st,stmpe811 (on i2c bus)
Vendor: STMicroelectronics N.V.
Note
An implementation of a driver matching this compatible is available in drivers/input/input_stmpe811.c.
Description
STMPE811 I2C touchscreen controller
Properties
Node specific properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
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Interrupt GPIO. Used by the controller to signal touch data is
available. Active low.
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Signed raw X axis start for scaling the reported coordinates.
No effect if screen size is not set.
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Signed raw Y axis start for scaling the reported coordinates.
No effect if screen size is not set.
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Raw X axis end for scaling the reported coordinates.
No effect if screen size is not set.
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Raw Y axis end for scaling the reported coordinates.
No effect if screen size is not set.
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Panel driver settling time (microseconds). For large panels (> 6"), a capacitor of 10 nF
is recommended at the touchscreen terminals for noise filtering.
As a general rule, 1-5 nF capacitors require around 500 us settling time, and 5-10 nF need
around 1 ms. When a larger capacitor is used, this value should be changed, as it can
lead to inaccuracy of the measurement.
This property is required. Legal values: |
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Touch detect delay (microseconds) is the delay from the activation of the pull-up resistor
in the X+ line to the time the device performs touch detection.
If no capacitor, or a smaller capacitor is used, this value can be lowered to
minimize detection latency, but it could lower the position stability.
This property is required. Legal values: |
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Average control (number of samples).
This parameter can be set to any of the possible values.
Higher values result in more filtering of noise, but also introduce
more latency in the touch detection process.
Use cases that require low touch detection latency
may benefit from using a lower value for this parameter,
at the cost of less noise filtering.
This property is required. Legal values: |
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Tracking index determines the minimal distance between
the current touch position and the previous touch position.
If the distance is shorter than the tracking index, it is discarded.
Lowering the tracking index increases the frequency of touch events,
but also increases the load on the system.
This property is required. Legal values: |
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GPIO specifier that controls power to the device.
This property should be provided when the device has a dedicated
switch that controls power to the device. The supply state is
entirely the responsibility of the device driver.
Contrast with vin-supply.
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Reference to the regulator that controls power to the device.
The referenced devicetree node must have a regulator compatible.
This property should be provided when device power is supplied
by a shared regulator. The supply state is dependent on the
request status of all devices fed by the regulator.
Contrast with supply-gpios. If both properties are provided
then the regulator must be requested before the supply GPIOS is
set to an active state, and the supply GPIOS must be set to an
inactive state before releasing the regulator.
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Horizontal resolution of touchscreen (maximum x coordinate reported + 1). The default
corresponds to a valid value for non-inverted axis, required for a display with an inverted x
axis.
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Vertical resolution of touchscreen (maximum y coordinate reported + 1). The default
corresponds to a valid value for non-inverted axis, required for a display with an inverted y
axis.
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X axis is inverted.
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Y axis is inverted.
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X and Y axis are swapped. Swapping is done after inverting the axis.
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Deprecated node specific properties
Deprecated properties not inherited from the base binding file.
(None)
Base properties
Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “st,stmpe811” compatible.
Name |
Type |
Details |
|---|---|---|
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device address on i2c bus
This property is required. See Important properties for more information. |
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indicates the operational status of a device
Legal values: See Important properties for more information. |
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compatible strings
This property is required. See Important properties for more information. |
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name of each register space
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interrupts for device
See Important properties for more information. |
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extended interrupt specifier for device
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name of each interrupt
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phandle to interrupt controller node
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Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
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Clock gate information
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name of each clock
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number of address cells in reg property
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number of size cells in reg property
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DMA channels specifiers
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Provided names of DMA channel specifiers
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IO channels specifiers
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Provided names of IO channel specifiers
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mailbox / IPM channels specifiers
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Provided names of mailbox / IPM channel specifiers
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Power domain specifiers
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Provided names of power domain specifiers
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Number of cells in power-domains property
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
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Property to identify that a device can be used as wake up source.
When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.
Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.
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Automatically configure the device for runtime power management after the
init function runs.
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List of power states that will disable this device power.
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