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