xref: /freebsd/sys/contrib/device-tree/Bindings/power/supply/ltc2941.txt (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1binding for LTC2941, LTC2942, LTC2943 and LTC2944 battery gauges
2
3All chips measure battery capacity.
4The LTC2942 is pin compatible with the LTC2941, it adds voltage and
5temperature monitoring, and is runtime detected. LTC2943 and LTC2944
6is software compatible, uses a slightly different conversion formula
7for the charge counter and adds voltage, current and temperature monitoring.
8
9Required properties:
10- compatible: Should contain "lltc,ltc2941", "lltc,ltc2942", "lltc,ltc2943"
11    or "lltc,ltc2944" which also indicates the type of I2C chip attached.
12- reg: The 7-bit I2C address.
13- lltc,resistor-sense: The sense resistor value in milli-ohms. Can be a 32-bit
14    negative value when the battery has been connected to the wrong end of the
15    resistor.
16- lltc,prescaler-exponent: The prescaler exponent as explained in the datasheet.
17    This determines the range and accuracy of the gauge. The value is programmed
18    into the chip only if it differs from the current setting. The setting is
19    lost when the battery is disconnected.
20
21Example from the Topic Miami Florida board:
22
23	fuelgauge: ltc2943@64 {
24		compatible = "lltc,ltc2943";
25		reg = <0x64>;
26		lltc,resistor-sense = <15>;
27		lltc,prescaler-exponent = <5>; /* 2^(2*5) = 1024 */
28	};
29