[net-next-2.6.git] / arch / x86 / boot / early_serial_console.c

#include "boot.h"

#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */

#define XMTRDY          0x20

#define DLAB		0x80

#define TXR             0       /*  Transmit register (WRITE) */
#define RXR             0       /*  Receive register  (READ)  */
#define IER             1       /*  Interrupt Enable          */
#define IIR             2       /*  Interrupt ID              */
#define FCR             2       /*  FIFO control              */
#define LCR             3       /*  Line control              */
#define MCR             4       /*  Modem control             */
#define LSR             5       /*  Line Status               */
#define MSR             6       /*  Modem Status              */
#define DLL             0       /*  Divisor Latch Low         */
#define DLH             1       /*  Divisor latch High        */

#define DEFAULT_BAUD 9600

static void early_serial_init(int port, int baud)
{
	unsigned char c;
	unsigned divisor;

	outb(0x3, port + LCR);	/* 8n1 */
	outb(0, port + IER);	/* no interrupt */
	outb(0, port + FCR);	/* no fifo */
	outb(0x3, port + MCR);	/* DTR + RTS */

	divisor	= 115200 / baud;
	c = inb(port + LCR);
	outb(c | DLAB, port + LCR);
	outb(divisor & 0xff, port + DLL);
	outb((divisor >> 8) & 0xff, port + DLH);
	outb(c & ~DLAB, port + LCR);

	early_serial_base = port;
}

static void parse_earlyprintk(void)
{
	int baud = DEFAULT_BAUD;
	char arg[32];
	int pos = 0;
	int port = 0;

	if (cmdline_find_option("earlyprintk", arg, sizeof arg) > 0) {
		char *e;

		if (!strncmp(arg, "serial", 6)) {
			port = DEFAULT_SERIAL_PORT;
			pos += 6;
		}

		if (arg[pos] == ',')
			pos++;

		/*
		 * make sure we have
		 *	"serial,0x3f8,115200"
		 *	"serial,ttyS0,115200"
		 *	"ttyS0,115200"
		 */
		if (pos == 7 && !strncmp(arg + pos, "0x", 2)) {
			port = simple_strtoull(arg + pos, &e, 16);
			if (port == 0 || arg + pos == e)
				port = DEFAULT_SERIAL_PORT;
			else
				pos = e - arg;
		} else if (!strncmp(arg + pos, "ttyS", 4)) {
			static const int bases[] = { 0x3f8, 0x2f8 };
			int idx = 0;

			if (!strncmp(arg + pos, "ttyS", 4))
				pos += 4;

			if (arg[pos++] == '1')
				idx = 1;

			port = bases[idx];
		}

		if (arg[pos] == ',')
			pos++;

		baud = simple_strtoull(arg + pos, &e, 0);
		if (baud == 0 || arg + pos == e)
			baud = DEFAULT_BAUD;
	}

	if (port)
		early_serial_init(port, baud);
}

#define BASE_BAUD (1843200/16)
static unsigned int probe_baud(int port)
{
	unsigned char lcr, dll, dlh;
	unsigned int quot;

	lcr = inb(port + LCR);
	outb(lcr | DLAB, port + LCR);
	dll = inb(port + DLL);
	dlh = inb(port + DLH);
	outb(lcr, port + LCR);
	quot = (dlh << 8) | dll;

	return BASE_BAUD / quot;
}

static void parse_console_uart8250(void)
{
	char optstr[64], *options;
	int baud = DEFAULT_BAUD;
	int port = 0;

	/*
	 * console=uart8250,io,0x3f8,115200n8
	 * need to make sure it is last one console !
	 */
	if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
		return;

	options = optstr;

	if (!strncmp(options, "uart8250,io,", 12))
		port = simple_strtoull(options + 12, &options, 0);
	else if (!strncmp(options, "uart,io,", 8))
		port = simple_strtoull(options + 8, &options, 0);
	else
		return;

	if (options && (options[0] == ','))
		baud = simple_strtoull(options + 1, &options, 0);
	else
		baud = probe_baud(port);

	if (port)
		early_serial_init(port, baud);
}

void console_init(void)
{
	parse_earlyprintk();

	if (!early_serial_base)
		parse_console_uart8250();
}
Commit	Line	Data
f4ed2877 YL	1	#include "boot.h"
	2
	3	#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */
	4
	5	#define XMTRDY 0x20
	6
	7	#define DLAB 0x80
	8
	9	#define TXR 0 /* Transmit register (WRITE) */
	10	#define RXR 0 /* Receive register (READ) */
	11	#define IER 1 /* Interrupt Enable */
	12	#define IIR 2 /* Interrupt ID */
	13	#define FCR 2 /* FIFO control */
	14	#define LCR 3 /* Line control */
	15	#define MCR 4 /* Modem control */
	16	#define LSR 5 /* Line Status */
	17	#define MSR 6 /* Modem Status */
	18	#define DLL 0 /* Divisor Latch Low */
	19	#define DLH 1 /* Divisor latch High */
	20
	21	#define DEFAULT_BAUD 9600
	22
	23	static void early_serial_init(int port, int baud)
	24	{
	25	unsigned char c;
	26	unsigned divisor;
	27
	28	outb(0x3, port + LCR); /* 8n1 */
	29	outb(0, port + IER); /* no interrupt */
	30	outb(0, port + FCR); /* no fifo */
	31	outb(0x3, port + MCR); /* DTR + RTS */
	32
	33	divisor = 115200 / baud;
	34	c = inb(port + LCR);
	35	outb(c \| DLAB, port + LCR);
	36	outb(divisor & 0xff, port + DLL);
	37	outb((divisor >> 8) & 0xff, port + DLH);
	38	outb(c & ~DLAB, port + LCR);
	39
	40	early_serial_base = port;
	41	}
	42
	43	static void parse_earlyprintk(void)
	44	{
	45	int baud = DEFAULT_BAUD;
	46	char arg[32];
	47	int pos = 0;
	48	int port = 0;
	49
	50	if (cmdline_find_option("earlyprintk", arg, sizeof arg) > 0) {
	51	char *e;
	52
	53	if (!strncmp(arg, "serial", 6)) {
	54	port = DEFAULT_SERIAL_PORT;
	55	pos += 6;
	56	}
	57
	58	if (arg[pos] == ',')
	59	pos++;
	60
74b3c444 YL	61	/*
	62	* make sure we have
	63	* "serial,0x3f8,115200"
	64	* "serial,ttyS0,115200"
	65	* "ttyS0,115200"
	66	*/
	67	if (pos == 7 && !strncmp(arg + pos, "0x", 2)) {
	68	port = simple_strtoull(arg + pos, &e, 16);
	69	if (port == 0 \|\| arg + pos == e)
	70	port = DEFAULT_SERIAL_PORT;
	71	else
	72	pos = e - arg;
	73	} else if (!strncmp(arg + pos, "ttyS", 4)) {
f4ed2877 YL	74	static const int bases[] = { 0x3f8, 0x2f8 };
	75	int idx = 0;
	76
	77	if (!strncmp(arg + pos, "ttyS", 4))
	78	pos += 4;
	79
	80	if (arg[pos++] == '1')
	81	idx = 1;
	82
	83	port = bases[idx];
	84	}
	85
	86	if (arg[pos] == ',')
	87	pos++;
	88
	89	baud = simple_strtoull(arg + pos, &e, 0);
	90	if (baud == 0 \|\| arg + pos == e)
	91	baud = DEFAULT_BAUD;
	92	}
	93
	94	if (port)
	95	early_serial_init(port, baud);
	96	}
	97
	98	#define BASE_BAUD (1843200/16)
	99	static unsigned int probe_baud(int port)
	100	{
	101	unsigned char lcr, dll, dlh;
	102	unsigned int quot;
	103
	104	lcr = inb(port + LCR);
	105	outb(lcr \| DLAB, port + LCR);
	106	dll = inb(port + DLL);
	107	dlh = inb(port + DLH);
	108	outb(lcr, port + LCR);
	109	quot = (dlh << 8) \| dll;
	110
	111	return BASE_BAUD / quot;
	112	}
	113
	114	static void parse_console_uart8250(void)
	115	{
	116	char optstr[64], *options;
	117	int baud = DEFAULT_BAUD;
	118	int port = 0;
	119
	120	/*
	121	* console=uart8250,io,0x3f8,115200n8
	122	* need to make sure it is last one console !
	123	*/
	124	if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
	125	return;
	126
	127	options = optstr;
	128
	129	if (!strncmp(options, "uart8250,io,", 12))
	130	port = simple_strtoull(options + 12, &options, 0);
	131	else if (!strncmp(options, "uart,io,", 8))
	132	port = simple_strtoull(options + 8, &options, 0);
	133	else
	134	return;
	135
	136	if (options && (options[0] == ','))
	137	baud = simple_strtoull(options + 1, &options, 0);
138	else
139	baud = probe_baud(port);
140
141	if (port)
142	early_serial_init(port, baud);
143	}
144
145	void console_init(void)
146	{
147	parse_earlyprintk();
148
149	if (!early_serial_base)
150	parse_console_uart8250();
151	}