arch/i386/kernel/legacy_serial.c

   1 /*
   2  * Legacy COM port devices for x86 platforms without PNPBIOS or ACPI.
   3  * Data taken from include/asm-i386/serial.h.
   4  *
   5  * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
   6  *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/pnp.h>
  15 #include <linux/serial_8250.h>
  16
  17 /* Standard COM flags (except for COM4, because of the 8514 problem) */
  18 #ifdef CONFIG_SERIAL_DETECT_IRQ
  19 #define COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_AUTO_IRQ)
  20 #define COM4_FLAGS (UPF_BOOT_AUTOCONF | UPF_AUTO_IRQ)
  21 #else
  22 #define COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST)
  23 #define COM4_FLAGS UPF_BOOT_AUTOCONF
  24 #endif
  25
  26 #define PORT(_base,_irq,_flags)                         \
  27         {                                               \
  28                 .iobase         = _base,                \
  29                 .irq            = _irq,                 \
  30                 .uartclk        = 1843200,              \
  31                 .iotype         = UPIO_PORT,            \
  32                 .flags          = _flags,               \
  33         }
  34
  35 static struct plat_serial8250_port x86_com_data[] = {
  36         PORT(0x3F8, 4, COM_FLAGS),
  37         PORT(0x2F8, 3, COM_FLAGS),
  38         PORT(0x3E8, 4, COM_FLAGS),
  39         PORT(0x2E8, 3, COM4_FLAGS),
  40         { },
  41 };
  42
  43 static struct platform_device x86_com_device = {
  44         .name                   = "serial8250",
  45         .id                     = PLAT8250_DEV_PLATFORM,
  46         .dev                    = {
  47                 .platform_data  = x86_com_data,
  48         },
  49 };
  50
  51 static int force_legacy_probe;
  52 module_param_named(force, force_legacy_probe, bool, 0);
  53 MODULE_PARM_DESC(force, "Force legacy serial port probe");
  54
  55 static int __init serial8250_x86_com_init(void)
  56 {
  57         if (pnp_platform_devices && !force_legacy_probe)
  58                 return -ENODEV;
  59
  60         return platform_device_register(&x86_com_device);
  61 }
  62
  63 module_init(serial8250_x86_com_init);
  64
  65 MODULE_AUTHOR("Bjorn Helgaas");
  66 MODULE_LICENSE("GPL");
  67 MODULE_DESCRIPTION("Generic 8250/16x50 legacy probe module");