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f18589576c
Some devices such as GPIO need to override the normal path that would be generated by driver model. Add a device-tree property for this. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
72 lines
2.2 KiB
Text
72 lines
2.2 KiB
Text
Devices
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=======
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Device bindings are described by their own individual binding files.
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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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- 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,path : Specifies the full ACPI path for a device. This overrides the
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normal path built from the driver-model hierarchy
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- acpi,name : Provides the ACPI name for a device, which is a string consisting
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of four alphanumeric character (upper case)
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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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Example
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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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pcie-a0@14,0 {
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reg = <0x0000a000 0 0 0 0>;
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acpi,name = "RP01";
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wifi: wifi {
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compatible = "intel,generic-wifi";
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acpi,ddn = "Intel WiFi";
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acpi,name = "WF00";
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interrupts-extended = <&acpi_gpe 0x3c 0>;
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};
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};
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p2sb: p2sb@d,0 {
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u-boot,dm-pre-reloc;
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reg = <0x02006810 0 0 0 0>;
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compatible = "intel,apl-p2sb";
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early-regs = <IOMAP_P2SB_BAR 0x100000>;
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pci,no-autoconfig;
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n {
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compatible = "intel,apl-pinctrl";
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u-boot,dm-pre-reloc;
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intel,p2sb-port-id = <PID_GPIO_N>;
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acpi,path = "\\_SB.GPO0";
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gpio_n: gpio-n {
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compatible = "intel,gpio";
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u-boot,dm-pre-reloc;
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gpio-controller;
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#gpio-cells = <2>;
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linux-name = "INT3452:00";
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};
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};
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