xref: /freebsd/sys/dev/uart/uart_dev_msm.c (revision 9268022b74279434ed6300244e3f977e56a8ceb5)
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_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 
125 	/* Set 115200 for both TX and RX. */;
126 	uart_setreg(bas, UART_DM_CSR, UART_DM_CSR_115200);
127 	uart_barrier(bas);
128 
129 	return (0);
130 }
131 
132 struct uart_ops uart_msm_ops = {
133 	.probe = msm_probe,
134 	.init = msm_init,
135 	.term = msm_term,
136 	.putc = msm_putc,
137 	.rxready = msm_rxready,
138 	.getc = msm_getc,
139 };
140 
141 static int
142 msm_probe(struct uart_bas *bas)
143 {
144 
145 	return (0);
146 }
147 
148 static void
149 msm_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
150     int parity)
151 {
152 
153 	if (bas->rclk == 0)
154 		bas->rclk = DEF_CLK;
155 
156 	KASSERT(bas->rclk != 0, ("msm_init: Invalid rclk"));
157 
158 	/* Set default parameters */
159 	msm_uart_param(bas, baudrate, databits, stopbits, parity);
160 
161 	/*
162 	 * Configure UART mode registers MR1 and MR2.
163 	 * Hardware flow control isn't supported.
164 	 */
165 	uart_setreg(bas, UART_DM_MR1, 0x0);
166 
167 	/* Reset interrupt mask register. */
168 	uart_setreg(bas, UART_DM_IMR, 0);
169 
170 	/*
171 	 * Configure Tx and Rx watermarks configuration registers.
172 	 * TX watermark value is set to 0 - interrupt is generated when
173 	 * FIFO level is less than or equal to 0.
174 	 */
175 	uart_setreg(bas, UART_DM_TFWR, UART_DM_TFW_VALUE);
176 
177 	/* Set RX watermark value */
178 	uart_setreg(bas, UART_DM_RFWR, UART_DM_RFW_VALUE);
179 
180 	/*
181 	 * Configure Interrupt Programming Register.
182 	 * Set initial Stale timeout value.
183 	 */
184 	uart_setreg(bas, UART_DM_IPR, UART_DM_STALE_TIMEOUT_LSB);
185 
186 	/* Disable IRDA mode */
187 	uart_setreg(bas, UART_DM_IRDA, 0x0);
188 
189 	/*
190 	 * Configure and enable sim interface if required.
191 	 * Configure hunt character value in HCR register.
192 	 * Keep it in reset state.
193 	 */
194 	uart_setreg(bas, UART_DM_HCR, 0x0);
195 
196 	/* Issue soft reset command */
197 	SETREG(bas, UART_DM_CR, UART_DM_RESET_TX);
198 	SETREG(bas, UART_DM_CR, UART_DM_RESET_RX);
199 	SETREG(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
200 	SETREG(bas, UART_DM_CR, UART_DM_RESET_BREAK_INT);
201 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
202 
203 	/* Enable/Disable Rx/Tx DM interfaces */
204 	/* Disable Data Mover for now. */
205 	uart_setreg(bas, UART_DM_DMEN, 0x0);
206 
207 	/* Enable transmitter and receiver */
208 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_RX_ENABLE);
209 	uart_setreg(bas, UART_DM_CR, UART_DM_CR_TX_ENABLE);
210 
211 	uart_barrier(bas);
212 }
213 
214 static void
215 msm_term(struct uart_bas *bas)
216 {
217 
218 	/* XXX */
219 }
220 
221 static void
222 msm_putc(struct uart_bas *bas, int c)
223 {
224 	int limit;
225 
226 	/*
227 	 * Write to NO_CHARS_FOR_TX register the number of characters
228 	 * to be transmitted. However, before writing TX_FIFO must
229 	 * be empty as indicated by TX_READY interrupt in IMR register
230 	 */
231 
232 	/*
233 	 * Check if transmit FIFO is empty.
234 	 * If not wait for TX_READY interrupt.
235 	 */
236 	limit = 1000;
237 	if (!(uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXEMT)) {
238 		while ((uart_getreg(bas, UART_DM_ISR) & UART_DM_TX_READY) == 0
239 		    && --limit)
240 			DELAY(4);
241 	}
242 	/* FIFO is ready, write number of characters to be written */
243 	uart_setreg(bas, UART_DM_NO_CHARS_FOR_TX, 1);
244 
245 	/* Wait till TX FIFO has space */
246 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_TXRDY) == 0)
247 		DELAY(4);
248 
249 	/* TX FIFO has space. Write char */
250 	SETREG(bas, UART_DM_TF(0), (c & 0xff));
251 }
252 
253 static int
254 msm_rxready(struct uart_bas *bas)
255 {
256 
257 	/* Wait for a character to come ready */
258 	return ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) ==
259 	    UART_DM_SR_RXRDY);
260 }
261 
262 static int
263 msm_getc(struct uart_bas *bas, struct mtx *mtx)
264 {
265 	int c;
266 
267 	uart_lock(mtx);
268 
269 	/* Wait for a character to come ready */
270 	while ((uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) !=
271 	    UART_DM_SR_RXRDY)
272 		DELAY(4);
273 
274 	/* Check for Overrun error. If so reset Error Status */
275 	if (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_UART_OVERRUN)
276 		uart_setreg(bas, UART_DM_CR, UART_DM_RESET_ERROR_STATUS);
277 
278 	/* Read char */
279 	c = uart_getreg(bas, UART_DM_RF(0));
280 
281 	uart_unlock(mtx);
282 
283 	return (c);
284 }
285 
286 /*
287  * High-level UART interface.
288  */
289 struct msm_uart_softc {
290 	struct uart_softc base;
291 	uint32_t ier;
292 };
293 
294 static int	msm_bus_probe(struct uart_softc *sc);
295 static int	msm_bus_attach(struct uart_softc *sc);
296 static int	msm_bus_flush(struct uart_softc *, int);
297 static int	msm_bus_getsig(struct uart_softc *);
298 static int	msm_bus_ioctl(struct uart_softc *, int, intptr_t);
299 static int	msm_bus_ipend(struct uart_softc *);
300 static int	msm_bus_param(struct uart_softc *, int, int, int, int);
301 static int	msm_bus_receive(struct uart_softc *);
302 static int	msm_bus_setsig(struct uart_softc *, int);
303 static int	msm_bus_transmit(struct uart_softc *);
304 static void	msm_bus_grab(struct uart_softc *);
305 static void	msm_bus_ungrab(struct uart_softc *);
306 
307 static kobj_method_t msm_methods[] = {
308 	KOBJMETHOD(uart_probe,		msm_bus_probe),
309 	KOBJMETHOD(uart_attach, 	msm_bus_attach),
310 	KOBJMETHOD(uart_flush,		msm_bus_flush),
311 	KOBJMETHOD(uart_getsig,		msm_bus_getsig),
312 	KOBJMETHOD(uart_ioctl,		msm_bus_ioctl),
313 	KOBJMETHOD(uart_ipend,		msm_bus_ipend),
314 	KOBJMETHOD(uart_param,		msm_bus_param),
315 	KOBJMETHOD(uart_receive,	msm_bus_receive),
316 	KOBJMETHOD(uart_setsig,		msm_bus_setsig),
317 	KOBJMETHOD(uart_transmit,	msm_bus_transmit),
318 	KOBJMETHOD(uart_grab,		msm_bus_grab),
319 	KOBJMETHOD(uart_ungrab,		msm_bus_ungrab),
320 	{0, 0 }
321 };
322 
323 int
324 msm_bus_probe(struct uart_softc *sc)
325 {
326 
327 	sc->sc_txfifosz = 64;
328 	sc->sc_rxfifosz = 64;
329 
330 	device_set_desc(sc->sc_dev, "Qualcomm HSUART");
331 
332 	return (0);
333 }
334 
335 static int
336 msm_bus_attach(struct uart_softc *sc)
337 {
338 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
339 	struct uart_bas *bas = &sc->sc_bas;
340 
341 	sc->sc_hwiflow = 0;
342 	sc->sc_hwoflow = 0;
343 
344 	/* Set TX_READY, TXLEV, RXLEV, RXSTALE */
345 	u->ier = UART_DM_IMR_ENABLED;
346 
347 	/* Configure Interrupt Mask register IMR */
348 	uart_setreg(bas, UART_DM_IMR, u->ier);
349 
350 	return (0);
351 }
352 
353 /*
354  * Write the current transmit buffer to the TX FIFO.
355  */
356 static int
357 msm_bus_transmit(struct uart_softc *sc)
358 {
359 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
360 	struct uart_bas *bas = &sc->sc_bas;
361 	int i;
362 
363 	uart_lock(sc->sc_hwmtx);
364 
365 	/* Write some data */
366 	for (i = 0; i < sc->sc_txdatasz; i++) {
367 		/* Write TX data */
368 		msm_putc(bas, sc->sc_txbuf[i]);
369 		uart_barrier(bas);
370 	}
371 
372 	/* TX FIFO is empty now, enable TX_READY interrupt */
373 	u->ier |= UART_DM_TX_READY;
374 	SETREG(bas, UART_DM_IMR, u->ier);
375 	uart_barrier(bas);
376 
377 	/*
378 	 * Inform upper layer that it is transmitting data to hardware,
379 	 * this will be cleared when TXIDLE interrupt occurs.
380 	 */
381 	sc->sc_txbusy = 1;
382 	uart_unlock(sc->sc_hwmtx);
383 
384 	return (0);
385 }
386 
387 static int
388 msm_bus_setsig(struct uart_softc *sc, int sig)
389 {
390 
391 	return (0);
392 }
393 
394 static int
395 msm_bus_receive(struct uart_softc *sc)
396 {
397 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
398 	struct uart_bas *bas;
399 	int c;
400 
401 	bas = &sc->sc_bas;
402 	uart_lock(sc->sc_hwmtx);
403 
404 	/* Initialize Receive Path and interrupt */
405 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
406 	SETREG(bas, UART_DM_CR, UART_DM_STALE_EVENT_ENABLE);
407 	u->ier |= UART_DM_RXLEV;
408 	SETREG(bas, UART_DM_IMR, u->ier);
409 
410 	/* Loop over until we are full, or no data is available */
411 	while (uart_getreg(bas, UART_DM_SR) & UART_DM_SR_RXRDY) {
412 		if (uart_rx_full(sc)) {
413 			/* No space left in input buffer */
414 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
415 			break;
416 		}
417 
418 		/* Read RX FIFO */
419 		c = uart_getreg(bas, UART_DM_RF(0));
420 		uart_barrier(bas);
421 
422 		uart_rx_put(sc, c);
423 	}
424 
425 	uart_unlock(sc->sc_hwmtx);
426 
427 	return (0);
428 }
429 
430 static int
431 msm_bus_param(struct uart_softc *sc, int baudrate, int databits,
432     int stopbits, int parity)
433 {
434 	int error;
435 
436 	if (sc->sc_bas.rclk == 0)
437 		sc->sc_bas.rclk = DEF_CLK;
438 
439 	KASSERT(sc->sc_bas.rclk != 0, ("msm_init: Invalid rclk"));
440 
441 	uart_lock(sc->sc_hwmtx);
442 	error = msm_uart_param(&sc->sc_bas, baudrate, databits, stopbits,
443 	    parity);
444 	uart_unlock(sc->sc_hwmtx);
445 
446 	return (error);
447 }
448 
449 static int
450 msm_bus_ipend(struct uart_softc *sc)
451 {
452 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
453 	struct uart_bas *bas = &sc->sc_bas;
454 	uint32_t isr;
455 	int ipend;
456 
457 	uart_lock(sc->sc_hwmtx);
458 
459 	/* Get ISR status */
460 	isr = GETREG(bas, UART_DM_MISR);
461 
462 	ipend = 0;
463 
464 	/* Uart RX starting, notify upper layer */
465 	if (isr & UART_DM_RXLEV) {
466 		u->ier &= ~UART_DM_RXLEV;
467 		SETREG(bas, UART_DM_IMR, u->ier);
468 		uart_barrier(bas);
469 		ipend |= SER_INT_RXREADY;
470 	}
471 
472 	/* Stale RX interrupt */
473 	if (isr & UART_DM_RXSTALE) {
474 		/* Disable and reset it */
475 		SETREG(bas, UART_DM_CR, UART_DM_STALE_EVENT_DISABLE);
476 		SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
477 		uart_barrier(bas);
478 		ipend |= SER_INT_RXREADY;
479 	}
480 
481 	/* TX READY interrupt */
482 	if (isr & UART_DM_TX_READY) {
483 		/* Clear  TX Ready */
484 		SETREG(bas, UART_DM_CR, UART_DM_CLEAR_TX_READY);
485 
486 		/* Disable TX_READY */
487 		u->ier &= ~UART_DM_TX_READY;
488 		SETREG(bas, UART_DM_IMR, u->ier);
489 		uart_barrier(bas);
490 
491 		if (sc->sc_txbusy != 0)
492 			ipend |= SER_INT_TXIDLE;
493 	}
494 
495 	if (isr & UART_DM_TXLEV) {
496 		/* TX FIFO is empty */
497 		u->ier &= ~UART_DM_TXLEV;
498 		SETREG(bas, UART_DM_IMR, u->ier);
499 		uart_barrier(bas);
500 
501 		if (sc->sc_txbusy != 0)
502 			ipend |= SER_INT_TXIDLE;
503 	}
504 
505 	uart_unlock(sc->sc_hwmtx);
506 	return (ipend);
507 }
508 
509 static int
510 msm_bus_flush(struct uart_softc *sc, int what)
511 {
512 
513 	return (0);
514 }
515 
516 static int
517 msm_bus_getsig(struct uart_softc *sc)
518 {
519 
520 	return (0);
521 }
522 
523 static int
524 msm_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
525 {
526 
527 	return (EINVAL);
528 }
529 
530 static void
531 msm_bus_grab(struct uart_softc *sc)
532 {
533 	struct uart_bas *bas = &sc->sc_bas;
534 
535 	/*
536 	 * XXX: Turn off all interrupts to enter polling mode. Leave the
537 	 * saved mask alone. We'll restore whatever it was in ungrab.
538 	 */
539 	uart_lock(sc->sc_hwmtx);
540 	SETREG(bas, UART_DM_CR, UART_DM_RESET_STALE_INT);
541 	SETREG(bas, UART_DM_IMR, 0);
542 	uart_barrier(bas);
543 	uart_unlock(sc->sc_hwmtx);
544 }
545 
546 static void
547 msm_bus_ungrab(struct uart_softc *sc)
548 {
549 	struct msm_uart_softc *u = (struct msm_uart_softc *)sc;
550 	struct uart_bas *bas = &sc->sc_bas;
551 
552 	/*
553 	 * Restore previous interrupt mask
554 	 */
555 	uart_lock(sc->sc_hwmtx);
556 	SETREG(bas, UART_DM_IMR, u->ier);
557 	uart_barrier(bas);
558 	uart_unlock(sc->sc_hwmtx);
559 }
560 
561 struct uart_class uart_msm_class = {
562 	"msm",
563 	msm_methods,
564 	sizeof(struct msm_uart_softc),
565 	.uc_ops = &uart_msm_ops,
566 	.uc_range = 8,
567 	.uc_rclk = DEF_CLK,
568 };
569