diff options
Diffstat (limited to 'drivers/leds/dell-led.c')
| -rw-r--r-- | drivers/leds/dell-led.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/leds/dell-led.c b/drivers/leds/dell-led.c new file mode 100644 index 00000000000..52590296af3 --- /dev/null +++ b/drivers/leds/dell-led.c @@ -0,0 +1,201 @@ +/* + * dell_led.c - Dell LED Driver + * + * Copyright (C) 2010 Dell Inc. + * Louis Davis <louis_davis@dell.com> + * Jim Dailey <jim_dailey@dell.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + */ + +#include <linux/acpi.h> +#include <linux/leds.h> +#include <linux/slab.h> + +MODULE_AUTHOR("Louis Davis/Jim Dailey"); +MODULE_DESCRIPTION("Dell LED Control Driver"); +MODULE_LICENSE("GPL"); + +#define DELL_LED_BIOS_GUID "F6E4FE6E-909D-47cb-8BAB-C9F6F2F8D396" +MODULE_ALIAS("wmi:" DELL_LED_BIOS_GUID); + +/* Error Result Codes: */ +#define INVALID_DEVICE_ID 250 +#define INVALID_PARAMETER 251 +#define INVALID_BUFFER 252 +#define INTERFACE_ERROR 253 +#define UNSUPPORTED_COMMAND 254 +#define UNSPECIFIED_ERROR 255 + +/* Device ID */ +#define DEVICE_ID_PANEL_BACK 1 + +/* LED Commands */ +#define CMD_LED_ON 16 +#define CMD_LED_OFF 17 +#define CMD_LED_BLINK 18 + +struct bios_args { + unsigned char length; + unsigned char result_code; + unsigned char device_id; + unsigned char command; + unsigned char on_time; + unsigned char off_time; +}; + +static int dell_led_perform_fn(u8 length, + u8 result_code, + u8 device_id, + u8 command, + u8 on_time, + u8 off_time) +{ + struct bios_args *bios_return; + u8 return_code; + union acpi_object *obj; + struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL }; + struct acpi_buffer input; + acpi_status status; + + struct bios_args args; + args.length = length; + args.result_code = result_code; + args.device_id = device_id; + args.command = command; + args.on_time = on_time; + args.off_time = off_time; + + input.length = sizeof(struct bios_args); + input.pointer = &args; + + status = wmi_evaluate_method(DELL_LED_BIOS_GUID, + 1, + 1, + &input, + &output); + + if (ACPI_FAILURE(status)) + return status; + + obj = output.pointer; + + if (!obj) + return -EINVAL; + else if (obj->type != ACPI_TYPE_BUFFER) { + kfree(obj); + return -EINVAL; + } + + bios_return = ((struct bios_args *)obj->buffer.pointer); + return_code = bios_return->result_code; + + kfree(obj); + + return return_code; +} + +static int led_on(void) +{ + return dell_led_perform_fn(3, /* Length of command */ + INTERFACE_ERROR, /* Init to INTERFACE_ERROR */ + DEVICE_ID_PANEL_BACK, /* Device ID */ + CMD_LED_ON, /* Command */ + 0, /* not used */ + 0); /* not used */ +} + +static int led_off(void) +{ + return dell_led_perform_fn(3, /* Length of command */ + INTERFACE_ERROR, /* Init to INTERFACE_ERROR */ + DEVICE_ID_PANEL_BACK, /* Device ID */ + CMD_LED_OFF, /* Command */ + 0, /* not used */ + 0); /* not used */ +} + +static int led_blink(unsigned char on_eighths, + unsigned char off_eighths) +{ + return dell_led_perform_fn(5, /* Length of command */ + INTERFACE_ERROR, /* Init to INTERFACE_ERROR */ + DEVICE_ID_PANEL_BACK, /* Device ID */ + CMD_LED_BLINK, /* Command */ + on_eighths, /* blink on in eigths of a second */ + off_eighths); /* blink off in eights of a second */ +} + +static void dell_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + if (value == LED_OFF) + led_off(); + else + led_on(); +} + +static int dell_led_blink(struct led_classdev *led_cdev, + unsigned long *delay_on, + unsigned long *delay_off) +{ + unsigned long on_eighths; + unsigned long off_eighths; + + /* The Dell LED delay is based on 125ms intervals. + Need to round up to next interval. */ + + on_eighths = (*delay_on + 124) / 125; + if (0 == on_eighths) + on_eighths = 1; + if (on_eighths > 255) + on_eighths = 255; + *delay_on = on_eighths * 125; + + off_eighths = (*delay_off + 124) / 125; + if (0 == off_eighths) + off_eighths = 1; + if (off_eighths > 255) + off_eighths = 255; + *delay_off = off_eighths * 125; + + led_blink(on_eighths, off_eighths); + + return 0; +} + +static struct led_classdev dell_led = { + .name = "dell::lid", + .brightness = LED_OFF, + .max_brightness = 1, + .brightness_set = dell_led_set, + .blink_set = dell_led_blink, + .flags = LED_CORE_SUSPENDRESUME, +}; + +static int __init dell_led_init(void) +{ + int error = 0; + + if (!wmi_has_guid(DELL_LED_BIOS_GUID)) + return -ENODEV; + + error = led_off(); + if (error != 0) + return -ENODEV; + + return led_classdev_register(NULL, &dell_led); +} + +static void __exit dell_led_exit(void) +{ + led_classdev_unregister(&dell_led); + + led_off(); +} + +module_init(dell_led_init); +module_exit(dell_led_exit); |