pcdp.c

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/*
 * Parse the EFI PCDP table to locate the console device.
 *
 * (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
 *  Khalid Aziz <[email protected]>
 *  Alex Williamson <[email protected]>
 *  Bjorn Helgaas <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/acpi.h>
#include <linux/console.h>
#include <linux/efi.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/vga.h>
#include "pcdp.h"

static int __init
setup_serial_console(struct pcdp_uart *uart)
{
#ifdef CONFIG_SERIAL_8250_CONSOLE
    int mmio;
    static char options[64], *p = options;
    char parity;

    mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
    p += sprintf(p, "uart8250,%s,0x%llx",
        mmio ? "mmio" : "io", uart->addr.address);
    if (uart->baud) {
        p += sprintf(p, ",%llu", uart->baud);
        if (uart->bits) {
            switch (uart->parity) {
                case 0x2: parity = 'e'; break;
                case 0x3: parity = 'o'; break;
                default:  parity = 'n';
            }
            p += sprintf(p, "%c%d", parity, uart->bits);
        }
    }

    add_preferred_console("uart", 8250, &options[9]);
    return setup_early_serial8250_console(options);
#else
    return -ENODEV;
#endif
}

static int __init
setup_vga_console(struct pcdp_device *dev)
{
#if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
    u8 *if_ptr;

    if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
    if (if_ptr[0] == PCDP_IF_PCI) {
        struct pcdp_if_pci if_pci;

        /* struct copy since ifptr might not be correctly aligned */

        memcpy(&if_pci, if_ptr, sizeof(if_pci));

        if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
            vga_console_iobase = if_pci.ioport_tra;

        if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
            vga_console_membase = if_pci.mmio_tra;
    }

    if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
        printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
        return -ENODEV;
    }

    conswitchp = &vga_con;
    printk(KERN_INFO "PCDP: VGA console\n");
    return 0;
#else
    return -ENODEV;
#endif
}

int __init
efi_setup_pcdp_console(char *cmdline)
{
    struct pcdp *pcdp;
    struct pcdp_uart *uart;
    struct pcdp_device *dev, *end;
    int i, serial = 0;
    int rc = -ENODEV;

    if (efi.hcdp == EFI_INVALID_TABLE_ADDR)
        return -ENODEV;

    pcdp = early_ioremap(efi.hcdp, 4096);
    printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, efi.hcdp);

    if (strstr(cmdline, "console=hcdp")) {
        if (pcdp->rev < 3)
            serial = 1;
    } else if (strstr(cmdline, "console=")) {
        printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
        goto out;
    }

    if (pcdp->rev < 3 && efi_uart_console_only())
        serial = 1;

    for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
        if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
            if (uart->type == PCDP_CONSOLE_UART) {
                rc = setup_serial_console(uart);
                goto out;
            }
        }
    }

    end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
    for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
         dev < end;
         dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
        if (dev->flags & PCDP_PRIMARY_CONSOLE) {
            if (dev->type == PCDP_CONSOLE_VGA) {
                rc = setup_vga_console(dev);
                goto out;
            }
        }
    }

out:
    early_iounmap(pcdp, 4096);
    return rc;
}