summaryrefslogtreecommitdiffstats
path: root/Documentation/driver-api/backlight
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
commit3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch)
treeb767d7f6e26bc64334d3f14f8422d187239dc45d /Documentation/driver-api/backlight
downloadlinux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz
linux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.zip
Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe: - Fix a task_work add use-after-free with SQPOLL. The sqpoll thread could pop and complete the last request while io_req_normal_work_add() was still looking at them after the mpscq push. Use the same approach as DEFER_TASKRUN to protect from that, holding an RCU read lock across the add, and have exit wait for an RCU grace period for SQPOLL rings as well. - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED rings - Mark the source filter table as COW when cloning bpf filters, so registering another filter on the source doesn't modify the shared table in place - Initialize the task context before running the BPF loop - Requeue zcrx multishot receives stopped by a local resource - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit) * tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring: fix task_work add use-after-free with SQPOLL io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full io_uring/zcrx: requeue multishot receives stopped by a local resource io_uring: initialize task context before running the BPF loop io_uring: zero big_cqe for aux CQEs on CQE32 rings io_uring: fix free entry check for 32b CQEs on CQE32 rings io_uring: only post the dummy skip CQE on CQE_MIXED rings io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'Documentation/driver-api/backlight')
-rw-r--r--Documentation/driver-api/backlight/lp855x-driver.rst81
1 files changed, 81 insertions, 0 deletions
diff --git a/Documentation/driver-api/backlight/lp855x-driver.rst b/Documentation/driver-api/backlight/lp855x-driver.rst
new file mode 100644
index 000000000..1e0b224fc
--- /dev/null
+++ b/Documentation/driver-api/backlight/lp855x-driver.rst
@@ -0,0 +1,81 @@
+====================
+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.
+
+Examples
+========
+
+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,
+ };
+
+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,
+ };