drivers/firmware/pcdp.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Parse the EFI PCDP table to locate the console device.
0004  *
0005  * (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
0006  *  Khalid Aziz <khalid.aziz@hp.com>
0007  *  Alex Williamson <alex.williamson@hp.com>
0008  *  Bjorn Helgaas <bjorn.helgaas@hp.com>
0009  */
0010
0011 #include <linux/acpi.h>
0012 #include <linux/console.h>
0013 #include <linux/efi.h>
0014 #include <linux/serial.h>
0015 #include <linux/serial_core.h>
0016 #include <asm/vga.h>
0017 #include "pcdp.h"
0018
0019 static int __init
0020 setup_serial_console(struct pcdp_uart *uart)
0021 {
0022 #ifdef CONFIG_SERIAL_8250_CONSOLE
0023     int mmio;
0024     static char options[64], *p = options;
0025     char parity;
0026
0027     mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
0028     p += sprintf(p, "uart8250,%s,0x%llx",
0029         mmio ? "mmio" : "io", uart->addr.address);
0030     if (uart->baud) {
0031         p += sprintf(p, ",%llu", uart->baud);
0032         if (uart->bits) {
0033             switch (uart->parity) {
0034                 case 0x2: parity = 'e'; break;
0035                 case 0x3: parity = 'o'; break;
0036                 default:  parity = 'n';
0037             }
0038             p += sprintf(p, "%c%d", parity, uart->bits);
0039         }
0040     }
0041
0042     add_preferred_console("uart", 8250, &options[9]);
0043     return setup_earlycon(options);
0044 #else
0045     return -ENODEV;
0046 #endif
0047 }
0048
0049 static int __init
0050 setup_vga_console(struct pcdp_device *dev)
0051 {
0052 #if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
0053     u8 *if_ptr;
0054
0055     if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
0056     if (if_ptr[0] == PCDP_IF_PCI) {
0057         struct pcdp_if_pci if_pci;
0058
0059         /* struct copy since ifptr might not be correctly aligned */
0060
0061         memcpy(&if_pci, if_ptr, sizeof(if_pci));
0062
0063         if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
0064             vga_console_iobase = if_pci.ioport_tra;
0065
0066         if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
0067             vga_console_membase = if_pci.mmio_tra;
0068     }
0069
0070     if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
0071         printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
0072         return -ENODEV;
0073     }
0074
0075     conswitchp = &vga_con;
0076     printk(KERN_INFO "PCDP: VGA console\n");
0077     return 0;
0078 #else
0079     return -ENODEV;
0080 #endif
0081 }
0082
0083 extern unsigned long hcdp_phys;
0084
0085 int __init
0086 efi_setup_pcdp_console(char *cmdline)
0087 {
0088     struct pcdp *pcdp;
0089     struct pcdp_uart *uart;
0090     struct pcdp_device *dev, *end;
0091     int i, serial = 0;
0092     int rc = -ENODEV;
0093
0094     if (hcdp_phys == EFI_INVALID_TABLE_ADDR)
0095         return -ENODEV;
0096
0097     pcdp = early_memremap(hcdp_phys, 4096);
0098     printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, hcdp_phys);
0099
0100     if (strstr(cmdline, "console=hcdp")) {
0101         if (pcdp->rev < 3)
0102             serial = 1;
0103     } else if (strstr(cmdline, "console=")) {
0104         printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
0105         goto out;
0106     }
0107
0108     if (pcdp->rev < 3 && efi_uart_console_only())
0109         serial = 1;
0110
0111     for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
0112         if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
0113             if (uart->type == PCDP_CONSOLE_UART) {
0114                 rc = setup_serial_console(uart);
0115                 goto out;
0116             }
0117         }
0118     }
0119
0120     end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
0121     for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
0122          dev < end;
0123          dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
0124         if (dev->flags & PCDP_PRIMARY_CONSOLE) {
0125             if (dev->type == PCDP_CONSOLE_VGA) {
0126                 rc = setup_vga_console(dev);
0127                 goto out;
0128             }
0129         }
0130     }
0131
0132 out:
0133     early_memunmap(pcdp, 4096);
0134     return rc;
0135 }