arch/x86/platform/geode/alix.c

   1 /*
   2  * System Specific setup for PCEngines ALIX.
   3  * At the moment this means setup of GPIO control of LEDs
   4  * on Alix.2/3/6 boards.
   5  *
   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  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License version 2
  17  * as published by the Free Software Foundation.
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/io.h>
  23 #include <linux/string.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/leds.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/gpio.h>
  28 #include <linux/input.h>
  29 #include <linux/gpio_keys.h>
  30 #include <linux/dmi.h>
  31
  32 #include <asm/geode.h>
  33
  34 #define BIOS_SIGNATURE_TINYBIOS         0xf0000
  35 #define BIOS_SIGNATURE_COREBOOT         0x500
  36 #define BIOS_REGION_SIZE                0x10000
  37
  38 /*
  39  * This driver is not modular, but to keep back compatibility
  40  * with existing use cases, continuing with module_param is
  41  * the easiest way forward.
  42  */
  43 static bool force = 0;
  44 module_param(force, bool, 0444);
  45 /* FIXME: Award bios is not automatically detected as Alix platform */
  46 MODULE_PARM_DESC(force, "Force detection as ALIX.2/ALIX.3 platform");
  47
  48 static struct gpio_keys_button alix_gpio_buttons[] = {
  49         {
  50                 .code                   = KEY_RESTART,
  51                 .gpio                   = 24,
  52                 .active_low             = 1,
  53                 .desc                   = "Reset button",
  54                 .type                   = EV_KEY,
  55                 .wakeup                 = 0,
  56                 .debounce_interval      = 100,
  57                 .can_disable            = 0,
  58         }
  59 };
  60 static struct gpio_keys_platform_data alix_buttons_data = {
  61         .buttons                        = alix_gpio_buttons,
  62         .nbuttons                       = ARRAY_SIZE(alix_gpio_buttons),
  63         .poll_interval                  = 20,
  64 };
  65
  66 static struct platform_device alix_buttons_dev = {
  67         .name                           = "gpio-keys-polled",
  68         .id                             = 1,
  69         .dev = {
  70                 .platform_data          = &alix_buttons_data,
  71         }
  72 };
  73
  74 static struct gpio_led alix_leds[] = {
  75         {
  76                 .name = "alix:1",
  77                 .gpio = 6,
  78                 .default_trigger = "default-on",
  79                 .active_low = 1,
  80         },
  81         {
  82                 .name = "alix:2",
  83                 .gpio = 25,
  84                 .default_trigger = "default-off",
  85                 .active_low = 1,
  86         },
  87         {
  88                 .name = "alix:3",
  89                 .gpio = 27,
  90                 .default_trigger = "default-off",
  91                 .active_low = 1,
  92         },
  93 };
  94
  95 static struct gpio_led_platform_data alix_leds_data = {
  96         .num_leds = ARRAY_SIZE(alix_leds),
  97         .leds = alix_leds,
  98 };
  99
 100 static struct platform_device alix_leds_dev = {
 101         .name = "leds-gpio",
 102         .id = -1,
 103         .dev.platform_data = &alix_leds_data,
 104 };
 105
 106 static struct platform_device *alix_devs[] __initdata = {
 107         &alix_buttons_dev,
 108         &alix_leds_dev,
 109 };
 110
 111 static void __init register_alix(void)
 112 {
 113         /* Setup LED control through leds-gpio driver */
 114         platform_add_devices(alix_devs, ARRAY_SIZE(alix_devs));
 115 }
 116
 117 static bool __init alix_present(unsigned long bios_phys,
 118                                 const char *alix_sig,
 119                                 size_t alix_sig_len)
 120 {
 121         const size_t bios_len = BIOS_REGION_SIZE;
 122         const char *bios_virt;
 123         const char *scan_end;
 124         const char *p;
 125         char name[64];
 126
 127         if (force) {
 128                 printk(KERN_NOTICE "%s: forced to skip BIOS test, "
 129                        "assume system is ALIX.2/ALIX.3\n",
 130                        KBUILD_MODNAME);
 131                 return true;
 132         }
 133
 134         bios_virt = phys_to_virt(bios_phys);
 135         scan_end = bios_virt + bios_len - (alix_sig_len + 2);
 136         for (p = bios_virt; p < scan_end; p++) {
 137                 const char *tail;
 138                 char *a;
 139
 140                 if (memcmp(p, alix_sig, alix_sig_len) != 0)
 141                         continue;
 142
 143                 memcpy(name, p, sizeof(name));
 144
 145                 /* remove the first \0 character from string */
 146                 a = strchr(name, '\0');
 147                 if (a)
 148                         *a = ' ';
 149
 150                 /* cut the string at a newline */
 151                 a = strchr(name, '\r');
 152                 if (a)
 153                         *a = '\0';
 154
 155                 tail = p + alix_sig_len;
 156                 if ((tail[0] == '2' || tail[0] == '3' || tail[0] == '6')) {
 157                         printk(KERN_INFO
 158                                "%s: system is recognized as \"%s\"\n",
 159                                KBUILD_MODNAME, name);
 160                         return true;
 161                 }
 162         }
 163
 164         return false;
 165 }
 166
 167 static bool __init alix_present_dmi(void)
 168 {
 169         const char *vendor, *product;
 170
 171         vendor = dmi_get_system_info(DMI_SYS_VENDOR);
 172         if (!vendor || strcmp(vendor, "PC Engines"))
 173                 return false;
 174
 175         product = dmi_get_system_info(DMI_PRODUCT_NAME);
 176         if (!product || (strcmp(product, "ALIX.2D") && strcmp(product, "ALIX.6")))
 177                 return false;
 178
 179         printk(KERN_INFO "%s: system is recognized as \"%s %s\"\n",
 180                KBUILD_MODNAME, vendor, product);
 181
 182         return true;
 183 }
 184
 185 static int __init alix_init(void)
 186 {
 187         const char tinybios_sig[] = "PC Engines ALIX.";
 188         const char coreboot_sig[] = "PC Engines\0ALIX.";
 189
 190         if (!is_geode())
 191                 return 0;
 192
 193         if (alix_present(BIOS_SIGNATURE_TINYBIOS, tinybios_sig, sizeof(tinybios_sig) - 1) ||
 194             alix_present(BIOS_SIGNATURE_COREBOOT, coreboot_sig, sizeof(coreboot_sig) - 1) ||
 195             alix_present_dmi())
 196                 register_alix();
 197
 198         return 0;
 199 }
 200 device_initcall(alix_init);