = UPIO_MEM;
987 
988 	writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
989 
990 	up->port.ops = &sunsab_pops;
991 	up->port.type = PORT_SUNSAB;
992 	up->port.uartclk = SAB_BASE_BAUD;
993 
994 	up->type = readb(&up->regs->r.vstr) & 0x0f;
995 	writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
996 	writeb(0xff, &up->regs->w.pim);
997 	if ((up->port.line & 0x1) == 0) {
998 		up->pvr_dsr_bit = (1 << 0);
999 		up->pvr_dtr_bit = (1 << 1);
1000 		up->gis_shift = 2;
1001 	} else {
1002 		up->pvr_dsr_bit = (1 << 3);
1003 		up->pvr_dtr_bit = (1 << 2);
1004 		up->gis_shift = 0;
1005 	}
1006 	up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1007 	writeb(up->cached_pvr, &up->regs->w.pvr);
1008 	up->cached_mode = readb(&up->regs->rw.mode);
1009 	up->cached_mode |= SAB82532_MODE_FRTS;
1010 	writeb(up->cached_mode, &up->regs->rw.mode);
1011 	up->cached_mode |= SAB82532_MODE_RTS;
1012 	writeb(up->cached_mode, &up->regs->rw.mode);
1013 
1014 	up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1015 	up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1016 
1017 	return 0;
1018 }
1019 
1020 static int sab_probe(struct platform_device *op)
1021 {
1022 	static int inst;
1023 	struct uart_sunsab_port *up;
1024 	int err;
1025 
1026 	up = &sunsab_ports[inst * 2];
1027 
1028 	err = sunsab_init_one(&up[0], op,
1029 			      0,
1030 			      (inst * 2) + 0);
1031 	if (err)
1032 		goto out;
1033 
1034 	err = sunsab_init_one(&up[1], op,
1035 			      sizeof(union sab82532_async_regs),
1036 			      (inst * 2) + 1);
1037 	if (err)
1038 		goto out1;
1039 
1040 	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1041 				&sunsab_reg, up[0].port.line,
1042 				false);
1043 
1044 	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1045 				&sunsab_reg, up[1].port.line,
1046 				false);
1047 
1048 	err = uart_add_one_port(&sunsab_reg, &up[0].port);
1049 	if (err)
1050 		goto out2;
1051 
1052 	err = uart_add_one_port(&sunsab_reg, &up[1].port);
1053 	if (err)
1054 		goto out3;
1055 
1056 	platform_set_drvdata(op, &up[0]);
1057 
1058 	inst++;
1059 
1060 	return 0;
1061 
1062 out3:
1063 	uart_remove_one_port(&sunsab_reg, &up[0].port);
1064 out2:
1065 	of_iounmap(&op->resource[0],
1066 		   up[1].port.membase,
1067 		   sizeof(union sab82532_async_regs));
1068 out1:
1069 	of_iounmap(&op->resource[0],
1070 		   up[0].port.membase,
1071 		   sizeof(union sab82532_async_regs));
1072 out:
1073 	return err;
1074 }
1075 
1076 static int sab_remove(struct platform_device *op)
1077 {
1078 	struct uart_sunsab_port *up = platform_get_drvdata(op);
1079 
1080 	uart_remove_one_port(&sunsab_reg, &up[1].port);
1081 	uart_remove_one_port(&sunsab_reg, &up[0].port);
1082 	of_iounmap(&op->resource[0],
1083 		   up[1].port.membase,
1084 		   sizeof(union sab82532_async_regs));
1085 	of_iounmap(&op->resource[0],
1086 		   up[0].port.membase,
1087 		   sizeof(union sab82532_async_regs));
1088 
1089 	return 0;
1090 }
1091 
1092 static const struct of_device_id sab_match[] = {
1093 	{
1094 		.name = "se",
1095 	},
1096 	{
1097 		.name = "serial",
1098 		.compatible = "sab82532",
1099 	},
1100 	{},
1101 };
1102 MODULE_DEVICE_TABLE(of, sab_match);
1103 
1104 static struct platform_driver sab_driver = {
1105 	.driver = {
1106 		.name = "sab",
1107 		.of_match_table = sab_match,
1108 	},
1109 	.probe		= sab_probe,
1110 	.remove		= sab_remove,
1111 };
1112 
1113 static int __init sunsab_init(void)
1114 {
1115 	struct device_node *dp;
1116 	int err;
1117 	int num_channels = 0;
1118 
1119 	for_each_node_by_name(dp, "se")
1120 		num_channels += 2;
1121 	for_each_node_by_name(dp, "serial") {
1122 		if (of_device_is_compatible(dp, "sab82532"))
1123 			num_channels += 2;
1124 	}
1125 
1126 	if (num_channels) {
1127 		sunsab_ports = kzalloc(sizeof(struct uart_sunsab_port) *
1128 				       num_channels, GFP_KERNEL);
1129 		if (!sunsab_ports)
1130 			return -ENOMEM;
1131 
1132 		err = sunserial_register_minors(&sunsab_reg, num_channels);
1133 		if (err) {
1134 			kfree(sunsab_ports);
1135 			sunsab_ports = NULL;
1136 
1137 			return err;
1138 		}
1139 	}
1140 
1141 	return platform_driver_register(&sab_driver);
1142 }
1143 
1144 static void __exit sunsab_exit(void)
1145 {
1146 	platform_driver_unregister(&sab_driver);
1147 	if (sunsab_reg.nr) {
1148 		sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
1149 	}
1150 
1151 	kfree(sunsab_ports);
1152 	sunsab_ports = NULL;
1153 }
1154 
1155 module_init(sunsab_init);
1156 module_exit(sunsab_exit);
1157 
1158 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1159 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1160 MODULE_LICENSE("GPL");
1161