xref: /freebsd-11-stable/stand/i386/libi386/comconsole.c

/*-
 * Copyright (c) 1998 Michael Smith (msmith@freebsd.org)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/11/sys/boot/i386/libi386/comconsole.c 329070 2018-02-09 17:25:34Z kevans $");

#include <stand.h>
#include <bootstrap.h>
#include <machine/cpufunc.h>
#include <dev/ic/ns16550.h>
#include <dev/pci/pcireg.h>
#include "libi386.h"

#define COMC_FMT	0x3		/* 8N1 */
#define COMC_TXWAIT	0x40000		/* transmit timeout */
#define COMC_BPS(x)	(115200 / (x))	/* speed to DLAB divisor */
#define COMC_DIV2BPS(x)	(115200 / (x))	/* DLAB divisor to speed */

#ifndef	COMPORT
#define COMPORT		0x3f8
#endif
#ifndef	COMSPEED
#define COMSPEED	9600
#endif

static void	comc_probe(struct console *cp);
static int	comc_init(int arg);
static void	comc_putchar(int c);
static int	comc_getchar(void);
static int	comc_getspeed(void);
static int	comc_ischar(void);
static int	comc_parseint(const char *string);
static uint32_t comc_parse_pcidev(const char *string);
static int	comc_pcidev_set(struct env_var *ev, int flags,
		    const void *value);
static int	comc_pcidev_handle(uint32_t locator);
static int	comc_port_set(struct env_var *ev, int flags,
		    const void *value);
static void	comc_setup(int speed, int port);
static int	comc_speed_set(struct env_var *ev, int flags,
		    const void *value);

static int	comc_curspeed;
static int	comc_port = COMPORT;
static uint32_t	comc_locator;

struct console comconsole = {
    "comconsole",
    "serial port",
    0,
    comc_probe,
    comc_init,
    comc_putchar,
    comc_getchar,
    comc_ischar
};

static void
comc_probe(struct console *cp)
{
    char intbuf[16];
    char *cons, *env;
    int speed, port;
    uint32_t locator;

    if (comc_curspeed == 0) {
	comc_curspeed = COMSPEED;
	/*
	 * Assume that the speed was set by an earlier boot loader if
	 * comconsole is already the preferred console.
	 */
	cons = getenv("console");
	if ((cons != NULL && strcmp(cons, comconsole.c_name) == 0) ||
	    getenv("boot_multicons") != NULL) {
		comc_curspeed = comc_getspeed();
	}

	env = getenv("comconsole_speed");
	if (env != NULL) {
	    speed = comc_parseint(env);
	    if (speed > 0)
		comc_curspeed = speed;
	}

	sprintf(intbuf, "%d", comc_curspeed);
	unsetenv("comconsole_speed");
	env_setenv("comconsole_speed", EV_VOLATILE, intbuf, comc_speed_set,
	    env_nounset);

	env = getenv("comconsole_port");
	if (env != NULL) {
	    port = comc_parseint(env);
	    if (port > 0)
		comc_port = port;
	}

	sprintf(intbuf, "%d", comc_port);
	unsetenv("comconsole_port");
	env_setenv("comconsole_port", EV_VOLATILE, intbuf, comc_port_set,
	    env_nounset);

	env = getenv("comconsole_pcidev");
	if (env != NULL) {
	    locator = comc_parse_pcidev(env);
	    if (locator != 0)
		    comc_pcidev_handle(locator);
	}

	unsetenv("comconsole_pcidev");
	env_setenv("comconsole_pcidev", EV_VOLATILE, env, comc_pcidev_set,
	    env_nounset);
    }
    comc_setup(comc_curspeed, comc_port);
}

static int
comc_init(int arg)
{

    comc_setup(comc_curspeed, comc_port);

    if ((comconsole.c_flags & (C_PRESENTIN | C_PRESENTOUT)) ==
	(C_PRESENTIN | C_PRESENTOUT))
	return (CMD_OK);
    return (CMD_ERROR);
}

static void
comc_putchar(int c)
{
    int wait;

    for (wait = COMC_TXWAIT; wait > 0; wait--)
        if (inb(comc_port + com_lsr) & LSR_TXRDY) {
	    outb(comc_port + com_data, (u_char)c);
	    break;
	}
}

static int
comc_getchar(void)
{
    return (comc_ischar() ? inb(comc_port + com_data) : -1);
}

static int
comc_ischar(void)
{
    return (inb(comc_port + com_lsr) & LSR_RXRDY);
}

static int
comc_speed_set(struct env_var *ev, int flags, const void *value)
{
    int speed;

    if (value == NULL || (speed = comc_parseint(value)) <= 0) {
	printf("Invalid speed\n");
	return (CMD_ERROR);
    }

    if (comc_curspeed != speed)
	comc_setup(speed, comc_port);

    env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);

    return (CMD_OK);
}

static int
comc_port_set(struct env_var *ev, int flags, const void *value)
{
    int port;

    if (value == NULL || (port = comc_parseint(value)) <= 0) {
	printf("Invalid port\n");
	return (CMD_ERROR);
    }

    if (comc_port != port)
	comc_setup(comc_curspeed, port);

    env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);

    return (CMD_OK);
}

/*
 * Input: bus:dev:func[:bar]. If bar is not specified, it is 0x10.
 * Output: bar[24:16] bus[15:8] dev[7:3] func[2:0]
 */
static uint32_t
comc_parse_pcidev(const char *string)
{
#ifdef NO_PCI
	return (0);
#else
	char *p, *p1;
	uint8_t bus, dev, func, bar;
	uint32_t locator;
	int pres;

	pres = strtol(string, &p, 0);
	if (p == string || *p != ':' || pres < 0 )
		return (0);
	bus = pres;
	p1 = ++p;

	pres = strtol(p1, &p, 0);
	if (p == string || *p != ':' || pres < 0 )
		return (0);
	dev = pres;
	p1 = ++p;

	pres = strtol(p1, &p, 0);
	if (p == string || (*p != ':' && *p != '\0') || pres < 0 )
		return (0);
	func = pres;

	if (*p == ':') {
		p1 = ++p;
		pres = strtol(p1, &p, 0);
		if (p == string || *p != '\0' || pres <= 0 )
			return (0);
		bar = pres;
	} else
		bar = 0x10;

	locator = (bar << 16) | biospci_locator(bus, dev, func);
	return (locator);
#endif
}

static int
comc_pcidev_handle(uint32_t locator)
{
#ifdef NO_PCI
	return (CMD_ERROR);
#else
	char intbuf[64];
	uint32_t port;

	if (biospci_read_config(locator & 0xffff,
				(locator & 0xff0000) >> 16, 2, &port) == -1) {
		printf("Cannot read bar at 0x%x\n", locator);
		return (CMD_ERROR);
	}

	/*
	 * biospci_read_config() sets port == 0xffffffff if the pcidev
	 * isn't found on the bus.  Check for 0xffffffff and return to not
	 * panic in BTX.
	 */
	if (port == 0xffffffff) {
		printf("Cannot find specified pcidev\n");
		return (CMD_ERROR);
	}
	if (!PCI_BAR_IO(port)) {
		printf("Memory bar at 0x%x\n", locator);
		return (CMD_ERROR);
	}
        port &= PCIM_BAR_IO_BASE;

	sprintf(intbuf, "%d", port);
	unsetenv("comconsole_port");
	env_setenv("comconsole_port", EV_VOLATILE, intbuf,
		   comc_port_set, env_nounset);

	comc_setup(comc_curspeed, port);
	comc_locator = locator;

	return (CMD_OK);
#endif
}

static int
comc_pcidev_set(struct env_var *ev, int flags, const void *value)
{
	uint32_t locator;
	int error;

	if (value == NULL || (locator = comc_parse_pcidev(value)) <= 0) {
		printf("Invalid pcidev\n");
		return (CMD_ERROR);
	}
	if ((comconsole.c_flags & (C_ACTIVEIN | C_ACTIVEOUT)) != 0 &&
	    comc_locator != locator) {
		error = comc_pcidev_handle(locator);
		if (error != CMD_OK)
			return (error);
	}
	env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
	return (CMD_OK);
}

static void
comc_setup(int speed, int port)
{
    static int TRY_COUNT = 1000000;
    char intbuf[64];
    int tries;

    unsetenv("hw.uart.console");
    comc_curspeed = speed;
    comc_port = port;
    if ((comconsole.c_flags & (C_ACTIVEIN | C_ACTIVEOUT)) == 0)
	return;

    outb(comc_port + com_cfcr, CFCR_DLAB | COMC_FMT);
    outb(comc_port + com_dlbl, COMC_BPS(speed) & 0xff);
    outb(comc_port + com_dlbh, COMC_BPS(speed) >> 8);
    outb(comc_port + com_cfcr, COMC_FMT);
    outb(comc_port + com_mcr, MCR_RTS | MCR_DTR);

    tries = 0;
    do
        inb(comc_port + com_data);
    while (inb(comc_port + com_lsr) & LSR_RXRDY && ++tries < TRY_COUNT);

    if (tries < TRY_COUNT) {
	comconsole.c_flags |= (C_PRESENTIN | C_PRESENTOUT);
	sprintf(intbuf, "io:%d,br:%d", comc_port, comc_curspeed);
	env_setenv("hw.uart.console", EV_VOLATILE, intbuf, NULL, NULL);
    } else
	comconsole.c_flags &= ~(C_PRESENTIN | C_PRESENTOUT);
}

static int
comc_parseint(const char *speedstr)
{
    char *p;
    int speed;

    speed = strtol(speedstr, &p, 0);
    if (p == speedstr || *p != '\0' || speed <= 0)
	return (-1);

    return (speed);
}

static int
comc_getspeed(void)
{
	u_int	divisor;
	u_char	dlbh;
	u_char	dlbl;
	u_char	cfcr;

	cfcr = inb(comc_port + com_cfcr);
	outb(comc_port + com_cfcr, CFCR_DLAB | cfcr);

	dlbl = inb(comc_port + com_dlbl);
	dlbh = inb(comc_port + com_dlbh);

	outb(comc_port + com_cfcr, cfcr);

	divisor = dlbh << 8 | dlbl;

	/* XXX there should be more sanity checking. */
	if (divisor == 0)
		return (COMSPEED);
	return (COMC_DIV2BPS(divisor));
}