xref: /freebsd/sys/dev/uart/uart_dev_pl011.c (revision efe3b0de1438e7a8473d92f2be57072394559e3c)
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_RXFE		(1 << 4)	/* Receive FIFO/reg empty */
65 #define	FR_TXFF		(1 << 5)	/* Transmit FIFO/reg full */
66 #define	FR_RXFF		(1 << 6)	/* Receive FIFO/reg full */
67 #define	FR_TXFE		(1 << 7)	/* Transmit FIFO/reg empty */
68 
69 #define	UART_IBRD	0x09		/* Integer baud rate register */
70 #define	IBRD_BDIVINT	0xffff	/* Significant part of int. divisor value */
71 
72 #define	UART_FBRD	0x0a		/* Fractional baud rate register */
73 #define	FBRD_BDIVFRAC	0x3f	/* Significant part of frac. divisor value */
74 
75 #define	UART_LCR_H	0x0b		/* Line control register */
76 #define	LCR_H_WLEN8	(0x3 << 5)
77 #define	LCR_H_WLEN7	(0x2 << 5)
78 #define	LCR_H_WLEN6	(0x1 << 5)
79 #define	LCR_H_FEN	(1 << 4)	/* FIFO mode enable */
80 #define	LCR_H_STP2	(1 << 3)	/* 2 stop frames at the end */
81 #define	LCR_H_EPS	(1 << 2)	/* Even parity select */
82 #define	LCR_H_PEN	(1 << 1)	/* Parity enable */
83 
84 #define	UART_CR		0x0c		/* Control register */
85 #define	CR_RXE		(1 << 9)	/* Receive enable */
86 #define	CR_TXE		(1 << 8)	/* Transmit enable */
87 #define	CR_UARTEN	(1 << 0)	/* UART enable */
88 
89 #define	UART_IMSC	0x0e		/* Interrupt mask set/clear register */
90 #define	IMSC_MASK_ALL	0x7ff		/* Mask all interrupts */
91 
92 #define	UART_RIS	0x0f		/* Raw interrupt status register */
93 #define	UART_RXREADY	(1 << 4)	/* RX buffer full */
94 #define	UART_TXEMPTY	(1 << 5)	/* TX buffer empty */
95 #define	RIS_RTIM	(1 << 6)	/* Receive timeout */
96 #define	RIS_FE		(1 << 7)	/* Framing error interrupt status */
97 #define	RIS_PE		(1 << 8)	/* Parity error interrupt status */
98 #define	RIS_BE		(1 << 9)	/* Break error interrupt status */
99 #define	RIS_OE		(1 << 10)	/* Overrun interrupt status */
100 
101 #define	UART_MIS	0x10		/* Masked interrupt status register */
102 #define	UART_ICR	0x11		/* Interrupt clear register */
103 
104 /*
105  * FIXME: actual register size is SoC-dependent, we need to handle it
106  */
107 #define	__uart_getreg(bas, reg)		\
108 	bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
109 #define	__uart_setreg(bas, reg, value)	\
110 	bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
111 
112 /*
113  * Low-level UART interface.
114  */
115 static int uart_pl011_probe(struct uart_bas *bas);
116 static void uart_pl011_init(struct uart_bas *bas, int, int, int, int);
117 static void uart_pl011_term(struct uart_bas *bas);
118 static void uart_pl011_putc(struct uart_bas *bas, int);
119 static int uart_pl011_rxready(struct uart_bas *bas);
120 static int uart_pl011_getc(struct uart_bas *bas, struct mtx *);
121 
122 static struct uart_ops uart_pl011_ops = {
123 	.probe = uart_pl011_probe,
124 	.init = uart_pl011_init,
125 	.term = uart_pl011_term,
126 	.putc = uart_pl011_putc,
127 	.rxready = uart_pl011_rxready,
128 	.getc = uart_pl011_getc,
129 };
130 
131 static int
132 uart_pl011_probe(struct uart_bas *bas)
133 {
134 
135 	return (0);
136 }
137 
138 static void
139 uart_pl011_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
140     int parity)
141 {
142 	uint32_t ctrl, line;
143 	uint32_t baud;
144 
145 	/*
146 	 * Zero all settings to make sure
147 	 * UART is disabled and not configured
148 	 */
149 	ctrl = line = 0x0;
150 	__uart_setreg(bas, UART_CR, ctrl);
151 
152 	/* As we know UART is disabled we may setup the line */
153 	switch (databits) {
154 	case 7:
155 		line |= LCR_H_WLEN7;
156 		break;
157 	case 6:
158 		line |= LCR_H_WLEN6;
159 		break;
160 	case 8:
161 	default:
162 		line |= LCR_H_WLEN8;
163 		break;
164 	}
165 
166 	if (stopbits == 2)
167 		line |= LCR_H_STP2;
168 	else
169 		line &= ~LCR_H_STP2;
170 
171 	if (parity)
172 		line |= LCR_H_PEN;
173 	else
174 		line &= ~LCR_H_PEN;
175 	line |= LCR_H_FEN;
176 
177 	/* Configure the rest */
178 	ctrl |= (CR_RXE | CR_TXE | CR_UARTEN);
179 
180 	if (bas->rclk != 0 && baudrate != 0) {
181 		baud = bas->rclk * 4 / baudrate;
182 		__uart_setreg(bas, UART_IBRD, ((uint32_t)(baud >> 6)) & IBRD_BDIVINT);
183 		__uart_setreg(bas, UART_FBRD, (uint32_t)(baud & 0x3F) & FBRD_BDIVFRAC);
184 	}
185 
186 	/* Add config. to line before reenabling UART */
187 	__uart_setreg(bas, UART_LCR_H, (__uart_getreg(bas, UART_LCR_H) &
188 	    ~0xff) | line);
189 
190 	__uart_setreg(bas, UART_CR, ctrl);
191 }
192 
193 static void
194 uart_pl011_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
195     int parity)
196 {
197 	/* Mask all interrupts */
198 	__uart_setreg(bas, UART_IMSC, __uart_getreg(bas, UART_IMSC) &
199 	    ~IMSC_MASK_ALL);
200 
201 	uart_pl011_param(bas, baudrate, databits, stopbits, parity);
202 }
203 
204 static void
205 uart_pl011_term(struct uart_bas *bas)
206 {
207 }
208 
209 static void
210 uart_pl011_putc(struct uart_bas *bas, int c)
211 {
212 
213 	/* Wait when TX FIFO full. Push character otherwise. */
214 	while (__uart_getreg(bas, UART_FR) & FR_TXFF)
215 		;
216 	__uart_setreg(bas, UART_DR, c & 0xff);
217 }
218 
219 static int
220 uart_pl011_rxready(struct uart_bas *bas)
221 {
222 
223 	return !(__uart_getreg(bas, UART_FR) & FR_RXFE);
224 }
225 
226 static int
227 uart_pl011_getc(struct uart_bas *bas, struct mtx *hwmtx)
228 {
229 	int c;
230 
231 	while (!uart_pl011_rxready(bas))
232 		;
233 	c = __uart_getreg(bas, UART_DR) & 0xff;
234 
235 	return (c);
236 }
237 
238 /*
239  * High-level UART interface.
240  */
241 struct uart_pl011_softc {
242 	struct uart_softc	base;
243 	uint16_t		imsc; /* Interrupt mask */
244 };
245 
246 static int uart_pl011_bus_attach(struct uart_softc *);
247 static int uart_pl011_bus_detach(struct uart_softc *);
248 static int uart_pl011_bus_flush(struct uart_softc *, int);
249 static int uart_pl011_bus_getsig(struct uart_softc *);
250 static int uart_pl011_bus_ioctl(struct uart_softc *, int, intptr_t);
251 static int uart_pl011_bus_ipend(struct uart_softc *);
252 static int uart_pl011_bus_param(struct uart_softc *, int, int, int, int);
253 static int uart_pl011_bus_probe(struct uart_softc *);
254 static int uart_pl011_bus_receive(struct uart_softc *);
255 static int uart_pl011_bus_setsig(struct uart_softc *, int);
256 static int uart_pl011_bus_transmit(struct uart_softc *);
257 static void uart_pl011_bus_grab(struct uart_softc *);
258 static void uart_pl011_bus_ungrab(struct uart_softc *);
259 
260 static kobj_method_t uart_pl011_methods[] = {
261 	KOBJMETHOD(uart_attach,		uart_pl011_bus_attach),
262 	KOBJMETHOD(uart_detach,		uart_pl011_bus_detach),
263 	KOBJMETHOD(uart_flush,		uart_pl011_bus_flush),
264 	KOBJMETHOD(uart_getsig,		uart_pl011_bus_getsig),
265 	KOBJMETHOD(uart_ioctl,		uart_pl011_bus_ioctl),
266 	KOBJMETHOD(uart_ipend,		uart_pl011_bus_ipend),
267 	KOBJMETHOD(uart_param,		uart_pl011_bus_param),
268 	KOBJMETHOD(uart_probe,		uart_pl011_bus_probe),
269 	KOBJMETHOD(uart_receive,	uart_pl011_bus_receive),
270 	KOBJMETHOD(uart_setsig,		uart_pl011_bus_setsig),
271 	KOBJMETHOD(uart_transmit,	uart_pl011_bus_transmit),
272 	KOBJMETHOD(uart_grab,		uart_pl011_bus_grab),
273 	KOBJMETHOD(uart_ungrab,		uart_pl011_bus_ungrab),
274 
275 	{ 0, 0 }
276 };
277 
278 static struct uart_class uart_pl011_class = {
279 	"uart_pl011",
280 	uart_pl011_methods,
281 	sizeof(struct uart_pl011_softc),
282 	.uc_ops = &uart_pl011_ops,
283 	.uc_range = 0x48,
284 	.uc_rclk = 0,
285 	.uc_rshift = 2
286 };
287 
288 
289 #ifdef FDT
290 static struct ofw_compat_data compat_data[] = {
291 	{"arm,pl011",		(uintptr_t)&uart_pl011_class},
292 	{NULL,			(uintptr_t)NULL},
293 };
294 UART_FDT_CLASS_AND_DEVICE(compat_data);
295 #endif
296 
297 #ifdef DEV_ACPI
298 static struct acpi_uart_compat_data acpi_compat_data[] = {
299 	{"ARMH0011", &uart_pl011_class, ACPI_DBG2_ARM_PL011},
300 	{NULL, NULL, 0},
301 };
302 UART_ACPI_CLASS_AND_DEVICE(acpi_compat_data);
303 #endif
304 
305 static int
306 uart_pl011_bus_attach(struct uart_softc *sc)
307 {
308 	struct uart_pl011_softc *psc;
309 	struct uart_bas *bas;
310 
311 	psc = (struct uart_pl011_softc *)sc;
312 	bas = &sc->sc_bas;
313 
314 	/* Enable interrupts */
315 	psc->imsc = (UART_RXREADY | RIS_RTIM | UART_TXEMPTY);
316 	__uart_setreg(bas, UART_IMSC, psc->imsc);
317 
318 	/* Clear interrupts */
319 	__uart_setreg(bas, UART_ICR, IMSC_MASK_ALL);
320 
321 	return (0);
322 }
323 
324 static int
325 uart_pl011_bus_detach(struct uart_softc *sc)
326 {
327 
328 	return (0);
329 }
330 
331 static int
332 uart_pl011_bus_flush(struct uart_softc *sc, int what)
333 {
334 
335 	return (0);
336 }
337 
338 static int
339 uart_pl011_bus_getsig(struct uart_softc *sc)
340 {
341 
342 	return (0);
343 }
344 
345 static int
346 uart_pl011_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
347 {
348 	struct uart_bas *bas;
349 	int error;
350 
351 	bas = &sc->sc_bas;
352 	error = 0;
353 	uart_lock(sc->sc_hwmtx);
354 	switch (request) {
355 	case UART_IOCTL_BREAK:
356 		break;
357 	case UART_IOCTL_BAUD:
358 		*(int*)data = 115200;
359 		break;
360 	default:
361 		error = EINVAL;
362 		break;
363 	}
364 	uart_unlock(sc->sc_hwmtx);
365 
366 	return (error);
367 }
368 
369 static int
370 uart_pl011_bus_ipend(struct uart_softc *sc)
371 {
372 	struct uart_pl011_softc *psc;
373 	struct uart_bas *bas;
374 	uint32_t ints;
375 	int ipend;
376 
377 	psc = (struct uart_pl011_softc *)sc;
378 	bas = &sc->sc_bas;
379 
380 	uart_lock(sc->sc_hwmtx);
381 	ints = __uart_getreg(bas, UART_MIS);
382 	ipend = 0;
383 
384 	if (ints & (UART_RXREADY | RIS_RTIM))
385 		ipend |= SER_INT_RXREADY;
386 	if (ints & RIS_BE)
387 		ipend |= SER_INT_BREAK;
388 	if (ints & RIS_OE)
389 		ipend |= SER_INT_OVERRUN;
390 	if (ints & UART_TXEMPTY) {
391 		if (sc->sc_txbusy)
392 			ipend |= SER_INT_TXIDLE;
393 
394 		/* Disable TX interrupt */
395 		__uart_setreg(bas, UART_IMSC, psc->imsc & ~UART_TXEMPTY);
396 	}
397 
398 	uart_unlock(sc->sc_hwmtx);
399 
400 	return (ipend);
401 }
402 
403 static int
404 uart_pl011_bus_param(struct uart_softc *sc, int baudrate, int databits,
405     int stopbits, int parity)
406 {
407 
408 	uart_lock(sc->sc_hwmtx);
409 	uart_pl011_param(&sc->sc_bas, baudrate, databits, stopbits, parity);
410 	uart_unlock(sc->sc_hwmtx);
411 
412 	return (0);
413 }
414 
415 static int
416 uart_pl011_bus_probe(struct uart_softc *sc)
417 {
418 
419 	device_set_desc(sc->sc_dev, "PrimeCell UART (PL011)");
420 
421 	sc->sc_rxfifosz = 16;
422 	sc->sc_txfifosz = 16;
423 
424 	return (0);
425 }
426 
427 static int
428 uart_pl011_bus_receive(struct uart_softc *sc)
429 {
430 	struct uart_bas *bas;
431 	uint32_t ints, xc;
432 	int rx;
433 
434 	bas = &sc->sc_bas;
435 	uart_lock(sc->sc_hwmtx);
436 
437 	ints = __uart_getreg(bas, UART_MIS);
438 	while (ints & (UART_RXREADY | RIS_RTIM)) {
439 		if (uart_rx_full(sc)) {
440 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
441 			break;
442 		}
443 
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 	/* Mark busy and enable TX interrupt */
485 	sc->sc_txbusy = 1;
486 	__uart_setreg(bas, UART_IMSC, psc->imsc);
487 
488 	uart_unlock(sc->sc_hwmtx);
489 
490 	return (0);
491 }
492 
493 static void
494 uart_pl011_bus_grab(struct uart_softc *sc)
495 {
496 	struct uart_pl011_softc *psc;
497 	struct uart_bas *bas;
498 
499 	psc = (struct uart_pl011_softc *)sc;
500 	bas = &sc->sc_bas;
501 
502 	/* Disable interrupts on switch to polling */
503 	uart_lock(sc->sc_hwmtx);
504 	__uart_setreg(bas, UART_IMSC, psc->imsc & ~IMSC_MASK_ALL);
505 	uart_unlock(sc->sc_hwmtx);
506 }
507 
508 static void
509 uart_pl011_bus_ungrab(struct uart_softc *sc)
510 {
511 	struct uart_pl011_softc *psc;
512 	struct uart_bas *bas;
513 
514 	psc = (struct uart_pl011_softc *)sc;
515 	bas = &sc->sc_bas;
516 
517 	/* Switch to using interrupts while not grabbed */
518 	uart_lock(sc->sc_hwmtx);
519 	__uart_setreg(bas, UART_IMSC, psc->imsc);
520 	uart_unlock(sc->sc_hwmtx);
521 }
522