From f838eb5bd257e8a666aa8c451058fa198df7e299 Mon Sep 17 00:00:00 2001 From: Corentin Chary Date: Wed, 13 Jun 2012 09:32:01 +0200 Subject: acpi: add a way to promote/demote vendor backlight drivers Instead of adding a big blacklist in video_detect.c to set ACPI_VIDEO_BACKLIGHT_DMI_VENDOR correctly, let external modules promote or demote themselves when they know the generic video module won't work. Currently drivers where using acpi_video_unregister() directly but: - That didn't respect any acpi_backlight=[video|vendor] parameter provided by the user. - Any later call to acpi_video_register() would still re-load the generic video module (and some gpu drivers are doing that). This patch fix those two issues. Signed-off-by: Corentin Chary Signed-off-by: Matthew Garrett --- drivers/acpi/video_detect.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) (limited to 'drivers/acpi/video_detect.c') diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 45d8097..942fa2a 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -182,8 +182,7 @@ long acpi_video_get_capabilities(acpi_handle graphics_handle) } EXPORT_SYMBOL(acpi_video_get_capabilities); -/* Returns true if video.ko can do backlight switching */ -int acpi_video_backlight_support(void) +static void acpi_video_caps_check(void) { /* * We must check whether the ACPI graphics device is physically plugged @@ -191,6 +190,34 @@ int acpi_video_backlight_support(void) */ if (!acpi_video_caps_checked) acpi_video_get_capabilities(NULL); +} + +/* Promote the vendor interface instead of the generic video module. + * This function allow DMI blacklists to be implemented by externals + * platform drivers instead of putting a big blacklist in video_detect.c + * After calling this function you will probably want to call + * acpi_video_unregister() to make sure the video module is not loaded + */ +void acpi_video_dmi_promote_vendor(void) +{ + acpi_video_caps_check(); + acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; +} +EXPORT_SYMBOL(acpi_video_dmi_promote_vendor); + +/* To be called when a driver who previously promoted the vendor + * interface */ +void acpi_video_dmi_demote_vendor(void) +{ + acpi_video_caps_check(); + acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; +} +EXPORT_SYMBOL(acpi_video_dmi_demote_vendor); + +/* Returns true if video.ko can do backlight switching */ +int acpi_video_backlight_support(void) +{ + acpi_video_caps_check(); /* First check for boot param -> highest prio */ if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR) -- cgit v1.1