61 lines
2.8 KiB
Plaintext
61 lines
2.8 KiB
Plaintext
|
* ROHM BH1730FVC ambient light sensor
|
||
|
|
|
||
|
|
nvs_ drivers use the NVidia Sensor (NVS) framework.
|
||
|
|
See the nvs.txt documentation for NVS DT capabilities.
|
||
|
|
|
||
|
|
Required properties:
|
||
|
|
- compatible: must be "rohm,bh1730fvc"
|
||
|
|
- reg: i2c address of the device. It should be 0x29.
|
||
|
|
|
||
|
|
Optional properties:
|
||
|
|
- status: set to "ok" or "okay" for normal operation. Set to anything else
|
||
|
|
to unload the driver without ever communicating with the device.
|
||
|
|
Note: The "anything else" above is typically "disabled".
|
||
|
|
Since the driver will unload without communicating with the device, the
|
||
|
|
device will be left in its POR state.
|
||
|
|
- vdd-supply: regulator supply for the chip vcc
|
||
|
|
- vid-supply: regulator supply for the chip dvi
|
||
|
|
Note: This is required if the driver is to control the regulator.
|
||
|
|
- bh1730fvc-lux-coeff-size: array size of bh1730fvc-lux-coeff.
|
||
|
|
- bh1730fvc-lux-coeff: Lux calculation coefficient table. See the note.
|
||
|
|
- bh1730fvc-lux-resolution: See the note.
|
||
|
|
- bh1730fvc-lux-multiplier: See the note.
|
||
|
|
Note: If lux coefficient data is not present, default calculation table is used.
|
||
|
|
If present, lux calculation is done with following equation.
|
||
|
|
Let following is set in dt:
|
||
|
|
bh1730fvc-lux-coeff-size = <5>;
|
||
|
|
bh1730fvc-lux-coeff = < 500 5002 7502>,
|
||
|
|
< 754 2250 2000>,
|
||
|
|
<1029 1999 1667>,
|
||
|
|
<1373 884 583>,
|
||
|
|
<1879 309 165>;
|
||
|
|
bh1730fvc-lux-resolution = <1000>;
|
||
|
|
bh1730fvc-lux-multiplier = <360>;
|
||
|
|
Then lux is calculated with this equation:
|
||
|
|
if (data1 * 1000 / data0 < 500)
|
||
|
|
lux = 5002 * data0 - 7502 * data1
|
||
|
|
else if (data1 * 1000 / data0 < 754)
|
||
|
|
lux = 2250 * data0 - 2000 * data1
|
||
|
|
else if (data1 * 1000 / data0 < 1029)
|
||
|
|
lux = 1999 * data0 - 1667 * data1
|
||
|
|
else if (data1 * 1000 / data0 < 1373)
|
||
|
|
lux = 884 * data0 - 583 * data1
|
||
|
|
else if (data1 * 1000 / data0 < 1879)
|
||
|
|
lux = 309 * data0 - 165 * data1
|
||
|
|
lux = lux * 360 / (gain * itime_us)
|
||
|
|
|
||
|
|
Example:
|
||
|
|
bh1730fvc@29 {
|
||
|
|
compatible = "rohm,bh1730fvc";
|
||
|
|
reg = <0x29>;
|
||
|
|
bh1730fvc-lux-coeff-size = <5>;
|
||
|
|
bh1730fvc-lux-coeff = < 500 5002 7502>,
|
||
|
|
< 754 2250 2000>,
|
||
|
|
<1029 1999 1667>,
|
||
|
|
<1373 884 583>,
|
||
|
|
<1879 309 165>;
|
||
|
|
bh1730fvc-lux-resolution = <1000>;
|
||
|
|
bh1730fvc-lux-multiplier = <360>;
|
||
|
|
};
|
||
|
|
|