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 <linux/serial_core.h>
  19 #include <asm/vga.h>
  20 #include "pcdp.h"
  21
  22 static int __init
  23 setup_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%llx",
  32                 mmio ? "mmio" : "io", uart->addr.address);
  33         if (uart->baud) {
  34                 p += sprintf(p, ",%llu", 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_earlycon(options);
  47 #else
  48         return -ENODEV;
  49 #endif
  50 }
  51
  52 static int __init
  53 setup_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
  86 int __init
  87 efi_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 = early_memremap(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
 133 out:
 134         early_memunmap(pcdp, 4096);
 135         return rc;
 136 }