kernel/linux.git/drivers/video/backlight, branch v5.4.50

backlight: lp855x: Ensure regulators are disabled on probe failure

2020-06-24T15:50:09+00:00

[ Upstream commit d8207c155a7c6015eb7f43739baa7dfb1fa638af ] If probing the LP885x backlight fails after the regulators have been enabled, then the following warning is seen when releasing the regulators ... WARNING: CPU: 1 PID: 289 at drivers/regulator/core.c:2051 _regulator_put.part.28+0x158/0x160 Modules linked in: tegra_xudc lp855x_bl(+) host1x pwm_tegra ip_tables x_tables ipv6 nf_defrag_ipv6 CPU: 1 PID: 289 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200224 #1 Hardware name: NVIDIA Jetson TX1 Developer Kit (DT) ... Call trace: _regulator_put.part.28+0x158/0x160 regulator_put+0x34/0x50 devm_regulator_release+0x10/0x18 release_nodes+0x12c/0x230 devres_release_all+0x34/0x50 really_probe+0x1c0/0x370 driver_probe_device+0x58/0x100 device_driver_attach+0x6c/0x78 __driver_attach+0xb0/0xf0 bus_for_each_dev+0x68/0xc8 driver_attach+0x20/0x28 bus_add_driver+0x160/0x1f0 driver_register+0x60/0x110 i2c_register_driver+0x40/0x80 lp855x_driver_init+0x20/0x1000 [lp855x_bl] do_one_initcall+0x58/0x1a0 do_init_module+0x54/0x1d0 load_module+0x1d80/0x21c8 __do_sys_finit_module+0xe8/0x100 __arm64_sys_finit_module+0x18/0x20 el0_svc_common.constprop.3+0xb0/0x168 do_el0_svc+0x20/0x98 el0_sync_handler+0xf4/0x1b0 el0_sync+0x140/0x180 Fix this by ensuring that the regulators are disabled, if enabled, on probe failure. Finally, ensure that the vddio regulator is disabled in the driver remove handler. Signed-off-by: Jon Hunter Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

Merge tag 'backlight-next-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

2019-09-24T02:33:56+00:00

Pull backlight updates from Lee Jones: "Core Frameworks - Obtain scale type through sysfs New Functionality: - Provide Device Tree functionality in rave-sp-backlight - Calculate if scale type is (non-)linear in pwm_bl Fix-ups: - Simplify code in lm3630a_bl - Trivial rename/whitespace/typo fixes in lms283gf05 - Remove superfluous NULL check in tosa_lcd - Fix power state initialisation in gpio_backlight - List supported file in MAINTAINERS Bug Fixes: - Kconfig - default to not building unless requested in {LED,BACKLIGHT}_CLASS_DEVICE" * tag 'backlight-next-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: backlight: pwm_bl: Set scale type for brightness curves specified in the DT backlight: pwm_bl: Set scale type for CIE 1931 curves backlight: Expose brightness curve type through sysfs MAINTAINERS: Add entry for stable backlight sysfs ABI documentation backlight: gpio-backlight: Correct initial power state handling video: backlight: tosa_lcd: drop check because i2c_unregister_device() is NULL safe video: backlight: Drop default m for {LCD,BACKLIGHT_CLASS_DEVICE} backlight: lms283gf05: Fix a typo in the description passed to 'devm_gpio_request_one()' backlight: lm3630a: Switch to use fwnode_property_count_uXX() backlight: rave-sp: Leave initial state and register with correct device

backlight: pwm_bl: Set scale type for brightness curves specified in the DT

2019-09-02T14:55:15+00:00

Check if a brightness curve specified in the device tree is linear or not and set the corresponding property accordingly. This makes the scale type available to userspace via the 'scale' sysfs attribute. To determine if a curve is linear it is compared to a interpolated linear curve between min and max brightness. The curve is considered linear if no value deviates more than +/-5% of ${brightness_range} from their interpolated value. Signed-off-by: Matthias Kaehlcke Acked-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: pwm_bl: Set scale type for CIE 1931 curves

2019-09-02T14:55:11+00:00

For backlight curves calculated with the CIE 1931 algorithm set the brightness scale type to non-linear. This makes the scale type available to userspace via the 'scale' sysfs attribute. Signed-off-by: Matthias Kaehlcke Tested-by: Enric Balletbo i Serra Acked-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: Expose brightness curve type through sysfs

2019-09-02T14:55:03+00:00

Backlight brightness curves can have different shapes. The two main types are linear and non-linear curves. The human eye doesn't perceive linearly increasing/decreasing brightness as linear (see also 88ba95bedb79 "backlight: pwm_bl: Compute brightness of LED linearly to human eye"), hence many backlights use non-linear (often logarithmic) brightness curves. The type of curve currently is opaque to userspace, so userspace often uses more or less reliable heuristics (like the number of brightness levels) to decide whether to treat a backlight device as linear or non-linear. Export the type of the brightness curve via the new sysfs attribute 'scale'. The value of the attribute can be 'linear', 'non-linear' or 'unknown'. For devices that don't provide information about the scale of their brightness curve the value of the 'scale' attribute is 'unknown'. Signed-off-by: Matthias Kaehlcke Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: gpio-backlight: Correct initial power state handling

2019-09-02T14:54:52+00:00

The default-on property - or the def_value via legacy pdata) should be handled as: if it is 1, the backlight must be enabled (kept enabled) if it is 0, the backlight must be disabled (kept disabled) This only works for the case when default-on is set. If it is not set then the brightness of the backlight is set to 0. Now if the backlight is enabled by external driver (graphics) the backlight will stay disabled since the brightness is configured as 0. The backlight will not turn on. In order to minimize screen flickering during device boot: The initial brightness should be set to 1. If booted in non DT mode or no phandle link to the backlight node: follow the def_value/default-on to select UNBLANK or POWERDOWN If in DT boot we have phandle link then leave the GPIO in a state which the bootloader left it and let the user of the backlight to configure it further. Signed-off-by: Peter Ujfalusi Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

video: backlight: tosa_lcd: drop check because i2c_unregister_device() is NULL safe

2019-09-02T14:54:47+00:00

No need to check the argument of i2c_unregister_device() because the function itself does it. Signed-off-by: Wolfram Sang Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

video: backlight: Drop default m for {LCD,BACKLIGHT_CLASS_DEVICE}

2019-09-02T14:54:29+00:00

When running "make oldconfig" on a .config where CONFIG_BACKLIGHT_LCD_SUPPORT is not set, two new config options ("Lowlevel LCD controls" and "Lowlevel Backlight controls") appear, both defaulting to "m". Drop the "default m", as options should default to disabled, and because several driver config options already select LCD_CLASS_DEVICE or BACKLIGHT_CLASS_DEVICE when needed. Fixes: 8c5dc8d9f19c7992 ("video: backlight: Remove useless BACKLIGHT_LCD_SUPPORT kernel symbol") Signed-off-by: Geert Uytterhoeven Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: lms283gf05: Fix a typo in the description passed to 'devm_gpio_request_one()'

2019-08-12T08:11:22+00:00

The description passed to 'devm_gpio_request_one()' should be related to LMS283GF05, not LMS285GF05. Signed-off-by: Christophe JAILLET Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones

backlight: lm3630a: Switch to use fwnode_property_count_uXX()

2019-08-12T08:11:16+00:00

Use use fwnode_property_count_uXX() directly, that makes code neater. Signed-off-by: Andy Shevchenko Reviewed-by: Daniel Thompson Signed-off-by: Lee Jones