xref: /freebsd/sys/dev/uart/uart_dev_mvebu.c (revision 202890922e31382f9b11bf5f78d3dd0350d69dc1)
1 /*-
2  * Copyright (c) 2017 Semihalf.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25 */
26 
27 #include <sys/param.h>
28 #include <sys/bus.h>
29 #include <sys/conf.h>
30 #include <sys/kernel.h>
31 #include <sys/sysctl.h>
32 #include <sys/systm.h>
33 
34 #include <machine/bus.h>
35 
36 #include <dev/ofw/ofw_bus_subr.h>
37 #include <dev/uart/uart.h>
38 #include <dev/uart/uart_bus.h>
39 #include <dev/uart/uart_cpu.h>
40 #include <dev/uart/uart_cpu_fdt.h>
41 
42 #include "uart_if.h"
43 
44 #define	UART_RBR		0x00		/* Receiver Buffer */
45 #define	RBR_BRK_DET		(1 << 15)	/* Break Detect */
46 #define	RBR_FRM_ERR_DET		(1 << 14)	/* Frame Error Detect */
47 #define	RBR_PAR_ERR_DET		(1 << 13)	/* Parity Error Detect */
48 #define	RBR_OVR_ERR_DET		(1 << 12)	/* Overrun Error */
49 
50 #define	UART_TSH		0x04		/* Transmitter Holding Register */
51 
52 #define	UART_CTRL		0x08		/* Control Register */
53 #define	CTRL_SOFT_RST		(1 << 31)	/* Soft Reset */
54 #define	CTRL_TX_FIFO_RST	(1 << 15)	/* TX FIFO Reset */
55 #define	CTRL_RX_FIFO_RST	(1 << 14)	/* RX FIFO Reset */
56 #define	CTRL_ST_MIRR_EN		(1 << 13)	/* Status Mirror Enable */
57 #define	CTRL_LPBK_EN		(1 << 12)	/* Loopback Mode Enable */
58 #define	CTRL_SND_BRK_SEQ	(1 << 11)	/* Send Break Sequence */
59 #define	CTRL_PAR_EN		(1 << 10)	/* Parity Enable */
60 #define	CTRL_TWO_STOP		(1 << 9)	/* Two Stop Bits */
61 #define	CTRL_TX_HALF_INT	(1 << 8)	/* TX Half-Full Interrupt Enable */
62 #define	CTRL_RX_HALF_INT	(1 << 7)	/* RX Half-Full Interrupt Enable */
63 #define	CTRL_TX_EMPT_INT	(1 << 6)	/* TX Empty Interrupt Enable */
64 #define	CTRL_TX_RDY_INT		(1 << 5)	/* TX Ready Interrupt Enable */
65 #define	CTRL_RX_RDY_INT		(1 << 4)	/* RX Ready Interrupt Enable */
66 #define	CTRL_BRK_DET_INT	(1 << 3)	/* Break Detect Interrupt Enable */
67 #define	CTRL_FRM_ERR_INT	(1 << 2)	/* Frame Error Interrupt Enable */
68 #define	CTRL_PAR_ERR_INT	(1 << 1)	/* Parity Error Interrupt Enable */
69 #define	CTRL_OVR_ERR_INT	(1 << 0)	/* Overrun Error Interrupt Enable */
70 #define	CTRL_INTR_MASK		0x1ff
71 #define	CTRL_TX_IDLE_INT	CTRL_TX_RDY_INT
72 #define	CTRL_IPEND_MASK		(CTRL_OVR_ERR_INT | CTRL_BRK_DET_INT | \
73     CTRL_RX_RDY_INT)
74 
75 #define	UART_STAT		0x0c		/* Status Register */
76 #define	STAT_TX_FIFO_EMPT	(1 << 13)	/* TX FIFO Empty */
77 #define	STAT_RX_FIFO_EMPT	(1 << 12)	/* RX FIFO Empty */
78 #define	STAT_TX_FIFO_FULL	(1 << 11)	/* TX FIFO Full */
79 #define	STAT_TX_FIFO_HALF	(1 << 10)	/* TX FIFO Half Full */
80 #define	STAT_RX_TOGL		(1 << 9)	/* RX Toogled */
81 #define	STAT_RX_FIFO_FULL	(1 << 8)	/* RX FIFO Full */
82 #define	STAT_RX_FIFO_HALF	(1 << 7)	/* RX FIFO Half Full */
83 #define	STAT_TX_EMPT		(1 << 6)	/* TX Empty */
84 #define	STAT_TX_RDY		(1 << 5)	/* TX Ready */
85 #define	STAT_RX_RDY		(1 << 4)	/* RX Ready */
86 #define	STAT_BRK_DET		(1 << 3)	/* Break Detect */
87 #define	STAT_FRM_ERR		(1 << 2)	/* Frame Error */
88 #define	STAT_PAR_ERR		(1 << 1)	/* Parity Error */
89 #define	STAT_OVR_ERR		(1 << 0)	/* Overrun Error */
90 #define	STAT_TX_IDLE		STAT_TX_RDY
91 #define	STAT_TRANS_MASK		(STAT_OVR_ERR | STAT_BRK_DET | STAT_RX_RDY)
92 
93 #define	UART_CCR		0x10		/* Clock Control Register */
94 #define	CCR_BAUDRATE_DIV	0x3ff		/* Baud Rate Divisor */
95 
96 #define	DEFAULT_RCLK		25804800
97 #define	ONE_FRAME_TIME		87
98 
99 #define	stat_ipend_trans(i) (			\
100 	    (i & STAT_OVR_ERR) << 16 |		\
101 	    (i & STAT_BRK_DET) << 14 |		\
102 	    (i & STAT_RX_RDY) << 14)
103 
104 /*
105  * For debugging purposes
106  */
107 #if CHECK_EARLY_PRINTF(mvebu)
108 static void
uart_mvebu_early_putc(int c)109 uart_mvebu_early_putc(int c)
110 {
111 	volatile uint32_t *tsh;
112 	volatile uint32_t *stat;
113 
114 	tsh = (uint32_t *)(socdev_va + UART_REG_OFFSET + UART_TSH);
115 	stat = (uint32_t *)(socdev_va + UART_REG_OFFSET + UART_STAT);
116 
117 	while(!(*stat & STAT_TX_RDY))
118 		;
119 
120 	*tsh = c & 0xff;
121 }
122 
123 early_putc_t *early_putc = uart_mvebu_early_putc;
124 #endif
125 
126 /*
127  * Low-level UART interface.
128  */
129 static int uart_mvebu_probe(struct uart_bas *);
130 static void uart_mvebu_init(struct uart_bas *, int, int, int, int);
131 static void uart_mvebu_putc(struct uart_bas *, int);
132 static int uart_mvebu_rxready(struct uart_bas *);
133 static int uart_mvebu_getc(struct uart_bas *, struct mtx *);
134 
135 static struct uart_ops uart_mvebu_ops = {
136 	.probe = uart_mvebu_probe,
137 	.init = uart_mvebu_init,
138 	.term = NULL,
139 	.putc = uart_mvebu_putc,
140 	.rxready = uart_mvebu_rxready,
141 	.getc = uart_mvebu_getc,
142 };
143 
144 static int
uart_mvebu_probe(struct uart_bas * bas)145 uart_mvebu_probe(struct uart_bas *bas)
146 {
147 
148 	return (0);
149 }
150 
151 static int
uart_mvebu_divisor(int rclk,int baudrate)152 uart_mvebu_divisor(int rclk, int baudrate)
153 {
154 	int divisor;
155 
156 	if (baudrate == 0)
157 		return (0);
158 
159 	divisor = (rclk >> 4) / baudrate;
160 	if (divisor <= 1 || divisor >= 1024)
161 		return (0);
162 
163 	return (divisor);
164 }
165 
166 static int
uart_mvebu_param(struct uart_bas * bas,int baudrate,int databits,int stopbits,int parity)167 uart_mvebu_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
168     int parity)
169 {
170 	uint32_t ctrl = 0;
171 	uint32_t ccr;
172 	int divisor, ret = 0;
173 
174 	/* Reset UART */
175 	ctrl = uart_getreg(bas, UART_CTRL);
176 	uart_setreg(bas, UART_CTRL, ctrl | CTRL_TX_FIFO_RST | CTRL_RX_FIFO_RST |
177 	    CTRL_LPBK_EN);
178 	uart_barrier(bas);
179 
180 	switch (stopbits) {
181 	case 2:
182 		ctrl |= CTRL_TWO_STOP;
183 		break;
184 	case 1:
185 	default:
186 		ctrl &=~ CTRL_TWO_STOP;
187 	}
188 
189 	switch (parity) {
190 	case 3: /* Even parity bit */
191 		ctrl |= CTRL_PAR_EN;
192 		break;
193 	default:
194 		ctrl &=~ CTRL_PAR_EN;
195 	}
196 
197 	/* Set baudrate. */
198 	if (baudrate > 0) {
199 		divisor = uart_mvebu_divisor(bas->rclk, baudrate);
200 		if (divisor == 0) {
201 			ret = EINVAL;
202 		} else {
203 			ccr = uart_getreg(bas, UART_CCR);
204 			ccr &=~CCR_BAUDRATE_DIV;
205 
206 			uart_setreg(bas, UART_CCR, ccr | divisor);
207 			uart_barrier(bas);
208 		}
209 	}
210 
211 	/* Set mirroring of status bits */
212 	ctrl |= CTRL_ST_MIRR_EN;
213 
214 	uart_setreg(bas, UART_CTRL, ctrl);
215 	uart_barrier(bas);
216 
217 	return (ret);
218 }
219 
220 static void
uart_mvebu_init(struct uart_bas * bas,int baudrate,int databits,int stopbits,int parity)221 uart_mvebu_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
222     int parity)
223 {
224 	/* Set default frequency */
225 	bas->rclk = DEFAULT_RCLK;
226 
227 	/* Mask interrupts */
228 	uart_setreg(bas, UART_CTRL, uart_getreg(bas, UART_CTRL) &
229 	    ~CTRL_INTR_MASK);
230 	uart_barrier(bas);
231 
232 	uart_mvebu_param(bas, baudrate, databits, stopbits, parity);
233 }
234 
235 static void
uart_mvebu_putc(struct uart_bas * bas,int c)236 uart_mvebu_putc(struct uart_bas *bas, int c)
237 {
238 	while (uart_getreg(bas, UART_STAT) & STAT_TX_FIFO_FULL)
239 		;
240 	uart_setreg(bas, UART_TSH, c & 0xff);
241 }
242 
243 static int
uart_mvebu_rxready(struct uart_bas * bas)244 uart_mvebu_rxready(struct uart_bas *bas)
245 {
246 	if (uart_getreg(bas, UART_STAT) & STAT_RX_RDY)
247 		return 1;
248 	return 0;
249 }
250 
251 static int
uart_mvebu_getc(struct uart_bas * bas,struct mtx * hwmtx)252 uart_mvebu_getc(struct uart_bas *bas, struct mtx *hwmtx)
253 {
254 	int c;
255 
256 	uart_lock(hwmtx);
257 	while (!(uart_getreg(bas, UART_STAT) & STAT_RX_RDY))
258 		;
259 
260 	c = uart_getreg(bas, UART_RBR) & 0xff;
261 	uart_unlock(hwmtx);
262 
263 	return c;
264 }
265 
266 /*
267  * UART driver methods implementation.
268  */
269 struct uart_mvebu_softc {
270 	struct uart_softc base;
271 	uint16_t intrm;
272 };
273 
274 static int uart_mvebu_bus_attach(struct uart_softc *);
275 static int uart_mvebu_bus_detach(struct uart_softc *);
276 static int uart_mvebu_bus_flush(struct uart_softc *, int);
277 static int uart_mvebu_bus_getsig(struct uart_softc *);
278 static int uart_mvebu_bus_ioctl(struct uart_softc *, int, intptr_t);
279 static int uart_mvebu_bus_ipend(struct uart_softc *);
280 static int uart_mvebu_bus_param(struct uart_softc *, int, int, int, int);
281 static int uart_mvebu_bus_probe(struct uart_softc *);
282 static int uart_mvebu_bus_receive(struct uart_softc *);
283 static int uart_mvebu_bus_setsig(struct uart_softc *, int);
284 static int uart_mvebu_bus_transmit(struct uart_softc *);
285 static void uart_mvebu_bus_grab(struct uart_softc *);
286 static void uart_mvebu_bus_ungrab(struct uart_softc *);
287 
288 static kobj_method_t uart_mvebu_methods[] = {
289 	KOBJMETHOD(uart_attach,		uart_mvebu_bus_attach),
290 	KOBJMETHOD(uart_detach,		uart_mvebu_bus_detach),
291 	KOBJMETHOD(uart_flush,		uart_mvebu_bus_flush),
292 	KOBJMETHOD(uart_getsig,		uart_mvebu_bus_getsig),
293 	KOBJMETHOD(uart_ioctl,		uart_mvebu_bus_ioctl),
294 	KOBJMETHOD(uart_ipend,		uart_mvebu_bus_ipend),
295 	KOBJMETHOD(uart_param,		uart_mvebu_bus_param),
296 	KOBJMETHOD(uart_probe,		uart_mvebu_bus_probe),
297 	KOBJMETHOD(uart_receive,	uart_mvebu_bus_receive),
298 	KOBJMETHOD(uart_setsig,		uart_mvebu_bus_setsig),
299 	KOBJMETHOD(uart_transmit,	uart_mvebu_bus_transmit),
300 	KOBJMETHOD(uart_grab,		uart_mvebu_bus_grab),
301 	KOBJMETHOD(uart_ungrab,		uart_mvebu_bus_ungrab),
302 	{ 0, 0 }
303 };
304 
305 struct uart_class uart_mvebu_class = {
306 	"mvebu-uart",
307 	uart_mvebu_methods,
308 	sizeof(struct uart_mvebu_softc),
309 	.uc_ops = &uart_mvebu_ops,
310 	.uc_range = 0x14,
311 	.uc_rclk = DEFAULT_RCLK,
312 	.uc_rshift = 0,
313 	.uc_riowidth = 4
314 };
315 
316 static struct ofw_compat_data compat_data[] = {
317 	{"marvell,armada-3700-uart",	(uintptr_t)&uart_mvebu_class},
318 	{NULL,				(uintptr_t)NULL},
319 };
320 UART_FDT_CLASS_AND_DEVICE(compat_data);
321 
322 static int
uart_mvebu_bus_attach(struct uart_softc * sc)323 uart_mvebu_bus_attach(struct uart_softc *sc)
324 {
325 	struct uart_bas *bas;
326 	int ctrl;
327 
328 	bas = &sc->sc_bas;
329 	uart_lock(sc->sc_hwmtx);
330 
331 	ctrl = uart_getreg(bas, UART_CTRL);
332 
333 	/* Enable interrupts */
334 	ctrl &=~ CTRL_INTR_MASK;
335 	ctrl |= CTRL_IPEND_MASK;
336 
337 	/* Set interrupts */
338 	uart_setreg(bas, UART_CTRL, ctrl);
339 	uart_barrier(bas);
340 
341 	uart_unlock(sc->sc_hwmtx);
342 
343 	return (0);
344 }
345 
346 static int
uart_mvebu_bus_detach(struct uart_softc * sc)347 uart_mvebu_bus_detach(struct uart_softc *sc)
348 {
349 
350 	return (0);
351 }
352 
353 static int
uart_mvebu_bus_flush(struct uart_softc * sc,int what)354 uart_mvebu_bus_flush(struct uart_softc *sc, int what)
355 {
356 	struct uart_bas *bas;
357 	int ctrl, ret = 0;
358 
359 	bas = &sc->sc_bas;
360 	uart_lock(sc->sc_hwmtx);
361 	ctrl = uart_getreg(bas, UART_CTRL);
362 
363 	switch (what) {
364 	case UART_FLUSH_RECEIVER:
365 		uart_setreg(bas, UART_CTRL, ctrl | CTRL_RX_FIFO_RST);
366 		uart_barrier(bas);
367 		break;
368 
369 	case UART_FLUSH_TRANSMITTER:
370 		uart_setreg(bas, UART_CTRL, ctrl | CTRL_TX_FIFO_RST);
371 		uart_barrier(bas);
372 		break;
373 
374 	default:
375 		ret = EINVAL;
376 		break;
377 	}
378 
379 	/* Back to normal operation */
380 	if (!ret) {
381 		uart_setreg(bas, UART_CTRL, ctrl);
382 		uart_barrier(bas);
383 	}
384 
385 	uart_unlock(sc->sc_hwmtx);
386 	return (ret);
387 }
388 
389 static int
uart_mvebu_bus_getsig(struct uart_softc * sc)390 uart_mvebu_bus_getsig(struct uart_softc *sc)
391 {
392 
393 	return (0);
394 }
395 
396 static int
uart_mvebu_bus_ioctl(struct uart_softc * sc,int request,intptr_t data)397 uart_mvebu_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
398 {
399 	struct uart_bas *bas;
400 	int ctrl, ret = 0;
401 	int divisor, baudrate;
402 
403 	bas = &sc->sc_bas;
404 	uart_lock(sc->sc_hwmtx);
405 	switch (request) {
406 	case UART_IOCTL_BREAK:
407 		ctrl = uart_getreg(bas, UART_CTRL);
408 		if (data)
409 			ctrl |= CTRL_SND_BRK_SEQ;
410 		else
411 			ctrl &=~ CTRL_SND_BRK_SEQ;
412 		uart_setreg(bas, UART_CTRL, ctrl);
413 		uart_barrier(bas);
414 		break;
415 
416 	case UART_IOCTL_BAUD:
417 		divisor = uart_getreg(bas, UART_CCR) & CCR_BAUDRATE_DIV;
418 		baudrate = bas->rclk/(divisor * 16);
419 		*(int *)data = baudrate;
420 		break;
421 
422 	default:
423 		ret = ENOTTY;
424 		break;
425 	}
426 	uart_unlock(sc->sc_hwmtx);
427 
428 	return (ret);
429 }
430 
431 static int
uart_mvebu_bus_ipend(struct uart_softc * sc)432 uart_mvebu_bus_ipend(struct uart_softc *sc)
433 {
434 	struct uart_bas *bas;
435 	int ipend, ctrl, ret = 0;
436 
437 	bas = &sc->sc_bas;
438 	uart_lock(sc->sc_hwmtx);
439 	ipend = uart_getreg(bas, UART_STAT);
440 	ctrl = uart_getreg(bas, UART_CTRL);
441 
442 	if (((ipend & STAT_TX_IDLE) == STAT_TX_IDLE) &&
443 	    (ctrl & CTRL_TX_IDLE_INT) == CTRL_TX_IDLE_INT) {
444 		/* Disable TX IDLE Interrupt generation */
445 		uart_setreg(bas, UART_CTRL, ctrl & ~CTRL_TX_IDLE_INT);
446 		uart_barrier(bas);
447 
448 		/* SER_INT_TXIDLE means empty TX FIFO. Wait until it cleans */
449 		while(!(uart_getreg(bas, UART_STAT) & STAT_TX_FIFO_EMPT))
450 			DELAY(ONE_FRAME_TIME/2);
451 
452 		ret |= SER_INT_TXIDLE;
453 	}
454 
455 	ret |= stat_ipend_trans(ipend & STAT_TRANS_MASK);
456 
457 	uart_unlock(sc->sc_hwmtx);
458 
459 	return (ret);
460 }
461 
462 static int
uart_mvebu_bus_param(struct uart_softc * sc,int baudrate,int databits,int stopbits,int parity)463 uart_mvebu_bus_param(struct uart_softc *sc, int baudrate, int databits,
464     int stopbits, int parity)
465 {
466 	int ret;
467 
468 	uart_lock(sc->sc_hwmtx);
469 	ret = uart_mvebu_param(&sc->sc_bas, baudrate, databits, stopbits, parity);
470 	uart_unlock(sc->sc_hwmtx);
471 
472 	return (ret);
473 }
474 
475 static int
uart_mvebu_bus_probe(struct uart_softc * sc)476 uart_mvebu_bus_probe(struct uart_softc *sc)
477 {
478 	if (!ofw_bus_status_okay(sc->sc_dev))
479 		return (ENXIO);
480 
481 	if (!ofw_bus_search_compatible(sc->sc_dev, compat_data)->ocd_data)
482 		return (ENXIO);
483 
484 	device_set_desc(sc->sc_dev, "Marvell Armada 3700 UART");
485 
486 	sc->sc_txfifosz = 32;
487 	sc->sc_rxfifosz = 64;
488 	sc->sc_hwiflow = 0;
489 	sc->sc_hwoflow = 0;
490 
491 	return (0);
492 }
493 
494 int
uart_mvebu_bus_receive(struct uart_softc * sc)495 uart_mvebu_bus_receive(struct uart_softc *sc)
496 {
497 	struct uart_bas *bas;
498 	uint32_t xc;
499 	int rx, er;
500 
501 	bas = &sc->sc_bas;
502 	uart_lock(sc->sc_hwmtx);
503 
504 	while (!(uart_getreg(bas, UART_STAT) & STAT_RX_FIFO_EMPT)) {
505 		if (uart_rx_full(sc)) {
506 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
507 			break;
508 		}
509 
510 		xc = uart_getreg(bas, UART_RBR);
511 		rx = xc & 0xff;
512 		er = xc & 0xf000;
513 		/*
514 		 * Formula which translates marvell error bits
515 		 * Only valid when CTRL_ST_MIRR_EN is set
516 		 */
517 		er = (er & RBR_BRK_DET) >> 7 |
518 		    (er & RBR_FRM_ERR_DET) >> 5 |
519 		    (er & RBR_PAR_ERR_DET) >> 2 |
520 		    (er & RBR_OVR_ERR_DET) >> 2;
521 
522 		uart_rx_put(sc, rx | er);
523 		uart_barrier(bas);
524 	}
525 	/*
526 	 * uart_if.m says that receive interrupt
527 	 * should be cleared, so we need to reset
528 	 * RX FIFO
529 	 */
530 
531 	if (!(uart_getreg(bas, UART_STAT) & STAT_RX_FIFO_EMPT)) {
532 		uart_mvebu_bus_flush(sc, UART_FLUSH_RECEIVER);
533 	}
534 
535 	uart_unlock(sc->sc_hwmtx);
536 	return (0);
537 }
538 
539 static int
uart_mvebu_bus_setsig(struct uart_softc * sc,int sig)540 uart_mvebu_bus_setsig(struct uart_softc *sc, int sig)
541 {
542 	/* Not supported by hardware */
543 	return (0);
544 }
545 
546 int
uart_mvebu_bus_transmit(struct uart_softc * sc)547 uart_mvebu_bus_transmit(struct uart_softc *sc)
548 {
549 	struct uart_bas *bas;
550 	int i, ctrl;
551 
552 	bas = &sc->sc_bas;
553 	uart_lock(sc->sc_hwmtx);
554 
555 	/* Turn off all interrupts during send */
556 	ctrl = uart_getreg(bas, UART_CTRL);
557 	uart_setreg(bas, UART_CTRL, ctrl & ~CTRL_INTR_MASK);
558 	uart_barrier(bas);
559 
560 	for (i = 0; i < sc->sc_txdatasz; i++) {
561 		uart_setreg(bas, UART_TSH, sc->sc_txbuf[i] & 0xff);
562 		uart_barrier(bas);
563 	}
564 
565 	/*
566 	 * Make sure that interrupt is generated
567 	 * when FIFO can get more data.
568 	 */
569 	uart_setreg(bas, UART_CTRL, ctrl | CTRL_TX_IDLE_INT);
570 	uart_barrier(bas);
571 
572 	/* Mark busy */
573 	sc->sc_txbusy = 1;
574 
575 	uart_unlock(sc->sc_hwmtx);
576 	return (0);
577 }
578 
579 static void
uart_mvebu_bus_grab(struct uart_softc * sc)580 uart_mvebu_bus_grab(struct uart_softc *sc)
581 {
582 	struct uart_mvebu_softc *msc = (struct uart_mvebu_softc *)sc;
583 	struct uart_bas *bas = &sc->sc_bas;
584 	uint32_t ctrl;
585 
586 	/* Mask all interrupts */
587 	uart_lock(sc->sc_hwmtx);
588 	ctrl = uart_getreg(bas, UART_CTRL);
589 	msc->intrm = ctrl & CTRL_INTR_MASK;
590 	uart_setreg(bas, UART_CTRL, ctrl & ~CTRL_INTR_MASK);
591 	uart_barrier(bas);
592 	uart_unlock(sc->sc_hwmtx);
593 }
594 
595 static void
uart_mvebu_bus_ungrab(struct uart_softc * sc)596 uart_mvebu_bus_ungrab(struct uart_softc *sc)
597 {
598 	struct uart_mvebu_softc *msc = (struct uart_mvebu_softc *)sc;
599 	struct uart_bas *bas = &sc->sc_bas;
600 	uint32_t ctrl;
601 
602 	/* Restore interrupts */
603 	uart_lock(sc->sc_hwmtx);
604 	ctrl = uart_getreg(bas, UART_CTRL) & ~CTRL_INTR_MASK;
605 	uart_setreg(bas, UART_CTRL, ctrl | msc->intrm);
606 	uart_barrier(bas);
607 	uart_unlock(sc->sc_hwmtx);
608 }
609