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 <linux/io.h>
38
39 #include <asm/sibyte/sb1250.h>
40 #include <asm/sibyte/sb1250_uart.h>
41 #include <asm/sibyte/swarm.h>
42
43
44 #if defined(CONFIG_SIBYTE_BCM1x80)
45 #include <asm/sibyte/bcm1480_regs.h>
46 #include <asm/sibyte/bcm1480_int.h>
47
48 #define SBD_CHANREGS(line) A_BCM1480_DUART_CHANREG((line), 0)
49 #define SBD_CTRLREGS(line) A_BCM1480_DUART_CTRLREG((line), 0)
50 #define SBD_INT(line) (K_BCM1480_INT_UART_0 + (line))
51
52 #define DUART_CHANREG_SPACING BCM1480_DUART_CHANREG_SPACING
53
54 #define R_DUART_IMRREG(line) R_BCM1480_DUART_IMRREG(line)
55 #define R_DUART_INCHREG(line) R_BCM1480_DUART_INCHREG(line)
56 #define R_DUART_ISRREG(line) R_BCM1480_DUART_ISRREG(line)
57
58 #elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
59 #include <asm/sibyte/sb1250_regs.h>
60 #include <asm/sibyte/sb1250_int.h>
61
62 #define SBD_CHANREGS(line) A_DUART_CHANREG((line), 0)
63 #define SBD_CTRLREGS(line) A_DUART_CTRLREG(0)
64 #define SBD_INT(line) (K_INT_UART_0 + (line))
65
66 #else
67 #error invalid SB1250 UART configuration
68
69 #endif
70
71
72 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
73 MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver");
74 MODULE_LICENSE("GPL");
75
76
77 #define DUART_MAX_CHIP 2
78 #define DUART_MAX_SIDE 2
79
80 /*
81 * Per-port state.
82 */
83 struct sbd_port {
84 struct sbd_duart *duart;
85 struct uart_port port;
86 unsigned char __iomem *memctrl;
87 int tx_stopped;
88 int initialised;
89 };
90
91 /*
92 * Per-DUART state for the shared register space.
93 */
94 struct sbd_duart {
95 struct sbd_port sport[2];
96 unsigned long mapctrl;
97 refcount_t map_guard;
98 };
99
100 #define to_sport(uport) container_of(uport, struct sbd_port, port)
101
102 static struct sbd_duart sbd_duarts[DUART_MAX_CHIP];
103
104
105 /*
106 * Reading and writing SB1250 DUART registers.
107 *
108 * There are three register spaces: two per-channel ones and
109 * a shared one. We have to define accessors appropriately.
110 * All registers are 64-bit and all but the Baud Rate Clock
111 * registers only define 8 least significant bits. There is
112 * also a workaround to take into account. Raw accessors use
113 * the full register width, but cooked ones truncate it
114 * intentionally so that the rest of the driver does not care.
115 */
__read_sbdchn(struct sbd_port * sport,int reg)116 static u64 __read_sbdchn(struct sbd_port *sport, int reg)
117 {
118 void __iomem *csr = sport->port.membase + reg;
119
120 return __raw_readq(csr);
121 }
122
__read_sbdshr(struct sbd_port * sport,int reg)123 static u64 __read_sbdshr(struct sbd_port *sport, int reg)
124 {
125 void __iomem *csr = sport->memctrl + reg;
126
127 return __raw_readq(csr);
128 }
129
__write_sbdchn(struct sbd_port * sport,int reg,u64 value)130 static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value)
131 {
132 void __iomem *csr = sport->port.membase + reg;
133
134 __raw_writeq(value, csr);
135 }
136
__write_sbdshr(struct sbd_port * sport,int reg,u64 value)137 static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value)
138 {
139 void __iomem *csr = sport->memctrl + reg;
140
141 __raw_writeq(value, csr);
142 }
143
144 /*
145 * In bug 1956, we get glitches that can mess up uart registers. This
146 * "read-mode-reg after any register access" is an accepted workaround.
147 */
__war_sbd1956(struct sbd_port * sport)148 static void __war_sbd1956(struct sbd_port *sport)
149 {
150 __read_sbdchn(sport, R_DUART_MODE_REG_1);
151 __read_sbdchn(sport, R_DUART_MODE_REG_2);
152 }
153
read_sbdchn(struct sbd_port * sport,int reg)154 static unsigned char read_sbdchn(struct sbd_port *sport, int reg)
155 {
156 unsigned char retval;
157
158 retval = __read_sbdchn(sport, reg);
159 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
160 __war_sbd1956(sport);
161 return retval;
162 }
163
read_sbdshr(struct sbd_port * sport,int reg)164 static unsigned char read_sbdshr(struct sbd_port *sport, int reg)
165 {
166 unsigned char retval;
167
168 retval = __read_sbdshr(sport, reg);
169 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
170 __war_sbd1956(sport);
171 return retval;
172 }
173
write_sbdchn(struct sbd_port * sport,int reg,unsigned int value)174 static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value)
175 {
176 __write_sbdchn(sport, reg, value);
177 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
178 __war_sbd1956(sport);
179 }
180
write_sbdshr(struct sbd_port * sport,int reg,unsigned int value)181 static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value)
182 {
183 __write_sbdshr(sport, reg, value);
184 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
185 __war_sbd1956(sport);
186 }
187
188
sbd_receive_ready(struct sbd_port * sport)189 static int sbd_receive_ready(struct sbd_port *sport)
190 {
191 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY;
192 }
193
sbd_receive_drain(struct sbd_port * sport)194 static int sbd_receive_drain(struct sbd_port *sport)
195 {
196 int loops = 10000;
197
198 while (sbd_receive_ready(sport) && --loops)
199 read_sbdchn(sport, R_DUART_RX_HOLD);
200 return loops;
201 }
202
sbd_transmit_ready(struct sbd_port * sport)203 static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport)
204 {
205 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY;
206 }
207
sbd_transmit_drain(struct sbd_port * sport)208 static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
209 {
210 int loops = 10000;
211
212 while (!sbd_transmit_ready(sport) && --loops)
213 udelay(2);
214 return loops;
215 }
216
sbd_transmit_empty(struct sbd_port * sport)217 static int sbd_transmit_empty(struct sbd_port *sport)
218 {
219 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT;
220 }
221
sbd_line_drain(struct sbd_port * sport)222 static int sbd_line_drain(struct sbd_port *sport)
223 {
224 int loops = 10000;
225
226 while (!sbd_transmit_empty(sport) && --loops)
227 udelay(2);
228 return loops;
229 }
230
231
sbd_tx_empty(struct uart_port * uport)232 static unsigned int sbd_tx_empty(struct uart_port *uport)
233 {
234 struct sbd_port *sport = to_sport(uport);
235
236 return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0;
237 }
238
sbd_get_mctrl(struct uart_port * uport)239 static unsigned int sbd_get_mctrl(struct uart_port *uport)
240 {
241 struct sbd_port *sport = to_sport(uport);
242 unsigned int mctrl, status;
243
244 status = read_sbdshr(sport, R_DUART_IN_PORT);
245 status >>= (uport->line) % 2;
246 mctrl = (!(status & M_DUART_IN_PIN0_VAL) ? TIOCM_CTS : 0) |
247 (!(status & M_DUART_IN_PIN4_VAL) ? TIOCM_CAR : 0) |
248 (!(status & M_DUART_RIN0_PIN) ? TIOCM_RNG : 0) |
249 (!(status & M_DUART_IN_PIN2_VAL) ? TIOCM_DSR : 0);
250 return mctrl;
251 }
252
sbd_set_mctrl(struct uart_port * uport,unsigned int mctrl)253 static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl)
254 {
255 struct sbd_port *sport = to_sport(uport);
256 unsigned int clr = 0, set = 0, mode2;
257
258 if (mctrl & TIOCM_DTR)
259 set |= M_DUART_SET_OPR2;
260 else
261 clr |= M_DUART_CLR_OPR2;
262 if (mctrl & TIOCM_RTS)
263 set |= M_DUART_SET_OPR0;
264 else
265 clr |= M_DUART_CLR_OPR0;
266 clr <<= (uport->line) % 2;
267 set <<= (uport->line) % 2;
268
269 mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2);
270 mode2 &= ~M_DUART_CHAN_MODE;
271 if (mctrl & TIOCM_LOOP)
272 mode2 |= V_DUART_CHAN_MODE_LCL_LOOP;
273 else
274 mode2 |= V_DUART_CHAN_MODE_NORMAL;
275
276 write_sbdshr(sport, R_DUART_CLEAR_OPR, clr);
277 write_sbdshr(sport, R_DUART_SET_OPR, set);
278 write_sbdchn(sport, R_DUART_MODE_REG_2, mode2);
279 }
280
sbd_stop_tx(struct uart_port * uport)281 static void sbd_stop_tx(struct uart_port *uport)
282 {
283 struct sbd_port *sport = to_sport(uport);
284
285 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
286 sport->tx_stopped = 1;
287 };
288
sbd_start_tx(struct uart_port * uport)289 static void sbd_start_tx(struct uart_port *uport)
290 {
291 struct sbd_port *sport = to_sport(uport);
292 unsigned int mask;
293
294 /* Enable tx interrupts. */
295 mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
296 mask |= M_DUART_IMR_TX;
297 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
298
299 /* Go!, go!, go!... */
300 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
301 sport->tx_stopped = 0;
302 };
303
sbd_stop_rx(struct uart_port * uport)304 static void sbd_stop_rx(struct uart_port *uport)
305 {
306 struct sbd_port *sport = to_sport(uport);
307
308 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
309 };
310
sbd_enable_ms(struct uart_port * uport)311 static void sbd_enable_ms(struct uart_port *uport)
312 {
313 struct sbd_port *sport = to_sport(uport);
314
315 write_sbdchn(sport, R_DUART_AUXCTL_X,
316 M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA);
317 }
318
sbd_break_ctl(struct uart_port * uport,int break_state)319 static void sbd_break_ctl(struct uart_port *uport, int break_state)
320 {
321 struct sbd_port *sport = to_sport(uport);
322
323 if (break_state == -1)
324 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_START_BREAK);
325 else
326 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_STOP_BREAK);
327 }
328
329
sbd_receive_chars(struct sbd_port * sport)330 static void sbd_receive_chars(struct sbd_port *sport)
331 {
332 struct uart_port *uport = &sport->port;
333 struct uart_icount *icount;
334 unsigned int status;
335 int count;
336 u8 ch, flag;
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
sbd_transmit_chars(struct sbd_port * sport)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 uart_xmit_advance(&sport->port, 1);
404
405 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
406 uart_write_wakeup(&sport->port);
407 }
408
409 /* Are we are done? */
410 if (stop_tx || uart_circ_empty(xmit)) {
411 /* Disable tx interrupts. */
412 mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
413 mask &= ~M_DUART_IMR_TX;
414 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
415 }
416 }
417
sbd_status_handle(struct sbd_port * sport)418 static void sbd_status_handle(struct sbd_port *sport)
419 {
420 struct uart_port *uport = &sport->port;
421 unsigned int delta;
422
423 delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
424 delta >>= (uport->line) % 2;
425
426 if (delta & (M_DUART_IN_PIN0_VAL << S_DUART_IN_PIN_CHNG))
427 uart_handle_cts_change(uport, !(delta & M_DUART_IN_PIN0_VAL));
428
429 if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG))
430 uport->icount.dsr++;
431
432 if (delta & ((M_DUART_IN_PIN2_VAL | M_DUART_IN_PIN0_VAL) <<
433 S_DUART_IN_PIN_CHNG))
434 wake_up_interruptible(&uport->state->port.delta_msr_wait);
435 }
436
sbd_interrupt(int irq,void * dev_id)437 static irqreturn_t sbd_interrupt(int irq, void *dev_id)
438 {
439 struct sbd_port *sport = dev_id;
440 struct uart_port *uport = &sport->port;
441 irqreturn_t status = IRQ_NONE;
442 unsigned int intstat;
443 int count;
444
445 for (count = 16; count; count--) {
446 intstat = read_sbdshr(sport,
447 R_DUART_ISRREG((uport->line) % 2));
448 intstat &= read_sbdshr(sport,
449 R_DUART_IMRREG((uport->line) % 2));
450 intstat &= M_DUART_ISR_ALL;
451 if (!intstat)
452 break;
453
454 if (intstat & M_DUART_ISR_RX)
455 sbd_receive_chars(sport);
456 if (intstat & M_DUART_ISR_IN)
457 sbd_status_handle(sport);
458 if (intstat & M_DUART_ISR_TX)
459 sbd_transmit_chars(sport);
460
461 status = IRQ_HANDLED;
462 }
463
464 return status;
465 }
466
467
sbd_startup(struct uart_port * uport)468 static int sbd_startup(struct uart_port *uport)
469 {
470 struct sbd_port *sport = to_sport(uport);
471 unsigned int mode1;
472 int ret;
473
474 ret = request_irq(sport->port.irq, sbd_interrupt,
475 IRQF_SHARED, "sb1250-duart", sport);
476 if (ret)
477 return ret;
478
479 /* Clear the receive FIFO. */
480 sbd_receive_drain(sport);
481
482 /* Clear the interrupt registers. */
483 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT);
484 read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
485
486 /* Set rx/tx interrupt to FIFO available. */
487 mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1);
488 mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT);
489 write_sbdchn(sport, R_DUART_MODE_REG_1, mode1);
490
491 /* Disable tx, enable rx. */
492 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN);
493 sport->tx_stopped = 1;
494
495 /* Enable interrupts. */
496 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
497 M_DUART_IMR_IN | M_DUART_IMR_RX);
498
499 return 0;
500 }
501
sbd_shutdown(struct uart_port * uport)502 static void sbd_shutdown(struct uart_port *uport)
503 {
504 struct sbd_port *sport = to_sport(uport);
505
506 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
507 sport->tx_stopped = 1;
508 free_irq(sport->port.irq, sport);
509 }
510
511
sbd_init_port(struct sbd_port * sport)512 static void sbd_init_port(struct sbd_port *sport)
513 {
514 struct uart_port *uport = &sport->port;
515
516 if (sport->initialised)
517 return;
518
519 /* There is no DUART reset feature, so just set some sane defaults. */
520 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX);
521 write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX);
522 write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8);
523 write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
524 write_sbdchn(sport, R_DUART_FULL_CTL,
525 V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15));
526 write_sbdchn(sport, R_DUART_OPCR_X, 0);
527 write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
528 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
529
530 sport->initialised = 1;
531 }
532
sbd_set_termios(struct uart_port * uport,struct ktermios * termios,const struct ktermios * old_termios)533 static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
534 const struct ktermios *old_termios)
535 {
536 struct sbd_port *sport = to_sport(uport);
537 unsigned int mode1 = 0, mode2 = 0, aux = 0;
538 unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0;
539 unsigned int oldmode1, oldmode2, oldaux;
540 unsigned int baud, brg;
541 unsigned int command;
542
543 mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD |
544 M_DUART_BITS_PER_CHAR);
545 mode2mask |= ~M_DUART_STOP_BIT_LEN_2;
546 auxmask |= ~M_DUART_CTS_CHNG_ENA;
547
548 /* Byte size. */
549 switch (termios->c_cflag & CSIZE) {
550 case CS5:
551 case CS6:
552 /* Unsupported, leave unchanged. */
553 mode1mask |= M_DUART_PARITY_MODE;
554 break;
555 case CS7:
556 mode1 |= V_DUART_BITS_PER_CHAR_7;
557 break;
558 case CS8:
559 default:
560 mode1 |= V_DUART_BITS_PER_CHAR_8;
561 break;
562 }
563
564 /* Parity and stop bits. */
565 if (termios->c_cflag & CSTOPB)
566 mode2 |= M_DUART_STOP_BIT_LEN_2;
567 else
568 mode2 |= M_DUART_STOP_BIT_LEN_1;
569 if (termios->c_cflag & PARENB)
570 mode1 |= V_DUART_PARITY_MODE_ADD;
571 else
572 mode1 |= V_DUART_PARITY_MODE_NONE;
573 if (termios->c_cflag & PARODD)
574 mode1 |= M_DUART_PARITY_TYPE_ODD;
575 else
576 mode1 |= M_DUART_PARITY_TYPE_EVEN;
577
578 baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000);
579 brg = V_DUART_BAUD_RATE(baud);
580 /* The actual lower bound is 1221bps, so compensate. */
581 if (brg > M_DUART_CLK_COUNTER)
582 brg = M_DUART_CLK_COUNTER;
583
584 uart_update_timeout(uport, termios->c_cflag, baud);
585
586 uport->read_status_mask = M_DUART_OVRUN_ERR;
587 if (termios->c_iflag & INPCK)
588 uport->read_status_mask |= M_DUART_FRM_ERR |
589 M_DUART_PARITY_ERR;
590 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
591 uport->read_status_mask |= M_DUART_RCVD_BRK;
592
593 uport->ignore_status_mask = 0;
594 if (termios->c_iflag & IGNPAR)
595 uport->ignore_status_mask |= M_DUART_FRM_ERR |
596 M_DUART_PARITY_ERR;
597 if (termios->c_iflag & IGNBRK) {
598 uport->ignore_status_mask |= M_DUART_RCVD_BRK;
599 if (termios->c_iflag & IGNPAR)
600 uport->ignore_status_mask |= M_DUART_OVRUN_ERR;
601 }
602
603 if (termios->c_cflag & CREAD)
604 command = M_DUART_RX_EN;
605 else
606 command = M_DUART_RX_DIS;
607
608 if (termios->c_cflag & CRTSCTS)
609 aux |= M_DUART_CTS_CHNG_ENA;
610 else
611 aux &= ~M_DUART_CTS_CHNG_ENA;
612
613 spin_lock(&uport->lock);
614
615 if (sport->tx_stopped)
616 command |= M_DUART_TX_DIS;
617 else
618 command |= M_DUART_TX_EN;
619
620 oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask;
621 oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
622 oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;
623
624 if (!sport->tx_stopped)
625 sbd_line_drain(sport);
626 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
627
628 write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1);
629 write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);
630 write_sbdchn(sport, R_DUART_CLK_SEL, brg);
631 write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);
632
633 write_sbdchn(sport, R_DUART_CMD, command);
634
635 spin_unlock(&uport->lock);
636 }
637
638
sbd_type(struct uart_port * uport)639 static const char *sbd_type(struct uart_port *uport)
640 {
641 return "SB1250 DUART";
642 }
643
sbd_release_port(struct uart_port * uport)644 static void sbd_release_port(struct uart_port *uport)
645 {
646 struct sbd_port *sport = to_sport(uport);
647 struct sbd_duart *duart = sport->duart;
648
649 iounmap(sport->memctrl);
650 sport->memctrl = NULL;
651 iounmap(uport->membase);
652 uport->membase = NULL;
653
654 if(refcount_dec_and_test(&duart->map_guard))
655 release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING);
656 release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
657 }
658
sbd_map_port(struct uart_port * uport)659 static int sbd_map_port(struct uart_port *uport)
660 {
661 const char *err = KERN_ERR "sbd: Cannot map MMIO\n";
662 struct sbd_port *sport = to_sport(uport);
663 struct sbd_duart *duart = sport->duart;
664
665 if (!uport->membase)
666 uport->membase = ioremap(uport->mapbase,
667 DUART_CHANREG_SPACING);
668 if (!uport->membase) {
669 printk(err);
670 return -ENOMEM;
671 }
672
673 if (!sport->memctrl)
674 sport->memctrl = ioremap(duart->mapctrl,
675 DUART_CHANREG_SPACING);
676 if (!sport->memctrl) {
677 printk(err);
678 iounmap(uport->membase);
679 uport->membase = NULL;
680 return -ENOMEM;
681 }
682
683 return 0;
684 }
685
sbd_request_port(struct uart_port * uport)686 static int sbd_request_port(struct uart_port *uport)
687 {
688 const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n";
689 struct sbd_duart *duart = to_sport(uport)->duart;
690 int ret = 0;
691
692 if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
693 "sb1250-duart")) {
694 printk(err);
695 return -EBUSY;
696 }
697 refcount_inc(&duart->map_guard);
698 if (refcount_read(&duart->map_guard) == 1) {
699 if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING,
700 "sb1250-duart")) {
701 refcount_dec(&duart->map_guard);
702 printk(err);
703 ret = -EBUSY;
704 }
705 }
706 if (!ret) {
707 ret = sbd_map_port(uport);
708 if (ret) {
709 if (refcount_dec_and_test(&duart->map_guard))
710 release_mem_region(duart->mapctrl,
711 DUART_CHANREG_SPACING);
712 }
713 }
714 if (ret) {
715 release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
716 return ret;
717 }
718 return 0;
719 }
720
sbd_config_port(struct uart_port * uport,int flags)721 static void sbd_config_port(struct uart_port *uport, int flags)
722 {
723 struct sbd_port *sport = to_sport(uport);
724
725 if (flags & UART_CONFIG_TYPE) {
726 if (sbd_request_port(uport))
727 return;
728
729 uport->type = PORT_SB1250_DUART;
730
731 sbd_init_port(sport);
732 }
733 }
734
sbd_verify_port(struct uart_port * uport,struct serial_struct * ser)735 static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
736 {
737 int ret = 0;
738
739 if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART)
740 ret = -EINVAL;
741 if (ser->irq != uport->irq)
742 ret = -EINVAL;
743 if (ser->baud_base != uport->uartclk / 16)
744 ret = -EINVAL;
745 return ret;
746 }
747
748
749 static const struct uart_ops sbd_ops = {
750 .tx_empty = sbd_tx_empty,
751 .set_mctrl = sbd_set_mctrl,
752 .get_mctrl = sbd_get_mctrl,
753 .stop_tx = sbd_stop_tx,
754 .start_tx = sbd_start_tx,
755 .stop_rx = sbd_stop_rx,
756 .enable_ms = sbd_enable_ms,
757 .break_ctl = sbd_break_ctl,
758 .startup = sbd_startup,
759 .shutdown = sbd_shutdown,
760 .set_termios = sbd_set_termios,
761 .type = sbd_type,
762 .release_port = sbd_release_port,
763 .request_port = sbd_request_port,
764 .config_port = sbd_config_port,
765 .verify_port = sbd_verify_port,
766 };
767
768 /* Initialize SB1250 DUART port structures. */
sbd_probe_duarts(void)769 static void __init sbd_probe_duarts(void)
770 {
771 static int probed;
772 int chip, side;
773 int max_lines, line;
774
775 if (probed)
776 return;
777
778 /* Set the number of available units based on the SOC type. */
779 switch (soc_type) {
780 case K_SYS_SOC_TYPE_BCM1x55:
781 case K_SYS_SOC_TYPE_BCM1x80:
782 max_lines = 4;
783 break;
784 default:
785 /* Assume at least two serial ports at the normal address. */
786 max_lines = 2;
787 break;
788 }
789
790 probed = 1;
791
792 for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
793 chip++) {
794 sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);
795
796 for (side = 0; side < DUART_MAX_SIDE && line < max_lines;
797 side++, line++) {
798 struct sbd_port *sport = &sbd_duarts[chip].sport[side];
799 struct uart_port *uport = &sport->port;
800
801 sport->duart = &sbd_duarts[chip];
802
803 uport->irq = SBD_INT(line);
804 uport->uartclk = 100000000 / 20 * 16;
805 uport->fifosize = 16;
806 uport->iotype = UPIO_MEM;
807 uport->flags = UPF_BOOT_AUTOCONF;
808 uport->ops = &sbd_ops;
809 uport->line = line;
810 uport->mapbase = SBD_CHANREGS(line);
811 uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SB1250_DUART_CONSOLE);
812 }
813 }
814 }
815
816
817 #ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
818 /*
819 * Serial console stuff. Very basic, polling driver for doing serial
820 * console output. The console_lock is held by the caller, so we
821 * shouldn't be interrupted for more console activity.
822 */
sbd_console_putchar(struct uart_port * uport,unsigned char ch)823 static void sbd_console_putchar(struct uart_port *uport, unsigned char ch)
824 {
825 struct sbd_port *sport = to_sport(uport);
826
827 sbd_transmit_drain(sport);
828 write_sbdchn(sport, R_DUART_TX_HOLD, ch);
829 }
830
sbd_console_write(struct console * co,const char * s,unsigned int count)831 static void sbd_console_write(struct console *co, const char *s,
832 unsigned int count)
833 {
834 int chip = co->index / DUART_MAX_SIDE;
835 int side = co->index % DUART_MAX_SIDE;
836 struct sbd_port *sport = &sbd_duarts[chip].sport[side];
837 struct uart_port *uport = &sport->port;
838 unsigned long flags;
839 unsigned int mask;
840
841 /* Disable transmit interrupts and enable the transmitter. */
842 spin_lock_irqsave(&uport->lock, flags);
843 mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
844 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
845 mask & ~M_DUART_IMR_TX);
846 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
847 spin_unlock_irqrestore(&uport->lock, flags);
848
849 uart_console_write(&sport->port, s, count, sbd_console_putchar);
850
851 /* Restore transmit interrupts and the transmitter enable. */
852 spin_lock_irqsave(&uport->lock, flags);
853 sbd_line_drain(sport);
854 if (sport->tx_stopped)
855 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
856 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
857 spin_unlock_irqrestore(&uport->lock, flags);
858 }
859
sbd_console_setup(struct console * co,char * options)860 static int __init sbd_console_setup(struct console *co, char *options)
861 {
862 int chip = co->index / DUART_MAX_SIDE;
863 int side = co->index % DUART_MAX_SIDE;
864 struct sbd_port *sport = &sbd_duarts[chip].sport[side];
865 struct uart_port *uport = &sport->port;
866 int baud = 115200;
867 int bits = 8;
868 int parity = 'n';
869 int flow = 'n';
870 int ret;
871
872 if (!sport->duart)
873 return -ENXIO;
874
875 ret = sbd_map_port(uport);
876 if (ret)
877 return ret;
878
879 sbd_init_port(sport);
880
881 if (options)
882 uart_parse_options(options, &baud, &parity, &bits, &flow);
883 return uart_set_options(uport, co, baud, parity, bits, flow);
884 }
885
886 static struct uart_driver sbd_reg;
887 static struct console sbd_console = {
888 .name = "duart",
889 .write = sbd_console_write,
890 .device = uart_console_device,
891 .setup = sbd_console_setup,
892 .flags = CON_PRINTBUFFER,
893 .index = -1,
894 .data = &sbd_reg
895 };
896
sbd_serial_console_init(void)897 static int __init sbd_serial_console_init(void)
898 {
899 sbd_probe_duarts();
900 register_console(&sbd_console);
901
902 return 0;
903 }
904
905 console_initcall(sbd_serial_console_init);
906
907 #define SERIAL_SB1250_DUART_CONSOLE &sbd_console
908 #else
909 #define SERIAL_SB1250_DUART_CONSOLE NULL
910 #endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */
911
912
913 static struct uart_driver sbd_reg = {
914 .owner = THIS_MODULE,
915 .driver_name = "sb1250_duart",
916 .dev_name = "duart",
917 .major = TTY_MAJOR,
918 .minor = SB1250_DUART_MINOR_BASE,
919 .nr = DUART_MAX_CHIP * DUART_MAX_SIDE,
920 .cons = SERIAL_SB1250_DUART_CONSOLE,
921 };
922
923 /* Set up the driver and register it. */
sbd_init(void)924 static int __init sbd_init(void)
925 {
926 int i, ret;
927
928 sbd_probe_duarts();
929
930 ret = uart_register_driver(&sbd_reg);
931 if (ret)
932 return ret;
933
934 for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) {
935 struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
936 struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
937 struct uart_port *uport = &sport->port;
938
939 if (sport->duart)
940 uart_add_one_port(&sbd_reg, uport);
941 }
942
943 return 0;
944 }
945
946 /* Unload the driver. Unregister stuff, get ready to go away. */
sbd_exit(void)947 static void __exit sbd_exit(void)
948 {
949 int i;
950
951 for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) {
952 struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
953 struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
954 struct uart_port *uport = &sport->port;
955
956 if (sport->duart)
957 uart_remove_one_port(&sbd_reg, uport);
958 }
959
960 uart_unregister_driver(&sbd_reg);
961 }
962
963 module_init(sbd_init);
964 module_exit(sbd_exit);
965