drivers/leds/dell-led.c

   1 /*
   2  * dell_led.c - Dell LED Driver
   3  *
   4  * Copyright (C) 2010 Dell Inc.
   5  * Louis Davis <louis_davis@dell.com>
   6  * Jim Dailey <jim_dailey@dell.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/acpi.h>
  15 #include <linux/leds.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/dmi.h>
  19 #include <linux/dell-led.h>
  20 #include "../platform/x86/dell-smbios.h"
  21
  22 MODULE_AUTHOR("Louis Davis/Jim Dailey");
  23 MODULE_DESCRIPTION("Dell LED Control Driver");
  24 MODULE_LICENSE("GPL");
  25
  26 #define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"
  27 #define DELL_APP_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
  28 MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID);
  29
  30 /* Error Result Codes: */
  31 #define INVALID_DEVICE_ID       250
  32 #define INVALID_PARAMETER       251
  33 #define INVALID_BUFFER          252
  34 #define INTERFACE_ERROR         253
  35 #define UNSUPPORTED_COMMAND     254
  36 #define UNSPECIFIED_ERROR       255
  37
  38 /* Device ID */
  39 #define DEVICE_ID_PANEL_BACK    1
  40
  41 /* LED Commands */
  42 #define CMD_LED_ON      16
  43 #define CMD_LED_OFF     17
  44 #define CMD_LED_BLINK   18
  45
  46 #define GLOBAL_MIC_MUTE_ENABLE  0x364
  47 #define GLOBAL_MIC_MUTE_DISABLE 0x365
  48
  49 static int dell_micmute_led_set(int state)
  50 {
  51         struct calling_interface_buffer *buffer;
  52         struct calling_interface_token *token;
  53
  54         if (!wmi_has_guid(DELL_APP_GUID))
  55                 return -ENODEV;
  56
  57         if (state == 0)
  58                 token = dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE);
  59         else if (state == 1)
  60                 token = dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE);
  61         else
  62                 return -EINVAL;
  63
  64         if (!token)
  65                 return -ENODEV;
  66
  67         buffer = dell_smbios_get_buffer();
  68         buffer->input[0] = token->location;
  69         buffer->input[1] = token->value;
  70         dell_smbios_send_request(1, 0);
  71         dell_smbios_release_buffer();
  72
  73         return state;
  74 }
  75
  76 int dell_app_wmi_led_set(int whichled, int on)
  77 {
  78         int state = 0;
  79
  80         switch (whichled) {
  81         case DELL_LED_MICMUTE:
  82                 state = dell_micmute_led_set(on);
  83                 break;
  84         default:
  85                 pr_warn("led type %x is not supported\n", whichled);
  86                 break;
  87         }
  88
  89         return state;
  90 }
  91 EXPORT_SYMBOL_GPL(dell_app_wmi_led_set);
  92
  93 struct bios_args {
  94         unsigned char length;
  95         unsigned char result_code;
  96         unsigned char device_id;
  97         unsigned char command;
  98         unsigned char on_time;
  99         unsigned char off_time;
 100 };
 101
 102 static int dell_led_perform_fn(u8 length,
 103                 u8 result_code,
 104                 u8 device_id,
 105                 u8 command,
 106                 u8 on_time,
 107                 u8 off_time)
 108 {
 109         struct bios_args *bios_return;
 110         u8 return_code;
 111         union acpi_object *obj;
 112         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
 113         struct acpi_buffer input;
 114         acpi_status status;
 115
 116         struct bios_args args;
 117         args.length = length;
 118         args.result_code = result_code;
 119         args.device_id = device_id;
 120         args.command = command;
 121         args.on_time = on_time;
 122         args.off_time = off_time;
 123
 124         input.length = sizeof(struct bios_args);
 125         input.pointer = &args;
 126
 127         status = wmi_evaluate_method(DELL_LED_BIOS_GUID,
 128                 1,
 129                 1,
 130                 &input,
 131                 &output);
 132
 133         if (ACPI_FAILURE(status))
 134                 return status;
 135
 136         obj = output.pointer;
 137
 138         if (!obj)
 139                 return -EINVAL;
 140         else if (obj->type != ACPI_TYPE_BUFFER) {
 141                 kfree(obj);
 142                 return -EINVAL;
 143         }
 144
 145         bios_return = ((struct bios_args *)obj->buffer.pointer);
 146         return_code = bios_return->result_code;
 147
 148         kfree(obj);
 149
 150         return return_code;
 151 }
 152
 153 static int led_on(void)
 154 {
 155         return dell_led_perform_fn(3,   /* Length of command */
 156                 INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
 157                 DEVICE_ID_PANEL_BACK,   /* Device ID */
 158                 CMD_LED_ON,             /* Command */
 159                 0,                      /* not used */
 160                 0);                     /* not used */
 161 }
 162
 163 static int led_off(void)
 164 {
 165         return dell_led_perform_fn(3,   /* Length of command */
 166                 INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
 167                 DEVICE_ID_PANEL_BACK,   /* Device ID */
 168                 CMD_LED_OFF,            /* Command */
 169                 0,                      /* not used */
 170                 0);                     /* not used */
 171 }
 172
 173 static int led_blink(unsigned char on_eighths,
 174                 unsigned char off_eighths)
 175 {
 176         return dell_led_perform_fn(5,   /* Length of command */
 177                 INTERFACE_ERROR,        /* Init to  INTERFACE_ERROR */
 178                 DEVICE_ID_PANEL_BACK,   /* Device ID */
 179                 CMD_LED_BLINK,          /* Command */
 180                 on_eighths,             /* blink on in eigths of a second */
 181                 off_eighths);           /* blink off in eights of a second */
 182 }
 183
 184 static void dell_led_set(struct led_classdev *led_cdev,
 185                 enum led_brightness value)
 186 {
 187         if (value == LED_OFF)
 188                 led_off();
 189         else
 190                 led_on();
 191 }
 192
 193 static int dell_led_blink(struct led_classdev *led_cdev,
 194                 unsigned long *delay_on,
 195                 unsigned long *delay_off)
 196 {
 197         unsigned long on_eighths;
 198         unsigned long off_eighths;
 199
 200         /* The Dell LED delay is based on 125ms intervals.
 201            Need to round up to next interval. */
 202
 203         on_eighths = (*delay_on + 124) / 125;
 204         if (0 == on_eighths)
 205                 on_eighths = 1;
 206         if (on_eighths > 255)
 207                 on_eighths = 255;
 208         *delay_on = on_eighths * 125;
 209
 210         off_eighths = (*delay_off + 124) / 125;
 211         if (0 == off_eighths)
 212                 off_eighths = 1;
 213         if (off_eighths > 255)
 214                 off_eighths = 255;
 215         *delay_off = off_eighths * 125;
 216
 217         led_blink(on_eighths, off_eighths);
 218
 219         return 0;
 220 }
 221
 222 static struct led_classdev dell_led = {
 223         .name           = "dell::lid",
 224         .brightness     = LED_OFF,
 225         .max_brightness = 1,
 226         .brightness_set = dell_led_set,
 227         .blink_set      = dell_led_blink,
 228         .flags          = LED_CORE_SUSPENDRESUME,
 229 };
 230
 231 static int __init dell_led_init(void)
 232 {
 233         int error = 0;
 234
 235         if (!wmi_has_guid(DELL_LED_BIOS_GUID) && !wmi_has_guid(DELL_APP_GUID))
 236                 return -ENODEV;
 237
 238         if (wmi_has_guid(DELL_LED_BIOS_GUID)) {
 239                 error = led_off();
 240                 if (error != 0)
 241                         return -ENODEV;
 242
 243                 error = led_classdev_register(NULL, &dell_led);
 244         }
 245
 246         return error;
 247 }
 248
 249 static void __exit dell_led_exit(void)
 250 {
 251         int error = 0;
 252
 253         if (wmi_has_guid(DELL_LED_BIOS_GUID)) {
 254                 error = led_off();
 255                 if (error == 0)
 256                         led_classdev_unregister(&dell_led);
 257         }
 258 }
 259
 260 module_init(dell_led_init);
 261 module_exit(dell_led_exit);