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/acpi.h>
  15 #include <linux/console.h>
  16 #include <linux/efi.h>
  17 #include <linux/serial.h>
  18 #include "pcdp.h"
  19
  20 static int __init
  21 setup_serial_console(struct pcdp_uart *uart)
  22 {
  23 #ifdef CONFIG_SERIAL_8250_CONSOLE
  24         int mmio;
  25         static char options[64];
  26
  27         mmio = (uart->addr.address_space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
  28         snprintf(options, sizeof(options), "console=uart,%s,0x%lx,%lun%d",
  29                 mmio ? "mmio" : "io", uart->addr.address, uart->baud,
  30                 uart->bits ? uart->bits : 8);
  31
  32         return early_serial_console_init(options);
  33 #else
  34         return -ENODEV;
  35 #endif
  36 }
  37
  38 static int __init
  39 setup_vga_console(struct pcdp_vga *vga)
  40 {
  41 #if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
  42         if (efi_mem_type(0xA0000) == EFI_CONVENTIONAL_MEMORY) {
  43                 printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
  44                 return -ENODEV;
  45         }
  46
  47         conswitchp = &vga_con;
  48         printk(KERN_INFO "PCDP: VGA console\n");
  49         return 0;
  50 #else
  51         return -ENODEV;
  52 #endif
  53 }
  54
  55 int __init
  56 efi_setup_pcdp_console(char *cmdline)
  57 {
  58         struct pcdp *pcdp;
  59         struct pcdp_uart *uart;
  60         struct pcdp_device *dev, *end;
  61         int i, serial = 0;
  62
  63         pcdp = efi.hcdp;
  64         if (!pcdp)
  65                 return -ENODEV;
  66
  67         printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, __pa(pcdp));
  68
  69         if (strstr(cmdline, "console=hcdp")) {
  70                 if (pcdp->rev < 3)
  71                         serial = 1;
  72         } else if (strstr(cmdline, "console=")) {
  73                 printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
  74                 return -ENODEV;
  75         }
  76
  77         if (pcdp->rev < 3 && efi_uart_console_only())
  78                 serial = 1;
  79
  80         for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
  81                 if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
  82                         if (uart->type == PCDP_CONSOLE_UART) {
  83                                 return setup_serial_console(uart);
  84                         }
  85                 }
  86         }
  87
  88         end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
  89         for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
  90              dev < end;
  91              dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
  92                 if (dev->flags & PCDP_PRIMARY_CONSOLE) {
  93                         if (dev->type == PCDP_CONSOLE_VGA) {
  94                                 return setup_vga_console((struct pcdp_vga *) dev);
  95                         }
  96                 }
  97         }
  98
  99         return -ENODEV;
 100 }