xref: /openbmc/linux/drivers/firmware/pcdp.c (revision 87c2ce3b)
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/config.h>
15 #include <linux/acpi.h>
16 #include <linux/console.h>
17 #include <linux/efi.h>
18 #include <linux/serial.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.address_space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
31 	p += sprintf(p, "console=uart,%s,0x%lx",
32 		mmio ? "mmio" : "io", uart->addr.address);
33 	if (uart->baud) {
34 		p += sprintf(p, ",%lu", 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 	return early_serial_console_init(options);
46 #else
47 	return -ENODEV;
48 #endif
49 }
50 
51 static int __init
52 setup_vga_console(struct pcdp_device *dev)
53 {
54 #if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
55 	u8 *if_ptr;
56 
57 	if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
58 	if (if_ptr[0] == PCDP_IF_PCI) {
59 		struct pcdp_if_pci if_pci;
60 
61 		/* struct copy since ifptr might not be correctly aligned */
62 
63 		memcpy(&if_pci, if_ptr, sizeof(if_pci));
64 
65 		if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
66 			vga_console_iobase = if_pci.ioport_tra;
67 
68 		if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
69 			vga_console_membase = if_pci.mmio_tra;
70 	}
71 
72 	if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
73 		printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
74 		return -ENODEV;
75 	}
76 
77 	conswitchp = &vga_con;
78 	printk(KERN_INFO "PCDP: VGA console\n");
79 	return 0;
80 #else
81 	return -ENODEV;
82 #endif
83 }
84 
85 int __init
86 efi_setup_pcdp_console(char *cmdline)
87 {
88 	struct pcdp *pcdp;
89 	struct pcdp_uart *uart;
90 	struct pcdp_device *dev, *end;
91 	int i, serial = 0;
92 
93 	pcdp = efi.hcdp;
94 	if (!pcdp)
95 		return -ENODEV;
96 
97 	printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, __pa(pcdp));
98 
99 	if (strstr(cmdline, "console=hcdp")) {
100 		if (pcdp->rev < 3)
101 			serial = 1;
102 	} else if (strstr(cmdline, "console=")) {
103 		printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
104 		return -ENODEV;
105 	}
106 
107 	if (pcdp->rev < 3 && efi_uart_console_only())
108 		serial = 1;
109 
110 	for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
111 		if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
112 			if (uart->type == PCDP_CONSOLE_UART) {
113 				return setup_serial_console(uart);
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 				return setup_vga_console(dev);
125 			}
126 		}
127 	}
128 
129 	return -ENODEV;
130 }
131