xref: /openbmc/linux/drivers/firmware/pcdp.c (revision d3964221)
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/acpi.h>
15 #include <linux/console.h>
16 #include <linux/efi.h>
17 #include <linux/serial.h>
18 #include <linux/serial_core.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.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
31 	p += sprintf(p, "uart8250,%s,0x%llx",
32 		mmio ? "mmio" : "io", uart->addr.address);
33 	if (uart->baud) {
34 		p += sprintf(p, ",%llu", 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 	add_preferred_console("uart", 8250, &options[9]);
46 	return setup_earlycon(options);
47 #else
48 	return -ENODEV;
49 #endif
50 }
51 
52 static int __init
53 setup_vga_console(struct pcdp_device *dev)
54 {
55 #if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
56 	u8 *if_ptr;
57 
58 	if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
59 	if (if_ptr[0] == PCDP_IF_PCI) {
60 		struct pcdp_if_pci if_pci;
61 
62 		/* struct copy since ifptr might not be correctly aligned */
63 
64 		memcpy(&if_pci, if_ptr, sizeof(if_pci));
65 
66 		if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
67 			vga_console_iobase = if_pci.ioport_tra;
68 
69 		if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
70 			vga_console_membase = if_pci.mmio_tra;
71 	}
72 
73 	if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
74 		printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
75 		return -ENODEV;
76 	}
77 
78 	conswitchp = &vga_con;
79 	printk(KERN_INFO "PCDP: VGA console\n");
80 	return 0;
81 #else
82 	return -ENODEV;
83 #endif
84 }
85 
86 int __init
87 efi_setup_pcdp_console(char *cmdline)
88 {
89 	struct pcdp *pcdp;
90 	struct pcdp_uart *uart;
91 	struct pcdp_device *dev, *end;
92 	int i, serial = 0;
93 	int rc = -ENODEV;
94 
95 	if (efi.hcdp == EFI_INVALID_TABLE_ADDR)
96 		return -ENODEV;
97 
98 	pcdp = early_memremap(efi.hcdp, 4096);
99 	printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, efi.hcdp);
100 
101 	if (strstr(cmdline, "console=hcdp")) {
102 		if (pcdp->rev < 3)
103 			serial = 1;
104 	} else if (strstr(cmdline, "console=")) {
105 		printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
106 		goto out;
107 	}
108 
109 	if (pcdp->rev < 3 && efi_uart_console_only())
110 		serial = 1;
111 
112 	for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
113 		if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
114 			if (uart->type == PCDP_CONSOLE_UART) {
115 				rc = setup_serial_console(uart);
116 				goto out;
117 			}
118 		}
119 	}
120 
121 	end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
122 	for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
123 	     dev < end;
124 	     dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
125 		if (dev->flags & PCDP_PRIMARY_CONSOLE) {
126 			if (dev->type == PCDP_CONSOLE_VGA) {
127 				rc = setup_vga_console(dev);
128 				goto out;
129 			}
130 		}
131 	}
132 
133 out:
134 	early_memunmap(pcdp, 4096);
135 	return rc;
136 }
137