xref: /freebsd/sys/arm/xilinx/uart_dev_cdnc.c (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /*-
2  * Copyright (c) 2005 M. Warner Losh
3  * Copyright (c) 2005 Olivier Houchard
4  * Copyright (c) 2012 Thomas Skibo
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /* A driver for the Cadence AMBA UART as used by the Xilinx Zynq-7000.
31  *
32  * Reference: Zynq-7000 All Programmable SoC Technical Reference Manual.
33  * (v1.4) November 16, 2012.  Xilinx doc UG585.  UART is covered in Ch. 19
34  * and register definitions are in appendix B.33.
35  */
36 
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include "opt_global.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/bus.h>
46 #include <sys/conf.h>
47 #include <sys/cons.h>
48 #include <sys/tty.h>
49 #include <machine/bus.h>
50 
51 #include <dev/uart/uart.h>
52 #include <dev/uart/uart_cpu.h>
53 #include <dev/uart/uart_bus.h>
54 
55 #include "uart_if.h"
56 
57 #define	UART_FIFO_SIZE	64
58 
59 #define	RD4(bas, reg)		\
60 	bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs((bas), (reg)))
61 #define	WR4(bas, reg, value)	\
62 	bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs((bas), (reg)), \
63 			  (value))
64 
65 /* Register definitions for Cadence UART Controller.
66  */
67 #define CDNC_UART_CTRL_REG	0x00		/* Control Register. */
68 #define CDNC_UART_CTRL_REG_STOPBRK	(1<<8)
69 #define CDNC_UART_CTRL_REG_STARTBRK	(1<<7)
70 #define CDNC_UART_CTRL_REG_TORST	(1<<6)
71 #define CDNC_UART_CTRL_REG_TX_DIS	(1<<5)
72 #define CDNC_UART_CTRL_REG_TX_EN	(1<<4)
73 #define CDNC_UART_CTRL_REG_RX_DIS	(1<<3)
74 #define CDNC_UART_CTRL_REG_RX_EN	(1<<2)
75 #define CDNC_UART_CTRL_REG_TXRST	(1<<1)
76 #define CDNC_UART_CTRL_REG_RXRST	(1<<0)
77 
78 #define CDNC_UART_MODE_REG	0x04		/* Mode Register. */
79 #define CDNC_UART_MODE_REG_CHMOD_R_LOOP	(3<<8)	/* [9:8] - channel mode */
80 #define CDNC_UART_MODE_REG_CHMOD_L_LOOP	(2<<8)
81 #define CDNC_UART_MODE_REG_CHMOD_AUTECHO (1<<8)
82 #define CDNC_UART_MODE_REG_STOP2	(2<<6)	/* [7:6] - stop bits */
83 #define CDNC_UART_MODE_REG_PAR_NONE	(4<<3)	/* [5:3] - parity type */
84 #define CDNC_UART_MODE_REG_PAR_MARK	(3<<3)
85 #define CDNC_UART_MODE_REG_PAR_SPACE	(2<<3)
86 #define CDNC_UART_MODE_REG_PAR_ODD	(1<<3)
87 #define CDNC_UART_MODE_REG_PAR_EVEN	(0<<3)
88 #define CDNC_UART_MODE_REG_6BIT		(3<<1)	/* [2:1] - character len */
89 #define CDNC_UART_MODE_REG_7BIT		(2<<1)
90 #define CDNC_UART_MODE_REG_8BIT		(0<<1)
91 #define CDNC_UART_MODE_REG_CLKSEL	(1<<0)
92 
93 #define CDNC_UART_IEN_REG	0x08		/* Interrupt registers. */
94 #define CDNC_UART_IDIS_REG	0x0C
95 #define CDNC_UART_IMASK_REG	0x10
96 #define CDNC_UART_ISTAT_REG	0x14
97 #define CDNC_UART_INT_TXOVR		(1<<12)
98 #define CDNC_UART_INT_TXNRLYFUL		(1<<11)	/* tx "nearly" full */
99 #define CDNC_UART_INT_TXTRIG		(1<<10)
100 #define CDNC_UART_INT_DMSI		(1<<9)	/* delta modem status */
101 #define CDNC_UART_INT_RXTMOUT		(1<<8)
102 #define CDNC_UART_INT_PARITY		(1<<7)
103 #define CDNC_UART_INT_FRAMING		(1<<6)
104 #define CDNC_UART_INT_RXOVR		(1<<5)
105 #define CDNC_UART_INT_TXFULL		(1<<4)
106 #define CDNC_UART_INT_TXEMPTY		(1<<3)
107 #define CDNC_UART_INT_RXFULL		(1<<2)
108 #define CDNC_UART_INT_RXEMPTY		(1<<1)
109 #define CDNC_UART_INT_RXTRIG		(1<<0)
110 #define CDNC_UART_INT_ALL		0x1FFF
111 
112 #define CDNC_UART_BAUDGEN_REG	0x18
113 #define CDNC_UART_RX_TIMEO_REG	0x1C
114 #define CDNC_UART_RX_WATER_REG	0x20
115 
116 #define CDNC_UART_MODEM_CTRL_REG 0x24
117 #define CDNC_UART_MODEM_CTRL_REG_FCM	(1<<5)	/* automatic flow control */
118 #define CDNC_UART_MODEM_CTRL_REG_RTS	(1<<1)
119 #define CDNC_UART_MODEM_CTRL_REG_DTR	(1<<0)
120 
121 #define CDNC_UART_MODEM_STAT_REG 0x28
122 #define CDNC_UART_MODEM_STAT_REG_FCMS	(1<<8)	/* flow control mode (rw) */
123 #define CDNC_UART_MODEM_STAT_REG_DCD	(1<<7)
124 #define CDNC_UART_MODEM_STAT_REG_RI	(1<<6)
125 #define CDNC_UART_MODEM_STAT_REG_DSR	(1<<5)
126 #define CDNC_UART_MODEM_STAT_REG_CTS	(1<<4)
127 #define CDNC_UART_MODEM_STAT_REG_DDCD	(1<<3)	/* change in DCD (w1tc) */
128 #define CDNC_UART_MODEM_STAT_REG_TERI	(1<<2)	/* trail edge ring (w1tc) */
129 #define CDNC_UART_MODEM_STAT_REG_DDSR	(1<<1)	/* change in DSR (w1tc) */
130 #define CDNC_UART_MODEM_STAT_REG_DCTS	(1<<0)	/* change in CTS (w1tc) */
131 
132 #define CDNC_UART_CHAN_STAT_REG	0x2C		/* Channel status register. */
133 #define CDNC_UART_CHAN_STAT_REG_TXNRLYFUL (1<<14) /* tx "nearly" full */
134 #define CDNC_UART_CHAN_STAT_REG_TXTRIG	(1<<13)
135 #define CDNC_UART_CHAN_STAT_REG_FDELT	(1<<12)
136 #define CDNC_UART_CHAN_STAT_REG_TXACTIVE (1<<11)
137 #define CDNC_UART_CHAN_STAT_REG_RXACTIVE (1<<10)
138 #define CDNC_UART_CHAN_STAT_REG_TXFULL	(1<<4)
139 #define CDNC_UART_CHAN_STAT_REG_TXEMPTY	(1<<3)
140 #define CDNC_UART_CHAN_STAT_REG_RXEMPTY	(1<<1)
141 #define CDNC_UART_CHAN_STAT_REG_RXTRIG	(1<<0)
142 
143 #define CDNC_UART_FIFO		0x30		/* Data FIFO (tx and rx) */
144 #define CDNC_UART_BAUDDIV_REG	0x34
145 #define CDNC_UART_FLOWDEL_REG	0x38
146 #define CDNC_UART_TX_WATER_REG	0x44
147 
148 
149 /*
150  * Low-level UART interface.
151  */
152 static int cdnc_uart_probe(struct uart_bas *bas);
153 static void cdnc_uart_init(struct uart_bas *bas, int, int, int, int);
154 static void cdnc_uart_term(struct uart_bas *bas);
155 static void cdnc_uart_putc(struct uart_bas *bas, int);
156 static int cdnc_uart_rxready(struct uart_bas *bas);
157 static int cdnc_uart_getc(struct uart_bas *bas, struct mtx *mtx);
158 
159 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
160 
161 static struct uart_ops cdnc_uart_ops = {
162 	.probe = cdnc_uart_probe,
163 	.init = cdnc_uart_init,
164 	.term = cdnc_uart_term,
165 	.putc = cdnc_uart_putc,
166 	.rxready = cdnc_uart_rxready,
167 	.getc = cdnc_uart_getc,
168 };
169 
170 #define	SIGCHG(c, i, s, d)				\
171 	if (c) {					\
172 		i |= (i & s) ? s : s | d;		\
173 	} else {					\
174 		i = (i & s) ? (i & ~s) | d : i;		\
175 	}
176 
177 static int
178 cdnc_uart_probe(struct uart_bas *bas)
179 {
180 
181 	return (0);
182 }
183 
184 static int
185 cdnc_uart_set_baud(struct uart_bas *bas, int baudrate)
186 {
187 	uint32_t baudgen, bauddiv;
188 	uint32_t best_bauddiv, best_baudgen, best_error;
189 	uint32_t baud_out, err;
190 
191 	best_bauddiv = 0;
192 	best_baudgen = 0;
193 	best_error = ~0;
194 
195 	/* Try all possible bauddiv values and pick best match. */
196 	for (bauddiv = 4; bauddiv <= 255; bauddiv++) {
197 		baudgen = (bas->rclk + (baudrate * (bauddiv + 1)) / 2) /
198 			(baudrate * (bauddiv + 1));
199 		if (baudgen < 1 || baudgen > 0xffff)
200 			continue;
201 
202 		baud_out = bas->rclk / (baudgen * (bauddiv + 1));
203 		err = baud_out > baudrate ?
204 			baud_out - baudrate : baudrate - baud_out;
205 
206 		if (err < best_error) {
207 			best_error = err;
208 			best_bauddiv = bauddiv;
209 			best_baudgen = baudgen;
210 		}
211 	}
212 
213 	if (best_bauddiv > 0) {
214 		WR4(bas, CDNC_UART_BAUDDIV_REG, best_bauddiv);
215 		WR4(bas, CDNC_UART_BAUDGEN_REG, best_baudgen);
216 		return (0);
217 	} else
218 		return (-1); /* out of range */
219 }
220 
221 static int
222 cdnc_uart_set_params(struct uart_bas *bas, int baudrate, int databits,
223 		      int stopbits, int parity)
224 {
225 	uint32_t mode_reg_value = 0;
226 
227 	switch (databits) {
228 	case 6:
229 		mode_reg_value |= CDNC_UART_MODE_REG_6BIT;
230 		break;
231 	case 7:
232 		mode_reg_value |= CDNC_UART_MODE_REG_7BIT;
233 		break;
234 	case 8:
235 	default:
236 		mode_reg_value |= CDNC_UART_MODE_REG_8BIT;
237 		break;
238 	}
239 
240 	if (stopbits == 2)
241 		mode_reg_value |= CDNC_UART_MODE_REG_STOP2;
242 
243 	switch (parity) {
244 	case UART_PARITY_MARK:
245 		mode_reg_value |= CDNC_UART_MODE_REG_PAR_MARK;
246 		break;
247 	case UART_PARITY_SPACE:
248 		mode_reg_value |= CDNC_UART_MODE_REG_PAR_SPACE;
249 		break;
250 	case UART_PARITY_ODD:
251 		mode_reg_value |= CDNC_UART_MODE_REG_PAR_ODD;
252 		break;
253 	case UART_PARITY_EVEN:
254 		mode_reg_value |= CDNC_UART_MODE_REG_PAR_EVEN;
255 		break;
256 	case UART_PARITY_NONE:
257 	default:
258 		mode_reg_value |= CDNC_UART_MODE_REG_PAR_NONE;
259 		break;
260 	}
261 
262 	WR4(bas, CDNC_UART_MODE_REG, mode_reg_value);
263 
264 	if (baudrate > 0 && cdnc_uart_set_baud(bas, baudrate) < 0)
265 		return (EINVAL);
266 
267 	return(0);
268 }
269 
270 static void
271 cdnc_uart_hw_init(struct uart_bas *bas)
272 {
273 
274 	/* Reset RX and TX. */
275 	WR4(bas, CDNC_UART_CTRL_REG,
276 	    CDNC_UART_CTRL_REG_RXRST | CDNC_UART_CTRL_REG_TXRST);
277 
278 	/* Interrupts all off. */
279 	WR4(bas, CDNC_UART_IDIS_REG, CDNC_UART_INT_ALL);
280 	WR4(bas, CDNC_UART_ISTAT_REG, CDNC_UART_INT_ALL);
281 
282 	/* Clear delta bits. */
283 	WR4(bas, CDNC_UART_MODEM_STAT_REG,
284 	    CDNC_UART_MODEM_STAT_REG_DDCD | CDNC_UART_MODEM_STAT_REG_TERI |
285 	    CDNC_UART_MODEM_STAT_REG_DDSR | CDNC_UART_MODEM_STAT_REG_DCTS);
286 
287 	/* RX FIFO water level, stale timeout */
288 	WR4(bas, CDNC_UART_RX_WATER_REG, UART_FIFO_SIZE/2);
289 	WR4(bas, CDNC_UART_RX_TIMEO_REG, 10);
290 
291 	/* TX FIFO water level (not used.) */
292 	WR4(bas, CDNC_UART_TX_WATER_REG, UART_FIFO_SIZE/2);
293 
294 	/* Bring RX and TX online. */
295 	WR4(bas, CDNC_UART_CTRL_REG,
296 	    CDNC_UART_CTRL_REG_RX_EN | CDNC_UART_CTRL_REG_TX_EN |
297 	    CDNC_UART_CTRL_REG_TORST | CDNC_UART_CTRL_REG_STOPBRK);
298 
299 	/* Set DTR and RTS. */
300 	WR4(bas, CDNC_UART_MODEM_CTRL_REG, CDNC_UART_MODEM_CTRL_REG_DTR |
301 	    CDNC_UART_MODEM_CTRL_REG_RTS);
302 }
303 
304 /*
305  * Initialize this device for use as a console.
306  */
307 static void
308 cdnc_uart_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
309 	      int parity)
310 {
311 
312 	/* Initialize hardware. */
313 	cdnc_uart_hw_init(bas);
314 
315 	/* Set baudrate, parameters. */
316 	(void)cdnc_uart_set_params(bas, baudrate, databits, stopbits, parity);
317 }
318 
319 /*
320  * Free resources now that we're no longer the console.  This appears to
321  * be never called, and I'm unsure quite what to do if I am called.
322  */
323 static void
324 cdnc_uart_term(struct uart_bas *bas)
325 {
326 
327 	/* XXX */
328 }
329 
330 /*
331  * Put a character of console output (so we do it here polling rather than
332  * interrutp driven).
333  */
334 static void
335 cdnc_uart_putc(struct uart_bas *bas, int c)
336 {
337 
338 	/* Wait for room. */
339 	while ((RD4(bas,CDNC_UART_CHAN_STAT_REG) &
340 		CDNC_UART_CHAN_STAT_REG_TXFULL) != 0)
341 		;
342 
343 	WR4(bas, CDNC_UART_FIFO, c);
344 
345 	while ((RD4(bas,CDNC_UART_CHAN_STAT_REG) &
346 		CDNC_UART_CHAN_STAT_REG_TXEMPTY) == 0)
347 		;
348 }
349 
350 /*
351  * Check for a character available.
352  */
353 static int
354 cdnc_uart_rxready(struct uart_bas *bas)
355 {
356 
357 	return ((RD4(bas, CDNC_UART_CHAN_STAT_REG) &
358 		 CDNC_UART_CHAN_STAT_REG_RXEMPTY) == 0);
359 }
360 
361 /*
362  * Block waiting for a character.
363  */
364 static int
365 cdnc_uart_getc(struct uart_bas *bas, struct mtx *mtx)
366 {
367 	int c;
368 
369 	uart_lock(mtx);
370 
371 	while ((RD4(bas, CDNC_UART_CHAN_STAT_REG) &
372 		CDNC_UART_CHAN_STAT_REG_RXEMPTY) != 0) {
373 		uart_unlock(mtx);
374 		DELAY(4);
375 		uart_lock(mtx);
376 	}
377 
378 	c = RD4(bas, CDNC_UART_FIFO);
379 
380 	uart_unlock(mtx);
381 
382 	c &= 0xff;
383 	return (c);
384 }
385 
386 /*****************************************************************************/
387 /*
388  * High-level UART interface.
389  */
390 
391 static int cdnc_uart_bus_probe(struct uart_softc *sc);
392 static int cdnc_uart_bus_attach(struct uart_softc *sc);
393 static int cdnc_uart_bus_flush(struct uart_softc *, int);
394 static int cdnc_uart_bus_getsig(struct uart_softc *);
395 static int cdnc_uart_bus_ioctl(struct uart_softc *, int, intptr_t);
396 static int cdnc_uart_bus_ipend(struct uart_softc *);
397 static int cdnc_uart_bus_param(struct uart_softc *, int, int, int, int);
398 static int cdnc_uart_bus_receive(struct uart_softc *);
399 static int cdnc_uart_bus_setsig(struct uart_softc *, int);
400 static int cdnc_uart_bus_transmit(struct uart_softc *);
401 static void cdnc_uart_bus_grab(struct uart_softc *);
402 static void cdnc_uart_bus_ungrab(struct uart_softc *);
403 
404 static kobj_method_t cdnc_uart_bus_methods[] = {
405 	KOBJMETHOD(uart_probe,		cdnc_uart_bus_probe),
406 	KOBJMETHOD(uart_attach, 	cdnc_uart_bus_attach),
407 	KOBJMETHOD(uart_flush,		cdnc_uart_bus_flush),
408 	KOBJMETHOD(uart_getsig,		cdnc_uart_bus_getsig),
409 	KOBJMETHOD(uart_ioctl,		cdnc_uart_bus_ioctl),
410 	KOBJMETHOD(uart_ipend,		cdnc_uart_bus_ipend),
411 	KOBJMETHOD(uart_param,		cdnc_uart_bus_param),
412 	KOBJMETHOD(uart_receive,	cdnc_uart_bus_receive),
413 	KOBJMETHOD(uart_setsig,		cdnc_uart_bus_setsig),
414 	KOBJMETHOD(uart_transmit,	cdnc_uart_bus_transmit),
415 	KOBJMETHOD(uart_grab,		cdnc_uart_bus_grab),
416 	KOBJMETHOD(uart_ungrab,		cdnc_uart_bus_ungrab),
417 
418 	KOBJMETHOD_END
419 };
420 
421 int
422 cdnc_uart_bus_probe(struct uart_softc *sc)
423 {
424 
425 	sc->sc_txfifosz = UART_FIFO_SIZE;
426 	sc->sc_rxfifosz = UART_FIFO_SIZE;
427 	sc->sc_hwiflow = 0;
428 	sc->sc_hwoflow = 0;
429 
430 	device_set_desc(sc->sc_dev, "Cadence UART");
431 
432 	return (0);
433 }
434 
435 static int
436 cdnc_uart_bus_attach(struct uart_softc *sc)
437 {
438 	struct uart_bas *bas = &sc->sc_bas;
439 	struct uart_devinfo *di;
440 
441 	if (sc->sc_sysdev != NULL) {
442 		di = sc->sc_sysdev;
443 		(void)cdnc_uart_set_params(bas, di->baudrate, di->databits,
444 					   di->stopbits, di->parity);
445 	} else
446 		cdnc_uart_hw_init(bas);
447 
448 	(void)cdnc_uart_bus_getsig(sc);
449 
450 	/* Enable interrupts. */
451 	WR4(bas, CDNC_UART_IEN_REG,
452 	    CDNC_UART_INT_RXTRIG | CDNC_UART_INT_RXTMOUT |
453 	    CDNC_UART_INT_TXOVR | CDNC_UART_INT_RXOVR |
454 	    CDNC_UART_INT_DMSI);
455 
456 	return (0);
457 }
458 
459 static int
460 cdnc_uart_bus_transmit(struct uart_softc *sc)
461 {
462 	int i;
463 	struct uart_bas *bas = &sc->sc_bas;
464 
465 	uart_lock(sc->sc_hwmtx);
466 
467 	/* Clear sticky TXEMPTY status bit. */
468 	WR4(bas, CDNC_UART_ISTAT_REG, CDNC_UART_INT_TXEMPTY);
469 
470 	for (i = 0; i < sc->sc_txdatasz; i++)
471 		WR4(bas, CDNC_UART_FIFO, sc->sc_txbuf[i]);
472 
473 	/* Enable TX empty interrupt. */
474 	WR4(bas, CDNC_UART_IEN_REG, CDNC_UART_INT_TXEMPTY);
475 	sc->sc_txbusy = 1;
476 
477 	uart_unlock(sc->sc_hwmtx);
478 
479 	return (0);
480 }
481 
482 static int
483 cdnc_uart_bus_setsig(struct uart_softc *sc, int sig)
484 {
485 	struct uart_bas *bas = &sc->sc_bas;
486 	uint32_t new, old, modem_ctrl;
487 
488 	do {
489 		old = sc->sc_hwsig;
490 		new = old;
491 		if (sig & SER_DDTR) {
492 			SIGCHG(sig & SER_DTR, new, SER_DTR, SER_DDTR);
493 		}
494 		if (sig & SER_DRTS) {
495 			SIGCHG(sig & SER_RTS, new, SER_RTS, SER_DRTS);
496 		}
497 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
498 	uart_lock(sc->sc_hwmtx);
499 	modem_ctrl = RD4(bas, CDNC_UART_MODEM_CTRL_REG) &
500 		~(CDNC_UART_MODEM_CTRL_REG_DTR | CDNC_UART_MODEM_CTRL_REG_RTS);
501 	if ((new & SER_DTR) != 0)
502 		modem_ctrl |= CDNC_UART_MODEM_CTRL_REG_DTR;
503 	if ((new & SER_RTS) != 0)
504 		modem_ctrl |= CDNC_UART_MODEM_CTRL_REG_RTS;
505 	WR4(bas, CDNC_UART_MODEM_CTRL_REG, modem_ctrl);
506 
507 	uart_unlock(sc->sc_hwmtx);
508 	return (0);
509 }
510 
511 static int
512 cdnc_uart_bus_receive(struct uart_softc *sc)
513 {
514 	struct uart_bas *bas = &sc->sc_bas;
515 	uint32_t status;
516 	int c, c_status = 0;
517 
518 	uart_lock(sc->sc_hwmtx);
519 
520 	/* Check for parity or framing errors and clear the status bits. */
521 	status = RD4(bas, CDNC_UART_ISTAT_REG);
522 	if ((status & (CDNC_UART_INT_FRAMING | CDNC_UART_INT_PARITY)) != 0) {
523 		WR4(bas, CDNC_UART_ISTAT_REG,
524 		    status & (CDNC_UART_INT_FRAMING | CDNC_UART_INT_PARITY));
525 		if ((status & CDNC_UART_INT_PARITY) != 0)
526 			c_status |= UART_STAT_PARERR;
527 		if ((status & CDNC_UART_INT_FRAMING) != 0)
528 			c_status |= UART_STAT_FRAMERR;
529 	}
530 
531 	while ((RD4(bas, CDNC_UART_CHAN_STAT_REG) &
532 		CDNC_UART_CHAN_STAT_REG_RXEMPTY) == 0) {
533 		c = RD4(bas, CDNC_UART_FIFO) & 0xff;
534 #ifdef KDB
535 		/* Detect break and drop into debugger. */
536 		if (c == 0 && (c_status & UART_STAT_FRAMERR) != 0 &&
537 		    sc->sc_sysdev != NULL &&
538 		    sc->sc_sysdev->type == UART_DEV_CONSOLE) {
539 			kdb_break();
540 			WR4(bas, CDNC_UART_ISTAT_REG, CDNC_UART_INT_FRAMING);
541 		}
542 #endif
543 		uart_rx_put(sc, c | c_status);
544 	}
545 
546 	uart_unlock(sc->sc_hwmtx);
547 
548 	return (0);
549 }
550 
551 static int
552 cdnc_uart_bus_param(struct uart_softc *sc, int baudrate, int databits,
553 		   int stopbits, int parity)
554 {
555 
556 	return (cdnc_uart_set_params(&sc->sc_bas, baudrate,
557 				    databits, stopbits, parity));
558 }
559 
560 static int
561 cdnc_uart_bus_ipend(struct uart_softc *sc)
562 {
563 	int ipend = 0;
564 	struct uart_bas *bas = &sc->sc_bas;
565 	uint32_t istatus;
566 
567 	uart_lock(sc->sc_hwmtx);
568 
569 	istatus = RD4(bas, CDNC_UART_ISTAT_REG);
570 
571 	/* Clear interrupt bits. */
572 	WR4(bas, CDNC_UART_ISTAT_REG, istatus &
573 	    (CDNC_UART_INT_RXTRIG | CDNC_UART_INT_RXTMOUT |
574 	     CDNC_UART_INT_TXOVR | CDNC_UART_INT_RXOVR |
575 	     CDNC_UART_INT_TXEMPTY | CDNC_UART_INT_DMSI));
576 
577 	/* Receive data. */
578 	if ((istatus & (CDNC_UART_INT_RXTRIG | CDNC_UART_INT_RXTMOUT)) != 0)
579 		ipend |= SER_INT_RXREADY;
580 
581 	/* Transmit fifo empty. */
582 	if (sc->sc_txbusy && (istatus & CDNC_UART_INT_TXEMPTY) != 0) {
583 		/* disable txempty interrupt. */
584 		WR4(bas, CDNC_UART_IDIS_REG, CDNC_UART_INT_TXEMPTY);
585 		ipend |= SER_INT_TXIDLE;
586 	}
587 
588 	/* TX Overflow. */
589 	if ((istatus & CDNC_UART_INT_TXOVR) != 0)
590 		ipend |= SER_INT_OVERRUN;
591 
592 	/* RX Overflow. */
593 	if ((istatus & CDNC_UART_INT_RXOVR) != 0)
594 		ipend |= SER_INT_OVERRUN;
595 
596 	/* Modem signal change. */
597 	if ((istatus & CDNC_UART_INT_DMSI) != 0) {
598 		WR4(bas, CDNC_UART_MODEM_STAT_REG,
599 		    CDNC_UART_MODEM_STAT_REG_DDCD |
600 		    CDNC_UART_MODEM_STAT_REG_TERI |
601 		    CDNC_UART_MODEM_STAT_REG_DDSR |
602 		    CDNC_UART_MODEM_STAT_REG_DCTS);
603 		ipend |= SER_INT_SIGCHG;
604 	}
605 
606 	uart_unlock(sc->sc_hwmtx);
607 	return (ipend);
608 }
609 
610 static int
611 cdnc_uart_bus_flush(struct uart_softc *sc, int what)
612 {
613 
614 	return (0);
615 }
616 
617 static int
618 cdnc_uart_bus_getsig(struct uart_softc *sc)
619 {
620 	struct uart_bas *bas = &sc->sc_bas;
621 	uint32_t new, old, sig;
622 	uint8_t modem_status;
623 
624 	do {
625 		old = sc->sc_hwsig;
626 		sig = old;
627 		uart_lock(sc->sc_hwmtx);
628 		modem_status = RD4(bas, CDNC_UART_MODEM_STAT_REG);
629 		uart_unlock(sc->sc_hwmtx);
630 		SIGCHG(modem_status & CDNC_UART_MODEM_STAT_REG_DSR,
631 		       sig, SER_DSR, SER_DDSR);
632 		SIGCHG(modem_status & CDNC_UART_MODEM_STAT_REG_CTS,
633 		       sig, SER_CTS, SER_DCTS);
634 		SIGCHG(modem_status & CDNC_UART_MODEM_STAT_REG_DCD,
635 		       sig, SER_DCD, SER_DDCD);
636 		SIGCHG(modem_status & CDNC_UART_MODEM_STAT_REG_RI,
637 		       sig, SER_RI,  SER_DRI);
638 		new = sig & ~SER_MASK_DELTA;
639 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
640 	return (sig);
641 }
642 
643 static int
644 cdnc_uart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
645 {
646 	struct uart_bas *bas = &sc->sc_bas;
647 	uint32_t uart_ctrl, modem_ctrl;
648 	int error = 0;
649 
650 	uart_lock(sc->sc_hwmtx);
651 
652 	switch (request) {
653 	case UART_IOCTL_BREAK:
654 		uart_ctrl = RD4(bas, CDNC_UART_CTRL_REG);
655 		if (data) {
656 			uart_ctrl |= CDNC_UART_CTRL_REG_STARTBRK;
657 			uart_ctrl &= ~CDNC_UART_CTRL_REG_STOPBRK;
658 		} else {
659 			uart_ctrl |= CDNC_UART_CTRL_REG_STOPBRK;
660 			uart_ctrl &= ~CDNC_UART_CTRL_REG_STARTBRK;
661 		}
662 		WR4(bas, CDNC_UART_CTRL_REG, uart_ctrl);
663 		break;
664 	case UART_IOCTL_IFLOW:
665 		modem_ctrl = RD4(bas, CDNC_UART_MODEM_CTRL_REG);
666 		if (data)
667 			modem_ctrl |= CDNC_UART_MODEM_CTRL_REG_RTS;
668 		else
669 			modem_ctrl &= ~CDNC_UART_MODEM_CTRL_REG_RTS;
670 		WR4(bas, CDNC_UART_MODEM_CTRL_REG, modem_ctrl);
671 		break;
672 	default:
673 		error = EINVAL;
674 		break;
675 	}
676 
677 	uart_unlock(sc->sc_hwmtx);
678 
679 	return (error);
680 }
681 
682 static void
683 cdnc_uart_bus_grab(struct uart_softc *sc)
684 {
685 
686 	/* Enable interrupts. */
687 	WR4(&sc->sc_bas, CDNC_UART_IEN_REG,
688 	    CDNC_UART_INT_TXOVR | CDNC_UART_INT_RXOVR |
689 	    CDNC_UART_INT_DMSI);
690 }
691 
692 static void
693 cdnc_uart_bus_ungrab(struct uart_softc *sc)
694 {
695 
696 	/* Enable interrupts. */
697 	WR4(&sc->sc_bas, CDNC_UART_IEN_REG,
698 	    CDNC_UART_INT_RXTRIG | CDNC_UART_INT_RXTMOUT |
699 	    CDNC_UART_INT_TXOVR | CDNC_UART_INT_RXOVR |
700 	    CDNC_UART_INT_DMSI);
701 }
702 
703 struct uart_class uart_cdnc_class = {
704 	"cdnc_uart",
705 	cdnc_uart_bus_methods,
706 	sizeof(struct uart_softc),
707 	.uc_ops = &cdnc_uart_ops,
708 	.uc_range = 8
709 };
710