xref: /freebsd/sys/dev/uart/uart_dev_msm.c (revision e8e8c939350bdf3c228a411caa9660c607c27a11)
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 #include <machine/fdt.h>
41 
42 #include <dev/uart/uart.h>
43 #include <dev/uart/uart_cpu.h>
44 #include <dev/uart/uart_cpu_fdt.h>
45 #include <dev/uart/uart_bus.h>
46 #include <dev/uart/uart_dev_msm.h>
47 
48 #include "uart_if.h"
49 
50 #define	DEF_CLK		7372800
51 
52 #define	GETREG(bas, reg)	\
53     bus_space_read_4((bas)->bst, (bas)->bsh, (reg))
54 #define	SETREG(bas, reg, value)	\
55     bus_space_write_4((bas)->bst, (bas)->bsh, (reg), (value))
56 
57 static int msm_uart_param(struct uart_bas *, int, int, int, int);
58 
59 /*
60  * Low-level UART interface.
61  */
62 static int	msm_probe(struct uart_bas *bas);
63 static void	msm_init(struct uart_bas *bas, int, int, int, int);
64 static void	msm_term(struct uart_bas *bas);
65 static void	msm_putc(struct uart_bas *bas, int);
66 static int	msm_rxready(struct uart_bas *bas);
67 static int	msm_getc(struct uart_bas *bas, struct mtx *mtx);
68 
69 extern SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs;
70 
71 static int
72 msm_uart_param(struct uart_bas *bas, int baudrate, int databits,
73     int stopbits, int parity)
74 {
75 	int ulcon;
76 
77 	ulcon = 0;
78 
79 	switch (databits) {
80 	case 5:
81 		ulcon |= (UART_DM_5_BPS << 4);
82 		break;
83 	case 6:
84 		ulcon |= (UART_DM_6_BPS << 4);
85 		break;
86 	case 7:
87 		ulcon |= (UART_DM_7_BPS << 4);
88 		break;
89 	case 8:
90 		ulcon |= (UART_DM_8_BPS << 4);
91 		break;
92 	default:
93 		return (EINVAL);
94 	}
95 
96 	switch (parity) {
97 	case UART_PARITY_NONE:
98 		ulcon |= UART_DM_NO_PARITY;
99 		break;
100 	case UART_PARITY_ODD:
101 		ulcon |= UART_DM_ODD_PARITY;
102 		break;
103 	case UART_PARITY_EVEN:
104 		ulcon |= UART_DM_EVEN_PARITY;
105 		break;
106 	case UART_PARITY_SPACE:
107 		ulcon |= UART_DM_SPACE_PARITY;
108 		break;
109 	case UART_PARITY_MARK:
110 	default:
111 		return (EINVAL);
112 	}
113 
114 	switch (stopbits) {
115 	case 1:
116 		ulcon |= (UART_DM_SBL_1 << 2);
117 		break;
118 	case 2:
119 		ulcon |= (UART_DM_SBL_2 << 2);
120 		break;
121 	default:
122 		return (EINVAL);
123 	}
124 	uart_setreg(bas, UART_DM_MR2, ulcon);
125 
126 	/* Set 115200 for both TX and RX. */;
127 	uart_setreg(bas, UART_DM_CSR, UART_DM_CSR_115200);
128 	uart_barrier(bas);
129 
130 	return (0);
131 }
132 
133 struct uart_ops uart_msm_ops = {
134 	.probe = msm_probe,
135 	.init = msm_init,
136 	.term = msm_term,
137 	.putc = msm_putc,
138 	.rxready = msm_rxready,
139 	.getc = msm_getc,
140 };
141 
142 static int
143 msm_probe(struct uart_bas *bas)
144 {
145 
146 	return (0);
147 }
148 
149 static void
150 msm_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
151     int parity)
152 {
153 
154 	if (bas->rclk == 0)
155 		bas->rclk = DEF_CLK;
156 
157 	KASSERT(bas->rclk != 0, ("msm_init: Invalid rclk"));
158 
159 	/* Set default parameters */
160 	msm_uart_param(bas, baudrate, databits, stopbits, parity);
161 
162 	/*
163 	 * Configure UART mode registers MR1 and MR2.
164 	 * Hardware flow control isn't supported.
165 	 */
166 	uart_setreg(bas, UART_DM_MR1, 0x0);
167 
168 	/* Reset interrupt mask register. */
169 	uart_setreg(bas, UART_DM_IMR, 0);
170 
171 	/*
172 	 * Configure Tx and Rx watermarks configuration registers.
173 	 * TX watermark value is set to 0 - interrupt is generated when
174 	 * FIFO level is less than or equal to 0.
175 	 */
176 	uart_setreg(bas, UART_DM_TFWR, UART_DM_TFW_VALUE);
177 
178 	/* Set RX watermark value */
179 	uart_setreg(bas, UART_DM_RFWR, UART_DM_RFW_VALUE);
180 
181 	/*
182 	 * Configure Interrupt Programming Register.
183 	 * Set initial Stale timeout value.
184 	 */
185 	uart_setreg(bas, UART_DM_IPR, UART_DM_STALE_TIMEOUT_LSB);
186 
187 	/* Disable IRDA mode */
188 	uart_setreg(bas, UART_DM_IRDA, 0x0);
189 
190 	/*
191 	 * Configure and enable sim interface if required.
192 	 * Configure hunt character value in HCR register.
193 	 * Keep it in reset state.
194 	 */
195 	uart_setreg(bas, UART_DM_HCR, 0x0);
196 
197 	/* Issue soft reset command */
198 	SETREG(bas, UART_DM_CR, UART_DM_RESET_TX);
199 	SETREG(bas, UART_DM_CR, UART_DM_RESET_RX);
200 	SETREG(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
201 	SETREG(bas, UART_DM_CR, UART_DM_RESET_BREAK_INT);
202 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
203 
204 	/* Enable/Disable Rx/Tx DM interfaces */
205 	/* Disable Data Mover for now. */
206 	uart_setreg(bas, UART_DM_DMEN, 0x0);
207 
208 	/* Enable transmitter and receiver */
209 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_RX_ENABLE);
210 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_TX_ENABLE);
211 
212 	uart_barrier(bas);
213 }
214 
215 static void
216 msm_term(struct uart_bas *bas)
217 {
218 
219 	/* XXX */
220 }
221 
222 static void
223 msm_putc(struct uart_bas *bas, int c)
224 {
225 	int limit;
226 
227 	/*
228 	 * Write to NO_CHARS_FOR_TX register the number of characters
229 	 * to be transmitted. However, before writing TX_FIFO must
230 	 * be empty as indicated by TX_READY interrupt in IMR register
231 	 */
232 
233 	/*
234 	 * Check if transmit FIFO is empty.
235 	 * If not wait for TX_READY interrupt.
236 	 */
237 	limit = 1000;
238 	if (!(uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXEMT)) {
239 		while ((uart_getreg(bas, UART_DM_ISR) & UART_DM_TX_READY) == 0
240 		    && --limit)
241 			DELAY(4);
242 	}
243 	/* FIFO is ready, write number of characters to be written */
244 	uart_setreg(bas, UART_DM_NO_CHARS_FOR_TX, 1);
245 
246 	/* Wait till TX FIFO has space */
247 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXRDY) == 0)
248 		DELAY(4);
249 
250 	/* TX FIFO has space. Write char */
251 	SETREG(bas, UART_DM_TF(0), (c & 0xff));
252 }
253 
254 static int
255 msm_rxready(struct uart_bas *bas)
256 {
257 
258 	/* Wait for a character to come ready */
259 	return ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) ==
260 	    UART_DM_SR_RXRDY);
261 }
262 
263 static int
264 msm_getc(struct uart_bas *bas, struct mtx *mtx)
265 {
266 	int c;
267 
268 	uart_lock(mtx);
269 
270 	/* Wait for a character to come ready */
271 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) !=
272 	    UART_DM_SR_RXRDY)
273 		DELAY(4);
274 
275 	/* Check for Overrun error. If so reset Error Status */
276 	if (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_UART_OVERRUN)
277 		uart_setreg(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
278 
279 	/* Read char */
280 	c = uart_getreg(bas, UART_DM_RF(0));
281 
282 	uart_unlock(mtx);
283 
284 	return (c);
285 }
286 
287 /*
288  * High-level UART interface.
289  */
290 struct msm_uart_softc {
291 	struct uart_softc base;
292 	uint32_t ier;
293 };
294 
295 static int	msm_bus_probe(struct uart_softc *sc);
296 static int	msm_bus_attach(struct uart_softc *sc);
297 static int	msm_bus_flush(struct uart_softc *, int);
298 static int	msm_bus_getsig(struct uart_softc *);
299 static int	msm_bus_ioctl(struct uart_softc *, int, intptr_t);
300 static int	msm_bus_ipend(struct uart_softc *);
301 static int	msm_bus_param(struct uart_softc *, int, int, int, int);
302 static int	msm_bus_receive(struct uart_softc *);
303 static int	msm_bus_setsig(struct uart_softc *, int);
304 static int	msm_bus_transmit(struct uart_softc *);
305 static void	msm_bus_grab(struct uart_softc *);
306 static void	msm_bus_ungrab(struct uart_softc *);
307 
308 static kobj_method_t msm_methods[] = {
309 	KOBJMETHOD(uart_probe,		msm_bus_probe),
310 	KOBJMETHOD(uart_attach, 	msm_bus_attach),
311 	KOBJMETHOD(uart_flush,		msm_bus_flush),
312 	KOBJMETHOD(uart_getsig,		msm_bus_getsig),
313 	KOBJMETHOD(uart_ioctl,		msm_bus_ioctl),
314 	KOBJMETHOD(uart_ipend,		msm_bus_ipend),
315 	KOBJMETHOD(uart_param,		msm_bus_param),
316 	KOBJMETHOD(uart_receive,	msm_bus_receive),
317 	KOBJMETHOD(uart_setsig,		msm_bus_setsig),
318 	KOBJMETHOD(uart_transmit,	msm_bus_transmit),
319 	KOBJMETHOD(uart_grab,		msm_bus_grab),
320 	KOBJMETHOD(uart_ungrab,		msm_bus_ungrab),
321 	{0, 0 }
322 };
323 
324 int
325 msm_bus_probe(struct uart_softc *sc)
326 {
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",	(uintptr_t)&uart_msm_class},
574 	{NULL,			(uintptr_t)NULL},
575 };
576 UART_FDT_CLASS_AND_DEVICE(compat_data);
577