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