The mp3309 has two configuration registers, named according to their
address (0x00 and 0x01).
In the second register (0x01), the bit DIMS (Dimming Mode Select) must
be always 0 (zero), in both analog (via I2C commands) and PWM dimming
mode.
In the initial driver version, the DIMS bit was set in PWM mode and
reset in analog mode.
But if the DIMS bit is set in pwm dimming mode and other devices are
connected on the same I2C bus, every I2C commands on the bus generates a
flickering on the LEDs powered by the mp3309c.
This change concerns the chip initialization and does not impact any
existing device-tree configuration.
Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240417153105.1794134-2-f.suligoi@asem.it
Signed-off-by: Lee Jones <lee@kernel.org>
The "num_levels" variable is used to store error codes from
device_property_count_u32() so it needs to be signed. This doesn't
cause an issue at runtime because devm_kcalloc() won't allocate negative
sizes. However, it's still worth fixing.
Fixes: b54c828bdb ("backlight: mp3309c: Make use of device properties")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/74347f67-360d-4513-8939-595e3c4764fa@moroto.mountain
Signed-off-by: Lee Jones <lee@kernel.org>
Remove the field fb_blank from struct backlight_properties and remove
all code that still sets or reads it. Backlight blank status is now
tracked exclusively in struct backlight_properties.state.
The core backlight code keeps the fb_blank and state fields in sync,
but doesn't do anything else with fb_blank. Several drivers initialize
fb_blank to FB_BLANK_UNBLANK to enable the backlight. This is already
the default for the state field. So we can delete the fb_blank code
from core and drivers and rely on the state field.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Flavio Suligoi <f.suligoi@asem.it>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240319093915.31778-7-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>
props is stack allocated and, although this driver initializes all the
fields that are not "owned" by the framework, we'd still like to ensure
it is zeroed to avoid problems from this driver if the fields change.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240220153532.76613-5-daniel.thompson@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
We have a temporary variable to keep pointer to struct device.
Utilise it where it makes sense.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Link: https://lore.kernel.org/r/20240208184313.2224579-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Lee Jones <lee@kernel.org>
Replace dev_err() with dev_err_probe().
This helps in simplifing code and standardizing the error output.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240208184313.2224579-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Lee Jones <lee@kernel.org>
Convert the module to be property provider agnostic and allow
it to be used on non-OF platforms.
Add mod_devicetable.h include.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240208184313.2224579-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Lee Jones <lee@kernel.org>
pwm_apply_state() is deprecated since commit c748a6d77c ("pwm: Rename
pwm_apply_state() to pwm_apply_might_sleep()"). This is the final user
in the tree.
Signed-off-by: Sean Young <sean@mess.org>
Tested-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240128154905.407302-1-sean@mess.org
Signed-off-by: Lee Jones <lee@kernel.org>
In the function "pm3309c_parse_dt_node", when the dimming analog control
mode (by I2C messages) is enabled, the local variable "prop_levels" is
tested without any initialization, as indicated by the following smatch
warning:
drivers/video/backlight/mp3309c.c:279 pm3309c_parse_dt_node() error: uninitialized symbol 'prop_levels'.
To avoid any problem in case of undefined behavior, we need to initialize
it to "NULL".
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/dri-devel/af0a1870-693b-442f-9b11-0503cfcd944a@moroto.mountain/
Fixes: 2e914516a5 ("backlight: mp3309c: Add support for MPS MP3309C")
Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20231129164514.2772719-1-f.suligoi@asem.it
Signed-off-by: Lee Jones <lee@kernel.org>
The Monolithic Power (MPS) MP3309C is a WLED step-up converter, featuring a
programmable switching frequency to optimize efficiency.
The brightness can be controlled either by I2C commands (called "analog"
mode) or by a PWM input signal (PWM mode).
This driver supports both modes.
For DT configuration details, please refer to:
- Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
The datasheet is available at:
- https://www.monolithicpower.com/en/mp3309c.html
Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20231116105319.957600-3-f.suligoi@asem.it
Signed-off-by: Lee Jones <lee@kernel.org>
