static int platform_probe(struct platform_device *dev)
{
struct backlight_properties props;
int ret;
mutex_init(&dev_priv.mutex);
INIT_DELAYED_WORK(&dev_priv.work, brightness_work);
ret = lp8550_probe();
if (ret)
return ret;
ret = lp8550_save();
if (ret)
return ret;
memset(&props, 0, sizeof(struct backlight_properties));
props.max_brightness = 255;
props.type = BACKLIGHT_FIRMWARE;
props.power = 0; /* Power is on */
backlight_device = backlight_device_register("mba6x_backlight",
NULL, NULL,
&backlight_ops, &props);
if (IS_ERR(backlight_device)) {
pr_err("mba6x_bl: Failed to register backlight device\n");
return PTR_ERR(backlight_device);
}
backlight_device->props.brightness = INIT_BRIGHTNESS;
backlight_update_status(backlight_device);
acpi_video_dmi_promote_vendor();
acpi_video_unregister();
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 15, 0)
backlight_register_notifier(&backlight_nb);
#endif
return 0;
}
/*
* Determine which type of backlight interface to use on this system,
* First check cmdline, then dmi quirks, then do autodetect.
*
* The autodetect order is:
* 1) Is the acpi-video backlight interface supported ->
* no, use a vendor interface
* 2) Is this a win8 "ready" BIOS and do we have a native interface ->
* yes, use a native interface
* 3) Else use the acpi-video interface
*
* Arguably the native on win8 check should be done first, but that would
* be a behavior change, which may causes issues.
*/
enum acpi_backlight_type acpi_video_get_backlight_type(void)
{
static DEFINE_MUTEX(init_mutex);
static bool init_done;
static long video_caps;
/* Parse cmdline, dmi and acpi only once */
mutex_lock(&init_mutex);
if (!init_done) {
acpi_video_parse_cmdline();
dmi_check_system(video_detect_dmi_table);
acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX, find_video, NULL,
&video_caps, NULL);
INIT_WORK(&backlight_notify_work,
acpi_video_backlight_notify_work);
backlight_nb.notifier_call = acpi_video_backlight_notify;
backlight_nb.priority = 0;
if (backlight_register_notifier(&backlight_nb) == 0)
backlight_notifier_registered = true;
init_done = true;
}
mutex_unlock(&init_mutex);
if (acpi_backlight_cmdline != acpi_backlight_undef)
return acpi_backlight_cmdline;
if (acpi_backlight_dmi != acpi_backlight_undef)
return acpi_backlight_dmi;
if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
return acpi_backlight_vendor;
if (acpi_osi_is_win8() && backlight_device_registered(BACKLIGHT_RAW))
return acpi_backlight_native;
return acpi_backlight_video;
}
