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author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/backlight/lp855x-driver.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/backlight/lp855x-driver.txt')
-rw-r--r-- | kernel/Documentation/backlight/lp855x-driver.txt | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/kernel/Documentation/backlight/lp855x-driver.txt b/kernel/Documentation/backlight/lp855x-driver.txt new file mode 100644 index 000000000..01bce243d --- /dev/null +++ b/kernel/Documentation/backlight/lp855x-driver.txt @@ -0,0 +1,66 @@ +Kernel driver lp855x +==================== + +Backlight driver for LP855x ICs + +Supported chips: + Texas Instruments LP8550, LP8551, LP8552, LP8553, LP8555, LP8556 and + LP8557 + +Author: Milo(Woogyom) Kim <milo.kim@ti.com> + +Description +----------- + +* Brightness control + +Brightness can be controlled by the pwm input or the i2c command. +The lp855x driver supports both cases. + +* Device attributes + +1) bl_ctl_mode +Backlight control mode. +Value : pwm based or register based + +2) chip_id +The lp855x chip id. +Value : lp8550/lp8551/lp8552/lp8553/lp8555/lp8556/lp8557 + +Platform data for lp855x +------------------------ + +For supporting platform specific data, the lp855x platform data can be used. + +* name : Backlight driver name. If it is not defined, default name is set. +* device_control : Value of DEVICE CONTROL register. +* initial_brightness : Initial value of backlight brightness. +* period_ns : Platform specific PWM period value. unit is nano. + Only valid when brightness is pwm input mode. +* size_program : Total size of lp855x_rom_data. +* rom_data : List of new eeprom/eprom registers. + +example 1) lp8552 platform data : i2c register mode with new eeprom data + +#define EEPROM_A5_ADDR 0xA5 +#define EEPROM_A5_VAL 0x4f /* EN_VSYNC=0 */ + +static struct lp855x_rom_data lp8552_eeprom_arr[] = { + {EEPROM_A5_ADDR, EEPROM_A5_VAL}, +}; + +static struct lp855x_platform_data lp8552_pdata = { + .name = "lcd-bl", + .device_control = I2C_CONFIG(LP8552), + .initial_brightness = INITIAL_BRT, + .size_program = ARRAY_SIZE(lp8552_eeprom_arr), + .rom_data = lp8552_eeprom_arr, +}; + +example 2) lp8556 platform data : pwm input mode with default rom data + +static struct lp855x_platform_data lp8556_pdata = { + .device_control = PWM_CONFIG(LP8556), + .initial_brightness = INITIAL_BRT, + .period_ns = 1000000, +}; |