xref: /freebsd/stand/i386/libi386/comconsole.c (revision d411c1d6)
1 /*-
2  * Copyright (c) 1998 Michael Smith (msmith@freebsd.org)
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <stand.h>
30 #include <bootstrap.h>
31 #include <machine/cpufunc.h>
32 #include <dev/ic/ns16550.h>
33 #include <dev/pci/pcireg.h>
34 #include "libi386.h"
35 
36 #define COMC_FMT	0x3		/* 8N1 */
37 #define COMC_TXWAIT	0x40000		/* transmit timeout */
38 #define COMC_BPS(x)	(115200 / (x))	/* speed to DLAB divisor */
39 #define COMC_DIV2BPS(x)	(115200 / (x))	/* DLAB divisor to speed */
40 
41 #ifndef	COMPORT
42 #define COMPORT		0x3f8
43 #endif
44 #ifndef	COMSPEED
45 #define COMSPEED	9600
46 #endif
47 
48 static void	comc_probe(struct console *cp);
49 static int	comc_init(int arg);
50 static void	comc_putchar(int c);
51 static int	comc_getchar(void);
52 static int	comc_getspeed(void);
53 static int	comc_ischar(void);
54 static int	comc_parseint(const char *string);
55 static uint32_t comc_parse_pcidev(const char *string);
56 static int	comc_pcidev_set(struct env_var *ev, int flags,
57 		    const void *value);
58 static int	comc_pcidev_handle(uint32_t locator);
59 static int	comc_port_set(struct env_var *ev, int flags,
60 		    const void *value);
61 static void	comc_setup(int speed, int port);
62 static int	comc_speed_set(struct env_var *ev, int flags,
63 		    const void *value);
64 
65 static int	comc_curspeed;
66 static int	comc_port = COMPORT;
67 static uint32_t	comc_locator;
68 
69 struct console comconsole = {
70 	.c_name = "comconsole",
71 	.c_desc = "serial port",
72 	.c_flags = 0,
73 	.c_probe = comc_probe,
74 	.c_init = comc_init,
75 	.c_out = comc_putchar,
76 	.c_in = comc_getchar,
77 	.c_ready = comc_ischar
78 };
79 
80 static void
81 comc_probe(struct console *cp)
82 {
83 	char intbuf[16];
84 	char *cons, *env;
85 	int speed, port;
86 	uint32_t locator;
87 
88 #if defined(__amd64__)
89 	extern bool efi_comconsole_avail;
90 
91 	if (efi_comconsole_avail) {
92 		/*
93 		 * If EFI provides serial I/O, then don't use this legacy
94 		 * com driver to avoid conflicts with the firmware's driver.
95 		 * Change c_name so that it cannot be found in the lookup.
96 		 */
97 		comconsole.c_name = "xcomconsole";
98 		return;
99 	}
100 #endif
101 
102 	if (comc_curspeed == 0) {
103 		comc_curspeed = COMSPEED;
104 		/*
105 		 * Assume that the speed was set by an earlier boot loader if
106 		 * comconsole is already the preferred console.
107 		 */
108 		cons = getenv("console");
109 		if ((cons != NULL && strcmp(cons, comconsole.c_name) == 0) ||
110 		    getenv("boot_multicons") != NULL) {
111 			comc_curspeed = comc_getspeed();
112 		}
113 
114 		env = getenv("comconsole_speed");
115 		if (env != NULL) {
116 			speed = comc_parseint(env);
117 			if (speed > 0)
118 				comc_curspeed = speed;
119 		}
120 
121 		sprintf(intbuf, "%d", comc_curspeed);
122 		unsetenv("comconsole_speed");
123 		env_setenv("comconsole_speed", EV_VOLATILE, intbuf,
124 		    comc_speed_set, env_nounset);
125 
126 		env = getenv("comconsole_port");
127 		if (env != NULL) {
128 			port = comc_parseint(env);
129 			if (port > 0)
130 				comc_port = port;
131 		}
132 
133 		sprintf(intbuf, "%d", comc_port);
134 		unsetenv("comconsole_port");
135 		env_setenv("comconsole_port", EV_VOLATILE, intbuf,
136 		    comc_port_set, env_nounset);
137 
138 		env = getenv("comconsole_pcidev");
139 		if (env != NULL) {
140 			locator = comc_parse_pcidev(env);
141 			if (locator != 0)
142 				comc_pcidev_handle(locator);
143 		}
144 
145 		unsetenv("comconsole_pcidev");
146 		env_setenv("comconsole_pcidev", EV_VOLATILE, env,
147 		    comc_pcidev_set, env_nounset);
148 	}
149 	comc_setup(comc_curspeed, comc_port);
150 }
151 
152 static int
153 comc_init(int arg)
154 {
155 
156 	comc_setup(comc_curspeed, comc_port);
157 
158 	if ((comconsole.c_flags & (C_PRESENTIN | C_PRESENTOUT)) ==
159 	    (C_PRESENTIN | C_PRESENTOUT))
160 		return (CMD_OK);
161 	return (CMD_ERROR);
162 }
163 
164 static void
165 comc_putchar(int c)
166 {
167 	int wait;
168 
169 	for (wait = COMC_TXWAIT; wait > 0; wait--)
170 		if (inb(comc_port + com_lsr) & LSR_TXRDY) {
171 			outb(comc_port + com_data, (u_char)c);
172 			break;
173 		}
174 }
175 
176 static int
177 comc_getchar(void)
178 {
179 	return (comc_ischar() ? inb(comc_port + com_data) : -1);
180 }
181 
182 static int
183 comc_ischar(void)
184 {
185 	return (inb(comc_port + com_lsr) & LSR_RXRDY);
186 }
187 
188 static int
189 comc_speed_set(struct env_var *ev, int flags, const void *value)
190 {
191 	int speed;
192 
193 	if (value == NULL || (speed = comc_parseint(value)) <= 0) {
194 		printf("Invalid speed\n");
195 		return (CMD_ERROR);
196 	}
197 
198 	if (comc_curspeed != speed)
199 		comc_setup(speed, comc_port);
200 
201 	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
202 
203 	return (CMD_OK);
204 }
205 
206 static int
207 comc_port_set(struct env_var *ev, int flags, const void *value)
208 {
209 	int port;
210 
211 	if (value == NULL || (port = comc_parseint(value)) <= 0) {
212 		printf("Invalid port\n");
213 		return (CMD_ERROR);
214 	}
215 
216 	if (comc_port != port)
217 		comc_setup(comc_curspeed, port);
218 
219 	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
220 
221 	return (CMD_OK);
222 }
223 
224 /*
225  * Input: bus:dev:func[:bar]. If bar is not specified, it is 0x10.
226  * Output: bar[24:16] bus[15:8] dev[7:3] func[2:0]
227  */
228 static uint32_t
229 comc_parse_pcidev(const char *string)
230 {
231 #ifdef EFI
232 	/* We don't support PCI in EFI yet */
233 	return (0);
234 #else
235 	char *p, *p1;
236 	uint8_t bus, dev, func, bar;
237 	uint32_t locator;
238 	int pres;
239 
240 	pres = strtol(string, &p, 0);
241 	if (p == string || *p != ':' || pres < 0 )
242 		return (0);
243 	bus = pres;
244 	p1 = ++p;
245 
246 	pres = strtol(p1, &p, 0);
247 	if (p == string || *p != ':' || pres < 0 )
248 		return (0);
249 	dev = pres;
250 	p1 = ++p;
251 
252 	pres = strtol(p1, &p, 0);
253 	if (p == string || (*p != ':' && *p != '\0') || pres < 0 )
254 		return (0);
255 	func = pres;
256 
257 	if (*p == ':') {
258 		p1 = ++p;
259 		pres = strtol(p1, &p, 0);
260 		if (p == string || *p != '\0' || pres <= 0 )
261 			return (0);
262 		bar = pres;
263 	} else
264 		bar = 0x10;
265 
266 	locator = (bar << 16) | biospci_locator(bus, dev, func);
267 	return (locator);
268 #endif
269 }
270 
271 static int
272 comc_pcidev_handle(uint32_t locator)
273 {
274 #ifdef EFI
275 	/* We don't support PCI in EFI yet */
276 	return (CMD_ERROR);
277 #else
278 	char intbuf[64];
279 	uint32_t port;
280 
281 	if (biospci_read_config(locator & 0xffff,
282 	    (locator & 0xff0000) >> 16, BIOSPCI_32BITS, &port) == -1) {
283 		printf("Cannot read bar at 0x%x\n", locator);
284 		return (CMD_ERROR);
285 	}
286 
287 	/*
288 	 * biospci_read_config() sets port == 0xffffffff if the pcidev
289 	 * isn't found on the bus.  Check for 0xffffffff and return to not
290 	 * panic in BTX.
291 	 */
292 	if (port == 0xffffffff) {
293 		printf("Cannot find specified pcidev\n");
294 		return (CMD_ERROR);
295 	}
296 	if (!PCI_BAR_IO(port)) {
297 		printf("Memory bar at 0x%x\n", locator);
298 		return (CMD_ERROR);
299 	}
300         port &= PCIM_BAR_IO_BASE;
301 
302 	sprintf(intbuf, "%d", port);
303 	unsetenv("comconsole_port");
304 	env_setenv("comconsole_port", EV_VOLATILE, intbuf,
305 		   comc_port_set, env_nounset);
306 
307 	comc_setup(comc_curspeed, port);
308 	comc_locator = locator;
309 
310 	return (CMD_OK);
311 #endif
312 }
313 
314 static int
315 comc_pcidev_set(struct env_var *ev, int flags, const void *value)
316 {
317 	uint32_t locator;
318 	int error;
319 
320 	if (value == NULL || (locator = comc_parse_pcidev(value)) <= 0) {
321 		printf("Invalid pcidev\n");
322 		return (CMD_ERROR);
323 	}
324 	if ((comconsole.c_flags & (C_ACTIVEIN | C_ACTIVEOUT)) != 0 &&
325 	    comc_locator != locator) {
326 		error = comc_pcidev_handle(locator);
327 		if (error != CMD_OK)
328 			return (error);
329 	}
330 	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
331 	return (CMD_OK);
332 }
333 
334 static void
335 comc_setup(int speed, int port)
336 {
337 	static int TRY_COUNT = 1000000;
338 	char intbuf[64];
339 	int tries;
340 
341 	comc_curspeed = speed;
342 	comc_port = port;
343 	if ((comconsole.c_flags & (C_ACTIVEIN | C_ACTIVEOUT)) == 0)
344 		return;
345 
346 	unsetenv("hw.uart.console");
347 
348 #define	COMC_TEST	0xbb
349 	/*
350 	 * Write byte to scratch register and read it out.
351 	 */
352 	outb(comc_port + com_scr, COMC_TEST);
353 	if (inb(comc_port + com_scr) != COMC_TEST) {
354 		comconsole.c_flags &= ~(C_PRESENTIN | C_PRESENTOUT);
355 		return;
356 	}
357 
358 	outb(comc_port + com_cfcr, CFCR_DLAB | COMC_FMT);
359 	outb(comc_port + com_dlbl, COMC_BPS(speed) & 0xff);
360 	outb(comc_port + com_dlbh, COMC_BPS(speed) >> 8);
361 	outb(comc_port + com_cfcr, COMC_FMT);
362 	outb(comc_port + com_mcr, MCR_RTS | MCR_DTR);
363 
364 	tries = 0;
365 	do
366 		inb(comc_port + com_data);
367 	while (inb(comc_port + com_lsr) & LSR_RXRDY && ++tries < TRY_COUNT);
368 
369 	if (tries < TRY_COUNT) {
370 		comconsole.c_flags |= (C_PRESENTIN | C_PRESENTOUT);
371 		sprintf(intbuf, "io:%d,br:%d", comc_port, comc_curspeed);
372 		env_setenv("hw.uart.console", EV_VOLATILE, intbuf, NULL, NULL);
373 	} else
374 		comconsole.c_flags &= ~(C_PRESENTIN | C_PRESENTOUT);
375 }
376 
377 static int
378 comc_parseint(const char *speedstr)
379 {
380 	char *p;
381 	int speed;
382 
383 	speed = strtol(speedstr, &p, 0);
384 	if (p == speedstr || *p != '\0' || speed <= 0)
385 		return (-1);
386 
387 	return (speed);
388 }
389 
390 static int
391 comc_getspeed(void)
392 {
393 	u_int	divisor;
394 	u_char	dlbh;
395 	u_char	dlbl;
396 	u_char	cfcr;
397 
398 	cfcr = inb(comc_port + com_cfcr);
399 	outb(comc_port + com_cfcr, CFCR_DLAB | cfcr);
400 
401 	dlbl = inb(comc_port + com_dlbl);
402 	dlbh = inb(comc_port + com_dlbh);
403 
404 	outb(comc_port + com_cfcr, cfcr);
405 
406 	divisor = dlbh << 8 | dlbl;
407 
408 	/* XXX there should be more sanity checking. */
409 	if (divisor == 0)
410 		return (COMSPEED);
411 	return (COMC_DIV2BPS(divisor));
412 }
413