Commit Graph

10 Commits

Author SHA1 Message Date
Kim, Milo
9e9cdc8969 backlight: lp855x_bl: simplify bl_get_brightness()
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>
2013-02-21 17:22:25 -08:00
Kim, Milo
26e8ccc223 backlight: lp855x_bl: support new LP8557 device
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>
2013-02-21 17:22:25 -08:00
Kim, Milo
68853bc2b3 backlight: lp855x_bl: introduce device configuration flow
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>
2013-02-21 17:22:25 -08:00
Kim, Milo
eaa4d02fba drivers/video/backlight/lp855x_bl.c: remove unnecessary mutex code
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>
2012-12-17 17:15:16 -08:00
Kim, Milo
8cc9764c9c drivers/video/backlight/lp855x_bl.c: use generic PWM functions
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>
2012-12-17 17:15:16 -08:00
Bill Pemberton
7e4b9d0bb2 backlight: remove use of __devexit
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>
2012-11-28 12:06:39 -08:00
Bill Pemberton
d1723fa266 backlight: remove use of __devexit_p
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>
2012-11-28 12:03:45 -08:00
Kim, Milo
f7f9505677 backlight: move lp855x header into platform_data directory
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>
2012-07-30 17:25:15 -07:00
Kim, Milo
a1fcb2e318 backlight: move register definitions from header to source
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>
2012-07-30 17:25:15 -07:00
Kim, Milo
7be865ab86 backlight: new backlight driver for LP855x devices
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>
2012-03-23 16:58:33 -07:00