xref: /freebsd/sys/dev/uart/uart_dev_imx.c (revision d4ae33f0721c1b170fe37d97e395228ffcfb3f80)
1 /*-
2  * Copyright (c) 2012 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Oleksandr Rybalko under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1.	Redistributions of source code must retain the above copyright
12  *	notice, this list of conditions and the following disclaimer.
13  * 2.	Redistributions in binary form must reproduce the above copyright
14  *	notice, this list of conditions and the following disclaimer in the
15  *	documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_ddb.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/kdb.h>
40 #include <machine/bus.h>
41 #include <machine/fdt.h>
42 
43 #include <dev/uart/uart.h>
44 #include <dev/uart/uart_cpu.h>
45 #include <dev/uart/uart_bus.h>
46 
47 #include <dev/uart/uart_dev_imx5xx.h>
48 
49 #include "uart_if.h"
50 /*
51  * Low-level UART interface.
52  */
53 static int imx_uart_probe(struct uart_bas *bas);
54 static void imx_uart_init(struct uart_bas *bas, int, int, int, int);
55 static void imx_uart_term(struct uart_bas *bas);
56 static void imx_uart_putc(struct uart_bas *bas, int);
57 static int imx_uart_rxready(struct uart_bas *bas);
58 static int imx_uart_getc(struct uart_bas *bas, struct mtx *);
59 
60 static struct uart_ops uart_imx_uart_ops = {
61 	.probe = imx_uart_probe,
62 	.init = imx_uart_init,
63 	.term = imx_uart_term,
64 	.putc = imx_uart_putc,
65 	.rxready = imx_uart_rxready,
66 	.getc = imx_uart_getc,
67 };
68 
69 static int
70 imx_uart_probe(struct uart_bas *bas)
71 {
72 
73 	return (0);
74 }
75 
76 static void
77 imx_uart_init(struct uart_bas *bas, int baudrate, int databits,
78     int stopbits, int parity)
79 {
80 
81 }
82 
83 static void
84 imx_uart_term(struct uart_bas *bas)
85 {
86 
87 }
88 
89 static void
90 imx_uart_putc(struct uart_bas *bas, int c)
91 {
92 
93 	while (!(IS(bas, USR2, TXFE)))
94 		;
95 	SETREG(bas, REG(UTXD), c);
96 }
97 
98 static int
99 imx_uart_rxready(struct uart_bas *bas)
100 {
101 
102 	return ((IS(bas, USR2, RDR)) ? 1 : 0);
103 }
104 
105 static int
106 imx_uart_getc(struct uart_bas *bas, struct mtx *hwmtx)
107 {
108 	int c;
109 
110 	uart_lock(hwmtx);
111 	while (!(IS(bas, USR2, RDR)))
112 		;
113 
114 	c = GETREG(bas, REG(URXD));
115 	uart_unlock(hwmtx);
116 #if defined(KDB)
117 	if (c & FLD(URXD, BRK)) {
118 		if (kdb_break())
119 			return (0);
120 	}
121 #endif
122 	return (c & 0xff);
123 }
124 
125 /*
126  * High-level UART interface.
127  */
128 struct imx_uart_softc {
129 	struct uart_softc base;
130 };
131 
132 static int imx_uart_bus_attach(struct uart_softc *);
133 static int imx_uart_bus_detach(struct uart_softc *);
134 static int imx_uart_bus_flush(struct uart_softc *, int);
135 static int imx_uart_bus_getsig(struct uart_softc *);
136 static int imx_uart_bus_ioctl(struct uart_softc *, int, intptr_t);
137 static int imx_uart_bus_ipend(struct uart_softc *);
138 static int imx_uart_bus_param(struct uart_softc *, int, int, int, int);
139 static int imx_uart_bus_probe(struct uart_softc *);
140 static int imx_uart_bus_receive(struct uart_softc *);
141 static int imx_uart_bus_setsig(struct uart_softc *, int);
142 static int imx_uart_bus_transmit(struct uart_softc *);
143 
144 static kobj_method_t imx_uart_methods[] = {
145 	KOBJMETHOD(uart_attach,		imx_uart_bus_attach),
146 	KOBJMETHOD(uart_detach,		imx_uart_bus_detach),
147 	KOBJMETHOD(uart_flush,		imx_uart_bus_flush),
148 	KOBJMETHOD(uart_getsig,		imx_uart_bus_getsig),
149 	KOBJMETHOD(uart_ioctl,		imx_uart_bus_ioctl),
150 	KOBJMETHOD(uart_ipend,		imx_uart_bus_ipend),
151 	KOBJMETHOD(uart_param,		imx_uart_bus_param),
152 	KOBJMETHOD(uart_probe,		imx_uart_bus_probe),
153 	KOBJMETHOD(uart_receive,	imx_uart_bus_receive),
154 	KOBJMETHOD(uart_setsig,		imx_uart_bus_setsig),
155 	KOBJMETHOD(uart_transmit,	imx_uart_bus_transmit),
156 	{ 0, 0 }
157 };
158 
159 struct uart_class uart_imx_class = {
160 	"imx",
161 	imx_uart_methods,
162 	sizeof(struct imx_uart_softc),
163 	.uc_ops = &uart_imx_uart_ops,
164 	.uc_range = 0x100,
165 	.uc_rclk = 24000000 /* TODO: get value from CCM */
166 };
167 
168 #define	SIGCHG(c, i, s, d)				\
169 	if (c) {					\
170 		i |= (i & s) ? s : s | d;		\
171 	} else {					\
172 		i = (i & s) ? (i & ~s) | d : i;		\
173 	}
174 
175 static int
176 imx_uart_bus_attach(struct uart_softc *sc)
177 {
178 	struct uart_bas *bas;
179 	struct uart_devinfo *di;
180 
181 	bas = &sc->sc_bas;
182 	if (sc->sc_sysdev != NULL) {
183 		di = sc->sc_sysdev;
184 		imx_uart_init(bas, di->baudrate, di->databits, di->stopbits,
185 		    di->parity);
186 	} else {
187 		imx_uart_init(bas, 115200, 8, 1, 0);
188 	}
189 
190 	(void)imx_uart_bus_getsig(sc);
191 
192 	/* XXX workaround to have working console on mount prompt */
193 	if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE){
194 		DIS(bas, UCR4, DREN);
195 	} else {
196 		ENA(bas, UCR4, DREN);
197 	}
198 	DIS(bas, UCR1, RRDYEN);
199 	DIS(bas, UCR1, IDEN);
200 	DIS(bas, UCR3, RXDSEN);
201 	DIS(bas, UCR2, ATEN);
202 	DIS(bas, UCR1, TXMPTYEN);
203 	DIS(bas, UCR1, TRDYEN);
204 	DIS(bas, UCR4, TCEN);
205 	DIS(bas, UCR4, OREN);
206 	ENA(bas, UCR4, BKEN);
207 	DIS(bas, UCR4, WKEN);
208 	DIS(bas, UCR1, ADEN);
209 	DIS(bas, UCR3, ACIEN);
210 	DIS(bas, UCR2, ESCI);
211 	DIS(bas, UCR4, ENIRI);
212 	DIS(bas, UCR3, AIRINTEN);
213 	DIS(bas, UCR3, AWAKEN);
214 	DIS(bas, UCR3, FRAERREN);
215 	DIS(bas, UCR3, PARERREN);
216 	DIS(bas, UCR1, RTSDEN);
217 	DIS(bas, UCR2, RTSEN);
218 	DIS(bas, UCR3, DTREN);
219 	DIS(bas, UCR3, RI);
220 	DIS(bas, UCR3, DCD);
221 	DIS(bas, UCR3, DTRDEN);
222 
223 	/* ACK all interrupts */
224 	SETREG(bas, REG(USR1), 0xffff);
225 	SETREG(bas, REG(USR2), 0xffff);
226 	return (0);
227 }
228 
229 static int
230 imx_uart_bus_detach(struct uart_softc *sc)
231 {
232 
233 	SETREG(&sc->sc_bas, REG(UCR4), 0);
234 
235 	return (0);
236 }
237 
238 static int
239 imx_uart_bus_flush(struct uart_softc *sc, int what)
240 {
241 
242 	/* TODO */
243 	return (0);
244 }
245 
246 static int
247 imx_uart_bus_getsig(struct uart_softc *sc)
248 {
249 	uint32_t new, old, sig;
250 	uint8_t bes;
251 
252 	do {
253 		old = sc->sc_hwsig;
254 		sig = old;
255 		uart_lock(sc->sc_hwmtx);
256 		bes = GETREG(&sc->sc_bas, REG(USR2));
257 		uart_unlock(sc->sc_hwmtx);
258 		/* XXX: chip can show delta */
259 		SIGCHG(bes & FLD(USR2, DCDIN), sig, SER_DCD, SER_DDCD);
260 		new = sig & ~SER_MASK_DELTA;
261 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
262 
263 	return (sig);
264 }
265 
266 static int
267 imx_uart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
268 {
269 	struct uart_bas *bas;
270 	int error;
271 
272 	bas = &sc->sc_bas;
273 	error = 0;
274 	uart_lock(sc->sc_hwmtx);
275 	switch (request) {
276 	case UART_IOCTL_BREAK:
277 		/* TODO */
278 		break;
279 	case UART_IOCTL_BAUD:
280 		/* TODO */
281 		*(int*)data = 115200;
282 		break;
283 	default:
284 		error = EINVAL;
285 		break;
286 	}
287 	uart_unlock(sc->sc_hwmtx);
288 
289 	return (error);
290 }
291 
292 static int
293 imx_uart_bus_ipend(struct uart_softc *sc)
294 {
295 	struct uart_bas *bas;
296 	int ipend;
297 	uint32_t usr1, usr2;
298 	uint32_t ucr1, ucr4;
299 
300 	bas = &sc->sc_bas;
301 	ipend = 0;
302 
303 	uart_lock(sc->sc_hwmtx);
304 
305 	/* Read pending interrupts */
306 	usr1 = GETREG(bas, REG(USR1));
307 	usr2 = GETREG(bas, REG(USR2));
308 	/* ACK interrupts */
309 	SETREG(bas, REG(USR1), usr1);
310 	SETREG(bas, REG(USR2), usr2);
311 
312 	ucr1 = GETREG(bas, REG(UCR1));
313 	ucr4 = GETREG(bas, REG(UCR4));
314 
315 	if ((usr2 & FLD(USR2, TXFE)) && (ucr1 & FLD(UCR1, TXMPTYEN))) {
316 		DIS(bas, UCR1, TXMPTYEN);
317 		/* Continue TXing */
318 		ipend |= SER_INT_TXIDLE;
319 	}
320 	if ((usr2 & FLD(USR2, RDR)) && (ucr4 & FLD(UCR4, DREN))) {
321 		DIS(bas, UCR4, DREN);
322 		/* Wow, new char on input */
323 		ipend |= SER_INT_RXREADY;
324 	}
325 	if ((usr2 & FLD(USR2, BRCD)) && (ucr4 & FLD(UCR4, BKEN)))
326 		ipend |= SER_INT_BREAK;
327 
328 	uart_unlock(sc->sc_hwmtx);
329 
330 	return (ipend);
331 }
332 
333 static int
334 imx_uart_bus_param(struct uart_softc *sc, int baudrate, int databits,
335     int stopbits, int parity)
336 {
337 
338 	uart_lock(sc->sc_hwmtx);
339 	imx_uart_init(&sc->sc_bas, baudrate, databits, stopbits, parity);
340 	uart_unlock(sc->sc_hwmtx);
341 	return (0);
342 }
343 
344 static int
345 imx_uart_bus_probe(struct uart_softc *sc)
346 {
347 	int error;
348 
349 	error = imx_uart_probe(&sc->sc_bas);
350 	if (error)
351 		return (error);
352 
353 	sc->sc_rxfifosz = 1;
354 	sc->sc_txfifosz = 1;
355 
356 	device_set_desc(sc->sc_dev, "imx_uart");
357 	return (0);
358 }
359 
360 static int
361 imx_uart_bus_receive(struct uart_softc *sc)
362 {
363 	struct uart_bas *bas;
364 	int xc, out;
365 
366 	bas = &sc->sc_bas;
367 	uart_lock(sc->sc_hwmtx);
368 
369 	/* Read while we have anything in FIFO */
370 	while (IS(bas, USR2, RDR)) {
371 		if (uart_rx_full(sc)) {
372 			/* No space left in input buffer */
373 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
374 			break;
375 		}
376 		out = 0;
377 		xc = GETREG(bas, REG(URXD));
378 
379 		/* We have valid char */
380 		if (xc & FLD(URXD, CHARRDY))
381 			out = xc & 0x000000ff;
382 
383 		if (xc & FLD(URXD, FRMERR))
384 			out |= UART_STAT_FRAMERR;
385 		if (xc & FLD(URXD, PRERR))
386 			out |= UART_STAT_PARERR;
387 		if (xc & FLD(URXD, OVRRUN))
388 			out |= UART_STAT_OVERRUN;
389 		if (xc & FLD(URXD, BRK))
390 			out |= UART_STAT_BREAK;
391 
392 		uart_rx_put(sc, out);
393 	}
394 	/* Reenable Data Ready interrupt */
395 	ENA(bas, UCR4, DREN);
396 
397 	uart_unlock(sc->sc_hwmtx);
398 	return (0);
399 }
400 
401 static int
402 imx_uart_bus_setsig(struct uart_softc *sc, int sig)
403 {
404 
405 	/* TODO: implement (?) */
406 
407 	/* XXX workaround to have working console on mount prompt */
408 	/* Enable RX interrupt */
409 	if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE)
410 		if (!IS(&sc->sc_bas, UCR4, DREN))
411 			ENA(&sc->sc_bas, UCR4, DREN);
412 	return (0);
413 }
414 
415 static int
416 imx_uart_bus_transmit(struct uart_softc *sc)
417 {
418 	struct uart_bas *bas = &sc->sc_bas;
419 	int i;
420 
421 	bas = &sc->sc_bas;
422 	uart_lock(sc->sc_hwmtx);
423 
424 	/* Fill TX FIFO */
425 	for (i = 0; i < sc->sc_txdatasz; i++) {
426 		SETREG(bas, REG(UTXD), sc->sc_txbuf[i] & 0xff);
427 	}
428 
429 	sc->sc_txbusy = 1;
430 	/* Call me when ready */
431 	ENA(bas, UCR1, TXMPTYEN);
432 
433 	uart_unlock(sc->sc_hwmtx);
434 
435 	return (0);
436 }
437