LXR linux/drivers/firmware/pcdp.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Parse the EFI PCDP table to locate the console device.
   4 *
   5 * (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
   6 *      Khalid Aziz <khalid.aziz@hp.com>
   7 *      Alex Williamson <alex.williamson@hp.com>
   8 *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   9 */
  10
  11#include <linux/acpi.h>
  12#include <linux/console.h>
  13#include <linux/efi.h>
  14#include <linux/serial.h>
  15#include <linux/serial_core.h>
  16#include <asm/vga.h>
  17#include "pcdp.h"
  18
  19static int __init
  20setup_serial_console(struct pcdp_uart *uart)
  21{
  22#ifdef CONFIG_SERIAL_8250_CONSOLE
  23        int mmio;
  24        static char options[64], *p = options;
  25        char parity;
  26
  27        mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
  28        p += sprintf(p, "uart8250,%s,0x%llx",
  29                mmio ? "mmio" : "io", uart->addr.address);
  30        if (uart->baud) {
  31                p += sprintf(p, ",%llu", uart->baud);
  32                if (uart->bits) {
  33                        switch (uart->parity) {
  34                            case 0x2: parity = 'e'; break;
  35                            case 0x3: parity = 'o'; break;
  36                            default:  parity = 'n';
  37                        }
  38                        p += sprintf(p, "%c%d", parity, uart->bits);
  39                }
  40        }
  41
  42        add_preferred_console("uart", 8250, &options[9]);
  43        return setup_earlycon(options);
  44#else
  45        return -ENODEV;
  46#endif
  47}
  48
  49static int __init
  50setup_vga_console(struct pcdp_device *dev)
  51{
  52#if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
  53        u8 *if_ptr;
  54
  55        if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
  56        if (if_ptr[0] == PCDP_IF_PCI) {
  57                struct pcdp_if_pci if_pci;
  58
  59                /* struct copy since ifptr might not be correctly aligned */
  60
  61                memcpy(&if_pci, if_ptr, sizeof(if_pci));
  62
  63                if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
  64                        vga_console_iobase = if_pci.ioport_tra;
  65
  66                if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
  67                        vga_console_membase = if_pci.mmio_tra;
  68        }
  69
  70        if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
  71                printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
  72                return -ENODEV;
  73        }
  74
  75        conswitchp = &vga_con;
  76        printk(KERN_INFO "PCDP: VGA console\n");
  77        return 0;
  78#else
  79        return -ENODEV;
  80#endif
  81}
  82
  83int __init
  84efi_setup_pcdp_console(char *cmdline)
  85{
  86        struct pcdp *pcdp;
  87        struct pcdp_uart *uart;
  88        struct pcdp_device *dev, *end;
  89        int i, serial = 0;
  90        int rc = -ENODEV;
  91
  92        if (efi.hcdp == EFI_INVALID_TABLE_ADDR)
  93                return -ENODEV;
  94
  95        pcdp = early_memremap(efi.hcdp, 4096);
  96        printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, efi.hcdp);
  97
  98        if (strstr(cmdline, "console=hcdp")) {
  99                if (pcdp->rev < 3)
 100                        serial = 1;
 101        } else if (strstr(cmdline, "console=")) {
 102                printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
 103                goto out;
 104        }
 105
 106        if (pcdp->rev < 3 && efi_uart_console_only())
 107                serial = 1;
 108
 109        for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
 110                if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
 111                        if (uart->type == PCDP_CONSOLE_UART) {
 112                                rc = setup_serial_console(uart);
 113                                goto out;
 114                        }
 115                }
 116        }
 117
 118        end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
 119        for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
 120             dev < end;
 121             dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
 122                if (dev->flags & PCDP_PRIMARY_CONSOLE) {
 123                        if (dev->type == PCDP_CONSOLE_VGA) {
 124                                rc = setup_vga_console(dev);
 125                                goto out;
 126                        }
 127                }
 128        }
 129
 130out:
 131        early_memunmap(pcdp, 4096);
 132        return rc;
 133}
 134