xref: /freebsd/sys/dev/uart/uart_dev_pl011.c (revision 792bbaba989533a1fc93823df1720c8c4aaf0442)
1 /*-
2  * Copyright (c) 2012 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 "opt_acpi.h"
28 #include "opt_platform.h"
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/bus.h>
37 #include <machine/bus.h>
38 
39 #include <dev/uart/uart.h>
40 #include <dev/uart/uart_cpu.h>
41 #ifdef FDT
42 #include <dev/uart/uart_cpu_fdt.h>
43 #endif
44 #include <dev/uart/uart_bus.h>
45 #include "uart_if.h"
46 
47 #ifdef DEV_ACPI
48 #include <dev/uart/uart_cpu_acpi.h>
49 #include <contrib/dev/acpica/include/acpi.h>
50 #include <contrib/dev/acpica/include/accommon.h>
51 #include <contrib/dev/acpica/include/actables.h>
52 #endif
53 
54 #include <sys/kdb.h>
55 
56 /* PL011 UART registers and masks*/
57 #define	UART_DR		0x00		/* Data register */
58 #define	DR_FE		(1 << 8)	/* Framing error */
59 #define	DR_PE		(1 << 9)	/* Parity error */
60 #define	DR_BE		(1 << 10)	/* Break error */
61 #define	DR_OE		(1 << 11)	/* Overrun error */
62 
63 #define	UART_FR		0x06		/* Flag register */
64 #define	FR_TXFF		(1 << 5)	/* Transmit FIFO/reg full */
65 #define	FR_RXFF		(1 << 6)	/* Receive FIFO/reg full */
66 #define	FR_TXFE		(1 << 7)	/* Transmit FIFO/reg empty */
67 
68 #define	UART_IBRD	0x09		/* Integer baud rate register */
69 #define	IBRD_BDIVINT	0xffff	/* Significant part of int. divisor value */
70 
71 #define	UART_FBRD	0x0a		/* Fractional baud rate register */
72 #define	FBRD_BDIVFRAC	0x3f	/* Significant part of frac. divisor value */
73 
74 #define	UART_LCR_H	0x0b		/* Line control register */
75 #define	LCR_H_WLEN8	(0x3 << 5)
76 #define	LCR_H_WLEN7	(0x2 << 5)
77 #define	LCR_H_WLEN6	(0x1 << 5)
78 #define	LCR_H_FEN	(1 << 4)	/* FIFO mode enable */
79 #define	LCR_H_STP2	(1 << 3)	/* 2 stop frames at the end */
80 #define	LCR_H_EPS	(1 << 2)	/* Even parity select */
81 #define	LCR_H_PEN	(1 << 1)	/* Parity enable */
82 
83 #define	UART_CR		0x0c		/* Control register */
84 #define	CR_RXE		(1 << 9)	/* Receive enable */
85 #define	CR_TXE		(1 << 8)	/* Transmit enable */
86 #define	CR_UARTEN	(1 << 0)	/* UART enable */
87 
88 #define	UART_IMSC	0x0e		/* Interrupt mask set/clear register */
89 #define	IMSC_MASK_ALL	0x7ff		/* Mask all interrupts */
90 
91 #define	UART_RIS	0x0f		/* Raw interrupt status register */
92 #define	UART_RXREADY	(1 << 4)	/* RX buffer full */
93 #define	UART_TXEMPTY	(1 << 5)	/* TX buffer empty */
94 #define	RIS_RTIM	(1 << 6)	/* Receive timeout */
95 #define	RIS_FE		(1 << 7)	/* Framing error interrupt status */
96 #define	RIS_PE		(1 << 8)	/* Parity error interrupt status */
97 #define	RIS_BE		(1 << 9)	/* Break error interrupt status */
98 #define	RIS_OE		(1 << 10)	/* Overrun interrupt status */
99 
100 #define	UART_MIS	0x10		/* Masked interrupt status register */
101 #define	UART_ICR	0x11		/* Interrupt clear register */
102 
103 /*
104  * FIXME: actual register size is SoC-dependent, we need to handle it
105  */
106 #define	__uart_getreg(bas, reg)		\
107 	bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
108 #define	__uart_setreg(bas, reg, value)	\
109 	bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
110 
111 /*
112  * Low-level UART interface.
113  */
114 static int uart_pl011_probe(struct uart_bas *bas);
115 static void uart_pl011_init(struct uart_bas *bas, int, int, int, int);
116 static void uart_pl011_term(struct uart_bas *bas);
117 static void uart_pl011_putc(struct uart_bas *bas, int);
118 static int uart_pl011_rxready(struct uart_bas *bas);
119 static int uart_pl011_getc(struct uart_bas *bas, struct mtx *);
120 
121 static struct uart_ops uart_pl011_ops = {
122 	.probe = uart_pl011_probe,
123 	.init = uart_pl011_init,
124 	.term = uart_pl011_term,
125 	.putc = uart_pl011_putc,
126 	.rxready = uart_pl011_rxready,
127 	.getc = uart_pl011_getc,
128 };
129 
130 static int
131 uart_pl011_probe(struct uart_bas *bas)
132 {
133 
134 	return (0);
135 }
136 
137 static void
138 uart_pl011_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
139     int parity)
140 {
141 	uint32_t ctrl, line;
142 	uint32_t baud;
143 
144 	/*
145 	 * Zero all settings to make sure
146 	 * UART is disabled and not configured
147 	 */
148 	ctrl = line = 0x0;
149 	__uart_setreg(bas, UART_CR, ctrl);
150 
151 	/* As we know UART is disabled we may setup the line */
152 	switch (databits) {
153 	case 7:
154 		line |= LCR_H_WLEN7;
155 		break;
156 	case 6:
157 		line |= LCR_H_WLEN6;
158 		break;
159 	case 8:
160 	default:
161 		line |= LCR_H_WLEN8;
162 		break;
163 	}
164 
165 	if (stopbits == 2)
166 		line |= LCR_H_STP2;
167 	else
168 		line &= ~LCR_H_STP2;
169 
170 	if (parity)
171 		line |= LCR_H_PEN;
172 	else
173 		line &= ~LCR_H_PEN;
174 
175 	/* Configure the rest */
176 	line &= ~LCR_H_FEN;
177 	ctrl |= (CR_RXE | CR_TXE | CR_UARTEN);
178 
179 	if (bas->rclk != 0 && baudrate != 0) {
180 		baud = bas->rclk * 4 / baudrate;
181 		__uart_setreg(bas, UART_IBRD, ((uint32_t)(baud >> 6)) & IBRD_BDIVINT);
182 		__uart_setreg(bas, UART_FBRD, (uint32_t)(baud & 0x3F) & FBRD_BDIVFRAC);
183 	}
184 
185 	/* Add config. to line before reenabling UART */
186 	__uart_setreg(bas, UART_LCR_H, (__uart_getreg(bas, UART_LCR_H) &
187 	    ~0xff) | line);
188 
189 	__uart_setreg(bas, UART_CR, ctrl);
190 }
191 
192 static void
193 uart_pl011_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
194     int parity)
195 {
196 	/* Mask all interrupts */
197 	__uart_setreg(bas, UART_IMSC, __uart_getreg(bas, UART_IMSC) &
198 	    ~IMSC_MASK_ALL);
199 
200 	uart_pl011_param(bas, baudrate, databits, stopbits, parity);
201 }
202 
203 static void
204 uart_pl011_term(struct uart_bas *bas)
205 {
206 }
207 
208 static void
209 uart_pl011_putc(struct uart_bas *bas, int c)
210 {
211 
212 	/* Wait when TX FIFO full. Push character otherwise. */
213 	while (__uart_getreg(bas, UART_FR) & FR_TXFF)
214 		;
215 	__uart_setreg(bas, UART_DR, c & 0xff);
216 }
217 
218 static int
219 uart_pl011_rxready(struct uart_bas *bas)
220 {
221 
222 	return (__uart_getreg(bas, UART_FR) & FR_RXFF);
223 }
224 
225 static int
226 uart_pl011_getc(struct uart_bas *bas, struct mtx *hwmtx)
227 {
228 	int c;
229 
230 	while (!uart_pl011_rxready(bas))
231 		;
232 	c = __uart_getreg(bas, UART_DR) & 0xff;
233 
234 	return (c);
235 }
236 
237 /*
238  * High-level UART interface.
239  */
240 struct uart_pl011_softc {
241 	struct uart_softc	base;
242 	uint16_t		imsc; /* Interrupt mask */
243 };
244 
245 static int uart_pl011_bus_attach(struct uart_softc *);
246 static int uart_pl011_bus_detach(struct uart_softc *);
247 static int uart_pl011_bus_flush(struct uart_softc *, int);
248 static int uart_pl011_bus_getsig(struct uart_softc *);
249 static int uart_pl011_bus_ioctl(struct uart_softc *, int, intptr_t);
250 static int uart_pl011_bus_ipend(struct uart_softc *);
251 static int uart_pl011_bus_param(struct uart_softc *, int, int, int, int);
252 static int uart_pl011_bus_probe(struct uart_softc *);
253 static int uart_pl011_bus_receive(struct uart_softc *);
254 static int uart_pl011_bus_setsig(struct uart_softc *, int);
255 static int uart_pl011_bus_transmit(struct uart_softc *);
256 static void uart_pl011_bus_grab(struct uart_softc *);
257 static void uart_pl011_bus_ungrab(struct uart_softc *);
258 
259 static kobj_method_t uart_pl011_methods[] = {
260 	KOBJMETHOD(uart_attach,		uart_pl011_bus_attach),
261 	KOBJMETHOD(uart_detach,		uart_pl011_bus_detach),
262 	KOBJMETHOD(uart_flush,		uart_pl011_bus_flush),
263 	KOBJMETHOD(uart_getsig,		uart_pl011_bus_getsig),
264 	KOBJMETHOD(uart_ioctl,		uart_pl011_bus_ioctl),
265 	KOBJMETHOD(uart_ipend,		uart_pl011_bus_ipend),
266 	KOBJMETHOD(uart_param,		uart_pl011_bus_param),
267 	KOBJMETHOD(uart_probe,		uart_pl011_bus_probe),
268 	KOBJMETHOD(uart_receive,	uart_pl011_bus_receive),
269 	KOBJMETHOD(uart_setsig,		uart_pl011_bus_setsig),
270 	KOBJMETHOD(uart_transmit,	uart_pl011_bus_transmit),
271 	KOBJMETHOD(uart_grab,		uart_pl011_bus_grab),
272 	KOBJMETHOD(uart_ungrab,		uart_pl011_bus_ungrab),
273 
274 	{ 0, 0 }
275 };
276 
277 static struct uart_class uart_pl011_class = {
278 	"uart_pl011",
279 	uart_pl011_methods,
280 	sizeof(struct uart_pl011_softc),
281 	.uc_ops = &uart_pl011_ops,
282 	.uc_range = 0x48,
283 	.uc_rclk = 0,
284 	.uc_rshift = 2
285 };
286 
287 
288 #ifdef FDT
289 static struct ofw_compat_data compat_data[] = {
290 	{"arm,pl011",		(uintptr_t)&uart_pl011_class},
291 	{NULL,			(uintptr_t)NULL},
292 };
293 UART_FDT_CLASS_AND_DEVICE(compat_data);
294 #endif
295 
296 #ifdef DEV_ACPI
297 static struct acpi_uart_compat_data acpi_compat_data[] = {
298 	{"ARMH0011", &uart_pl011_class, ACPI_DBG2_ARM_PL011},
299 	{NULL, NULL, 0},
300 };
301 UART_ACPI_CLASS_AND_DEVICE(acpi_compat_data);
302 #endif
303 
304 static int
305 uart_pl011_bus_attach(struct uart_softc *sc)
306 {
307 	struct uart_pl011_softc *psc;
308 	struct uart_bas *bas;
309 
310 	psc = (struct uart_pl011_softc *)sc;
311 	bas = &sc->sc_bas;
312 
313 	/* Enable interrupts */
314 	psc->imsc = (UART_RXREADY | RIS_RTIM | UART_TXEMPTY);
315 	__uart_setreg(bas, UART_IMSC, psc->imsc);
316 
317 	/* Clear interrupts */
318 	__uart_setreg(bas, UART_ICR, IMSC_MASK_ALL);
319 
320 	return (0);
321 }
322 
323 static int
324 uart_pl011_bus_detach(struct uart_softc *sc)
325 {
326 
327 	return (0);
328 }
329 
330 static int
331 uart_pl011_bus_flush(struct uart_softc *sc, int what)
332 {
333 
334 	return (0);
335 }
336 
337 static int
338 uart_pl011_bus_getsig(struct uart_softc *sc)
339 {
340 
341 	return (0);
342 }
343 
344 static int
345 uart_pl011_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
346 {
347 	struct uart_bas *bas;
348 	int error;
349 
350 	bas = &sc->sc_bas;
351 	error = 0;
352 	uart_lock(sc->sc_hwmtx);
353 	switch (request) {
354 	case UART_IOCTL_BREAK:
355 		break;
356 	case UART_IOCTL_BAUD:
357 		*(int*)data = 115200;
358 		break;
359 	default:
360 		error = EINVAL;
361 		break;
362 	}
363 	uart_unlock(sc->sc_hwmtx);
364 
365 	return (error);
366 }
367 
368 static int
369 uart_pl011_bus_ipend(struct uart_softc *sc)
370 {
371 	struct uart_pl011_softc *psc;
372 	struct uart_bas *bas;
373 	uint32_t ints;
374 	int ipend;
375 
376 	psc = (struct uart_pl011_softc *)sc;
377 	bas = &sc->sc_bas;
378 
379 	uart_lock(sc->sc_hwmtx);
380 	ints = __uart_getreg(bas, UART_MIS);
381 	ipend = 0;
382 
383 	if (ints & (UART_RXREADY | RIS_RTIM))
384 		ipend |= SER_INT_RXREADY;
385 	if (ints & RIS_BE)
386 		ipend |= SER_INT_BREAK;
387 	if (ints & RIS_OE)
388 		ipend |= SER_INT_OVERRUN;
389 	if (ints & UART_TXEMPTY) {
390 		if (sc->sc_txbusy)
391 			ipend |= SER_INT_TXIDLE;
392 
393 		/* Disable TX interrupt */
394 		__uart_setreg(bas, UART_IMSC, psc->imsc & ~UART_TXEMPTY);
395 	}
396 
397 	uart_unlock(sc->sc_hwmtx);
398 
399 	return (ipend);
400 }
401 
402 static int
403 uart_pl011_bus_param(struct uart_softc *sc, int baudrate, int databits,
404     int stopbits, int parity)
405 {
406 
407 	uart_lock(sc->sc_hwmtx);
408 	uart_pl011_param(&sc->sc_bas, baudrate, databits, stopbits, parity);
409 	uart_unlock(sc->sc_hwmtx);
410 
411 	return (0);
412 }
413 
414 static int
415 uart_pl011_bus_probe(struct uart_softc *sc)
416 {
417 
418 	device_set_desc(sc->sc_dev, "PrimeCell UART (PL011)");
419 
420 	sc->sc_rxfifosz = 1;
421 	sc->sc_txfifosz = 1;
422 
423 	return (0);
424 }
425 
426 static int
427 uart_pl011_bus_receive(struct uart_softc *sc)
428 {
429 	struct uart_bas *bas;
430 	uint32_t ints, xc;
431 	int rx;
432 
433 	bas = &sc->sc_bas;
434 	uart_lock(sc->sc_hwmtx);
435 
436 	ints = __uart_getreg(bas, UART_MIS);
437 	while (ints & (UART_RXREADY | RIS_RTIM)) {
438 		if (uart_rx_full(sc)) {
439 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
440 			break;
441 		}
442 
443 		__uart_setreg(bas, UART_ICR, (UART_RXREADY | RIS_RTIM));
444 		xc = __uart_getreg(bas, UART_DR);
445 		rx = xc & 0xff;
446 
447 		if (xc & DR_FE)
448 			rx |= UART_STAT_FRAMERR;
449 		if (xc & DR_PE)
450 			rx |= UART_STAT_PARERR;
451 
452 		uart_rx_put(sc, rx);
453 		ints = __uart_getreg(bas, UART_MIS);
454 	}
455 
456 	uart_unlock(sc->sc_hwmtx);
457 
458 	return (0);
459 }
460 
461 static int
462 uart_pl011_bus_setsig(struct uart_softc *sc, int sig)
463 {
464 
465 	return (0);
466 }
467 
468 static int
469 uart_pl011_bus_transmit(struct uart_softc *sc)
470 {
471 	struct uart_pl011_softc *psc;
472 	struct uart_bas *bas;
473 	int i;
474 
475 	psc = (struct uart_pl011_softc *)sc;
476 	bas = &sc->sc_bas;
477 	uart_lock(sc->sc_hwmtx);
478 
479 	for (i = 0; i < sc->sc_txdatasz; i++) {
480 		__uart_setreg(bas, UART_DR, sc->sc_txbuf[i]);
481 		uart_barrier(bas);
482 	}
483 
484 	/* If not empty wait until it is */
485 	if ((__uart_getreg(bas, UART_FR) & FR_TXFE) != FR_TXFE) {
486 		sc->sc_txbusy = 1;
487 
488 		/* Enable TX interrupt */
489 		__uart_setreg(bas, UART_IMSC, psc->imsc);
490 	}
491 
492 	uart_unlock(sc->sc_hwmtx);
493 
494 	/* No interrupt expected, schedule the next fifo write */
495 	if (!sc->sc_txbusy)
496 		uart_sched_softih(sc, SER_INT_TXIDLE);
497 
498 	return (0);
499 }
500 
501 static void
502 uart_pl011_bus_grab(struct uart_softc *sc)
503 {
504 	struct uart_pl011_softc *psc;
505 	struct uart_bas *bas;
506 
507 	psc = (struct uart_pl011_softc *)sc;
508 	bas = &sc->sc_bas;
509 
510 	/* Disable interrupts on switch to polling */
511 	uart_lock(sc->sc_hwmtx);
512 	__uart_setreg(bas, UART_IMSC, psc->imsc & ~IMSC_MASK_ALL);
513 	uart_unlock(sc->sc_hwmtx);
514 }
515 
516 static void
517 uart_pl011_bus_ungrab(struct uart_softc *sc)
518 {
519 	struct uart_pl011_softc *psc;
520 	struct uart_bas *bas;
521 
522 	psc = (struct uart_pl011_softc *)sc;
523 	bas = &sc->sc_bas;
524 
525 	/* Switch to using interrupts while not grabbed */
526 	uart_lock(sc->sc_hwmtx);
527 	__uart_setreg(bas, UART_IMSC, psc->imsc);
528 	uart_unlock(sc->sc_hwmtx);
529 }
530