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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'Documentation/driver-api/backlight')
-rw-r--r--Documentation/driver-api/backlight/lp855x-driver.rst81
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diff --git a/Documentation/driver-api/backlight/lp855x-driver.rst b/Documentation/driver-api/backlight/lp855x-driver.rst
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+====================
+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,
+ };