The LP8556 datasheet describes an EN/VDDIO input, which serves "both as
a chip enable and as a power supply reference for PWM, SDA, and SCL
inputs." The LP8556 that I'm testing doesn't respond properly if I try
to talk I2C to it too quickly after enabling VDDIO, and the LP8555
datasheet mentions a t_RESPONSE delay of up to 1 millisecond.
Support this EN/VDDIO by adding a regulator property to the binding;
enabling this regulator at probe time; and sleeping for 1 to 2ms, if the
EN/VDDIO regulator was provided.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Milo Kim <milo.kim@ti.com>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Call pwm_apply_args() just after requesting the PWM device so that the
polarity and period are initialized according to the information
provided in pwm_args.
This is an intermediate state, and pwm_apply_args() should be dropped as
soon as the atomic PWM infrastructure is in place and the driver makes
use of it.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
The driver occasionally got stuck in suspend mode or other strange
states as those parts of the props struct were never initialized.
Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Acked-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
LP855x backlight device can be enabled by external VDD input. The
'supply' data is used for this purpose. It's kind of private data
which runs internally, so there is no reason to expose to the
platform data.
And devm_regulator_get() is moved from _parse_dt() to _probe().
Regulator consumer(lp855x) can control regulator not only from DT
but also from platform data configuration in a source file such
like board-*.c.
Signed-off-by: Milo Kim <milo.kim@ti.com>
Acked-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Don't clear the backlight level when we're going into suspend or
blanking. Instead, just temporarily set the level to 0 so we retain
the value when we resume.
Reported-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Acked-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This patch adds a supply regulator to the lp855x platform data to facilitate
powering on/off the 3V rail attached to the controller.
Cc: Stéphane Marchesin <marcheu@chromium.org>
Cc: Aaron Durbin <adurbin@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Milo Kim <milo.kim@ti.com>
Acked-by: Bryan Wu <cooloney@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This patch refactors the dt parsing code to avoid setting platform_data,
instead just setting lp->pdata directly. This facilitates easier
probe deferral since the current scheme would require us to clear out
dev->platform_data before deferring.
Cc: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Milo Kim <milo.kim@ti.com>
Acked-by: Bryan Wu <cooloney@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Fixed the following checkpatch warning.
WARNING: Missing a blank line after declarations
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Since backlight core returns props.brightness in case get_brightness
is not implemented trivial implementations are not needed anymore.
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Remove unnecessary parentheses in order to fix the following checkpatch
error.
ERROR: return is not a function, parentheses are not required
Signed-off-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>
Use devm_backlight_device_register() to make cleanup paths simpler. Also,
unnecessary lp855x_backlight_unregister() is removed.
Signed-off-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>
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly. This is a cosmetic change to
make the code simpler and enhance the readability.
Signed-off-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>
LP8555 is one of the LP855x family devices.
This device needs pre_init_device() and post_init_device() driver
structure. It's same as LP8557, so the device configuration code is
shared with LP8557. Backlight outputs are generated from dual DC-DC boost
converters. It's configurable EPROM settings which are defined in the
platform data.
Driver documentation and device tree bindings are updated.
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-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>
When backlight turns on early from display, a white line can be
seen on the screen. Therefore make sure backlight is off when we
are under an fb blank event.
Signed-off-by: Shingo Nakao <shingo.x.nakao@sonymobile.com>
Cc: Milo Kim <milo.kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Oskar Andero <oskar.andero@sonymobile.com>
Acked-by: Milo Kim <milo.kim@ti.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Enable supporting the DT structure of LP855x family devices. If the
platform data is NULL, the driver tries to parse a DT structure. Then,
the platform data is copied from the DT. Documentation is added as well.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 'load_new_rom_data' was used for checking whether new ROM data should
be updated or not.
However, we can decide it with 'size_program' data. If the size is
greater than 0, it means updating ROM area is required. Otherwise, the
default ROM data will be used. Therefore, this duplicate platform data
can be removed.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The brightness of LP855x devices is controlled by I2C register or PWM
input . This mode was selected through the platform data, but it can be
chosen by the driver internally without platform data configuration.
How to decide the control mode:
If the PWM period has specific value, the mode is PWM input.
On the other hand, the mode is register-based.
This mode selection is done on the _probe().
Move 'mode' from a header file to the driver private data structure,
'lp855 x'. And correlated code was replaced.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Configurable data, backlight device name is set to constant character type.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sysfs allocates PAGE_SIZE. It is used by each R/W operation method. Use
it instead of another buffer size.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
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>
While doing with make W=1 gcc (gcc (GCC) 4.7.2 20121109 (Red Hat
4.7.2-8)) I found
drivers/video/backlight/lp855x_bl.c: In function `lp855x_probe':
drivers/video/backlight/lp855x_bl.c:342:35: warning: variable `mode' set but not used [-Wunused-but-set-variable]
fixed by removing it as since its not used anywhere
Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Acked-by: Milo Kim <milo.kim@ti.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Getting the brightness value is not critical, no need to read the actual
register value. To simplify it, just return the 'bl->props.brightness'
value. Then, lp855x_read_byte() can be removed, not used any more.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
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>
LP8557 is one of LP855x family device, but it has different register map
and initialization process. To support this device, device specific
configuration is done through the lp855x_device_config structure.
Few register definitions are fixed for better readability.
BRIGHTNESS_CTRL -> LP855X_BRIGHTNESS_CTRL
DEVICE_CTRL -> LP855X_DEVICE_CTRL
EEPROM_START -> LP855X_EEPROM_START
EEPROM_END -> LP855X_EEPROM_END
EPROM_START -> LP8556_EPROM_START
EPROM_END -> LP8556_EPROM_END
And LP8557 register definitions are added. New register function,
lp855x_update_bit() is added.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
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>
At this moment, LP855x device driver has fixed register configuration.
For example, fixed register addresses and values are set on the device
initialization. But new device of LP855x family, LP8557 has different
register map and initialization sequence. To support new device
architecture, initialization process should be changed.
Introduce new structure: lp855x_device_config
=============================================
With lp855x_device_config, device specific features are configurable.
Use configurable function calls and register addresses rather than fixed values.
Change on device initialization
===============================
In old LP855x driver architecture, the device initialization was simple.
- Just update the brightness/device control register/ROM area(optional).
In new LP855x driver architecture, two more works are added - pre_init and
post_init.
Those init functions are optional, used for new device LP8557.
New device initialization flow: generic sequence
=================================================
1) pre_init_device()
2) update the brightness register
3) update the device control register
4) update ROM area if need
5) post_init_device()
Name change
===========
Use generic name 'lp855x_configure()' instead of 'lp855x_init_registers()'.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
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>
The mutex for accessing lp855x registers is used in case of the user-space
interaction. When the brightness is changed via sysfs, the mutex is
required. But the backlight class device already provides it. Thus, the
lp855x mutex is unnecessary.
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The LP855x family devices support the PWM input for the backlight control.
Period of the PWM is configurable in the platform side. Platform
specific functions are unnecessary anymore because generic PWM functions
are used inside the driver.
(PWM input mode)
To set the brightness, new lp855x_pwm_ctrl() is used.
If a PWM device is not allocated, devm_pwm_get() is called.
The PWM consumer name is from the chip name such as 'lp8550' and 'lp8556'.
To get the brightness value, no additional handling is required.
Just the value of 'props.brightness' is returned.
If the PWM driver is not ready while initializing the LP855x driver, it's
OK. The PWM device can be retrieved later, when the brightness value is
changed.
Documentation is updated with an example.
[akpm@linux-foundation.org: coding-style simplification, per Thierry]
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lp855x header is used only in the platform side, so it can be moved
into platform_data directory
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ROM boundary definitions do not need to be exported because these are
used only internally in the lp855x driver.
And few code cosmetic changes
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
THis driver supports TI LP8550/LP8551/LP8552/LP8553/LP8556 backlight
devices.
The brightness can be controlled by the I2C or PWM input. The lp855x
driver provides both modes. For the PWM control, pwm-specific functions
can be defined in the platform data. And some information can be read
via the sysfs(lp855x device attributes).
For details, please refer to Documentation/backlight/lp855x-driver.txt.
[axel.lin@gmail.com: add missing mutex_unlock in lp855x_read_byte() error path]
[axel.lin@gmail.com: check platform data in lp855x_probe()]
[axel.lin@gmail.com: small cleanups]
[dan.carpenter@oracle.com: silence a compiler warning]
[axel.lin@gmail.com: use id->driver_data to differentiate lp855x chips]
[akpm@linux-foundation.org: simplify boolean return expression]
Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kees Cook