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 <[email protected]>
   7  *      Alex Williamson <[email protected]>
   8  *      Bjorn Helgaas <[email protected]>
   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
  19 static int __init
  20 setup_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
  49 static int __init
  50 setup_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
  83 int __init
  84 efi_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
 130 out:
 131         early_memunmap(pcdp, 4096);
 132         return rc;
 133 }