1 // SPDX-License-Identifier: GPL-2.0
2 /* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
3 *
4 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
5 * Copyright (C) 2002, 2006 David S. Miller (davem@davemloft.net)
6 *
7 * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
8 * Maxim Krasnyanskiy <maxk@qualcomm.com>
9 *
10 * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
11 * rates to be programmed into the UART. Also eliminated a lot of
12 * duplicated code in the console setup.
13 * Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
14 *
15 * Ported to new 2.5.x UART layer.
16 * David S. Miller <davem@davemloft.net>
17 */
18
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/tty.h>
23 #include <linux/tty_flip.h>
24 #include <linux/major.h>
25 #include <linux/string.h>
26 #include <linux/ptrace.h>
27 #include <linux/ioport.h>
28 #include <linux/circ_buf.h>
29 #include <linux/serial.h>
30 #include <linux/sysrq.h>
31 #include <linux/console.h>
32 #include <linux/spinlock.h>
33 #include <linux/slab.h>
34 #include <linux/delay.h>
35 #include <linux/init.h>
36 #include <linux/of_device.h>
37
38 #include <asm/io.h>
39 #include <asm/irq.h>
40 #include <asm/prom.h>
41 #include <asm/setup.h>
42
43 #if defined(CONFIG_SERIAL_SUNSAB_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
44 #define SUPPORT_SYSRQ
45 #endif
46
47 #include <linux/serial_core.h>
48 #include <linux/sunserialcore.h>
49
50 #include "sunsab.h"
51
52 struct uart_sunsab_port {
53 struct uart_port port; /* Generic UART port */
54 union sab82532_async_regs __iomem *regs; /* Chip registers */
55 unsigned long irqflags; /* IRQ state flags */
56 int dsr; /* Current DSR state */
57 unsigned int cec_timeout; /* Chip poll timeout... */
58 unsigned int tec_timeout; /* likewise */
59 unsigned char interrupt_mask0;/* ISR0 masking */
60 unsigned char interrupt_mask1;/* ISR1 masking */
61 unsigned char pvr_dtr_bit; /* Which PVR bit is DTR */
62 unsigned char pvr_dsr_bit; /* Which PVR bit is DSR */
63 unsigned int gis_shift;
64 int type; /* SAB82532 version */
65
66 /* Setting configuration bits while the transmitter is active
67 * can cause garbage characters to get emitted by the chip.
68 * Therefore, we cache such writes here and do the real register
69 * write the next time the transmitter becomes idle.
70 */
71 unsigned int cached_ebrg;
72 unsigned char cached_mode;
73 unsigned char cached_pvr;
74 unsigned char cached_dafo;
75 };
76
77 /*
78 * This assumes you have a 29.4912 MHz clock for your UART.
79 */
80 #define SAB_BASE_BAUD ( 29491200 / 16 )
81
82 static char *sab82532_version[16] = {
83 "V1.0", "V2.0", "V3.2", "V(0x03)",
84 "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
85 "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
86 "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
87 };
88
89 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
90 #define SAB82532_MAX_CEC_TIMEOUT 50000 /* 2.5 TX CLKs (at 50 baud) */
91
92 #define SAB82532_RECV_FIFO_SIZE 32 /* Standard async fifo sizes */
93 #define SAB82532_XMIT_FIFO_SIZE 32
94
sunsab_tec_wait(struct uart_sunsab_port * up)95 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
96 {
97 int timeout = up->tec_timeout;
98
99 while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
100 udelay(1);
101 }
102
sunsab_cec_wait(struct uart_sunsab_port * up)103 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
104 {
105 int timeout = up->cec_timeout;
106
107 while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
108 udelay(1);
109 }
110
111 static struct tty_port *
receive_chars(struct uart_sunsab_port * up,union sab82532_irq_status * stat)112 receive_chars(struct uart_sunsab_port *up,
113 union sab82532_irq_status *stat)
114 {
115 struct tty_port *port = NULL;
116 unsigned char buf[32];
117 int saw_console_brk = 0;
118 int free_fifo = 0;
119 int count = 0;
120 int i;
121
122 if (up->port.state != NULL) /* Unopened serial console */
123 port = &up->port.state->port;
124
125 /* Read number of BYTES (Character + Status) available. */
126 if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
127 count = SAB82532_RECV_FIFO_SIZE;
128 free_fifo++;
129 }
130
131 if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
132 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
133 free_fifo++;
134 }
135
136 /* Issue a FIFO read command in case we where idle. */
137 if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
138 sunsab_cec_wait(up);
139 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
140 return port;
141 }
142
143 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
144 free_fifo++;
145
146 /* Read the FIFO. */
147 for (i = 0; i < count; i++)
148 buf[i] = readb(&up->regs->r.rfifo[i]);
149
150 /* Issue Receive Message Complete command. */
151 if (free_fifo) {
152 sunsab_cec_wait(up);
153 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
154 }
155
156 /* Count may be zero for BRK, so we check for it here */
157 if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
158 (up->port.line == up->port.cons->index))
159 saw_console_brk = 1;
160
161 if (count == 0) {
162 if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
163 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
164 SAB82532_ISR0_FERR);
165 up->port.icount.brk++;
166 uart_handle_break(&up->port);
167 }
168 }
169
170 for (i = 0; i < count; i++) {
171 unsigned char ch = buf[i], flag;
172
173 flag = TTY_NORMAL;
174 up->port.icount.rx++;
175
176 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
177 SAB82532_ISR0_FERR |
178 SAB82532_ISR0_RFO)) ||
179 unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
180 /*
181 * For statistics only
182 */
183 if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
184 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
185 SAB82532_ISR0_FERR);
186 up->port.icount.brk++;
187 /*
188 * We do the SysRQ and SAK checking
189 * here because otherwise the break
190 * may get masked by ignore_status_mask
191 * or read_status_mask.
192 */
193 if (uart_handle_break(&up->port))
194 continue;
195 } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
196 up->port.icount.parity++;
197 else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
198 up->port.icount.frame++;
199 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
200 up->port.icount.overrun++;
201
202 /*
203 * Mask off conditions which should be ingored.
204 */
205 stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
206 stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
207
208 if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
209 flag = TTY_BREAK;
210 } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
211 flag = TTY_PARITY;
212 else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
213 flag = TTY_FRAME;
214 }
215
216 if (uart_handle_sysrq_char(&up->port, ch) || !port)
217 continue;
218
219 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
220 (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
221 tty_insert_flip_char(port, ch, flag);
222 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
223 tty_insert_flip_char(port, 0, TTY_OVERRUN);
224 }
225
226 if (saw_console_brk)
227 sun_do_break();
228
229 return port;
230 }
231
232 static void sunsab_stop_tx(struct uart_port *);
233 static void sunsab_tx_idle(struct uart_sunsab_port *);
234
transmit_chars(struct uart_sunsab_port * up,union sab82532_irq_status * stat)235 static void transmit_chars(struct uart_sunsab_port *up,
236 union sab82532_irq_status *stat)
237 {
238 struct circ_buf *xmit = &up->port.state->xmit;
239 int i;
240
241 if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
242 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
243 writeb(up->interrupt_mask1, &up->regs->w.imr1);
244 set_bit(SAB82532_ALLS, &up->irqflags);
245 }
246
247 #if 0 /* bde@nwlink.com says this check causes problems */
248 if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
249 return;
250 #endif
251
252 if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
253 return;
254
255 set_bit(SAB82532_XPR, &up->irqflags);
256 sunsab_tx_idle(up);
257
258 if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
259 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
260 writeb(up->interrupt_mask1, &up->regs->w.imr1);
261 return;
262 }
263
264 up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
265 writeb(up->interrupt_mask1, &up->regs->w.imr1);
266 clear_bit(SAB82532_ALLS, &up->irqflags);
267
268 /* Stuff 32 bytes into Transmit FIFO. */
269 clear_bit(SAB82532_XPR, &up->irqflags);
270 for (i = 0; i < up->port.fifosize; i++) {
271 writeb(xmit->buf[xmit->tail],
272 &up->regs->w.xfifo[i]);
273 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
274 up->port.icount.tx++;
275 if (uart_circ_empty(xmit))
276 break;
277 }
278
279 /* Issue a Transmit Frame command. */
280 sunsab_cec_wait(up);
281 writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
282
283 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
284 uart_write_wakeup(&up->port);
285
286 if (uart_circ_empty(xmit))
287 sunsab_stop_tx(&up->port);
288 }
289
check_status(struct uart_sunsab_port * up,union sab82532_irq_status * stat)290 static void check_status(struct uart_sunsab_port *up,
291 union sab82532_irq_status *stat)
292 {
293 if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
294 uart_handle_dcd_change(&up->port,
295 !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
296
297 if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
298 uart_handle_cts_change(&up->port,
299 (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
300
301 if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
302 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
303 up->port.icount.dsr++;
304 }
305
306 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
307 }
308
sunsab_interrupt(int irq,void * dev_id)309 static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
310 {
311 struct uart_sunsab_port *up = dev_id;
312 struct tty_port *port = NULL;
313 union sab82532_irq_status status;
314 unsigned long flags;
315 unsigned char gis;
316
317 spin_lock_irqsave(&up->port.lock, flags);
318
319 status.stat = 0;
320 gis = readb(&up->regs->r.gis) >> up->gis_shift;
321 if (gis & 1)
322 status.sreg.isr0 = readb(&up->regs->r.isr0);
323 if (gis & 2)
324 status.sreg.isr1 = readb(&up->regs->r.isr1);
325
326 if (status.stat) {
327 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
328 SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
329 (status.sreg.isr1 & SAB82532_ISR1_BRK))
330 port = receive_chars(up, &status);
331 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
332 (status.sreg.isr1 & SAB82532_ISR1_CSC))
333 check_status(up, &status);
334 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
335 transmit_chars(up, &status);
336 }
337
338 spin_unlock_irqrestore(&up->port.lock, flags);
339
340 if (port)
341 tty_flip_buffer_push(port);
342
343 return IRQ_HANDLED;
344 }
345
346 /* port->lock is not held. */
sunsab_tx_empty(struct uart_port * port)347 static unsigned int sunsab_tx_empty(struct uart_port *port)
348 {
349 struct uart_sunsab_port *up =
350 container_of(port, struct uart_sunsab_port, port);
351 int ret;
352
353 /* Do not need a lock for a state test like this. */
354 if (test_bit(SAB82532_ALLS, &up->irqflags))
355 ret = TIOCSER_TEMT;
356 else
357 ret = 0;
358
359 return ret;
360 }
361
362 /* port->lock held by caller. */
sunsab_set_mctrl(struct uart_port * port,unsigned int mctrl)363 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
364 {
365 struct uart_sunsab_port *up =
366 container_of(port, struct uart_sunsab_port, port);
367
368 if (mctrl & TIOCM_RTS) {
369 up->cached_mode &= ~SAB82532_MODE_FRTS;
370 up->cached_mode |= SAB82532_MODE_RTS;
371 } else {
372 up->cached_mode |= (SAB82532_MODE_FRTS |
373 SAB82532_MODE_RTS);
374 }
375 if (mctrl & TIOCM_DTR) {
376 up->cached_pvr &= ~(up->pvr_dtr_bit);
377 } else {
378 up->cached_pvr |= up->pvr_dtr_bit;
379 }
380
381 set_bit(SAB82532_REGS_PENDING, &up->irqflags);
382 if (test_bit(SAB82532_XPR, &up->irqflags))
383 sunsab_tx_idle(up);
384 }
385
386 /* port->lock is held by caller and interrupts are disabled. */
sunsab_get_mctrl(struct uart_port * port)387 static unsigned int sunsab_get_mctrl(struct uart_port *port)
388 {
389 struct uart_sunsab_port *up =
390 container_of(port, struct uart_sunsab_port, port);
391 unsigned char val;
392 unsigned int result;
393
394 result = 0;
395
396 val = readb(&up->regs->r.pvr);
397 result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
398
399 val = readb(&up->regs->r.vstr);
400 result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
401
402 val = readb(&up->regs->r.star);
403 result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
404
405 return result;
406 }
407
408 /* port->lock held by caller. */
sunsab_stop_tx(struct uart_port * port)409 static void sunsab_stop_tx(struct uart_port *port)
410 {
411 struct uart_sunsab_port *up =
412 container_of(port, struct uart_sunsab_port, port);
413
414 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
415 writeb(up->interrupt_mask1, &up->regs->w.imr1);
416 }
417
418 /* port->lock held by caller. */
sunsab_tx_idle(struct uart_sunsab_port * up)419 static void sunsab_tx_idle(struct uart_sunsab_port *up)
420 {
421 if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
422 u8 tmp;
423
424 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
425 writeb(up->cached_mode, &up->regs->rw.mode);
426 writeb(up->cached_pvr, &up->regs->rw.pvr);
427 writeb(up->cached_dafo, &up->regs->w.dafo);
428
429 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
430 tmp = readb(&up->regs->rw.ccr2);
431 tmp &= ~0xc0;
432 tmp |= (up->cached_ebrg >> 2) & 0xc0;
433 writeb(tmp, &up->regs->rw.ccr2);
434 }
435 }
436
437 /* port->lock held by caller. */
sunsab_start_tx(struct uart_port * port)438 static void sunsab_start_tx(struct uart_port *port)
439 {
440 struct uart_sunsab_port *up =
441 container_of(port, struct uart_sunsab_port, port);
442 struct circ_buf *xmit = &up->port.state->xmit;
443 int i;
444
445 if (uart_circ_empty(xmit) || uart_tx_stopped(port))
446 return;
447
448 up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
449 writeb(up->interrupt_mask1, &up->regs->w.imr1);
450
451 if (!test_bit(SAB82532_XPR, &up->irqflags))
452 return;
453
454 clear_bit(SAB82532_ALLS, &up->irqflags);
455 clear_bit(SAB82532_XPR, &up->irqflags);
456
457 for (i = 0; i < up->port.fifosize; i++) {
458 writeb(xmit->buf[xmit->tail],
459 &up->regs->w.xfifo[i]);
460 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
461 up->port.icount.tx++;
462 if (uart_circ_empty(xmit))
463 break;
464 }
465
466 /* Issue a Transmit Frame command. */
467 sunsab_cec_wait(up);
468 writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
469 }
470
471 /* port->lock is not held. */
sunsab_send_xchar(struct uart_port * port,char ch)472 static void sunsab_send_xchar(struct uart_port *port, char ch)
473 {
474 struct uart_sunsab_port *up =
475 container_of(port, struct uart_sunsab_port, port);
476 unsigned long flags;
477
478 if (ch == __DISABLED_CHAR)
479 return;
480
481 spin_lock_irqsave(&up->port.lock, flags);
482
483 sunsab_tec_wait(up);
484 writeb(ch, &up->regs->w.tic);
485
486 spin_unlock_irqrestore(&up->port.lock, flags);
487 }
488
489 /* port->lock held by caller. */
sunsab_stop_rx(struct uart_port * port)490 static void sunsab_stop_rx(struct uart_port *port)
491 {
492 struct uart_sunsab_port *up =
493 container_of(port, struct uart_sunsab_port, port);
494
495 up->interrupt_mask0 |= SAB82532_IMR0_TCD;
496 writeb(up->interrupt_mask1, &up->regs->w.imr0);
497 }
498
499 /* port->lock is not held. */
sunsab_break_ctl(struct uart_port * port,int break_state)500 static void sunsab_break_ctl(struct uart_port *port, int break_state)
501 {
502 struct uart_sunsab_port *up =
503 container_of(port, struct uart_sunsab_port, port);
504 unsigned long flags;
505 unsigned char val;
506
507 spin_lock_irqsave(&up->port.lock, flags);
508
509 val = up->cached_dafo;
510 if (break_state)
511 val |= SAB82532_DAFO_XBRK;
512 else
513 val &= ~SAB82532_DAFO_XBRK;
514 up->cached_dafo = val;
515
516 set_bit(SAB82532_REGS_PENDING, &up->irqflags);
517 if (test_bit(SAB82532_XPR, &up->irqflags))
518 sunsab_tx_idle(up);
519
520 spin_unlock_irqrestore(&up->port.lock, flags);
521 }
522
523 /* port->lock is not held. */
sunsab_startup(struct uart_port * port)524 static int sunsab_startup(struct uart_port *port)
525 {
526 struct uart_sunsab_port *up =
527 container_of(port, struct uart_sunsab_port, port);
528 unsigned long flags;
529 unsigned char tmp;
530 int err = request_irq(up->port.irq, sunsab_interrupt,
531 IRQF_SHARED, "sab", up);
532 if (err)
533 return err;
534
535 spin_lock_irqsave(&up->port.lock, flags);
536
537 /*
538 * Wait for any commands or immediate characters
539 */
540 sunsab_cec_wait(up);
541 sunsab_tec_wait(up);
542
543 /*
544 * Clear the FIFO buffers.
545 */
546 writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
547 sunsab_cec_wait(up);
548 writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
549
550 /*
551 * Clear the interrupt registers.
552 */
553 (void) readb(&up->regs->r.isr0);
554 (void) readb(&up->regs->r.isr1);
555
556 /*
557 * Now, initialize the UART
558 */
559 writeb(0, &up->regs->w.ccr0); /* power-down */
560 writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
561 SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
562 writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
563 writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
564 SAB82532_CCR2_TOE, &up->regs->w.ccr2);
565 writeb(0, &up->regs->w.ccr3);
566 writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
567 up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
568 SAB82532_MODE_RAC);
569 writeb(up->cached_mode, &up->regs->w.mode);
570 writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
571
572 tmp = readb(&up->regs->rw.ccr0);
573 tmp |= SAB82532_CCR0_PU; /* power-up */
574 writeb(tmp, &up->regs->rw.ccr0);
575
576 /*
577 * Finally, enable interrupts
578 */
579 up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
580 SAB82532_IMR0_PLLA);
581 writeb(up->interrupt_mask0, &up->regs->w.imr0);
582 up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
583 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
584 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
585 SAB82532_IMR1_XPR);
586 writeb(up->interrupt_mask1, &up->regs->w.imr1);
587 set_bit(SAB82532_ALLS, &up->irqflags);
588 set_bit(SAB82532_XPR, &up->irqflags);
589
590 spin_unlock_irqrestore(&up->port.lock, flags);
591
592 return 0;
593 }
594
595 /* port->lock is not held. */
sunsab_shutdown(struct uart_port * port)596 static void sunsab_shutdown(struct uart_port *port)
597 {
598 struct uart_sunsab_port *up =
599 container_of(port, struct uart_sunsab_port, port);
600 unsigned long flags;
601
602 spin_lock_irqsave(&up->port.lock, flags);
603
604 /* Disable Interrupts */
605 up->interrupt_mask0 = 0xff;
606 writeb(up->interrupt_mask0, &up->regs->w.imr0);
607 up->interrupt_mask1 = 0xff;
608 writeb(up->interrupt_mask1, &up->regs->w.imr1);
609
610 /* Disable break condition */
611 up->cached_dafo = readb(&up->regs->rw.dafo);
612 up->cached_dafo &= ~SAB82532_DAFO_XBRK;
613 writeb(up->cached_dafo, &up->regs->rw.dafo);
614
615 /* Disable Receiver */
616 up->cached_mode &= ~SAB82532_MODE_RAC;
617 writeb(up->cached_mode, &up->regs->rw.mode);
618
619 /*
620 * XXX FIXME
621 *
622 * If the chip is powered down here the system hangs/crashes during
623 * reboot or shutdown. This needs to be investigated further,
624 * similar behaviour occurs in 2.4 when the driver is configured
625 * as a module only. One hint may be that data is sometimes
626 * transmitted at 9600 baud during shutdown (regardless of the
627 * speed the chip was configured for when the port was open).
628 */
629 #if 0
630 /* Power Down */
631 tmp = readb(&up->regs->rw.ccr0);
632 tmp &= ~SAB82532_CCR0_PU;
633 writeb(tmp, &up->regs->rw.ccr0);
634 #endif
635
636 spin_unlock_irqrestore(&up->port.lock, flags);
637 free_irq(up->port.irq, up);
638 }
639
640 /*
641 * This is used to figure out the divisor speeds.
642 *
643 * The formula is: Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
644 *
645 * with 0 <= N < 64 and 0 <= M < 16
646 */
647
calc_ebrg(int baud,int * n_ret,int * m_ret)648 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
649 {
650 int n, m;
651
652 if (baud == 0) {
653 *n_ret = 0;
654 *m_ret = 0;
655 return;
656 }
657
658 /*
659 * We scale numbers by 10 so that we get better accuracy
660 * without having to use floating point. Here we increment m
661 * until n is within the valid range.
662 */
663 n = (SAB_BASE_BAUD * 10) / baud;
664 m = 0;
665 while (n >= 640) {
666 n = n / 2;
667 m++;
668 }
669 n = (n+5) / 10;
670 /*
671 * We try very hard to avoid speeds with M == 0 since they may
672 * not work correctly for XTAL frequences above 10 MHz.
673 */
674 if ((m == 0) && ((n & 1) == 0)) {
675 n = n / 2;
676 m++;
677 }
678 *n_ret = n - 1;
679 *m_ret = m;
680 }
681
682 /* Internal routine, port->lock is held and local interrupts are disabled. */
sunsab_convert_to_sab(struct uart_sunsab_port * up,unsigned int cflag,unsigned int iflag,unsigned int baud,unsigned int quot)683 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
684 unsigned int iflag, unsigned int baud,
685 unsigned int quot)
686 {
687 unsigned char dafo;
688 int bits, n, m;
689
690 /* Byte size and parity */
691 switch (cflag & CSIZE) {
692 case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
693 case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
694 case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
695 case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
696 /* Never happens, but GCC is too dumb to figure it out */
697 default: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
698 }
699
700 if (cflag & CSTOPB) {
701 dafo |= SAB82532_DAFO_STOP;
702 bits++;
703 }
704
705 if (cflag & PARENB) {
706 dafo |= SAB82532_DAFO_PARE;
707 bits++;
708 }
709
710 if (cflag & PARODD) {
711 dafo |= SAB82532_DAFO_PAR_ODD;
712 } else {
713 dafo |= SAB82532_DAFO_PAR_EVEN;
714 }
715 up->cached_dafo = dafo;
716
717 calc_ebrg(baud, &n, &m);
718
719 up->cached_ebrg = n | (m << 6);
720
721 up->tec_timeout = (10 * 1000000) / baud;
722 up->cec_timeout = up->tec_timeout >> 2;
723
724 /* CTS flow control flags */
725 /* We encode read_status_mask and ignore_status_mask like so:
726 *
727 * ---------------------
728 * | ... | ISR1 | ISR0 |
729 * ---------------------
730 * .. 15 8 7 0
731 */
732
733 up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
734 SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
735 SAB82532_ISR0_CDSC);
736 up->port.read_status_mask |= (SAB82532_ISR1_CSC |
737 SAB82532_ISR1_ALLS |
738 SAB82532_ISR1_XPR) << 8;
739 if (iflag & INPCK)
740 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
741 SAB82532_ISR0_FERR);
742 if (iflag & (IGNBRK | BRKINT | PARMRK))
743 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
744
745 /*
746 * Characteres to ignore
747 */
748 up->port.ignore_status_mask = 0;
749 if (iflag & IGNPAR)
750 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
751 SAB82532_ISR0_FERR);
752 if (iflag & IGNBRK) {
753 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
754 /*
755 * If we're ignoring parity and break indicators,
756 * ignore overruns too (for real raw support).
757 */
758 if (iflag & IGNPAR)
759 up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
760 }
761
762 /*
763 * ignore all characters if CREAD is not set
764 */
765 if ((cflag & CREAD) == 0)
766 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
767 SAB82532_ISR0_TCD);
768
769 uart_update_timeout(&up->port, cflag,
770 (up->port.uartclk / (16 * quot)));
771
772 /* Now schedule a register update when the chip's
773 * transmitter is idle.
774 */
775 up->cached_mode |= SAB82532_MODE_RAC;
776 set_bit(SAB82532_REGS_PENDING, &up->irqflags);
777 if (test_bit(SAB82532_XPR, &up->irqflags))
778 sunsab_tx_idle(up);
779 }
780
781 /* port->lock is not held. */
sunsab_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)782 static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
783 struct ktermios *old)
784 {
785 struct uart_sunsab_port *up =
786 container_of(port, struct uart_sunsab_port, port);
787 unsigned long flags;
788 unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
789 unsigned int quot = uart_get_divisor(port, baud);
790
791 spin_lock_irqsave(&up->port.lock, flags);
792 sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
793 spin_unlock_irqrestore(&up->port.lock, flags);
794 }
795
sunsab_type(struct uart_port * port)796 static const char *sunsab_type(struct uart_port *port)
797 {
798 struct uart_sunsab_port *up = (void *)port;
799 static char buf[36];
800
801 sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
802 return buf;
803 }
804
sunsab_release_port(struct uart_port * port)805 static void sunsab_release_port(struct uart_port *port)
806 {
807 }
808
sunsab_request_port(struct uart_port * port)809 static int sunsab_request_port(struct uart_port *port)
810 {
811 return 0;
812 }
813
sunsab_config_port(struct uart_port * port,int flags)814 static void sunsab_config_port(struct uart_port *port, int flags)
815 {
816 }
817
sunsab_verify_port(struct uart_port * port,struct serial_struct * ser)818 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
819 {
820 return -EINVAL;
821 }
822
823 static const struct uart_ops sunsab_pops = {
824 .tx_empty = sunsab_tx_empty,
825 .set_mctrl = sunsab_set_mctrl,
826 .get_mctrl = sunsab_get_mctrl,
827 .stop_tx = sunsab_stop_tx,
828 .start_tx = sunsab_start_tx,
829 .send_xchar = sunsab_send_xchar,
830 .stop_rx = sunsab_stop_rx,
831 .break_ctl = sunsab_break_ctl,
832 .startup = sunsab_startup,
833 .shutdown = sunsab_shutdown,
834 .set_termios = sunsab_set_termios,
835 .type = sunsab_type,
836 .release_port = sunsab_release_port,
837 .request_port = sunsab_request_port,
838 .config_port = sunsab_config_port,
839 .verify_port = sunsab_verify_port,
840 };
841
842 static struct uart_driver sunsab_reg = {
843 .owner = THIS_MODULE,
844 .driver_name = "sunsab",
845 .dev_name = "ttyS",
846 .major = TTY_MAJOR,
847 };
848
849 static struct uart_sunsab_port *sunsab_ports;
850
851 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
852
sunsab_console_putchar(struct uart_port * port,int c)853 static void sunsab_console_putchar(struct uart_port *port, int c)
854 {
855 struct uart_sunsab_port *up =
856 container_of(port, struct uart_sunsab_port, port);
857
858 sunsab_tec_wait(up);
859 writeb(c, &up->regs->w.tic);
860 }
861
sunsab_console_write(struct console * con,const char * s,unsigned n)862 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
863 {
864 struct uart_sunsab_port *up = &sunsab_ports[con->index];
865 unsigned long flags;
866 int locked = 1;
867
868 if (up->port.sysrq || oops_in_progress)
869 locked = spin_trylock_irqsave(&up->port.lock, flags);
870 else
871 spin_lock_irqsave(&up->port.lock, flags);
872
873 uart_console_write(&up->port, s, n, sunsab_console_putchar);
874 sunsab_tec_wait(up);
875
876 if (locked)
877 spin_unlock_irqrestore(&up->port.lock, flags);
878 }
879
sunsab_console_setup(struct console * con,char * options)880 static int sunsab_console_setup(struct console *con, char *options)
881 {
882 struct uart_sunsab_port *up = &sunsab_ports[con->index];
883 unsigned long flags;
884 unsigned int baud, quot;
885
886 /*
887 * The console framework calls us for each and every port
888 * registered. Defer the console setup until the requested
889 * port has been properly discovered. A bit of a hack,
890 * though...
891 */
892 if (up->port.type != PORT_SUNSAB)
893 return -1;
894
895 printk("Console: ttyS%d (SAB82532)\n",
896 (sunsab_reg.minor - 64) + con->index);
897
898 sunserial_console_termios(con, up->port.dev->of_node);
899
900 switch (con->cflag & CBAUD) {
901 case B150: baud = 150; break;
902 case B300: baud = 300; break;
903 case B600: baud = 600; break;
904 case B1200: baud = 1200; break;
905 case B2400: baud = 2400; break;
906 case B4800: baud = 4800; break;
907 default: case B9600: baud = 9600; break;
908 case B19200: baud = 19200; break;
909 case B38400: baud = 38400; break;
910 case B57600: baud = 57600; break;
911 case B115200: baud = 115200; break;
912 case B230400: baud = 230400; break;
913 case B460800: baud = 460800; break;
914 }
915
916 /*
917 * Temporary fix.
918 */
919 spin_lock_init(&up->port.lock);
920
921 /*
922 * Initialize the hardware
923 */
924 sunsab_startup(&up->port);
925
926 spin_lock_irqsave(&up->port.lock, flags);
927
928 /*
929 * Finally, enable interrupts
930 */
931 up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
932 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
933 writeb(up->interrupt_mask0, &up->regs->w.imr0);
934 up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
935 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
936 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
937 SAB82532_IMR1_XPR;
938 writeb(up->interrupt_mask1, &up->regs->w.imr1);
939
940 quot = uart_get_divisor(&up->port, baud);
941 sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
942 sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
943
944 spin_unlock_irqrestore(&up->port.lock, flags);
945
946 return 0;
947 }
948
949 static struct console sunsab_console = {
950 .name = "ttyS",
951 .write = sunsab_console_write,
952 .device = uart_console_device,
953 .setup = sunsab_console_setup,
954 .flags = CON_PRINTBUFFER,
955 .index = -1,
956 .data = &sunsab_reg,
957 };
958
SUNSAB_CONSOLE(void)959 static inline struct console *SUNSAB_CONSOLE(void)
960 {
961 return &sunsab_console;
962 }
963 #else
964 #define SUNSAB_CONSOLE() (NULL)
965 #define sunsab_console_init() do { } while (0)
966 #endif
967
sunsab_init_one(struct uart_sunsab_port * up,struct platform_device * op,unsigned long offset,int line)968 static int sunsab_init_one(struct uart_sunsab_port *up,
969 struct platform_device *op,
970 unsigned long offset,
971 int line)
972 {
973 up->port.line = line;
974 up->port.dev = &op->dev;
975
976 up->port.mapbase = op->resource[0].start + offset;
977 up->port.membase = of_ioremap(&op->resource[0], offset,
978 sizeof(union sab82532_async_regs),
979 "sab");
980 if (!up->port.membase)
981 return -ENOMEM;
982 up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
983
984 up->port.irq = op->archdata.irqs[0];
985
986 up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
987 up->port.iotype = UPIO_MEM;
988
989 writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
990
991 up->port.ops = &sunsab_pops;
992 up->port.type = PORT_SUNSAB;
993 up->port.uartclk = SAB_BASE_BAUD;
994
995 up->type = readb(&up->regs->r.vstr) & 0x0f;
996 writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
997 writeb(0xff, &up->regs->w.pim);
998 if ((up->port.line & 0x1) == 0) {
999 up->pvr_dsr_bit = (1 << 0);
1000 up->pvr_dtr_bit = (1 << 1);
1001 up->gis_shift = 2;
1002 } else {
1003 up->pvr_dsr_bit = (1 << 3);
1004 up->pvr_dtr_bit = (1 << 2);
1005 up->gis_shift = 0;
1006 }
1007 up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1008 writeb(up->cached_pvr, &up->regs->w.pvr);
1009 up->cached_mode = readb(&up->regs->rw.mode);
1010 up->cached_mode |= SAB82532_MODE_FRTS;
1011 writeb(up->cached_mode, &up->regs->rw.mode);
1012 up->cached_mode |= SAB82532_MODE_RTS;
1013 writeb(up->cached_mode, &up->regs->rw.mode);
1014
1015 up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1016 up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1017
1018 return 0;
1019 }
1020
sab_probe(struct platform_device * op)1021 static int sab_probe(struct platform_device *op)
1022 {
1023 static int inst;
1024 struct uart_sunsab_port *up;
1025 int err;
1026
1027 up = &sunsab_ports[inst * 2];
1028
1029 err = sunsab_init_one(&up[0], op,
1030 0,
1031 (inst * 2) + 0);
1032 if (err)
1033 goto out;
1034
1035 err = sunsab_init_one(&up[1], op,
1036 sizeof(union sab82532_async_regs),
1037 (inst * 2) + 1);
1038 if (err)
1039 goto out1;
1040
1041 sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1042 &sunsab_reg, up[0].port.line,
1043 false);
1044
1045 sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
1046 &sunsab_reg, up[1].port.line,
1047 false);
1048
1049 err = uart_add_one_port(&sunsab_reg, &up[0].port);
1050 if (err)
1051 goto out2;
1052
1053 err = uart_add_one_port(&sunsab_reg, &up[1].port);
1054 if (err)
1055 goto out3;
1056
1057 platform_set_drvdata(op, &up[0]);
1058
1059 inst++;
1060
1061 return 0;
1062
1063 out3:
1064 uart_remove_one_port(&sunsab_reg, &up[0].port);
1065 out2:
1066 of_iounmap(&op->resource[0],
1067 up[1].port.membase,
1068 sizeof(union sab82532_async_regs));
1069 out1:
1070 of_iounmap(&op->resource[0],
1071 up[0].port.membase,
1072 sizeof(union sab82532_async_regs));
1073 out:
1074 return err;
1075 }
1076
sab_remove(struct platform_device * op)1077 static int sab_remove(struct platform_device *op)
1078 {
1079 struct uart_sunsab_port *up = platform_get_drvdata(op);
1080
1081 uart_remove_one_port(&sunsab_reg, &up[1].port);
1082 uart_remove_one_port(&sunsab_reg, &up[0].port);
1083 of_iounmap(&op->resource[0],
1084 up[1].port.membase,
1085 sizeof(union sab82532_async_regs));
1086 of_iounmap(&op->resource[0],
1087 up[0].port.membase,
1088 sizeof(union sab82532_async_regs));
1089
1090 return 0;
1091 }
1092
1093 static const struct of_device_id sab_match[] = {
1094 {
1095 .name = "se",
1096 },
1097 {
1098 .name = "serial",
1099 .compatible = "sab82532",
1100 },
1101 {},
1102 };
1103 MODULE_DEVICE_TABLE(of, sab_match);
1104
1105 static struct platform_driver sab_driver = {
1106 .driver = {
1107 .name = "sab",
1108 .of_match_table = sab_match,
1109 },
1110 .probe = sab_probe,
1111 .remove = sab_remove,
1112 };
1113
sunsab_init(void)1114 static int __init sunsab_init(void)
1115 {
1116 struct device_node *dp;
1117 int err;
1118 int num_channels = 0;
1119
1120 for_each_node_by_name(dp, "se")
1121 num_channels += 2;
1122 for_each_node_by_name(dp, "serial") {
1123 if (of_device_is_compatible(dp, "sab82532"))
1124 num_channels += 2;
1125 }
1126
1127 if (num_channels) {
1128 sunsab_ports = kcalloc(num_channels,
1129 sizeof(struct uart_sunsab_port),
1130 GFP_KERNEL);
1131 if (!sunsab_ports)
1132 return -ENOMEM;
1133
1134 err = sunserial_register_minors(&sunsab_reg, num_channels);
1135 if (err) {
1136 kfree(sunsab_ports);
1137 sunsab_ports = NULL;
1138
1139 return err;
1140 }
1141 }
1142
1143 return platform_driver_register(&sab_driver);
1144 }
1145
sunsab_exit(void)1146 static 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
1157 module_init(sunsab_init);
1158 module_exit(sunsab_exit);
1159
1160 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1161 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1162 MODULE_LICENSE("GPL");
1163
