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