drivers/firmware/pcdp.c

   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
  21 static int __init
  22 setup_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
  39 static int __init
  40 setup_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
  56 int __init
  57 efi_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 }