backlight_device_register has been expecting a const "ops" argument, and using
it as such, since 9905a43b. Let's make the
remaining backlight_ops instances const.

Inspired by hunks of the grsecurity patch, updated for newer kernels.
Signed-off-by: NLionel Debroux <lionel_debroux@yahoo.fr>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Values such as max_brightness should be set before backlights are
registered, but the current API doesn't allow that. Add a parameter to
backlight_device_register and update drivers to ensure that they
set this correctly.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NRichard Purdie <rpurdie@linux.intel.com>

Convert the backlight and LCD classes from struct class_device
to struct device since class_device is scheduled for removal.

One nasty API break is the backlight power attribute has had to be
renamed to bl_power and the LCD power attribute has had to be renamed
to lcd_power since the original names clash with the core. I can't see
a way around this.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/video/nvidia/nv_backlight.c: In function 'nvidia_bl_init':
drivers/video/nvidia/nv_backlight.c:103: error: implicit declaration of function 'pmac_has_backlight_type'
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a mix up when the nvidia driver was converted resulting
in the backlight having an incorrect initial brightness.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

Per device data such as brightness belongs to the indivdual device
and should therefore be separate from the the backlight operation
function pointers. This patch splits the two types of data and
allows simplifcation of some code.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

Move the setting/unsetting of pmac_backlight into the
backlight core instead of doing it in each driver.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

fb_info->bl_mutex is badly thought out and the backlight class doesn't
need it if the framebuffer/backlight register/unregister order is
consistent, particularly after the backlight locking fixes.

Fix the drivers to use the order:

backlight_device_register()
register_framebuffer()
unregister_framebuffer()
backlight_device_unregister()

and turn bl_mutex into a lock for the bl_curve data only.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

nvidia_bl_set_power isn't needed since the backlight class handles
this by receiving fb events itself and calling update_status so
remove it.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

backlight_device->sem has a very specific use as documented in the
header file. The external users of this are using it for a different
reason, to serialise access to the update_status() method.

backlight users were supposed to implement their own internal
serialisation of update_status() if needed but everyone is doing
things differently and incorrectly. Therefore add a global mutex to
take care of serialisation for everyone, once and for all.

Locking for get_brightness remains optional since most users don't
need it.

Also update the lcd class in a similar way.
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

Remove uneeded owner field from backlight_properties structure.

Nothing uses it and it is unlikely that it will ever be used. The
backlight class uses other means to ensure that nothing references
unloaded code.

Based on a patch from Dmitry Torokhov <dtor@insightbb.com>
Signed-off-by: NRichard Purdie <rpurdie@rpsys.net>

Update the frambuffer drivers to the backlight_device_registers changes.
Signed-off-by: NJames Simmons <jsimmons@infradead.org>
Cc: Luming Yu <Luming.yu@intel.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Fix some more problems (inverted use of semaphores in some places).  He
also moved my checks into within the protected section which is better.
Signed-off-by: NMichael Hanselmann <linux-kernel@hansmi.ch>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The backlight changes that went in had a bug where they could cause the
kernel to access an unitialized pointer when blanking if there is no
backlight control on a machine.

The bug affects atyfb, aty128fb, nvidiafb and rivafb.  radeonfb seems to
be ok.  This fixes it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch fixes several problems:
- pmac_backlight_key() is called under interrupt context, and therefore
  can't use mutexes or semaphores, so defer the backlight level for
  later, as it's not critical (original code by Aristeu S. Rozanski F.
  <aris@valeta.org>).
- Add exports for functions that might be called from modules
- Fix Kconfig depdencies on PMAC_BACKLIGHT.
- Fix locking issues on calls from inside the driver (reported by
  Aristeu S. Rozanski F., too)
- Fix wrong calculation of backlight values in some of the drivers
- Replace pmac_backlight_key_up/down by inline functions

[akpm@osdl.org: fix function prototypes]
Signed-off-by: NMichael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: NAristeu S. Rozanski F. <aris@valeta.org>
Acked-by: NRene Nussbaumer <linux-kernel@killerfox.forkbomb.ch>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch contains a total rewrite of the backlight infrastructure for
portable Apple computers.  Backward compatibility is retained.  A sysfs
interface allows userland to control the brightness with more steps than
before.  Userland is allowed to upload a brightness curve for different
monitors, similar to Mac OS X.

[akpm@osdl.org: add needed exports]
Signed-off-by: NMichael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>