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authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 16:59:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 16:59:10 -0700
commit8e3ade251bc7c0a4f0777df4dd34343a03efadba (patch)
tree6c0b78731e3d6609057951d07660efbd90992ad0 /Documentation/backlight/lp855x-driver.txt
parente317234975cb7463b8ca21a93bb6862d9dcf113f (diff)
parente075f59152890ffd7e3d704afc997dd686c8a781 (diff)
Merge branch 'akpm' (Andrew's patch-bomb)
Merge second batch of patches from Andrew Morton: - various misc things - core kernel changes to prctl, exit, exec, init, etc. - kernel/watchdog.c updates - get_maintainer - MAINTAINERS - the backlight driver queue - core bitops code cleanups - the led driver queue - some core prio_tree work - checkpatch udpates - largeish crc32 update - a new poll() feature for the v4l guys - the rtc driver queue - fatfs - ptrace - signals - kmod/usermodehelper updates - coredump - procfs updates * emailed from Andrew Morton <akpm@linux-foundation.org>: (141 commits) seq_file: add seq_set_overflow(), seq_overflow() proc-ns: use d_set_d_op() API to set dentry ops in proc_ns_instantiate(). procfs: speed up /proc/pid/stat, statm procfs: add num_to_str() to speed up /proc/stat proc: speed up /proc/stat handling fs/proc/kcore.c: make get_sparsemem_vmemmap_info() static coredump: add VM_NODUMP, MADV_NODUMP, MADV_CLEAR_NODUMP coredump: remove VM_ALWAYSDUMP flag kmod: make __request_module() killable kmod: introduce call_modprobe() helper usermodehelper: ____call_usermodehelper() doesn't need do_exit() usermodehelper: kill umh_wait, renumber UMH_* constants usermodehelper: implement UMH_KILLABLE usermodehelper: introduce umh_complete(sub_info) usermodehelper: use UMH_WAIT_PROC consistently signal: zap_pid_ns_processes: s/SEND_SIG_NOINFO/SEND_SIG_FORCED/ signal: oom_kill_task: use SEND_SIG_FORCED instead of force_sig() signal: cosmetic, s/from_ancestor_ns/force/ in prepare_signal() paths signal: give SEND_SIG_FORCED more power to beat SIGNAL_UNKILLABLE Hexagon: use set_current_blocked() and block_sigmask() ...
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+Kernel driver lp855x
+====================
+
+Backlight driver for LP855x ICs
+
+Supported chips:
+ Texas Instruments LP8550, LP8551, LP8552, LP8553 and LP8556
+
+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/lp8556
+
+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.
+* mode : Brightness control mode. PWM or register based.
+* device_control : Value of DEVICE CONTROL register.
+* initial_brightness : Initial value of backlight brightness.
+* pwm_data : Platform specific pwm generation functions.
+ Only valid when brightness is pwm input mode.
+ Functions should be implemented by PWM driver.
+ - pwm_set_intensity() : set duty of PWM
+ - pwm_get_intensity() : get current duty of PWM
+* load_new_rom_data :
+ 0 : use default configuration data
+ 1 : update values of eeprom or eprom registers on loading driver
+* 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",
+ .mode = REGISTER_BASED,
+ .device_control = I2C_CONFIG(LP8552),
+ .initial_brightness = INITIAL_BRT,
+ .load_new_rom_data = 1,
+ .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 = {
+ .mode = PWM_BASED,
+ .device_control = PWM_CONFIG(LP8556),
+ .initial_brightness = INITIAL_BRT,
+ .pwm_data = {
+ .pwm_set_intensity = platform_pwm_set_intensity,
+ .pwm_get_intensity = platform_pwm_get_intensity,
+ },
+};