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@@ -0,0 +1,36 @@
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+Devices
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+=======
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+
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+Device bindings are described by their own individual binding files.
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+
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+U-Boot provides for some optional properties which are documented here. See
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+also hid-over-i2c.txt which describes HID devices. See also
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+Documentation/firmware-guide/acpi/enumeration.rst in the Linux kernel for
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+the acpi,compatible property.
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+
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+ - acpi,has-power-resource : (boolean) true if this device has a power resource.
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+ This causes an ACPI PowerResource to be written containing the properties
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+ provided by this binding, to describe how to handle powering the device up
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+ and down using GPIOs
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+ - acpi,compatible : compatible string to report
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+ - acpi,ddn : Contains the string to use as the _DDN (DOS (Disk Operating
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+ System) Device Name)
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+ - acpi,hid : Contains the string to use as the HID (Hardware ID)
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+ identifier _HID
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+ - acpi,uid : _UID value for device
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+ - linux,probed : Tells U-Boot to add 'linux,probed' to the ACPI tables so that
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+ Linux will only load the driver if the device can be detected (e.g. on I2C
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+ bus). Note that this is an out-of-tree Linux feature.
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+
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+
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+Example
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+-------
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+
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+elan_touchscreen: elan-touchscreen@10 {
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+ compatible = "i2c-chip";
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+ reg = <0x10>;
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+ acpi,hid = "ELAN0001";
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+ acpi,ddn = "ELAN Touchscreen";
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+ interrupts-extended = <&acpi_gpe GPIO_21_IRQ IRQ_TYPE_EDGE_FALLING>;
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+ linux,probed;
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+};
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