Texas Instruments OPT3001EVM, Руководство по началу работы

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Chapter 4
The Linux Kernel
4.1 Writing Our DeviceTree
Now that we have OPT3001EVM connected to our Beagle Bone Black, we
need to tell Linux about it. Recent Linux Kernel release utilize Open Firmware
as the methodology for firmware to tell the Operating System about devices
which sit under non-enumerable buses. The language used by Open firmware is
known as DeviceTree
With a DeviceTree source such as below, we can tell Linux that we have
an OPT3001 device sitting under I2C Bus 2 and can be accessed through I2C
address 0x44.
/* arch/arm/boot/dts/am335x-boneblack.dts */
&i2c2 {
status = "okay" ;
pinctrl-names = "default" ;
pinctrl-0 = <&i2c2_pins>;
clock-frequency = <400000>;
light@44 {
status = "okay" ;
pinctrl-names = "default" ;
pinctrl-0 = <&light_pins>;
compatible = "opt3001" ;
reg = <0x44>;
interrupts-extended = <&gpio1 28 IRQ_TYPE_LEVEL_HIGH>;
};
};
Note that we have two undefined pinctrl DeviceTree nodes. Let’s define them:
/* arch/arm/boot/dts/am335x-boneblack.dts */
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