xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/regulator/regulator.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunVoltage/Current regulator
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunBinding:
4*4882a593SmuzhiyunThe regulator devices don't use the "compatible" property. The binding is done
5*4882a593Smuzhiyunby the prefix of regulator node's name, or, if this fails, by the prefix of the
6*4882a593Smuzhiyunregulator's "regulator-name" property. Usually the pmic I/O driver will provide
7*4882a593Smuzhiyunthe array of 'struct pmic_child_info' with the prefixes and compatible drivers.
8*4882a593SmuzhiyunThe bind is done by calling function: pmic_bind_childs().
9*4882a593SmuzhiyunExample drivers:
10*4882a593Smuzhiyunpmic: drivers/power/pmic/max77686.c
11*4882a593Smuzhiyunregulator: drivers/power/regulator/max77686.c
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunFor the node name e.g.: "prefix[:alpha:]num { ... }":
14*4882a593Smuzhiyun- the driver prefix should be: "prefix" - case sensitive
15*4882a593Smuzhiyun- the node name's "num" is set as "dev->driver_data" on bind
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunExample the prefix "ldo" will pass for: "ldo1", "ldo@1", "ldoreg@1, ...
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunBinding by means of the node's name is preferred. However if the node names
20*4882a593Smuzhiyunwould produce ambiguous prefixes (like "regulator@1" and "regualtor@11") and you
21*4882a593Smuzhiyuncan't or do not want to change them then binding against the "regulator-name"
22*4882a593Smuzhiyunproperty is possible. The syntax for the prefix of the "regulator-name" property
23*4882a593Smuzhiyunis the same as the one for the regulator's node name.
24*4882a593SmuzhiyunUse case: a regulator named "regulator@1" to be bound to a driver named
25*4882a593Smuzhiyun"LDO_DRV" and a regulator named "regualator@11" to be bound to an other driver
26*4882a593Smuzhiyunnamed "BOOST_DRV". Using prefix "regualtor@1" for driver matching would load
27*4882a593Smuzhiyunthe same driver for both regulators, hence the prefix is ambiguous.
28*4882a593Smuzhiyun
29*4882a593SmuzhiyunOptional properties:
30*4882a593Smuzhiyun- regulator-name: a string, required by the regulator uclass, used for driver
31*4882a593Smuzhiyun                  binding if binding by node's name prefix fails
32*4882a593Smuzhiyun- regulator-min-microvolt: a minimum allowed Voltage value
33*4882a593Smuzhiyun- regulator-max-microvolt: a maximum allowed Voltage value
34*4882a593Smuzhiyun- regulator-min-microamp: a minimum allowed Current value
35*4882a593Smuzhiyun- regulator-max-microamp: a maximum allowed Current value
36*4882a593Smuzhiyun- regulator-always-on: regulator should never be disabled
37*4882a593Smuzhiyun- regulator-boot-on: enabled by bootloader/firmware
38*4882a593Smuzhiyun
39*4882a593SmuzhiyunNote
40*4882a593SmuzhiyunThe "regulator-name" constraint is used for setting the device's uclass
41*4882a593Smuzhiyunplatform data '.name' field. And the regulator device name is set from
42*4882a593Smuzhiyunit's node name. If "regulator-name" is not provided in dts, node name
43*4882a593Smuzhiyunis chosen for setting the device's uclass platform data '.name' field.
44*4882a593Smuzhiyun
45*4882a593SmuzhiyunOther kernel-style properties, are currently not used.
46*4882a593Smuzhiyun
47*4882a593SmuzhiyunNote:
48*4882a593SmuzhiyunFor the regulator autoset from constraints, the framework expects that:
49*4882a593Smuzhiyun- regulator-min-microvolt is equal to regulator-max-microvolt
50*4882a593Smuzhiyun- regulator-min-microamp is equal to regulator-max-microamp
51*4882a593Smuzhiyun- regulator-always-on or regulator-boot-on is set
52*4882a593Smuzhiyun
53*4882a593SmuzhiyunExample:
54*4882a593Smuzhiyunldo0 {
55*4882a593Smuzhiyun	/* Optional */
56*4882a593Smuzhiyun	regulator-name = "VDDQ_EMMC_1.8V";
57*4882a593Smuzhiyun	regulator-min-microvolt = <1800000>;
58*4882a593Smuzhiyun	regulator-max-microvolt = <1800000>;
59*4882a593Smuzhiyun	regulator-min-microamp = <100000>;
60*4882a593Smuzhiyun	regulator-max-microamp = <100000>;
61*4882a593Smuzhiyun	regulator-always-on;
62*4882a593Smuzhiyun	regulator-boot-on;
63*4882a593Smuzhiyun};
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