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path: root/drivers/regulator/rpi-panel-attiny-regulator.c
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2022-04-06regulator: rpi-panel-attiny: Get rid of duplicate of_node assignmentAndy Shevchenko1-1/+0
GPIO library does copy the of_node from the parent device of the GPIO chip, there is no need to repeat this in the individual drivers. Remove these assignment all at once. For the details one may look into the of_gpio_dev_init() implementation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220325184508.45670-1-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator/rpi-panel-attiny: Use two transactions for I2C readDave Stevenson1-1/+34
The I2C to the Atmel is very fussy, and locks up easily on Pi0-3 particularly on reads. If running at 100kHz on Pi3, reading the ID register generally locks up the Atmel, but splitting the register select write and read into two transactions is reliable. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-10-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator/rpi-panel-attiny: Use the regmap cacheDave Stevenson1-1/+1
The I2C to the Atmel is very fussy, and locks up easily on Pi0-3 particularly on reads. The LCD power status is controlled solely by this driver, so rather than reading it back from the Atmel, use the regmap cache to avoid reading values. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-9-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Remove get_brightness hookDave Stevenson1-23/+0
The driver was implementing a get_brightness function that tried to read back the PWM setting of the display to report as the current brightness. The controller on the display does not support that, therefore we end up reporting a brightness of 0, and that confuses systemd's backlight service. Remove the hook so that the framework returns the current brightness automatically. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-8-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Add GPIO control for panel and touch resetsDave Stevenson1-18/+97
We need independent control of the resets for the panel&bridge, vs the touch controller. Expose the reset lines that are on the Atmel's port C via the GPIO API so that they can be controlled appropriately. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-7-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Convert to drive lines directlyDave Stevenson1-51/+60
The Atmel was doing a load of automatic sequencing of control lines, however it was combining the touch controller's reset with the bridge/panel control. Change to control the control signals directly rather than through the automatic POWERON control. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-6-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Ensure the backlight is off during probe.Dave Stevenson1-0/+1
The initial state of the Atmel is not defined, so ensure the backlight PWM is set to 0 by default. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-5-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Serialise operations.Dave Stevenson1-11/+80
The driver was using the regmap lock to serialise the individual accesses, but we really need to protect the timings of enabling the regulators, including any communication with the Atmel. Use a mutex within the driver to control overall accesses to the Atmel, instead of the regmap lock. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-4-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Handle I2C errors/timing to the AtmelDave Stevenson1-10/+46
The Atmel is doing some things in the I2C ISR, during which period it will not respond to further commands. This is particularly true of the POWERON command. Increase delays appropriately, and retry should I2C errors be reported. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-3-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2022-01-28regulator: rpi-panel: Register with a unique backlight nameDave Stevenson1-2/+1
There's no reason why 2 Raspberry Pi DSI displays can't be attached to a Pi Compute Module, so the backlight names need to be unique. Use the parent dev_name. It's not as readable, but is unique. Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> Link: https://lore.kernel.org/r/20220124220129.158891-2-detlev.casanova@collabora.com Signed-off-by: Mark Brown <broonie@kernel.org>
2020-08-18regulator: rpi-panel: Add regulator/backlight driver for RPi panelMarek Vasut1-0/+214
This regulator/backlight driver handles the ATTINY88 present on the RPi 7" touchscreen panel and exposes the power/backlight interfaces. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Eric Anholt <eric@anholt.net> Cc: Mark Brown <broonie@kernel.org> Cc: Sam Ravnborg <sam@ravnborg.org> To: dri-devel@lists.freedesktop.org Link: https://lore.kernel.org/r/20200809105938.6388-2-marex@denx.de Signed-off-by: Mark Brown <broonie@kernel.org>