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2019-09-02backlight: Expose brightness curve type through sysfsMatthias Kaehlcke1-0/+8
Backlight brightness curves can have different shapes. The two main types are linear and non-linear curves. The human eye doesn't perceive linearly increasing/decreasing brightness as linear (see also 88ba95bedb79 "backlight: pwm_bl: Compute brightness of LED linearly to human eye"), hence many backlights use non-linear (often logarithmic) brightness curves. The type of curve currently is opaque to userspace, so userspace often uses more or less reliable heuristics (like the number of brightness levels) to decide whether to treat a backlight device as linear or non-linear. Export the type of the brightness curve via the new sysfs attribute 'scale'. The value of the attribute can be 'linear', 'non-linear' or 'unknown'. For devices that don't provide information about the scale of their brightness curve the value of the 'scale' attribute is 'unknown'. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-07-04backlight: Remove obsolete comment for ->stateDaniel Vetter1-1/+0
Jani spotted this when reviewing my earlier patch to remove the driver internal usage of this field in: Commit 3cf91adaa594 ("backlight: Nuke BL_CORE_DRIVER1") Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-04-30backlight: Nuke BL_CORE_DRIVER1Daniel Vetter1-1/+0
Now that the 3 drivers using this are cleaned up we can also remove this final bit of confusion of leaking driver internals into the backlight power interface. The backlight power interface itself is still a massive mess. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-04-30backlight: Nuke unused backlight.props.state statesDaniel Vetter1-3/+0
The backlight power state handling is supremely confusing. We have: - props.power, using FB_BLANK_* defines - props.fb_blank, using the same, but deprecated int favour of props.state - props.state, using the BL_CORE_* defines - and finally a bunch of backlight drivers treat brightness == 0 as off. But of course not all of them. This is way too much confusion to fix in a simple patch, but at least prevent more hilarity from spreading by removing the unused BL_CORE_* defines. I have no idea why exactly anyone would need that. Wrt the ideal state, we really just want a boolean state. The 4 power saving states that the fbdev subsystem uses are overkill in todays hw (this was only relevant for VGA and similar analog circuits like TV-out), the new drm atomic modeset api simplified even the uapi to a simple bool. And there was never a valid technical reason to have the intermediate fbdev power states for backlights (those really only can be either off or on). Cleanup motivated by Meghana's questions about all this. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Jingoo Han <jingoohan1@gmail.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-01-29video: backlight: Add devres versions of of_find_backlightMeghana Madhyastha1-0/+7
Add devm_of_find_backlight and the corresponding release function because some drivers use devres versions of functions for acquiring device resources. Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/021f8fecfa3f374dc5dcb70fb07a6f6b019bea7b.1516810725.git.meghana.madhyastha@gmail.com
2018-01-29video: backlight: Add of_find_backlight helper in backlight.cMeghana Madhyastha1-0/+19
Add of_find_backlight, a helper function which is a generic version of tinydrm_of_find_backlight that can be used by other drivers to avoid repetition of code and simplify things. Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Reviewed-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/116d160ba78be2e6dcbdcb6855622bce67da9472.1516810725.git.meghana.madhyastha@gmail.com
2018-01-29video: backlight: Add helpers to enable and disable backlightMeghana Madhyastha1-0/+32
Add helper functions backlight_enable and backlight_disable to enable/disable a backlight device. These helper functions can then be used by different drm and tinydrm drivers to avoid repetition of code and also to enforce a uniform and consistent way to enable/disable a backlight device. Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Meghana Madhyastha <meghana.madhyastha@gmail.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/39b5bf0a02008a8072d910bdf8231c431e9ef504.1516810725.git.meghana.madhyastha@gmail.com
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04video / backlight: remove the backlight_device_registered APIAaron Lu1-1/+0
Since we will need the backlight_device_get_by_type API, we can use it instead of the backlight_device_registered API whenever necessary so remove the backlight_device_registered API. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-04video / backlight: add two APIs for drivers to useAaron Lu1-0/+2
It is useful to get the backlight device's pointer and use it to set backlight in some cases(the following patch will make use of it) so add the two APIs and export them. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Acked-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-06-23backlight: Change the return type of backlight_update_status() to intHyungwon Hwang1-2/+6
Backlight device returns the result of update_status(), but backlight_update_status() ignores it. So the consumers cannot confirm the result of their function call. This patch makes the result to be returned back for consumers. Signed-off-by: Hyungwon Hwang <human.hwang@samsung.com> Acked-by: Jingoo Han <jingoohan1@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-05-27backlight: Add backlight device (un)registration notificationHans de Goede1-0/+7
Some firmware drivers, ie acpi-video want to get themselves out of the way (in some cases) when their also is a raw backlight device available. Due to module loading ordering being unknown, acpi-video cannot be certain that the backlight_device_registered(BACKLIGHT_RAW) it does for this is the final verdict wrt there being a BACKLIGHT_RAW device. By adding notification acpi-video can listen for backlight devices showing up after it has loaded, and unregister its backlight device if desired. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-03backlight: update bd state & fb_blank properties when necessaryLiu Ying1-0/+6
We don't have to update the state and fb_blank properties of a backlight device every time a blanking or unblanking event comes because they may have already been what we want. Another thought is that one backlight device may be shared by multiple framebuffers. The backlight driver should take the backlight device as a resource shared by all the associated framebuffers. This patch adds some logic to record each framebuffer's backlight usage to determine the backlight device use count and whether the two properties should be updated or not. To be more specific, only one unblank operation on a certain blanked framebuffer may increase the backlight device's use count by one, while one blank operation on a certain unblanked framebuffer may decrease the use count by one, because the userspace is likely to unblank an unblanked framebuffer or blank a blanked framebuffer. Signed-off-by: Liu Ying <Ying.Liu@freescale.com> Cc: Jingoo Han <jg1.han@samsung.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16backlight: introduce backlight_device_registeredAaron Lu1-0/+4
Introduce a new API for modules to query if a specific type of backlight device has been registered. This is useful for some backlight device provider module (e.g. ACPI video) to know if a native control interface(e.g. the interface created by i915) is available and then do things accordingly (e.g. avoid registering its own on Win8 systems). Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-03backlight: add devm_backlight_device_{register,unregister}()Jingoo Han1-0/+6
These functions allow the driver core to automatically clean up any allocation made by backlight drivers. Thus it simplifies the error paths. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17backlight: add of_find_backlight_by_node()Thierry Reding1-0/+10
This function finds the struct backlight_device for a given device tree node. A dummy function is provided so that it safely compiles out if OF support is disabled. [akpm@linux-foundation.org: Don't use IS_ENABLED(CONFIG_OF)] Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Acked-by: Jingoo Han <jg1.han@samsung.com> Reviewed-by: Grant Likely <grant.likely@secretlab.ca> Cc: Thierry Reding <thierry.reding@avionic-design.de> Reviewed-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22backlight: add backlight typeMatthew Garrett1-0/+9
There may be multiple ways of controlling the backlight on a given machine. Allow drivers to expose the type of interface they are providing, making it possible for userspace to make appropriate policy decisions. Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Airlie <airlied@linux.ie> Cc: Alex Deucher <alexdeucher@gmail.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-16backlight: Allow properties to be passed at registrationMatthew Garrett1-1/+2
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: Matthew Garrett <mjg@redhat.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2010-03-16backlight: Add backlight_device parameter to check_fbBruno Prémont1-1/+1
check_fb from backlight_ops lacks a reference to the backlight_device that's being referred to. Add this parameter so a backlight_device can be mapped to a single framebuffer, especially if the same driver handles multiple devices on a single system. Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2010-03-16backlight: Revert some const qualifiersRichard Purdie1-4/+4
9905a43b2d563e6f89e4c63c4278ada03f2ebb14 went a little to far with const qualifiers as there are legitiment cases where the function pointers can change (machine specific setup code for example). Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-12-16backlight: Constify struct backlight_opsEmese Revfy1-6/+6
Signed-off-by: Emese Revfy <re.emese@gmail.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-09-21backlight: Allow drivers to update the core, and generate events on changesMatthew Garrett1-0/+7
Certain hardware will send us events when the backlight brightness changes. Add a function to update the value in the core, and additionally send a uevent so that userspace can pop up appropriate UI. The uevents are flagged depending on whether the update originated in the kernel or from userspace, making it easier to only display UI at the appropriate time. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-01-08backlight: Add suspend/resume support to the backlight coreRichard Purdie1-0/+16
Add suspend/resume support to the backlight core and enable use of it by appropriate drivers. Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2007-10-11backlight: Convert corgi backlight driver into a more generic driverRichard Purdie1-0/+9
Convert the corgi backlight driver to a more generic version so it can be reused by other code rather than being Zaurus/PXA specific. Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2007-07-16backlight: Convert from struct class_device to struct deviceRichard Purdie1-3/+8
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: Richard Purdie <rpurdie@rpsys.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-20backlight: Separate backlight properties from backlight ops pointersRichard Purdie1-14/+19
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: Richard Purdie <rpurdie@rpsys.net>
2007-02-20backlight: Convert semaphore -> mutexRichard Purdie1-3/+3
Convert internal semaphore to a mutex Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
2007-02-20backlight: Fix external uses of backlight internal semaphoreRichard Purdie1-0/+26
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: Richard Purdie <rpurdie@rpsys.net>
2007-02-20backlight: Remove unneeded owner fieldRichard Purdie1-3/+0
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: Richard Purdie <rpurdie@rpsys.net>
2006-12-20ACPI: video: Add dev argument for backlight_device_registerYu Luming1-1/+1
This patch set adds generic abstract layer support for acpi video driver to have generic user interface to control backlight and output switch control by leveraging the existing backlight sysfs class driver, and by adding a new video output sysfs class driver. This patch: Add dev argument for backlight_device_register to link the class device to real device object. The platform specific driver should find a way to get the real device object for their video device. [akpm@osdl.org: build fix] [akpm@osdl.org: fix msi-laptop.c] Signed-off-by: Luming Yu <Luming.yu@intel.com> Cc: "Antonino A. Daplas" <adaplas@pol.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Len Brown <len.brown@intel.com>
2006-03-31[PATCH] backlight: Backlight Class ImprovementsRichard Purdie1-10/+15
Backlight class attributes are currently easy to implement incorrectly. Moving certain handling into the backlight core prevents this whilst at the same time makes the drivers simpler and consistent. The following changes are included: The brightness attribute only sets and reads the brightness variable in the backlight_properties structure. The power attribute only sets and reads the power variable in the backlight_properties structure. Any framebuffer blanking events change a variable fb_blank in the backlight_properties structure. The backlight driver has only two functions to implement. One function is called when any of the above properties change (to update the backlight brightness), the second is called to return the current backlight brightness value. A new attribute "actual_brightness" is added to return this brightness as determined by the driver having combined all the above factors (and any driver/device specific factors). Additionally, the backlight core takes care of checking the maximum brightness is not exceeded and of turning off the backlight before device removal. The corgi backlight driver is updated to reflect these changes. Signed-off-by: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds1-0/+57
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!