xref: /freebsd/sys/dev/uart/uart_dev_msm.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * Copyright (c) 2014 Ganbold Tsagaankhuu <ganbold@freebsd.org>
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  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /* Qualcomm MSM7K/8K uart driver */
28 
29 #include <sys/cdefs.h>
30 #include "opt_ddb.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/conf.h>
36 #include <sys/kdb.h>
37 #include <machine/bus.h>
38 
39 #include <dev/uart/uart.h>
40 #include <dev/uart/uart_cpu.h>
41 #include <dev/uart/uart_cpu_fdt.h>
42 #include <dev/uart/uart_bus.h>
43 #include <dev/uart/uart_dev_msm.h>
44 
45 #include "uart_if.h"
46 
47 #define	DEF_CLK		7372800
48 
49 #define	GETREG(bas, reg)	\
50     bus_space_read_4((bas)->bst, (bas)->bsh, (reg))
51 #define	SETREG(bas, reg, value)	\
52     bus_space_write_4((bas)->bst, (bas)->bsh, (reg), (value))
53 
54 static int msm_uart_param(struct uart_bas *, int, int, int, int);
55 
56 /*
57  * Low-level UART interface.
58  */
59 static int	msm_probe(struct uart_bas *bas);
60 static void	msm_init(struct uart_bas *bas, int, int, int, int);
61 static void	msm_term(struct uart_bas *bas);
62 static void	msm_putc(struct uart_bas *bas, int);
63 static int	msm_rxready(struct uart_bas *bas);
64 static int	msm_getc(struct uart_bas *bas, struct mtx *mtx);
65 
66 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
67 
68 static int
69 msm_uart_param(struct uart_bas *bas, int baudrate, int databits,
70     int stopbits, int parity)
71 {
72 	int ulcon;
73 
74 	ulcon = 0;
75 
76 	switch (databits) {
77 	case 5:
78 		ulcon |= (UART_DM_5_BPS << 4);
79 		break;
80 	case 6:
81 		ulcon |= (UART_DM_6_BPS << 4);
82 		break;
83 	case 7:
84 		ulcon |= (UART_DM_7_BPS << 4);
85 		break;
86 	case 8:
87 		ulcon |= (UART_DM_8_BPS << 4);
88 		break;
89 	default:
90 		return (EINVAL);
91 	}
92 
93 	switch (parity) {
94 	case UART_PARITY_NONE:
95 		ulcon |= UART_DM_NO_PARITY;
96 		break;
97 	case UART_PARITY_ODD:
98 		ulcon |= UART_DM_ODD_PARITY;
99 		break;
100 	case UART_PARITY_EVEN:
101 		ulcon |= UART_DM_EVEN_PARITY;
102 		break;
103 	case UART_PARITY_SPACE:
104 		ulcon |= UART_DM_SPACE_PARITY;
105 		break;
106 	case UART_PARITY_MARK:
107 	default:
108 		return (EINVAL);
109 	}
110 
111 	switch (stopbits) {
112 	case 1:
113 		ulcon |= (UART_DM_SBL_1 << 2);
114 		break;
115 	case 2:
116 		ulcon |= (UART_DM_SBL_2 << 2);
117 		break;
118 	default:
119 		return (EINVAL);
120 	}
121 	uart_setreg(bas, UART_DM_MR2, ulcon);
122 	uart_barrier(bas);
123 
124 	return (0);
125 }
126 
127 struct uart_ops uart_msm_ops = {
128 	.probe = msm_probe,
129 	.init = msm_init,
130 	.term = msm_term,
131 	.putc = msm_putc,
132 	.rxready = msm_rxready,
133 	.getc = msm_getc,
134 };
135 
136 static int
137 msm_probe(struct uart_bas *bas)
138 {
139 
140 	bas->regiowidth = 4;
141 
142 	return (0);
143 }
144 
145 static void
146 msm_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
147     int parity)
148 {
149 
150 	if (bas->rclk == 0)
151 		bas->rclk = DEF_CLK;
152 
153 	KASSERT(bas->rclk != 0, ("msm_init: Invalid rclk"));
154 
155 	/* Set default parameters */
156 	msm_uart_param(bas, baudrate, databits, stopbits, parity);
157 
158 	/*
159 	 * Configure UART mode registers MR1 and MR2.
160 	 * Hardware flow control isn't supported.
161 	 */
162 	uart_setreg(bas, UART_DM_MR1, 0x0);
163 
164 	/* Reset interrupt mask register. */
165 	uart_setreg(bas, UART_DM_IMR, 0);
166 
167 	/*
168 	 * Configure Tx and Rx watermarks configuration registers.
169 	 * TX watermark value is set to 0 - interrupt is generated when
170 	 * FIFO level is less than or equal to 0.
171 	 */
172 	uart_setreg(bas, UART_DM_TFWR, UART_DM_TFW_VALUE);
173 
174 	/* Set RX watermark value */
175 	uart_setreg(bas, UART_DM_RFWR, UART_DM_RFW_VALUE);
176 
177 	/*
178 	 * Configure Interrupt Programming Register.
179 	 * Set initial Stale timeout value.
180 	 */
181 	uart_setreg(bas, UART_DM_IPR, UART_DM_STALE_TIMEOUT_LSB);
182 
183 	/* Disable IRDA mode */
184 	uart_setreg(bas, UART_DM_IRDA, 0x0);
185 
186 	/*
187 	 * Configure and enable sim interface if required.
188 	 * Configure hunt character value in HCR register.
189 	 * Keep it in reset state.
190 	 */
191 	uart_setreg(bas, UART_DM_HCR, 0x0);
192 
193 	/* Issue soft reset command */
194 	SETREG(bas, UART_DM_CR, UART_DM_RESET_TX);
195 	SETREG(bas, UART_DM_CR, UART_DM_RESET_RX);
196 	SETREG(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
197 	SETREG(bas, UART_DM_CR, UART_DM_RESET_BREAK_INT);
198 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
199 
200 	/* Enable/Disable Rx/Tx DM interfaces */
201 	uart_setreg(bas, UART_DM_DMEN, UART_DM_DMEN_RX_SC_ENABLE);
202 
203 	/* Enable transmitter and receiver */
204 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_RX_ENABLE);
205 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_TX_ENABLE);
206 
207 	uart_barrier(bas);
208 }
209 
210 static void
211 msm_term(struct uart_bas *bas)
212 {
213 
214 	/* XXX */
215 }
216 
217 static void
218 msm_putc(struct uart_bas *bas, int c)
219 {
220 	int limit;
221 
222 	/*
223 	 * Write to NO_CHARS_FOR_TX register the number of characters
224 	 * to be transmitted. However, before writing TX_FIFO must
225 	 * be empty as indicated by TX_READY interrupt in IMR register
226 	 */
227 
228 	/*
229 	 * Check if transmit FIFO is empty.
230 	 * If not wait for TX_READY interrupt.
231 	 */
232 	limit = 1000;
233 	if (!(uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXEMT)) {
234 		while ((uart_getreg(bas, UART_DM_ISR) & UART_DM_TX_READY) == 0
235 		    && --limit)
236 			DELAY(4);
237 		SETREG(bas, UART_DM_CR, UART_DM_CLEAR_TX_READY);
238 	}
239 	/* FIFO is ready, write number of characters to be written */
240 	uart_setreg(bas, UART_DM_NO_CHARS_FOR_TX, 1);
241 
242 	/* Wait till TX FIFO has space */
243 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXRDY) == 0)
244 		DELAY(4);
245 
246 	/* TX FIFO has space. Write char */
247 	SETREG(bas, UART_DM_TF(0), (c & 0xff));
248 }
249 
250 static int
251 msm_rxready(struct uart_bas *bas)
252 {
253 
254 	/* Wait for a character to come ready */
255 	return ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) ==
256 	    UART_DM_SR_RXRDY);
257 }
258 
259 static int
260 msm_getc(struct uart_bas *bas, struct mtx *mtx)
261 {
262 	int c;
263 
264 	uart_lock(mtx);
265 
266 	/* Wait for a character to come ready */
267 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) !=
268 	    UART_DM_SR_RXRDY)
269 		DELAY(4);
270 
271 	/* Check for Overrun error. If so reset Error Status */
272 	if (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_UART_OVERRUN)
273 		uart_setreg(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
274 
275 	/* Read char */
276 	c = uart_getreg(bas, UART_DM_RF(0));
277 
278 	uart_unlock(mtx);
279 
280 	return (c);
281 }
282 
283 /*
284  * High-level UART interface.
285  */
286 struct msm_uart_softc {
287 	struct uart_softc base;
288 	uint32_t ier;
289 };
290 
291 static int	msm_bus_probe(struct uart_softc *sc);
292 static int	msm_bus_attach(struct uart_softc *sc);
293 static int	msm_bus_flush(struct uart_softc *, int);
294 static int	msm_bus_getsig(struct uart_softc *);
295 static int	msm_bus_ioctl(struct uart_softc *, int, intptr_t);
296 static int	msm_bus_ipend(struct uart_softc *);
297 static int	msm_bus_param(struct uart_softc *, int, int, int, int);
298 static int	msm_bus_receive(struct uart_softc *);
299 static int	msm_bus_setsig(struct uart_softc *, int);
300 static int	msm_bus_transmit(struct uart_softc *);
301 static void	msm_bus_grab(struct uart_softc *);
302 static void	msm_bus_ungrab(struct uart_softc *);
303 
304 static kobj_method_t msm_methods[] = {
305 	KOBJMETHOD(uart_probe,		msm_bus_probe),
306 	KOBJMETHOD(uart_attach, 	msm_bus_attach),
307 	KOBJMETHOD(uart_flush,		msm_bus_flush),
308 	KOBJMETHOD(uart_getsig,		msm_bus_getsig),
309 	KOBJMETHOD(uart_ioctl,		msm_bus_ioctl),
310 	KOBJMETHOD(uart_ipend,		msm_bus_ipend),
311 	KOBJMETHOD(uart_param,		msm_bus_param),
312 	KOBJMETHOD(uart_receive,	msm_bus_receive),
313 	KOBJMETHOD(uart_setsig,		msm_bus_setsig),
314 	KOBJMETHOD(uart_transmit,	msm_bus_transmit),
315 	KOBJMETHOD(uart_grab,		msm_bus_grab),
316 	KOBJMETHOD(uart_ungrab,		msm_bus_ungrab),
317 	{0, 0 }
318 };
319 
320 int
321 msm_bus_probe(struct uart_softc *sc)
322 {
323 	struct uart_bas *bas;
324 
325 	bas = &sc->sc_bas;
326 	bas->regiowidth = 4;
327 
328 	sc->sc_txfifosz = 64;
329 	sc->sc_rxfifosz = 64;
330 
331 	device_set_desc(sc->sc_dev, "Qualcomm HSUART");
332 
333 	return (0);
334 }
335 
336 static int
337 msm_bus_attach(struct uart_softc *sc)
338 {
339 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
340 	struct uart_bas *bas = &sc->sc_bas;
341 
342 	sc->sc_hwiflow = 0;
343 	sc->sc_hwoflow = 0;
344 
345 	/* Set TX_READY, TXLEV, RXLEV, RXSTALE */
346 	u->ier = UART_DM_IMR_ENABLED;
347 
348 	/* Configure Interrupt Mask register IMR */
349 	uart_setreg(bas, UART_DM_IMR, u->ier);
350 
351 	return (0);
352 }
353 
354 /*
355  * Write the current transmit buffer to the TX FIFO.
356  */
357 static int
358 msm_bus_transmit(struct uart_softc *sc)
359 {
360 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
361 	struct uart_bas *bas = &sc->sc_bas;
362 	int i;
363 
364 	uart_lock(sc->sc_hwmtx);
365 
366 	/* Write some data */
367 	for (i = 0; i < sc->sc_txdatasz; i++) {
368 		/* Write TX data */
369 		msm_putc(bas, sc->sc_txbuf[i]);
370 		uart_barrier(bas);
371 	}
372 
373 	/* TX FIFO is empty now, enable TX_READY interrupt */
374 	u->ier |= UART_DM_TX_READY;
375 	SETREG(bas, UART_DM_IMR, u->ier);
376 	uart_barrier(bas);
377 
378 	/*
379 	 * Inform upper layer that it is transmitting data to hardware,
380 	 * this will be cleared when TXIDLE interrupt occurs.
381 	 */
382 	sc->sc_txbusy = 1;
383 	uart_unlock(sc->sc_hwmtx);
384 
385 	return (0);
386 }
387 
388 static int
389 msm_bus_setsig(struct uart_softc *sc, int sig)
390 {
391 
392 	return (0);
393 }
394 
395 static int
396 msm_bus_receive(struct uart_softc *sc)
397 {
398 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
399 	struct uart_bas *bas;
400 	int c;
401 
402 	bas = &sc->sc_bas;
403 	uart_lock(sc->sc_hwmtx);
404 
405 	/* Initialize Receive Path and interrupt */
406 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
407 	SETREG(bas, UART_DM_CR, UART_DM_STALE_EVENT_ENABLE);
408 	u->ier |= UART_DM_RXLEV;
409 	SETREG(bas, UART_DM_IMR, u->ier);
410 
411 	/* Loop over until we are full, or no data is available */
412 	while (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) {
413 		if (uart_rx_full(sc)) {
414 			/* No space left in input buffer */
415 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
416 			break;
417 		}
418 
419 		/* Read RX FIFO */
420 		c = uart_getreg(bas, UART_DM_RF(0));
421 		uart_barrier(bas);
422 
423 		uart_rx_put(sc, c);
424 	}
425 
426 	uart_unlock(sc->sc_hwmtx);
427 
428 	return (0);
429 }
430 
431 static int
432 msm_bus_param(struct uart_softc *sc, int baudrate, int databits,
433     int stopbits, int parity)
434 {
435 	int error;
436 
437 	if (sc->sc_bas.rclk == 0)
438 		sc->sc_bas.rclk = DEF_CLK;
439 
440 	KASSERT(sc->sc_bas.rclk != 0, ("msm_init: Invalid rclk"));
441 
442 	uart_lock(sc->sc_hwmtx);
443 	error = msm_uart_param(&sc->sc_bas, baudrate, databits, stopbits,
444 	    parity);
445 	uart_unlock(sc->sc_hwmtx);
446 
447 	return (error);
448 }
449 
450 static int
451 msm_bus_ipend(struct uart_softc *sc)
452 {
453 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
454 	struct uart_bas *bas = &sc->sc_bas;
455 	uint32_t isr;
456 	int ipend;
457 
458 	uart_lock(sc->sc_hwmtx);
459 
460 	/* Get ISR status */
461 	isr = GETREG(bas, UART_DM_MISR);
462 
463 	ipend = 0;
464 
465 	/* Uart RX starting, notify upper layer */
466 	if (isr & UART_DM_RXLEV) {
467 		u->ier &= ~UART_DM_RXLEV;
468 		SETREG(bas, UART_DM_IMR, u->ier);
469 		uart_barrier(bas);
470 		ipend |= SER_INT_RXREADY;
471 	}
472 
473 	/* Stale RX interrupt */
474 	if (isr & UART_DM_RXSTALE) {
475 		/* Disable and reset it */
476 		SETREG(bas, UART_DM_CR, UART_DM_STALE_EVENT_DISABLE);
477 		SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
478 		uart_barrier(bas);
479 		ipend |= SER_INT_RXREADY;
480 	}
481 
482 	/* TX READY interrupt */
483 	if (isr & UART_DM_TX_READY) {
484 		/* Clear  TX Ready */
485 		SETREG(bas, UART_DM_CR, UART_DM_CLEAR_TX_READY);
486 
487 		/* Disable TX_READY */
488 		u->ier &= ~UART_DM_TX_READY;
489 		SETREG(bas, UART_DM_IMR, u->ier);
490 		uart_barrier(bas);
491 
492 		if (sc->sc_txbusy != 0)
493 			ipend |= SER_INT_TXIDLE;
494 	}
495 
496 	if (isr & UART_DM_TXLEV) {
497 		/* TX FIFO is empty */
498 		u->ier &= ~UART_DM_TXLEV;
499 		SETREG(bas, UART_DM_IMR, u->ier);
500 		uart_barrier(bas);
501 
502 		if (sc->sc_txbusy != 0)
503 			ipend |= SER_INT_TXIDLE;
504 	}
505 
506 	uart_unlock(sc->sc_hwmtx);
507 	return (ipend);
508 }
509 
510 static int
511 msm_bus_flush(struct uart_softc *sc, int what)
512 {
513 
514 	return (0);
515 }
516 
517 static int
518 msm_bus_getsig(struct uart_softc *sc)
519 {
520 
521 	return (0);
522 }
523 
524 static int
525 msm_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
526 {
527 
528 	return (EINVAL);
529 }
530 
531 static void
532 msm_bus_grab(struct uart_softc *sc)
533 {
534 	struct uart_bas *bas = &sc->sc_bas;
535 
536 	/*
537 	 * XXX: Turn off all interrupts to enter polling mode. Leave the
538 	 * saved mask alone. We'll restore whatever it was in ungrab.
539 	 */
540 	uart_lock(sc->sc_hwmtx);
541 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
542 	SETREG(bas, UART_DM_IMR, 0);
543 	uart_barrier(bas);
544 	uart_unlock(sc->sc_hwmtx);
545 }
546 
547 static void
548 msm_bus_ungrab(struct uart_softc *sc)
549 {
550 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
551 	struct uart_bas *bas = &sc->sc_bas;
552 
553 	/*
554 	 * Restore previous interrupt mask
555 	 */
556 	uart_lock(sc->sc_hwmtx);
557 	SETREG(bas, UART_DM_IMR, u->ier);
558 	uart_barrier(bas);
559 	uart_unlock(sc->sc_hwmtx);
560 }
561 
562 static struct uart_class uart_msm_class = {
563 	"msm",
564 	msm_methods,
565 	sizeof(struct msm_uart_softc),
566 	.uc_ops = &uart_msm_ops,
567 	.uc_range = 8,
568 	.uc_rclk = DEF_CLK,
569 	.uc_rshift = 0
570 };
571 
572 static struct ofw_compat_data compat_data[] = {
573 	{"qcom,msm-uartdm-v1.4",	(uintptr_t)&uart_msm_class},
574 	{"qcom,msm-uartdm",		(uintptr_t)&uart_msm_class},
575 	{NULL,				(uintptr_t)NULL},
576 };
577 UART_FDT_CLASS_AND_DEVICE(compat_data);
578