pcdp.c revision 18a8bd949d6adb311ea816125ff65050df1f3f6e 
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/acpi.h>
15#include <linux/console.h>
16#include <linux/efi.h>
17#include <linux/serial.h>
18#include <linux/serial_8250.h>
19#include <asm/vga.h>
20#include "pcdp.h"
21
22static int __init
23setup_serial_console(struct pcdp_uart *uart)
24{
25#ifdef CONFIG_SERIAL_8250_CONSOLE
26	int mmio;
27	static char options[64], *p = options;
28	char parity;
29
30	mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
31	p += sprintf(p, "uart8250,%s,0x%lx",
32		mmio ? "mmio" : "io", uart->addr.address);
33	if (uart->baud) {
34		p += sprintf(p, ",%lu", uart->baud);
35		if (uart->bits) {
36			switch (uart->parity) {
37			    case 0x2: parity = 'e'; break;
38			    case 0x3: parity = 'o'; break;
39			    default:  parity = 'n';
40			}
41			p += sprintf(p, "%c%d", parity, uart->bits);
42		}
43	}
44
45	add_preferred_console("uart", 8250, &options[9]);
46	return setup_early_serial8250_console(options);
47#else
48	return -ENODEV;
49#endif
50}
51
52static int __init
53setup_vga_console(struct pcdp_device *dev)
54{
55#if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
56	u8 *if_ptr;
57
58	if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
59	if (if_ptr[0] == PCDP_IF_PCI) {
60		struct pcdp_if_pci if_pci;
61
62		/* struct copy since ifptr might not be correctly aligned */
63
64		memcpy(&if_pci, if_ptr, sizeof(if_pci));
65
66		if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
67			vga_console_iobase = if_pci.ioport_tra;
68
69		if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
70			vga_console_membase = if_pci.mmio_tra;
71	}
72
73	if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
74		printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
75		return -ENODEV;
76	}
77
78	conswitchp = &vga_con;
79	printk(KERN_INFO "PCDP: VGA console\n");
80	return 0;
81#else
82	return -ENODEV;
83#endif
84}
85
86int __init
87efi_setup_pcdp_console(char *cmdline)
88{
89	struct pcdp *pcdp;
90	struct pcdp_uart *uart;
91	struct pcdp_device *dev, *end;
92	int i, serial = 0;
93	int rc = -ENODEV;
94
95	if (efi.hcdp == EFI_INVALID_TABLE_ADDR)
96		return -ENODEV;
97
98	pcdp = ioremap(efi.hcdp, 4096);
99	printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, efi.hcdp);
100
101	if (strstr(cmdline, "console=hcdp")) {
102		if (pcdp->rev < 3)
103			serial = 1;
104	} else if (strstr(cmdline, "console=")) {
105		printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
106		goto out;
107	}
108
109	if (pcdp->rev < 3 && efi_uart_console_only())
110		serial = 1;
111
112	for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
113		if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
114			if (uart->type == PCDP_CONSOLE_UART) {
115				rc = setup_serial_console(uart);
116				goto out;
117			}
118		}
119	}
120
121	end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
122	for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
123	     dev < end;
124	     dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
125		if (dev->flags & PCDP_PRIMARY_CONSOLE) {
126			if (dev->type == PCDP_CONSOLE_VGA) {
127				rc = setup_vga_console(dev);
128				goto out;
129			}
130		}
131	}
132
133out:
134	iounmap(pcdp);
135	return rc;
136}
137