acpi-video-detect: video: Make video_detect code part of the video module

This is a preparation patch for the backlight interface selection logic
cleanup, there are 2 reasons to not always build the video_detect code
into the kernel:

1) In order for the video_detect.c to also deal with / select native
backlight interfaces on win8 systems, instead of doing this in video.c
where it does not belong, video_detect.c needs to call into the backlight
class code. Which cannot be done if it is builtin and the blacklight class
is not.

2) Currently all the platform/x86 drivers which have quirks to prefer
the vendor driver over acpi-video call acpi_video_unregister_backlight()
to remove the acpi-video backlight interface, this logic really belongs
in video_detect.c, which will cause video_detect.c to depend on symbols of
video.c and video.c already depends on video_detect.c symbols, so they
really need to be a single module.

Note that this commits make 2 changes so as to maintain 100% kernel
commandline compatibility:

1) The __setup call for the acpi_backlight= handling is moved to
   acpi/util.c as __setup may only be used by code which is alwasy builtin
2) video.c is renamed to acpi_video.c so that it can be combined with
   video_detect.c into video.ko

This commit also makes changes to drivers/platform/x86/Kconfig to ensure
that drivers which use acpi_video_backlight_support() from video_detect.c,
will not be built-in when acpi_video is not built in. This also changes
some "select" uses to "depends on" to avoid dependency loops.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index cd49a3982b6a..67c548ad3764 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -712,3 +712,18 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs)
 	return false;
 }
 EXPORT_SYMBOL(acpi_check_dsm);
+
+/*
+ * acpi_backlight= handling, this is done here rather then in video_detect.c
+ * because __setup cannot be used in modules.
+ */
+char acpi_video_backlight_string[16];
+EXPORT_SYMBOL(acpi_video_backlight_string);
+
+static int __init acpi_backlight(char *str)
+{
+	strlcpy(acpi_video_backlight_string, str,
+		sizeof(acpi_video_backlight_string));
+	return 1;
+}
+__setup("acpi_backlight=", acpi_backlight);