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serial: 8250: fix null-ptr-deref in serial8250_start_tx()
[linux/fpc-iii.git] / drivers / tty / serial / sb1250-duart.c
blobbd5e7e9938ce04fb40844d4bdc01cc5531c9b57a
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Support for the asynchronous serial interface (DUART) included
4 * in the BCM1250 and derived System-On-a-Chip (SOC) devices.
5 *
6 * Copyright (c) 2007 Maciej W. Rozycki
7 *
8 * Derived from drivers/char/sb1250_duart.c for which the following
9 * copyright applies:
10 *
11 * Copyright (c) 2000, 2001, 2002, 2003, 2004 Broadcom Corporation
12 *
13 * References:
14 *
15 * "BCM1250/BCM1125/BCM1125H User Manual", Broadcom Corporation
16 */
17
18 #include <linux/compiler.h>
19 #include <linux/console.h>
20 #include <linux/delay.h>
21 #include <linux/errno.h>
22 #include <linux/init.h>
23 #include <linux/interrupt.h>
24 #include <linux/ioport.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/major.h>
28 #include <linux/serial.h>
29 #include <linux/serial_core.h>
30 #include <linux/spinlock.h>
31 #include <linux/sysrq.h>
32 #include <linux/tty.h>
33 #include <linux/tty_flip.h>
34 #include <linux/types.h>
35
36 #include <linux/refcount.h>
37 #include <asm/io.h>
38 #include <asm/war.h>
39
40 #include <asm/sibyte/sb1250.h>
41 #include <asm/sibyte/sb1250_uart.h>
42 #include <asm/sibyte/swarm.h>
43
44
45 #if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
46 #include <asm/sibyte/bcm1480_regs.h>
47 #include <asm/sibyte/bcm1480_int.h>
48
49 #define SBD_CHANREGS(line) A_BCM1480_DUART_CHANREG((line), 0)
50 #define SBD_CTRLREGS(line) A_BCM1480_DUART_CTRLREG((line), 0)
51 #define SBD_INT(line) (K_BCM1480_INT_UART_0 + (line))
52
53 #define DUART_CHANREG_SPACING BCM1480_DUART_CHANREG_SPACING
54
55 #define R_DUART_IMRREG(line) R_BCM1480_DUART_IMRREG(line)
56 #define R_DUART_INCHREG(line) R_BCM1480_DUART_INCHREG(line)
57 #define R_DUART_ISRREG(line) R_BCM1480_DUART_ISRREG(line)
58
59 #elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
60 #include <asm/sibyte/sb1250_regs.h>
61 #include <asm/sibyte/sb1250_int.h>
62
63 #define SBD_CHANREGS(line) A_DUART_CHANREG((line), 0)
64 #define SBD_CTRLREGS(line) A_DUART_CTRLREG(0)
65 #define SBD_INT(line) (K_INT_UART_0 + (line))
66
67 #else
68 #error invalid SB1250 UART configuration
69
70 #endif
71
72
73 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
74 MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver");
75 MODULE_LICENSE("GPL");
76
77
78 #define DUART_MAX_CHIP 2
79 #define DUART_MAX_SIDE 2
80
81 /*
82 * Per-port state.
83 */
84 struct sbd_port {
85 struct sbd_duart *duart;
86 struct uart_port port;
87 unsigned char __iomem *memctrl;
88 int tx_stopped;
89 int initialised;
90 };
91
92 /*
93 * Per-DUART state for the shared register space.
94 */
95 struct sbd_duart {
96 struct sbd_port sport[2];
97 unsigned long mapctrl;
98 refcount_t map_guard;
99 };
100
101 #define to_sport(uport) container_of(uport, struct sbd_port, port)
102
103 static struct sbd_duart sbd_duarts[DUART_MAX_CHIP];
104
105
106 /*
107 * Reading and writing SB1250 DUART registers.
108 *
109 * There are three register spaces: two per-channel ones and
110 * a shared one. We have to define accessors appropriately.
111 * All registers are 64-bit and all but the Baud Rate Clock
112 * registers only define 8 least significant bits. There is
113 * also a workaround to take into account. Raw accessors use
114 * the full register width, but cooked ones truncate it
115 * intentionally so that the rest of the driver does not care.
116 */
117 static u64 __read_sbdchn(struct sbd_port *sport, int reg)
118 {
119 void __iomem *csr = sport->port.membase + reg;
120
121 return __raw_readq(csr);
122 }
123
124 static u64 __read_sbdshr(struct sbd_port *sport, int reg)
125 {
126 void __iomem *csr = sport->memctrl + reg;
127
128 return __raw_readq(csr);
129 }
130
131 static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value)
132 {
133 void __iomem *csr = sport->port.membase + reg;
134
135 __raw_writeq(value, csr);
136 }
137
138 static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value)
139 {
140 void __iomem *csr = sport->memctrl + reg;
141
142 __raw_writeq(value, csr);
143 }
144
145 /*
146 * In bug 1956, we get glitches that can mess up uart registers. This
147 * "read-mode-reg after any register access" is an accepted workaround.
148 */
149 static void __war_sbd1956(struct sbd_port *sport)
150 {
151 __read_sbdchn(sport, R_DUART_MODE_REG_1);
152 __read_sbdchn(sport, R_DUART_MODE_REG_2);
153 }
154
155 static unsigned char read_sbdchn(struct sbd_port *sport, int reg)
156 {
157 unsigned char retval;
158
159 retval = __read_sbdchn(sport, reg);
160 if (SIBYTE_1956_WAR)
161 __war_sbd1956(sport);
162 return retval;
163 }
164
165 static unsigned char read_sbdshr(struct sbd_port *sport, int reg)
166 {
167 unsigned char retval;
168
169 retval = __read_sbdshr(sport, reg);
170 if (SIBYTE_1956_WAR)
171 __war_sbd1956(sport);
172 return retval;
173 }
174
175 static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value)
176 {
177 __write_sbdchn(sport, reg, value);
178 if (SIBYTE_1956_WAR)
179 __war_sbd1956(sport);
180 }
181
182 static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value)
183 {
184 __write_sbdshr(sport, reg, value);
185 if (SIBYTE_1956_WAR)
186 __war_sbd1956(sport);
187 }
188
189
190 static int sbd_receive_ready(struct sbd_port *sport)
191 {
192 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY;
193 }
194
195 static int sbd_receive_drain(struct sbd_port *sport)
196 {
197 int loops = 10000;
198
199 while (sbd_receive_ready(sport) && --loops)
200 read_sbdchn(sport, R_DUART_RX_HOLD);
201 return loops;
202 }
203
204 static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport)
205 {
206 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY;
207 }
208
209 static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
210 {
211 int loops = 10000;
212
213 while (!sbd_transmit_ready(sport) && --loops)
214 udelay(2);
215 return loops;
216 }
217
218 static int sbd_transmit_empty(struct sbd_port *sport)
219 {
220 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT;
221 }
222
223 static int sbd_line_drain(struct sbd_port *sport)
224 {
225 int loops = 10000;
226
227 while (!sbd_transmit_empty(sport) && --loops)
228 udelay(2);
229 return loops;
230 }
231
232
233 static unsigned int sbd_tx_empty(struct uart_port *uport)
234 {
235 struct sbd_port *sport = to_sport(uport);
236
237 return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0;
238 }
239
240 static unsigned int sbd_get_mctrl(struct uart_port *uport)
241 {
242 struct sbd_port *sport = to_sport(uport);
243 unsigned int mctrl, status;
244
245 status = read_sbdshr(sport, R_DUART_IN_PORT);
246 status >>= (uport->line) % 2;
247 mctrl = (!(status & M_DUART_IN_PIN0_VAL) ? TIOCM_CTS : 0) |
248 (!(status & M_DUART_IN_PIN4_VAL) ? TIOCM_CAR : 0) |
249 (!(status & M_DUART_RIN0_PIN) ? TIOCM_RNG : 0) |
250 (!(status & M_DUART_IN_PIN2_VAL) ? TIOCM_DSR : 0);
251 return mctrl;
252 }
253
254 static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl)
255 {
256 struct sbd_port *sport = to_sport(uport);
257 unsigned int clr = 0, set = 0, mode2;
258
259 if (mctrl & TIOCM_DTR)
260 set |= M_DUART_SET_OPR2;
261 else
262 clr |= M_DUART_CLR_OPR2;
263 if (mctrl & TIOCM_RTS)
264 set |= M_DUART_SET_OPR0;
265 else
266 clr |= M_DUART_CLR_OPR0;
267 clr <<= (uport->line) % 2;
268 set <<= (uport->line) % 2;
269
270 mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2);
271 mode2 &= ~M_DUART_CHAN_MODE;
272 if (mctrl & TIOCM_LOOP)
273 mode2 |= V_DUART_CHAN_MODE_LCL_LOOP;
274 else
275 mode2 |= V_DUART_CHAN_MODE_NORMAL;
276
277 write_sbdshr(sport, R_DUART_CLEAR_OPR, clr);
278 write_sbdshr(sport, R_DUART_SET_OPR, set);
279 write_sbdchn(sport, R_DUART_MODE_REG_2, mode2);
280 }
281
282 static void sbd_stop_tx(struct uart_port *uport)
283 {
284 struct sbd_port *sport = to_sport(uport);
285
286 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
287 sport->tx_stopped = 1;
288 };
289
290 static void sbd_start_tx(struct uart_port *uport)
291 {
292 struct sbd_port *sport = to_sport(uport);
293 unsigned int mask;
294
295 /* Enable tx interrupts. */
296 mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
297 mask |= M_DUART_IMR_TX;
298 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
299
300 /* Go!, go!, go!... */
301 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
302 sport->tx_stopped = 0;
303 };
304
305 static void sbd_stop_rx(struct uart_port *uport)
306 {
307 struct sbd_port *sport = to_sport(uport);
308
309 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
310 };
311
312 static void sbd_enable_ms(struct uart_port *uport)
313 {
314 struct sbd_port *sport = to_sport(uport);
315
316 write_sbdchn(sport, R_DUART_AUXCTL_X,
317 M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA);
318 }
319
320 static void sbd_break_ctl(struct uart_port *uport, int break_state)
321 {
322 struct sbd_port *sport = to_sport(uport);
323
324 if (break_state == -1)
325 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_START_BREAK);
326 else
327 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_STOP_BREAK);
328 }
329
330
331 static void sbd_receive_chars(struct sbd_port *sport)
332 {
333 struct uart_port *uport = &sport->port;
334 struct uart_icount *icount;
335 unsigned int status, ch, flag;
336 int count;
337
338 for (count = 16; count; count--) {
339 status = read_sbdchn(sport, R_DUART_STATUS);
340 if (!(status & M_DUART_RX_RDY))
341 break;
342
343 ch = read_sbdchn(sport, R_DUART_RX_HOLD);
344
345 flag = TTY_NORMAL;
346
347 icount = &uport->icount;
348 icount->rx++;
349
350 if (unlikely(status &
351 (M_DUART_RCVD_BRK | M_DUART_FRM_ERR |
352 M_DUART_PARITY_ERR | M_DUART_OVRUN_ERR))) {
353 if (status & M_DUART_RCVD_BRK) {
354 icount->brk++;
355 if (uart_handle_break(uport))
356 continue;
357 } else if (status & M_DUART_FRM_ERR)
358 icount->frame++;
359 else if (status & M_DUART_PARITY_ERR)
360 icount->parity++;
361 if (status & M_DUART_OVRUN_ERR)
362 icount->overrun++;
363
364 status &= uport->read_status_mask;
365 if (status & M_DUART_RCVD_BRK)
366 flag = TTY_BREAK;
367 else if (status & M_DUART_FRM_ERR)
368 flag = TTY_FRAME;
369 else if (status & M_DUART_PARITY_ERR)
370 flag = TTY_PARITY;
371 }
372
373 if (uart_handle_sysrq_char(uport, ch))
374 continue;
375
376 uart_insert_char(uport, status, M_DUART_OVRUN_ERR, ch, flag);
377 }
378
379 tty_flip_buffer_push(&uport->state->port);
380 }
381
382 static void sbd_transmit_chars(struct sbd_port *sport)
383 {
384 struct uart_port *uport = &sport->port;
385 struct circ_buf *xmit = &sport->port.state->xmit;
386 unsigned int mask;
387 int stop_tx;
388
389 /* XON/XOFF chars. */
390 if (sport->port.x_char) {
391 write_sbdchn(sport, R_DUART_TX_HOLD, sport->port.x_char);
392 sport->port.icount.tx++;
393 sport->port.x_char = 0;
394 return;
395 }
396
397 /* If nothing to do or stopped or hardware stopped. */
398 stop_tx = (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port));
399
400 /* Send char. */
401 if (!stop_tx) {
402 write_sbdchn(sport, R_DUART_TX_HOLD, xmit->buf[xmit->tail]);
403 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
404 sport->port.icount.tx++;
405
406 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
407 uart_write_wakeup(&sport->port);
408 }
409
410 /* Are we are done? */
411 if (stop_tx || uart_circ_empty(xmit)) {
412 /* Disable tx interrupts. */
413 mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
414 mask &= ~M_DUART_IMR_TX;
415 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
416 }
417 }
418
419 static void sbd_status_handle(struct sbd_port *sport)
420 {
421 struct uart_port *uport = &sport->port;
422 unsigned int delta;
423
424 delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
425 delta >>= (uport->line) % 2;
426
427 if (delta & (M_DUART_IN_PIN0_VAL << S_DUART_IN_PIN_CHNG))
428 uart_handle_cts_change(uport, !(delta & M_DUART_IN_PIN0_VAL));
429
430 if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG))
431 uport->icount.dsr++;
432
433 if (delta & ((M_DUART_IN_PIN2_VAL | M_DUART_IN_PIN0_VAL) <<
434 S_DUART_IN_PIN_CHNG))
435 wake_up_interruptible(&uport->state->port.delta_msr_wait);
436 }
437
438 static irqreturn_t sbd_interrupt(int irq, void *dev_id)
439 {
440 struct sbd_port *sport = dev_id;
441 struct uart_port *uport = &sport->port;
442 irqreturn_t status = IRQ_NONE;
443 unsigned int intstat;
444 int count;
445
446 for (count = 16; count; count--) {
447 intstat = read_sbdshr(sport,
448 R_DUART_ISRREG((uport->line) % 2));
449 intstat &= read_sbdshr(sport,
450 R_DUART_IMRREG((uport->line) % 2));
451 intstat &= M_DUART_ISR_ALL;
452 if (!intstat)
453 break;
454
455 if (intstat & M_DUART_ISR_RX)
456 sbd_receive_chars(sport);
457 if (intstat & M_DUART_ISR_IN)
458 sbd_status_handle(sport);
459 if (intstat & M_DUART_ISR_TX)
460 sbd_transmit_chars(sport);
461
462 status = IRQ_HANDLED;
463 }
464
465 return status;
466 }
467
468
469 static int sbd_startup(struct uart_port *uport)
470 {
471 struct sbd_port *sport = to_sport(uport);
472 unsigned int mode1;
473 int ret;
474
475 ret = request_irq(sport->port.irq, sbd_interrupt,
476 IRQF_SHARED, "sb1250-duart", sport);
477 if (ret)
478 return ret;
479
480 /* Clear the receive FIFO. */
481 sbd_receive_drain(sport);
482
483 /* Clear the interrupt registers. */
484 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT);
485 read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
486
487 /* Set rx/tx interrupt to FIFO available. */
488 mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1);
489 mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT);
490 write_sbdchn(sport, R_DUART_MODE_REG_1, mode1);
491
492 /* Disable tx, enable rx. */
493 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN);
494 sport->tx_stopped = 1;
495
496 /* Enable interrupts. */
497 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
498 M_DUART_IMR_IN | M_DUART_IMR_RX);
499
500 return 0;
501 }
502
503 static void sbd_shutdown(struct uart_port *uport)
504 {
505 struct sbd_port *sport = to_sport(uport);
506
507 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
508 sport->tx_stopped = 1;
509 free_irq(sport->port.irq, sport);
510 }
511
512
513 static void sbd_init_port(struct sbd_port *sport)
514 {
515 struct uart_port *uport = &sport->port;
516
517 if (sport->initialised)
518 return;
519
520 /* There is no DUART reset feature, so just set some sane defaults. */
521 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX);
522 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX);
523 write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8);
524 write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
525 write_sbdchn(sport, R_DUART_FULL_CTL,
526 V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15));
527 write_sbdchn(sport, R_DUART_OPCR_X, 0);
528 write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
529 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
530
531 sport->initialised = 1;
532 }
533
534 static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
535 struct ktermios *old_termios)
536 {
537 struct sbd_port *sport = to_sport(uport);
538 unsigned int mode1 = 0, mode2 = 0, aux = 0;
539 unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0;
540 unsigned int oldmode1, oldmode2, oldaux;
541 unsigned int baud, brg;
542 unsigned int command;
543
544 mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD |
545 M_DUART_BITS_PER_CHAR);
546 mode2mask |= ~M_DUART_STOP_BIT_LEN_2;
547 auxmask |= ~M_DUART_CTS_CHNG_ENA;
548
549 /* Byte size. */
550 switch (termios->c_cflag & CSIZE) {
551 case CS5:
552 case CS6:
553 /* Unsupported, leave unchanged. */
554 mode1mask |= M_DUART_PARITY_MODE;
555 break;
556 case CS7:
557 mode1 |= V_DUART_BITS_PER_CHAR_7;
558 break;
559 case CS8:
560 default:
561 mode1 |= V_DUART_BITS_PER_CHAR_8;
562 break;
563 }
564
565 /* Parity and stop bits. */
566 if (termios->c_cflag & CSTOPB)
567 mode2 |= M_DUART_STOP_BIT_LEN_2;
568 else
569 mode2 |= M_DUART_STOP_BIT_LEN_1;
570 if (termios->c_cflag & PARENB)
571 mode1 |= V_DUART_PARITY_MODE_ADD;
572 else
573 mode1 |= V_DUART_PARITY_MODE_NONE;
574 if (termios->c_cflag & PARODD)
575 mode1 |= M_DUART_PARITY_TYPE_ODD;
576 else
577 mode1 |= M_DUART_PARITY_TYPE_EVEN;
578
579 baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000);
580 brg = V_DUART_BAUD_RATE(baud);
581 /* The actual lower bound is 1221bps, so compensate. */
582 if (brg > M_DUART_CLK_COUNTER)
583 brg = M_DUART_CLK_COUNTER;
584
585 uart_update_timeout(uport, termios->c_cflag, baud);
586
587 uport->read_status_mask = M_DUART_OVRUN_ERR;
588 if (termios->c_iflag & INPCK)
589 uport->read_status_mask |= M_DUART_FRM_ERR |
590 M_DUART_PARITY_ERR;
591 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
592 uport->read_status_mask |= M_DUART_RCVD_BRK;
593
594 uport->ignore_status_mask = 0;
595 if (termios->c_iflag & IGNPAR)
596 uport->ignore_status_mask |= M_DUART_FRM_ERR |
597 M_DUART_PARITY_ERR;
598 if (termios->c_iflag & IGNBRK) {
599 uport->ignore_status_mask |= M_DUART_RCVD_BRK;
600 if (termios->c_iflag & IGNPAR)
601 uport->ignore_status_mask |= M_DUART_OVRUN_ERR;
602 }
603
604 if (termios->c_cflag & CREAD)
605 command = M_DUART_RX_EN;
606 else
607 command = M_DUART_RX_DIS;
608
609 if (termios->c_cflag & CRTSCTS)
610 aux |= M_DUART_CTS_CHNG_ENA;
611 else
612 aux &= ~M_DUART_CTS_CHNG_ENA;
613
614 spin_lock(&uport->lock);
615
616 if (sport->tx_stopped)
617 command |= M_DUART_TX_DIS;
618 else
619 command |= M_DUART_TX_EN;
620
621 oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask;
622 oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
623 oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;
624
625 if (!sport->tx_stopped)
626 sbd_line_drain(sport);
627 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
628
629 write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1);
630 write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);
631 write_sbdchn(sport, R_DUART_CLK_SEL, brg);
632 write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);
633
634 write_sbdchn(sport, R_DUART_CMD, command);
635
636 spin_unlock(&uport->lock);
637 }
638
639
640 static const char *sbd_type(struct uart_port *uport)
641 {
642 return "SB1250 DUART";
643 }
644
645 static void sbd_release_port(struct uart_port *uport)
646 {
647 struct sbd_port *sport = to_sport(uport);
648 struct sbd_duart *duart = sport->duart;
649
650 iounmap(sport->memctrl);
651 sport->memctrl = NULL;
652 iounmap(uport->membase);
653 uport->membase = NULL;
654
655 if(refcount_dec_and_test(&duart->map_guard))
656 release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING);
657 release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
658 }
659
660 static int sbd_map_port(struct uart_port *uport)
661 {
662 const char *err = KERN_ERR "sbd: Cannot map MMIO\n";
663 struct sbd_port *sport = to_sport(uport);
664 struct sbd_duart *duart = sport->duart;
665
666 if (!uport->membase)
667 uport->membase = ioremap(uport->mapbase,
668 DUART_CHANREG_SPACING);
669 if (!uport->membase) {
670 printk(err);
671 return -ENOMEM;
672 }
673
674 if (!sport->memctrl)
675 sport->memctrl = ioremap(duart->mapctrl,
676 DUART_CHANREG_SPACING);
677 if (!sport->memctrl) {
678 printk(err);
679 iounmap(uport->membase);
680 uport->membase = NULL;
681 return -ENOMEM;
682 }
683
684 return 0;
685 }
686
687 static int sbd_request_port(struct uart_port *uport)
688 {
689 const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n";
690 struct sbd_duart *duart = to_sport(uport)->duart;
691 int ret = 0;
692
693 if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
694 "sb1250-duart")) {
695 printk(err);
696 return -EBUSY;
697 }
698 refcount_inc(&duart->map_guard);
699 if (refcount_read(&duart->map_guard) == 1) {
700 if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING,
701 "sb1250-duart")) {
702 refcount_dec(&duart->map_guard);
703 printk(err);
704 ret = -EBUSY;
705 }
706 }
707 if (!ret) {
708 ret = sbd_map_port(uport);
709 if (ret) {
710 if (refcount_dec_and_test(&duart->map_guard))
711 release_mem_region(duart->mapctrl,
712 DUART_CHANREG_SPACING);
713 }
714 }
715 if (ret) {
716 release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
717 return ret;
718 }
719 return 0;
720 }
721
722 static void sbd_config_port(struct uart_port *uport, int flags)
723 {
724 struct sbd_port *sport = to_sport(uport);
725
726 if (flags & UART_CONFIG_TYPE) {
727 if (sbd_request_port(uport))
728 return;
729
730 uport->type = PORT_SB1250_DUART;
731
732 sbd_init_port(sport);
733 }
734 }
735
736 static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
737 {
738 int ret = 0;
739
740 if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART)
741 ret = -EINVAL;
742 if (ser->irq != uport->irq)
743 ret = -EINVAL;
744 if (ser->baud_base != uport->uartclk / 16)
745 ret = -EINVAL;
746 return ret;
747 }
748
749
750 static const struct uart_ops sbd_ops = {
751 .tx_empty = sbd_tx_empty,
752 .set_mctrl = sbd_set_mctrl,
753 .get_mctrl = sbd_get_mctrl,
754 .stop_tx = sbd_stop_tx,
755 .start_tx = sbd_start_tx,
756 .stop_rx = sbd_stop_rx,
757 .enable_ms = sbd_enable_ms,
758 .break_ctl = sbd_break_ctl,
759 .startup = sbd_startup,
760 .shutdown = sbd_shutdown,
761 .set_termios = sbd_set_termios,
762 .type = sbd_type,
763 .release_port = sbd_release_port,
764 .request_port = sbd_request_port,
765 .config_port = sbd_config_port,
766 .verify_port = sbd_verify_port,
767 };
768
769 /* Initialize SB1250 DUART port structures. */
770 static void __init sbd_probe_duarts(void)
771 {
772 static int probed;
773 int chip, side;
774 int max_lines, line;
775
776 if (probed)
777 return;
778
779 /* Set the number of available units based on the SOC type. */
780 switch (soc_type) {
781 case K_SYS_SOC_TYPE_BCM1x55:
782 case K_SYS_SOC_TYPE_BCM1x80:
783 max_lines = 4;
784 break;
785 default:
786 /* Assume at least two serial ports at the normal address. */
787 max_lines = 2;
788 break;
789 }
790
791 probed = 1;
792
793 for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
794 chip++) {
795 sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);
796
797 for (side = 0; side < DUART_MAX_SIDE && line < max_lines;
798 side++, line++) {
799 struct sbd_port *sport = &sbd_duarts[chip].sport[side];
800 struct uart_port *uport = &sport->port;
801
802 sport->duart = &sbd_duarts[chip];
803
804 uport->irq = SBD_INT(line);
805 uport->uartclk = 100000000 / 20 * 16;
806 uport->fifosize = 16;
807 uport->iotype = UPIO_MEM;
808 uport->flags = UPF_BOOT_AUTOCONF;
809 uport->ops = &sbd_ops;
810 uport->line = line;
811 uport->mapbase = SBD_CHANREGS(line);
812 uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SB1250_DUART_CONSOLE);
813 }
814 }
815 }
816
817
818 #ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
819 /*
820 * Serial console stuff. Very basic, polling driver for doing serial
821 * console output. The console_lock is held by the caller, so we
822 * shouldn't be interrupted for more console activity.
823 */
824 static void sbd_console_putchar(struct uart_port *uport, int ch)
825 {
826 struct sbd_port *sport = to_sport(uport);
827
828 sbd_transmit_drain(sport);
829 write_sbdchn(sport, R_DUART_TX_HOLD, ch);
830 }
831
832 static void sbd_console_write(struct console *co, const char *s,
833 unsigned int count)
834 {
835 int chip = co->index / DUART_MAX_SIDE;
836 int side = co->index % DUART_MAX_SIDE;
837 struct sbd_port *sport = &sbd_duarts[chip].sport[side];
838 struct uart_port *uport = &sport->port;
839 unsigned long flags;
840 unsigned int mask;
841
842 /* Disable transmit interrupts and enable the transmitter. */
843 spin_lock_irqsave(&uport->lock, flags);
844 mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
845 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
846 mask & ~M_DUART_IMR_TX);
847 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
848 spin_unlock_irqrestore(&uport->lock, flags);
849
850 uart_console_write(&sport->port, s, count, sbd_console_putchar);
851
852 /* Restore transmit interrupts and the transmitter enable. */
853 spin_lock_irqsave(&uport->lock, flags);
854 sbd_line_drain(sport);
855 if (sport->tx_stopped)
856 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
857 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
858 spin_unlock_irqrestore(&uport->lock, flags);
859 }
860
861 static int __init sbd_console_setup(struct console *co, char *options)
862 {
863 int chip = co->index / DUART_MAX_SIDE;
864 int side = co->index % DUART_MAX_SIDE;
865 struct sbd_port *sport = &sbd_duarts[chip].sport[side];
866 struct uart_port *uport = &sport->port;
867 int baud = 115200;
868 int bits = 8;
869 int parity = 'n';
870 int flow = 'n';
871 int ret;
872
873 if (!sport->duart)
874 return -ENXIO;
875
876 ret = sbd_map_port(uport);
877 if (ret)
878 return ret;
879
880 sbd_init_port(sport);
881
882 if (options)
883 uart_parse_options(options, &baud, &parity, &bits, &flow);
884 return uart_set_options(uport, co, baud, parity, bits, flow);
885 }
886
887 static struct uart_driver sbd_reg;
888 static struct console sbd_console = {
889 .name = "duart",
890 .write = sbd_console_write,
891 .device = uart_console_device,
892 .setup = sbd_console_setup,
893 .flags = CON_PRINTBUFFER,
894 .index = -1,
895 .data = &sbd_reg
896 };
897
898 static int __init sbd_serial_console_init(void)
899 {
900 sbd_probe_duarts();
901 register_console(&sbd_console);
902
903 return 0;
904 }
905
906 console_initcall(sbd_serial_console_init);
907
908 #define SERIAL_SB1250_DUART_CONSOLE &sbd_console
909 #else
910 #define SERIAL_SB1250_DUART_CONSOLE NULL
911 #endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */
912
913
914 static struct uart_driver sbd_reg = {
915 .owner = THIS_MODULE,
916 .driver_name = "sb1250_duart",
917 .dev_name = "duart",
918 .major = TTY_MAJOR,
919 .minor = SB1250_DUART_MINOR_BASE,
920 .nr = DUART_MAX_CHIP * DUART_MAX_SIDE,
921 .cons = SERIAL_SB1250_DUART_CONSOLE,
922 };
923
924 /* Set up the driver and register it. */
925 static int __init sbd_init(void)
926 {
927 int i, ret;
928
929 sbd_probe_duarts();
930
931 ret = uart_register_driver(&sbd_reg);
932 if (ret)
933 return ret;
934
935 for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) {
936 struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
937 struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
938 struct uart_port *uport = &sport->port;
939
940 if (sport->duart)
941 uart_add_one_port(&sbd_reg, uport);
942 }
943
944 return 0;
945 }
946
947 /* Unload the driver. Unregister stuff, get ready to go away. */
948 static void __exit sbd_exit(void)
949 {
950 int i;
951
952 for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) {
953 struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
954 struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
955 struct uart_port *uport = &sport->port;
956
957 if (sport->duart)
958 uart_remove_one_port(&sbd_reg, uport);
959 }
960
961 uart_unregister_driver(&sbd_reg);
962 }
963
964 module_init(sbd_init);
965 module_exit(sbd_exit);
Linux with added FPC-III support