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1/*2 * Copyright (C) 2010 Dell Inc.3 * Louis Davis <louis_davis@dell.com>4 * Jim Dailey <jim_dailey@dell.com>5 *6 * This program is free software; you can redistribute it and/or modify7 * it under the terms of the GNU General Public License as8 * published by the Free Software Foundation.9 *10 */11 12#include <linux/acpi.h>13#include <linux/leds.h>14#include <linux/slab.h>15#include <linux/module.h>16 17MODULE_AUTHOR("Louis Davis/Jim Dailey");18MODULE_DESCRIPTION("Dell LED Control Driver");19MODULE_LICENSE("GPL");20 21#define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396"22MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID);23 24/* Error Result Codes: */25#define INVALID_DEVICE_ID 25026#define INVALID_PARAMETER 25127#define INVALID_BUFFER 25228#define INTERFACE_ERROR 25329#define UNSUPPORTED_COMMAND 25430#define UNSPECIFIED_ERROR 25531 32/* Device ID */33#define DEVICE_ID_PANEL_BACK 134 35/* LED Commands */36#define CMD_LED_ON 1637#define CMD_LED_OFF 1738#define CMD_LED_BLINK 1839 40struct bios_args {41 unsigned char length;42 unsigned char result_code;43 unsigned char device_id;44 unsigned char command;45 unsigned char on_time;46 unsigned char off_time;47};48 49static int dell_led_perform_fn(u8 length, u8 result_code, u8 device_id,50 u8 command, u8 on_time, u8 off_time)51{52 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };53 struct bios_args *bios_return;54 struct acpi_buffer input;55 union acpi_object *obj;56 acpi_status status;57 u8 return_code;58 59 struct bios_args args = {60 .length = length,61 .result_code = result_code,62 .device_id = device_id,63 .command = command,64 .on_time = on_time,65 .off_time = off_time66 };67 68 input.length = sizeof(struct bios_args);69 input.pointer = &args;70 71 status = wmi_evaluate_method(DELL_LED_BIOS_GUID, 0, 1, &input, &output);72 if (ACPI_FAILURE(status))73 return status;74 75 obj = output.pointer;76 77 if (!obj)78 return -EINVAL;79 if (obj->type != ACPI_TYPE_BUFFER) {80 kfree(obj);81 return -EINVAL;82 }83 84 bios_return = ((struct bios_args *)obj->buffer.pointer);85 return_code = bios_return->result_code;86 87 kfree(obj);88 89 return return_code;90}91 92static int led_on(void)93{94 return dell_led_perform_fn(3, /* Length of command */95 INTERFACE_ERROR, /* Init to INTERFACE_ERROR */96 DEVICE_ID_PANEL_BACK, /* Device ID */97 CMD_LED_ON, /* Command */98 0, /* not used */99 0); /* not used */100}101 102static int led_off(void)103{104 return dell_led_perform_fn(3, /* Length of command */105 INTERFACE_ERROR, /* Init to INTERFACE_ERROR */106 DEVICE_ID_PANEL_BACK, /* Device ID */107 CMD_LED_OFF, /* Command */108 0, /* not used */109 0); /* not used */110}111 112static int led_blink(unsigned char on_eighths, unsigned char off_eighths)113{114 return dell_led_perform_fn(5, /* Length of command */115 INTERFACE_ERROR, /* Init to INTERFACE_ERROR */116 DEVICE_ID_PANEL_BACK, /* Device ID */117 CMD_LED_BLINK, /* Command */118 on_eighths, /* blink on in eigths of a second */119 off_eighths); /* blink off in eights of a second */120}121 122static void dell_led_set(struct led_classdev *led_cdev,123 enum led_brightness value)124{125 if (value == LED_OFF)126 led_off();127 else128 led_on();129}130 131static int dell_led_blink(struct led_classdev *led_cdev,132 unsigned long *delay_on, unsigned long *delay_off)133{134 unsigned long on_eighths;135 unsigned long off_eighths;136 137 /*138 * The Dell LED delay is based on 125ms intervals.139 * Need to round up to next interval.140 */141 142 on_eighths = DIV_ROUND_UP(*delay_on, 125);143 on_eighths = clamp_t(unsigned long, on_eighths, 1, 255);144 *delay_on = on_eighths * 125;145 146 off_eighths = DIV_ROUND_UP(*delay_off, 125);147 off_eighths = clamp_t(unsigned long, off_eighths, 1, 255);148 *delay_off = off_eighths * 125;149 150 led_blink(on_eighths, off_eighths);151 152 return 0;153}154 155static struct led_classdev dell_led = {156 .name = "dell::lid",157 .brightness = LED_OFF,158 .max_brightness = 1,159 .brightness_set = dell_led_set,160 .blink_set = dell_led_blink,161 .flags = LED_CORE_SUSPENDRESUME,162};163 164static int __init dell_led_init(void)165{166 int error = 0;167 168 if (!wmi_has_guid(DELL_LED_BIOS_GUID))169 return -ENODEV;170 171 error = led_off();172 if (error != 0)173 return -ENODEV;174 175 return led_classdev_register(NULL, &dell_led);176}177 178static void __exit dell_led_exit(void)179{180 led_classdev_unregister(&dell_led);181 182 led_off();183}184 185module_init(dell_led_init);186module_exit(dell_led_exit);187