1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * System Specific setup for PCEngines ALIX. 4 * At the moment this means setup of GPIO control of LEDs 5 * on Alix.2/3/6 boards. 6 * 7 * Copyright (C) 2008 Constantin Baranov <const@mimas.ru> 8 * Copyright (C) 2011 Ed Wildgoose <kernel@wildgooses.com> 9 * and Philip Prindeville <philipp@redfish-solutions.com> 10 * 11 * TODO: There are large similarities with leds-net5501.c 12 * by Alessandro Zummo <a.zummo@towertech.it> 13 * In the future leds-net5501.c should be migrated over to platform 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/init.h> 18 #include <linux/io.h> 19 #include <linux/string.h> 20 #include <linux/moduleparam.h> 21 #include <linux/dmi.h> 22 23 #include <asm/geode.h> 24 25 #include "geode-common.h" 26 27 #define BIOS_SIGNATURE_TINYBIOS 0xf0000 28 #define BIOS_SIGNATURE_COREBOOT 0x500 29 #define BIOS_REGION_SIZE 0x10000 30 31 /* 32 * This driver is not modular, but to keep back compatibility 33 * with existing use cases, continuing with module_param is 34 * the easiest way forward. 35 */ 36 static bool force = 0; 37 module_param(force, bool, 0444); 38 /* FIXME: Award bios is not automatically detected as Alix platform */ 39 MODULE_PARM_DESC(force, "Force detection as ALIX.2/ALIX.3 platform"); 40 41 static const struct geode_led alix_leds[] __initconst = { 42 { 6, true }, 43 { 25, false }, 44 { 27, false }, 45 }; 46 47 static void __init register_alix(void) 48 { 49 geode_create_restart_key(24); 50 geode_create_leds("alix", alix_leds, ARRAY_SIZE(alix_leds)); 51 } 52 53 static bool __init alix_present(unsigned long bios_phys, 54 const char *alix_sig, 55 size_t alix_sig_len) 56 { 57 const size_t bios_len = BIOS_REGION_SIZE; 58 const char *bios_virt; 59 const char *scan_end; 60 const char *p; 61 char name[64]; 62 63 if (force) { 64 printk(KERN_NOTICE "%s: forced to skip BIOS test, " 65 "assume system is ALIX.2/ALIX.3\n", 66 KBUILD_MODNAME); 67 return true; 68 } 69 70 bios_virt = phys_to_virt(bios_phys); 71 scan_end = bios_virt + bios_len - (alix_sig_len + 2); 72 for (p = bios_virt; p < scan_end; p++) { 73 const char *tail; 74 char *a; 75 76 if (memcmp(p, alix_sig, alix_sig_len) != 0) 77 continue; 78 79 memcpy(name, p, sizeof(name)); 80 81 /* remove the first \0 character from string */ 82 a = strchr(name, '\0'); 83 if (a) 84 *a = ' '; 85 86 /* cut the string at a newline */ 87 a = strchr(name, '\r'); 88 if (a) 89 *a = '\0'; 90 91 tail = p + alix_sig_len; 92 if ((tail[0] == '2' || tail[0] == '3' || tail[0] == '6')) { 93 printk(KERN_INFO 94 "%s: system is recognized as \"%s\"\n", 95 KBUILD_MODNAME, name); 96 return true; 97 } 98 } 99 100 return false; 101 } 102 103 static bool __init alix_present_dmi(void) 104 { 105 const char *vendor, *product; 106 107 vendor = dmi_get_system_info(DMI_SYS_VENDOR); 108 if (!vendor || strcmp(vendor, "PC Engines")) 109 return false; 110 111 product = dmi_get_system_info(DMI_PRODUCT_NAME); 112 if (!product || (strcmp(product, "ALIX.2D") && strcmp(product, "ALIX.6"))) 113 return false; 114 115 printk(KERN_INFO "%s: system is recognized as \"%s %s\"\n", 116 KBUILD_MODNAME, vendor, product); 117 118 return true; 119 } 120 121 static int __init alix_init(void) 122 { 123 const char tinybios_sig[] = "PC Engines ALIX."; 124 const char coreboot_sig[] = "PC Engines\0ALIX."; 125 126 if (!is_geode()) 127 return 0; 128 129 if (alix_present(BIOS_SIGNATURE_TINYBIOS, tinybios_sig, sizeof(tinybios_sig) - 1) || 130 alix_present(BIOS_SIGNATURE_COREBOOT, coreboot_sig, sizeof(coreboot_sig) - 1) || 131 alix_present_dmi()) 132 register_alix(); 133 134 return 0; 135 } 136 device_initcall(alix_init); 137