drm/rockchip: Don't change hdmi reference clock rate
[drm/drm-misc.git] / drivers / tty / serial / sb1250-duart.c
blobb4e1b90e59608a7813866cde1b98be69782350db
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.
6 * Copyright (c) 2007 Maciej W. Rozycki
8 * Derived from drivers/char/sb1250_duart.c for which the following
9 * copyright applies:
11 * Copyright (c) 2000, 2001, 2002, 2003, 2004 Broadcom Corporation
13 * References:
15 * "BCM1250/BCM1125/BCM1125H User Manual", Broadcom Corporation
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>
36 #include <linux/refcount.h>
37 #include <linux/io.h>
39 #include <asm/sibyte/sb1250.h>
40 #include <asm/sibyte/sb1250_uart.h>
41 #include <asm/sibyte/swarm.h>
44 #if defined(CONFIG_SIBYTE_BCM1x80)
45 #include <asm/sibyte/bcm1480_regs.h>
46 #include <asm/sibyte/bcm1480_int.h>
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))
52 #define DUART_CHANREG_SPACING BCM1480_DUART_CHANREG_SPACING
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)
58 #elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
59 #include <asm/sibyte/sb1250_regs.h>
60 #include <asm/sibyte/sb1250_int.h>
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))
66 #else
67 #error invalid SB1250 UART configuration
69 #endif
72 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
73 MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver");
74 MODULE_LICENSE("GPL");
77 #define DUART_MAX_CHIP 2
78 #define DUART_MAX_SIDE 2
81 * Per-port state.
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;
92 * Per-DUART state for the shared register space.
94 struct sbd_duart {
95 struct sbd_port sport[2];
96 unsigned long mapctrl;
97 refcount_t map_guard;
100 #define to_sport(uport) container_of(uport, struct sbd_port, port)
102 static struct sbd_duart sbd_duarts[DUART_MAX_CHIP];
106 * Reading and writing SB1250 DUART registers.
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.
116 static u64 __read_sbdchn(struct sbd_port *sport, int reg)
118 void __iomem *csr = sport->port.membase + reg;
120 return __raw_readq(csr);
123 static u64 __read_sbdshr(struct sbd_port *sport, int reg)
125 void __iomem *csr = sport->memctrl + reg;
127 return __raw_readq(csr);
130 static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value)
132 void __iomem *csr = sport->port.membase + reg;
134 __raw_writeq(value, csr);
137 static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value)
139 void __iomem *csr = sport->memctrl + reg;
141 __raw_writeq(value, csr);
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.
148 static void __war_sbd1956(struct sbd_port *sport)
150 __read_sbdchn(sport, R_DUART_MODE_REG_1);
151 __read_sbdchn(sport, R_DUART_MODE_REG_2);
154 static unsigned char read_sbdchn(struct sbd_port *sport, int reg)
156 unsigned char retval;
158 retval = __read_sbdchn(sport, reg);
159 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
160 __war_sbd1956(sport);
161 return retval;
164 static unsigned char read_sbdshr(struct sbd_port *sport, int reg)
166 unsigned char retval;
168 retval = __read_sbdshr(sport, reg);
169 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
170 __war_sbd1956(sport);
171 return retval;
174 static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value)
176 __write_sbdchn(sport, reg, value);
177 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
178 __war_sbd1956(sport);
181 static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value)
183 __write_sbdshr(sport, reg, value);
184 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
185 __war_sbd1956(sport);
189 static int sbd_receive_ready(struct sbd_port *sport)
191 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY;
194 static int sbd_receive_drain(struct sbd_port *sport)
196 int loops = 10000;
198 while (sbd_receive_ready(sport) && --loops)
199 read_sbdchn(sport, R_DUART_RX_HOLD);
200 return loops;
203 static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport)
205 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY;
208 static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
210 int loops = 10000;
212 while (!sbd_transmit_ready(sport) && --loops)
213 udelay(2);
214 return loops;
217 static int sbd_transmit_empty(struct sbd_port *sport)
219 return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT;
222 static int sbd_line_drain(struct sbd_port *sport)
224 int loops = 10000;
226 while (!sbd_transmit_empty(sport) && --loops)
227 udelay(2);
228 return loops;
232 static unsigned int sbd_tx_empty(struct uart_port *uport)
234 struct sbd_port *sport = to_sport(uport);
236 return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0;
239 static unsigned int sbd_get_mctrl(struct uart_port *uport)
241 struct sbd_port *sport = to_sport(uport);
242 unsigned int mctrl, status;
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;
253 static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl)
255 struct sbd_port *sport = to_sport(uport);
256 unsigned int clr = 0, set = 0, mode2;
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;
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;
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);
281 static void sbd_stop_tx(struct uart_port *uport)
283 struct sbd_port *sport = to_sport(uport);
285 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
286 sport->tx_stopped = 1;
289 static void sbd_start_tx(struct uart_port *uport)
291 struct sbd_port *sport = to_sport(uport);
292 unsigned int mask;
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);
299 /* Go!, go!, go!... */
300 write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
301 sport->tx_stopped = 0;
304 static void sbd_stop_rx(struct uart_port *uport)
306 struct sbd_port *sport = to_sport(uport);
308 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
311 static void sbd_enable_ms(struct uart_port *uport)
313 struct sbd_port *sport = to_sport(uport);
315 write_sbdchn(sport, R_DUART_AUXCTL_X,
316 M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA);
319 static void sbd_break_ctl(struct uart_port *uport, int break_state)
321 struct sbd_port *sport = to_sport(uport);
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);
330 static void sbd_receive_chars(struct sbd_port *sport)
332 struct uart_port *uport = &sport->port;
333 struct uart_icount *icount;
334 unsigned int status;
335 int count;
336 u8 ch, flag;
338 for (count = 16; count; count--) {
339 status = read_sbdchn(sport, R_DUART_STATUS);
340 if (!(status & M_DUART_RX_RDY))
341 break;
343 ch = read_sbdchn(sport, R_DUART_RX_HOLD);
345 flag = TTY_NORMAL;
347 icount = &uport->icount;
348 icount->rx++;
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++;
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;
373 if (uart_handle_sysrq_char(uport, ch))
374 continue;
376 uart_insert_char(uport, status, M_DUART_OVRUN_ERR, ch, flag);
379 tty_flip_buffer_push(&uport->state->port);
382 static void sbd_transmit_chars(struct sbd_port *sport)
384 struct uart_port *uport = &sport->port;
385 struct tty_port *tport = &sport->port.state->port;
386 unsigned char ch;
387 unsigned int mask;
388 int stop_tx;
390 /* XON/XOFF chars. */
391 if (sport->port.x_char) {
392 write_sbdchn(sport, R_DUART_TX_HOLD, sport->port.x_char);
393 sport->port.icount.tx++;
394 sport->port.x_char = 0;
395 return;
398 /* If nothing to do or stopped or hardware stopped. */
399 stop_tx = uart_tx_stopped(&sport->port) ||
400 !uart_fifo_get(&sport->port, &ch);
402 /* Send char. */
403 if (!stop_tx) {
404 write_sbdchn(sport, R_DUART_TX_HOLD, ch);
406 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
407 uart_write_wakeup(&sport->port);
410 /* Are we are done? */
411 if (stop_tx || kfifo_is_empty(&tport->xmit_fifo)) {
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);
419 static void sbd_status_handle(struct sbd_port *sport)
421 struct uart_port *uport = &sport->port;
422 unsigned int delta;
424 delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
425 delta >>= (uport->line) % 2;
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));
430 if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG))
431 uport->icount.dsr++;
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);
438 static irqreturn_t sbd_interrupt(int irq, void *dev_id)
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;
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;
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);
462 status = IRQ_HANDLED;
465 return status;
469 static int sbd_startup(struct uart_port *uport)
471 struct sbd_port *sport = to_sport(uport);
472 unsigned int mode1;
473 int ret;
475 ret = request_irq(sport->port.irq, sbd_interrupt,
476 IRQF_SHARED, "sb1250-duart", sport);
477 if (ret)
478 return ret;
480 /* Clear the receive FIFO. */
481 sbd_receive_drain(sport);
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));
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);
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;
496 /* Enable interrupts. */
497 write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
498 M_DUART_IMR_IN | M_DUART_IMR_RX);
500 return 0;
503 static void sbd_shutdown(struct uart_port *uport)
505 struct sbd_port *sport = to_sport(uport);
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);
513 static void sbd_init_port(struct sbd_port *sport)
515 struct uart_port *uport = &sport->port;
517 if (sport->initialised)
518 return;
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);
531 sport->initialised = 1;
534 static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
535 const struct ktermios *old_termios)
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;
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;
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;
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;
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;
585 uart_update_timeout(uport, termios->c_cflag, baud);
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;
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;
604 if (termios->c_cflag & CREAD)
605 command = M_DUART_RX_EN;
606 else
607 command = M_DUART_RX_DIS;
609 if (termios->c_cflag & CRTSCTS)
610 aux |= M_DUART_CTS_CHNG_ENA;
611 else
612 aux &= ~M_DUART_CTS_CHNG_ENA;
614 uart_port_lock(uport);
616 if (sport->tx_stopped)
617 command |= M_DUART_TX_DIS;
618 else
619 command |= M_DUART_TX_EN;
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;
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);
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);
634 write_sbdchn(sport, R_DUART_CMD, command);
636 uart_port_unlock(uport);
640 static const char *sbd_type(struct uart_port *uport)
642 return "SB1250 DUART";
645 static void sbd_release_port(struct uart_port *uport)
647 struct sbd_port *sport = to_sport(uport);
648 struct sbd_duart *duart = sport->duart;
650 iounmap(sport->memctrl);
651 sport->memctrl = NULL;
652 iounmap(uport->membase);
653 uport->membase = NULL;
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);
660 static int sbd_map_port(struct uart_port *uport)
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;
666 if (!uport->membase)
667 uport->membase = ioremap(uport->mapbase,
668 DUART_CHANREG_SPACING);
669 if (!uport->membase) {
670 printk(err);
671 return -ENOMEM;
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;
684 return 0;
687 static int sbd_request_port(struct uart_port *uport)
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;
693 if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
694 "sb1250-duart")) {
695 printk(err);
696 return -EBUSY;
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;
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);
715 if (ret) {
716 release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
717 return ret;
719 return 0;
722 static void sbd_config_port(struct uart_port *uport, int flags)
724 struct sbd_port *sport = to_sport(uport);
726 if (flags & UART_CONFIG_TYPE) {
727 if (sbd_request_port(uport))
728 return;
730 uport->type = PORT_SB1250_DUART;
732 sbd_init_port(sport);
736 static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
738 int ret = 0;
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;
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,
769 /* Initialize SB1250 DUART port structures. */
770 static void __init sbd_probe_duarts(void)
772 static int probed;
773 int chip, side;
774 int max_lines, line;
776 if (probed)
777 return;
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;
791 probed = 1;
793 for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
794 chip++) {
795 sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);
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;
802 sport->duart = &sbd_duarts[chip];
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);
818 #ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
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.
824 static void sbd_console_putchar(struct uart_port *uport, unsigned char ch)
826 struct sbd_port *sport = to_sport(uport);
828 sbd_transmit_drain(sport);
829 write_sbdchn(sport, R_DUART_TX_HOLD, ch);
832 static void sbd_console_write(struct console *co, const char *s,
833 unsigned int count)
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;
842 /* Disable transmit interrupts and enable the transmitter. */
843 uart_port_lock_irqsave(uport, &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 uart_port_unlock_irqrestore(uport, flags);
850 uart_console_write(&sport->port, s, count, sbd_console_putchar);
852 /* Restore transmit interrupts and the transmitter enable. */
853 uart_port_lock_irqsave(uport, &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 uart_port_unlock_irqrestore(uport, flags);
861 static int __init sbd_console_setup(struct console *co, char *options)
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;
873 if (!sport->duart)
874 return -ENXIO;
876 ret = sbd_map_port(uport);
877 if (ret)
878 return ret;
880 sbd_init_port(sport);
882 if (options)
883 uart_parse_options(options, &baud, &parity, &bits, &flow);
884 return uart_set_options(uport, co, baud, parity, bits, flow);
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
898 static int __init sbd_serial_console_init(void)
900 sbd_probe_duarts();
901 register_console(&sbd_console);
903 return 0;
906 console_initcall(sbd_serial_console_init);
908 #define SERIAL_SB1250_DUART_CONSOLE &sbd_console
909 #else
910 #define SERIAL_SB1250_DUART_CONSOLE NULL
911 #endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */
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,
924 /* Set up the driver and register it. */
925 static int __init sbd_init(void)
927 int i, ret;
929 sbd_probe_duarts();
931 ret = uart_register_driver(&sbd_reg);
932 if (ret)
933 return ret;
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;
940 if (sport->duart)
941 uart_add_one_port(&sbd_reg, uport);
944 return 0;
947 /* Unload the driver. Unregister stuff, get ready to go away. */
948 static void __exit sbd_exit(void)
950 int i;
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;
957 if (sport->duart)
958 uart_remove_one_port(&sbd_reg, uport);
961 uart_unregister_driver(&sbd_reg);
964 module_init(sbd_init);
965 module_exit(sbd_exit);