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/leds.h> 22 #include <linux/platform_device.h> 23 #include <linux/gpio.h> 24 #include <linux/input.h> 25 #include <linux/gpio_keys.h> 26 #include <linux/dmi.h> 27 28 #include <asm/geode.h> 29 30 #define BIOS_SIGNATURE_TINYBIOS 0xf0000 31 #define BIOS_SIGNATURE_COREBOOT 0x500 32 #define BIOS_REGION_SIZE 0x10000 33 34 /* 35 * This driver is not modular, but to keep back compatibility 36 * with existing use cases, continuing with module_param is 37 * the easiest way forward. 38 */ 39 static bool force = 0; 40 module_param(force, bool, 0444); 41 /* FIXME: Award bios is not automatically detected as Alix platform */ 42 MODULE_PARM_DESC(force, "Force detection as ALIX.2/ALIX.3 platform"); 43 44 static struct gpio_keys_button alix_gpio_buttons[] = { 45 { 46 .code = KEY_RESTART, 47 .gpio = 24, 48 .active_low = 1, 49 .desc = "Reset button", 50 .type = EV_KEY, 51 .wakeup = 0, 52 .debounce_interval = 100, 53 .can_disable = 0, 54 } 55 }; 56 static struct gpio_keys_platform_data alix_buttons_data = { 57 .buttons = alix_gpio_buttons, 58 .nbuttons = ARRAY_SIZE(alix_gpio_buttons), 59 .poll_interval = 20, 60 }; 61 62 static struct platform_device alix_buttons_dev = { 63 .name = "gpio-keys-polled", 64 .id = 1, 65 .dev = { 66 .platform_data = &alix_buttons_data, 67 } 68 }; 69 70 static struct gpio_led alix_leds[] = { 71 { 72 .name = "alix:1", 73 .gpio = 6, 74 .default_trigger = "default-on", 75 .active_low = 1, 76 }, 77 { 78 .name = "alix:2", 79 .gpio = 25, 80 .default_trigger = "default-off", 81 .active_low = 1, 82 }, 83 { 84 .name = "alix:3", 85 .gpio = 27, 86 .default_trigger = "default-off", 87 .active_low = 1, 88 }, 89 }; 90 91 static struct gpio_led_platform_data alix_leds_data = { 92 .num_leds = ARRAY_SIZE(alix_leds), 93 .leds = alix_leds, 94 }; 95 96 static struct platform_device alix_leds_dev = { 97 .name = "leds-gpio", 98 .id = -1, 99 .dev.platform_data = &alix_leds_data, 100 }; 101 102 static struct platform_device *alix_devs[] __initdata = { 103 &alix_buttons_dev, 104 &alix_leds_dev, 105 }; 106 107 static void __init register_alix(void) 108 { 109 /* Setup LED control through leds-gpio driver */ 110 platform_add_devices(alix_devs, ARRAY_SIZE(alix_devs)); 111 } 112 113 static bool __init alix_present(unsigned long bios_phys, 114 const char *alix_sig, 115 size_t alix_sig_len) 116 { 117 const size_t bios_len = BIOS_REGION_SIZE; 118 const char *bios_virt; 119 const char *scan_end; 120 const char *p; 121 char name[64]; 122 123 if (force) { 124 printk(KERN_NOTICE "%s: forced to skip BIOS test, " 125 "assume system is ALIX.2/ALIX.3\n", 126 KBUILD_MODNAME); 127 return true; 128 } 129 130 bios_virt = phys_to_virt(bios_phys); 131 scan_end = bios_virt + bios_len - (alix_sig_len + 2); 132 for (p = bios_virt; p < scan_end; p++) { 133 const char *tail; 134 char *a; 135 136 if (memcmp(p, alix_sig, alix_sig_len) != 0) 137 continue; 138 139 memcpy(name, p, sizeof(name)); 140 141 /* remove the first \0 character from string */ 142 a = strchr(name, '\0'); 143 if (a) 144 *a = ' '; 145 146 /* cut the string at a newline */ 147 a = strchr(name, '\r'); 148 if (a) 149 *a = '\0'; 150 151 tail = p + alix_sig_len; 152 if ((tail[0] == '2' || tail[0] == '3' || tail[0] == '6')) { 153 printk(KERN_INFO 154 "%s: system is recognized as \"%s\"\n", 155 KBUILD_MODNAME, name); 156 return true; 157 } 158 } 159 160 return false; 161 } 162 163 static bool __init alix_present_dmi(void) 164 { 165 const char *vendor, *product; 166 167 vendor = dmi_get_system_info(DMI_SYS_VENDOR); 168 if (!vendor || strcmp(vendor, "PC Engines")) 169 return false; 170 171 product = dmi_get_system_info(DMI_PRODUCT_NAME); 172 if (!product || (strcmp(product, "ALIX.2D") && strcmp(product, "ALIX.6"))) 173 return false; 174 175 printk(KERN_INFO "%s: system is recognized as \"%s %s\"\n", 176 KBUILD_MODNAME, vendor, product); 177 178 return true; 179 } 180 181 static int __init alix_init(void) 182 { 183 const char tinybios_sig[] = "PC Engines ALIX."; 184 const char coreboot_sig[] = "PC Engines\0ALIX."; 185 186 if (!is_geode()) 187 return 0; 188 189 if (alix_present(BIOS_SIGNATURE_TINYBIOS, tinybios_sig, sizeof(tinybios_sig) - 1) || 190 alix_present(BIOS_SIGNATURE_COREBOOT, coreboot_sig, sizeof(coreboot_sig) - 1) || 191 alix_present_dmi()) 192 register_alix(); 193 194 return 0; 195 } 196 device_initcall(alix_init); 197