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2019-07-15docs: lp855x-driver.rst: add it to the driver-api bookMauro Carvalho Chehab
The content of this file is intended for backlight Kernel developers. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: lp855x-driver.txt: convert to ReST and move to kernel-apiMauro Carvalho Chehab
This small file seems to be an attempt to start documenting backlight drivers. It contains descriptions of the controls for the driver with could sound as an somewhat user-faced description, but it's main focus is to describe, instead, the data that should be passed via platform data and some driver-specific stuff. While this is not part of the driver-api book, mark it as :orphan:, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2013-11-13backlight: lp855x_bl: support new LP8555 deviceMilo Kim
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>
2013-04-29backlight: lp855x: remove duplicate platform dataKim, Milo
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>
2013-04-29backlight: lp855x: move backlight mode platform dataKim, Milo
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>
2013-02-21backlight: lp855x_bl: support new LP8557 deviceKim, Milo
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>
2012-12-17drivers/video/backlight/lp855x_bl.c: use generic PWM functionsKim, Milo
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>
2012-03-23backlight: new backlight driver for LP855x devicesKim, Milo
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>