xref: /freebsd/sys/dev/uart/uart_dev_msm.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
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 __FBSDID("$FreeBSD$");
31 
32 #include "opt_ddb.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/kdb.h>
39 #include <machine/bus.h>
40 
41 #include <dev/uart/uart.h>
42 #include <dev/uart/uart_cpu.h>
43 #include <dev/uart/uart_cpu_fdt.h>
44 #include <dev/uart/uart_bus.h>
45 #include <dev/uart/uart_dev_msm.h>
46 
47 #include "uart_if.h"
48 
49 #define	DEF_CLK		7372800
50 
51 #define	GETREG(bas, reg)	\
52     bus_space_read_4((bas)->bst, (bas)->bsh, (reg))
53 #define	SETREG(bas, reg, value)	\
54     bus_space_write_4((bas)->bst, (bas)->bsh, (reg), (value))
55 
56 static int msm_uart_param(struct uart_bas *, int, int, int, int);
57 
58 /*
59  * Low-level UART interface.
60  */
61 static int	msm_probe(struct uart_bas *bas);
62 static void	msm_init(struct uart_bas *bas, int, int, int, int);
63 static void	msm_term(struct uart_bas *bas);
64 static void	msm_putc(struct uart_bas *bas, int);
65 static int	msm_rxready(struct uart_bas *bas);
66 static int	msm_getc(struct uart_bas *bas, struct mtx *mtx);
67 
68 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
69 
70 static int
71 msm_uart_param(struct uart_bas *bas, int baudrate, int databits,
72     int stopbits, int parity)
73 {
74 	int ulcon;
75 
76 	ulcon = 0;
77 
78 	switch (databits) {
79 	case 5:
80 		ulcon |= (UART_DM_5_BPS << 4);
81 		break;
82 	case 6:
83 		ulcon |= (UART_DM_6_BPS << 4);
84 		break;
85 	case 7:
86 		ulcon |= (UART_DM_7_BPS << 4);
87 		break;
88 	case 8:
89 		ulcon |= (UART_DM_8_BPS << 4);
90 		break;
91 	default:
92 		return (EINVAL);
93 	}
94 
95 	switch (parity) {
96 	case UART_PARITY_NONE:
97 		ulcon |= UART_DM_NO_PARITY;
98 		break;
99 	case UART_PARITY_ODD:
100 		ulcon |= UART_DM_ODD_PARITY;
101 		break;
102 	case UART_PARITY_EVEN:
103 		ulcon |= UART_DM_EVEN_PARITY;
104 		break;
105 	case UART_PARITY_SPACE:
106 		ulcon |= UART_DM_SPACE_PARITY;
107 		break;
108 	case UART_PARITY_MARK:
109 	default:
110 		return (EINVAL);
111 	}
112 
113 	switch (stopbits) {
114 	case 1:
115 		ulcon |= (UART_DM_SBL_1 << 2);
116 		break;
117 	case 2:
118 		ulcon |= (UART_DM_SBL_2 << 2);
119 		break;
120 	default:
121 		return (EINVAL);
122 	}
123 	uart_setreg(bas, UART_DM_MR2, ulcon);
124 	uart_barrier(bas);
125 
126 	return (0);
127 }
128 
129 struct uart_ops uart_msm_ops = {
130 	.probe = msm_probe,
131 	.init = msm_init,
132 	.term = msm_term,
133 	.putc = msm_putc,
134 	.rxready = msm_rxready,
135 	.getc = msm_getc,
136 };
137 
138 static int
139 msm_probe(struct uart_bas *bas)
140 {
141 
142 	bas->regiowidth = 4;
143 
144 	return (0);
145 }
146 
147 static void
148 msm_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
149     int parity)
150 {
151 
152 	if (bas->rclk == 0)
153 		bas->rclk = DEF_CLK;
154 
155 	KASSERT(bas->rclk != 0, ("msm_init: Invalid rclk"));
156 
157 	/* Set default parameters */
158 	msm_uart_param(bas, baudrate, databits, stopbits, parity);
159 
160 	/*
161 	 * Configure UART mode registers MR1 and MR2.
162 	 * Hardware flow control isn't supported.
163 	 */
164 	uart_setreg(bas, UART_DM_MR1, 0x0);
165 
166 	/* Reset interrupt mask register. */
167 	uart_setreg(bas, UART_DM_IMR, 0);
168 
169 	/*
170 	 * Configure Tx and Rx watermarks configuration registers.
171 	 * TX watermark value is set to 0 - interrupt is generated when
172 	 * FIFO level is less than or equal to 0.
173 	 */
174 	uart_setreg(bas, UART_DM_TFWR, UART_DM_TFW_VALUE);
175 
176 	/* Set RX watermark value */
177 	uart_setreg(bas, UART_DM_RFWR, UART_DM_RFW_VALUE);
178 
179 	/*
180 	 * Configure Interrupt Programming Register.
181 	 * Set initial Stale timeout value.
182 	 */
183 	uart_setreg(bas, UART_DM_IPR, UART_DM_STALE_TIMEOUT_LSB);
184 
185 	/* Disable IRDA mode */
186 	uart_setreg(bas, UART_DM_IRDA, 0x0);
187 
188 	/*
189 	 * Configure and enable sim interface if required.
190 	 * Configure hunt character value in HCR register.
191 	 * Keep it in reset state.
192 	 */
193 	uart_setreg(bas, UART_DM_HCR, 0x0);
194 
195 	/* Issue soft reset command */
196 	SETREG(bas, UART_DM_CR, UART_DM_RESET_TX);
197 	SETREG(bas, UART_DM_CR, UART_DM_RESET_RX);
198 	SETREG(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
199 	SETREG(bas, UART_DM_CR, UART_DM_RESET_BREAK_INT);
200 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
201 
202 	/* Enable/Disable Rx/Tx DM interfaces */
203 	uart_setreg(bas, UART_DM_DMEN, UART_DM_DMEN_RX_SC_ENABLE);
204 
205 	/* Enable transmitter and receiver */
206 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_RX_ENABLE);
207 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_TX_ENABLE);
208 
209 	uart_barrier(bas);
210 }
211 
212 static void
213 msm_term(struct uart_bas *bas)
214 {
215 
216 	/* XXX */
217 }
218 
219 static void
220 msm_putc(struct uart_bas *bas, int c)
221 {
222 	int limit;
223 
224 	/*
225 	 * Write to NO_CHARS_FOR_TX register the number of characters
226 	 * to be transmitted. However, before writing TX_FIFO must
227 	 * be empty as indicated by TX_READY interrupt in IMR register
228 	 */
229 
230 	/*
231 	 * Check if transmit FIFO is empty.
232 	 * If not wait for TX_READY interrupt.
233 	 */
234 	limit = 1000;
235 	if (!(uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXEMT)) {
236 		while ((uart_getreg(bas, UART_DM_ISR) & UART_DM_TX_READY) == 0
237 		    && --limit)
238 			DELAY(4);
239 		SETREG(bas, UART_DM_CR, UART_DM_CLEAR_TX_READY);
240 	}
241 	/* FIFO is ready, write number of characters to be written */
242 	uart_setreg(bas, UART_DM_NO_CHARS_FOR_TX, 1);
243 
244 	/* Wait till TX FIFO has space */
245 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXRDY) == 0)
246 		DELAY(4);
247 
248 	/* TX FIFO has space. Write char */
249 	SETREG(bas, UART_DM_TF(0), (c & 0xff));
250 }
251 
252 static int
253 msm_rxready(struct uart_bas *bas)
254 {
255 
256 	/* Wait for a character to come ready */
257 	return ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) ==
258 	    UART_DM_SR_RXRDY);
259 }
260 
261 static int
262 msm_getc(struct uart_bas *bas, struct mtx *mtx)
263 {
264 	int c;
265 
266 	uart_lock(mtx);
267 
268 	/* Wait for a character to come ready */
269 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) !=
270 	    UART_DM_SR_RXRDY)
271 		DELAY(4);
272 
273 	/* Check for Overrun error. If so reset Error Status */
274 	if (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_UART_OVERRUN)
275 		uart_setreg(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
276 
277 	/* Read char */
278 	c = uart_getreg(bas, UART_DM_RF(0));
279 
280 	uart_unlock(mtx);
281 
282 	return (c);
283 }
284 
285 /*
286  * High-level UART interface.
287  */
288 struct msm_uart_softc {
289 	struct uart_softc base;
290 	uint32_t ier;
291 };
292 
293 static int	msm_bus_probe(struct uart_softc *sc);
294 static int	msm_bus_attach(struct uart_softc *sc);
295 static int	msm_bus_flush(struct uart_softc *, int);
296 static int	msm_bus_getsig(struct uart_softc *);
297 static int	msm_bus_ioctl(struct uart_softc *, int, intptr_t);
298 static int	msm_bus_ipend(struct uart_softc *);
299 static int	msm_bus_param(struct uart_softc *, int, int, int, int);
300 static int	msm_bus_receive(struct uart_softc *);
301 static int	msm_bus_setsig(struct uart_softc *, int);
302 static int	msm_bus_transmit(struct uart_softc *);
303 static void	msm_bus_grab(struct uart_softc *);
304 static void	msm_bus_ungrab(struct uart_softc *);
305 
306 static kobj_method_t msm_methods[] = {
307 	KOBJMETHOD(uart_probe,		msm_bus_probe),
308 	KOBJMETHOD(uart_attach, 	msm_bus_attach),
309 	KOBJMETHOD(uart_flush,		msm_bus_flush),
310 	KOBJMETHOD(uart_getsig,		msm_bus_getsig),
311 	KOBJMETHOD(uart_ioctl,		msm_bus_ioctl),
312 	KOBJMETHOD(uart_ipend,		msm_bus_ipend),
313 	KOBJMETHOD(uart_param,		msm_bus_param),
314 	KOBJMETHOD(uart_receive,	msm_bus_receive),
315 	KOBJMETHOD(uart_setsig,		msm_bus_setsig),
316 	KOBJMETHOD(uart_transmit,	msm_bus_transmit),
317 	KOBJMETHOD(uart_grab,		msm_bus_grab),
318 	KOBJMETHOD(uart_ungrab,		msm_bus_ungrab),
319 	{0, 0 }
320 };
321 
322 int
323 msm_bus_probe(struct uart_softc *sc)
324 {
325 	struct uart_bas *bas;
326 
327 	bas = &sc->sc_bas;
328 	bas->regiowidth = 4;
329 
330 	sc->sc_txfifosz = 64;
331 	sc->sc_rxfifosz = 64;
332 
333 	device_set_desc(sc->sc_dev, "Qualcomm HSUART");
334 
335 	return (0);
336 }
337 
338 static int
339 msm_bus_attach(struct uart_softc *sc)
340 {
341 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
342 	struct uart_bas *bas = &sc->sc_bas;
343 
344 	sc->sc_hwiflow = 0;
345 	sc->sc_hwoflow = 0;
346 
347 	/* Set TX_READY, TXLEV, RXLEV, RXSTALE */
348 	u->ier = UART_DM_IMR_ENABLED;
349 
350 	/* Configure Interrupt Mask register IMR */
351 	uart_setreg(bas, UART_DM_IMR, u->ier);
352 
353 	return (0);
354 }
355 
356 /*
357  * Write the current transmit buffer to the TX FIFO.
358  */
359 static int
360 msm_bus_transmit(struct uart_softc *sc)
361 {
362 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
363 	struct uart_bas *bas = &sc->sc_bas;
364 	int i;
365 
366 	uart_lock(sc->sc_hwmtx);
367 
368 	/* Write some data */
369 	for (i = 0; i < sc->sc_txdatasz; i++) {
370 		/* Write TX data */
371 		msm_putc(bas, sc->sc_txbuf[i]);
372 		uart_barrier(bas);
373 	}
374 
375 	/* TX FIFO is empty now, enable TX_READY interrupt */
376 	u->ier |= UART_DM_TX_READY;
377 	SETREG(bas, UART_DM_IMR, u->ier);
378 	uart_barrier(bas);
379 
380 	/*
381 	 * Inform upper layer that it is transmitting data to hardware,
382 	 * this will be cleared when TXIDLE interrupt occurs.
383 	 */
384 	sc->sc_txbusy = 1;
385 	uart_unlock(sc->sc_hwmtx);
386 
387 	return (0);
388 }
389 
390 static int
391 msm_bus_setsig(struct uart_softc *sc, int sig)
392 {
393 
394 	return (0);
395 }
396 
397 static int
398 msm_bus_receive(struct uart_softc *sc)
399 {
400 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
401 	struct uart_bas *bas;
402 	int c;
403 
404 	bas = &sc->sc_bas;
405 	uart_lock(sc->sc_hwmtx);
406 
407 	/* Initialize Receive Path and interrupt */
408 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
409 	SETREG(bas, UART_DM_CR, UART_DM_STALE_EVENT_ENABLE);
410 	u->ier |= UART_DM_RXLEV;
411 	SETREG(bas, UART_DM_IMR, u->ier);
412 
413 	/* Loop over until we are full, or no data is available */
414 	while (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) {
415 		if (uart_rx_full(sc)) {
416 			/* No space left in input buffer */
417 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
418 			break;
419 		}
420 
421 		/* Read RX FIFO */
422 		c = uart_getreg(bas, UART_DM_RF(0));
423 		uart_barrier(bas);
424 
425 		uart_rx_put(sc, c);
426 	}
427 
428 	uart_unlock(sc->sc_hwmtx);
429 
430 	return (0);
431 }
432 
433 static int
434 msm_bus_param(struct uart_softc *sc, int baudrate, int databits,
435     int stopbits, int parity)
436 {
437 	int error;
438 
439 	if (sc->sc_bas.rclk == 0)
440 		sc->sc_bas.rclk = DEF_CLK;
441 
442 	KASSERT(sc->sc_bas.rclk != 0, ("msm_init: Invalid rclk"));
443 
444 	uart_lock(sc->sc_hwmtx);
445 	error = msm_uart_param(&sc->sc_bas, baudrate, databits, stopbits,
446 	    parity);
447 	uart_unlock(sc->sc_hwmtx);
448 
449 	return (error);
450 }
451 
452 static int
453 msm_bus_ipend(struct uart_softc *sc)
454 {
455 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
456 	struct uart_bas *bas = &sc->sc_bas;
457 	uint32_t isr;
458 	int ipend;
459 
460 	uart_lock(sc->sc_hwmtx);
461 
462 	/* Get ISR status */
463 	isr = GETREG(bas, UART_DM_MISR);
464 
465 	ipend = 0;
466 
467 	/* Uart RX starting, notify upper layer */
468 	if (isr & UART_DM_RXLEV) {
469 		u->ier &= ~UART_DM_RXLEV;
470 		SETREG(bas, UART_DM_IMR, u->ier);
471 		uart_barrier(bas);
472 		ipend |= SER_INT_RXREADY;
473 	}
474 
475 	/* Stale RX interrupt */
476 	if (isr & UART_DM_RXSTALE) {
477 		/* Disable and reset it */
478 		SETREG(bas, UART_DM_CR, UART_DM_STALE_EVENT_DISABLE);
479 		SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
480 		uart_barrier(bas);
481 		ipend |= SER_INT_RXREADY;
482 	}
483 
484 	/* TX READY interrupt */
485 	if (isr & UART_DM_TX_READY) {
486 		/* Clear  TX Ready */
487 		SETREG(bas, UART_DM_CR, UART_DM_CLEAR_TX_READY);
488 
489 		/* Disable TX_READY */
490 		u->ier &= ~UART_DM_TX_READY;
491 		SETREG(bas, UART_DM_IMR, u->ier);
492 		uart_barrier(bas);
493 
494 		if (sc->sc_txbusy != 0)
495 			ipend |= SER_INT_TXIDLE;
496 	}
497 
498 	if (isr & UART_DM_TXLEV) {
499 		/* TX FIFO is empty */
500 		u->ier &= ~UART_DM_TXLEV;
501 		SETREG(bas, UART_DM_IMR, u->ier);
502 		uart_barrier(bas);
503 
504 		if (sc->sc_txbusy != 0)
505 			ipend |= SER_INT_TXIDLE;
506 	}
507 
508 	uart_unlock(sc->sc_hwmtx);
509 	return (ipend);
510 }
511 
512 static int
513 msm_bus_flush(struct uart_softc *sc, int what)
514 {
515 
516 	return (0);
517 }
518 
519 static int
520 msm_bus_getsig(struct uart_softc *sc)
521 {
522 
523 	return (0);
524 }
525 
526 static int
527 msm_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
528 {
529 
530 	return (EINVAL);
531 }
532 
533 static void
534 msm_bus_grab(struct uart_softc *sc)
535 {
536 	struct uart_bas *bas = &sc->sc_bas;
537 
538 	/*
539 	 * XXX: Turn off all interrupts to enter polling mode. Leave the
540 	 * saved mask alone. We'll restore whatever it was in ungrab.
541 	 */
542 	uart_lock(sc->sc_hwmtx);
543 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
544 	SETREG(bas, UART_DM_IMR, 0);
545 	uart_barrier(bas);
546 	uart_unlock(sc->sc_hwmtx);
547 }
548 
549 static void
550 msm_bus_ungrab(struct uart_softc *sc)
551 {
552 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
553 	struct uart_bas *bas = &sc->sc_bas;
554 
555 	/*
556 	 * Restore previous interrupt mask
557 	 */
558 	uart_lock(sc->sc_hwmtx);
559 	SETREG(bas, UART_DM_IMR, u->ier);
560 	uart_barrier(bas);
561 	uart_unlock(sc->sc_hwmtx);
562 }
563 
564 static struct uart_class uart_msm_class = {
565 	"msm",
566 	msm_methods,
567 	sizeof(struct msm_uart_softc),
568 	.uc_ops = &uart_msm_ops,
569 	.uc_range = 8,
570 	.uc_rclk = DEF_CLK,
571 	.uc_rshift = 0
572 };
573 
574 static struct ofw_compat_data compat_data[] = {
575 	{"qcom,msm-uartdm-v1.4",	(uintptr_t)&uart_msm_class},
576 	{"qcom,msm-uartdm",		(uintptr_t)&uart_msm_class},
577 	{NULL,				(uintptr_t)NULL},
578 };
579 UART_FDT_CLASS_AND_DEVICE(compat_data);
580