| Simon Glass | 9427867 | 2020-04-26 09:19:45 -0600 | [diff] [blame] | 1 | Devices |
| 2 | ======= |
| 3 | |
| 4 | Device bindings are described by their own individual binding files. |
| 5 | |
| 6 | U-Boot provides for some optional properties which are documented here. See |
| 7 | also hid-over-i2c.txt which describes HID devices. See also |
| 8 | Documentation/firmware-guide/acpi/enumeration.rst in the Linux kernel for |
| 9 | the acpi,compatible property. |
| 10 | |
| 11 | - acpi,has-power-resource : (boolean) true if this device has a power resource. |
| 12 | This causes an ACPI PowerResource to be written containing the properties |
| 13 | provided by this binding, to describe how to handle powering the device up |
| 14 | and down using GPIOs |
| 15 | - acpi,compatible : compatible string to report |
| 16 | - acpi,ddn : Contains the string to use as the _DDN (DOS (Disk Operating |
| 17 | System) Device Name) |
| 18 | - acpi,hid : Contains the string to use as the HID (Hardware ID) |
| 19 | identifier _HID |
| 20 | - acpi,uid : _UID value for device |
| 21 | - linux,probed : Tells U-Boot to add 'linux,probed' to the ACPI tables so that |
| 22 | Linux will only load the driver if the device can be detected (e.g. on I2C |
| 23 | bus). Note that this is an out-of-tree Linux feature. |
| 24 | |
| 25 | |
| 26 | Example |
| 27 | ------- |
| 28 | |
| 29 | elan_touchscreen: elan-touchscreen@10 { |
| 30 | compatible = "i2c-chip"; |
| 31 | reg = <0x10>; |
| 32 | acpi,hid = "ELAN0001"; |
| 33 | acpi,ddn = "ELAN Touchscreen"; |
| 34 | interrupts-extended = <&acpi_gpe GPIO_21_IRQ IRQ_TYPE_EDGE_FALLING>; |
| 35 | linux,probed; |
| 36 | }; |