pcdp.c revision 97d3a00f77fa527886d53dd943017654ce142186 
1/*
2 * Parse the EFI PCDP table to locate the console device.
3 *
4 * (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
5 *	Khalid Aziz <khalid.aziz@hp.com>
6 *	Alex Williamson <alex.williamson@hp.com>
7 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/config.h>
15#include <linux/acpi.h>
16#include <linux/console.h>
17#include <linux/efi.h>
18#include <linux/serial.h>
19#include "pcdp.h"
20
21static int __init
22setup_serial_console(struct pcdp_uart *uart)
23{
24#ifdef CONFIG_SERIAL_8250_CONSOLE
25	int mmio;
26	static char options[64];
27
28	mmio = (uart->addr.address_space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
29	snprintf(options, sizeof(options), "console=uart,%s,0x%lx,%lun%d",
30		mmio ? "mmio" : "io", uart->addr.address, uart->baud,
31		uart->bits ? uart->bits : 8);
32
33	return early_serial_console_init(options);
34#else
35	return -ENODEV;
36#endif
37}
38
39static int __init
40setup_vga_console(struct pcdp_vga *vga)
41{
42#if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
43	if (efi_mem_type(0xA0000) == EFI_CONVENTIONAL_MEMORY) {
44		printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
45		return -ENODEV;
46	}
47
48	conswitchp = &vga_con;
49	printk(KERN_INFO "PCDP: VGA console\n");
50	return 0;
51#else
52	return -ENODEV;
53#endif
54}
55
56int __init
57efi_setup_pcdp_console(char *cmdline)
58{
59	struct pcdp *pcdp;
60	struct pcdp_uart *uart;
61	struct pcdp_device *dev, *end;
62	int i, serial = 0;
63
64	pcdp = efi.hcdp;
65	if (!pcdp)
66		return -ENODEV;
67
68	printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, __pa(pcdp));
69
70	if (strstr(cmdline, "console=hcdp")) {
71		if (pcdp->rev < 3)
72			serial = 1;
73	} else if (strstr(cmdline, "console=")) {
74		printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
75		return -ENODEV;
76	}
77
78	if (pcdp->rev < 3 && efi_uart_console_only())
79		serial = 1;
80
81	for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
82		if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
83			if (uart->type == PCDP_CONSOLE_UART) {
84				return setup_serial_console(uart);
85			}
86		}
87	}
88
89	end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
90	for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
91	     dev < end;
92	     dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
93		if (dev->flags & PCDP_PRIMARY_CONSOLE) {
94			if (dev->type == PCDP_CONSOLE_VGA) {
95				return setup_vga_console((struct pcdp_vga *) dev);
96			}
97		}
98	}
99
100	return -ENODEV;
101}
102