Support ROHM BD72720 PMIC

The ROHM BD72720 is a new PMIC with 10 BUCk and 11 LDO regulators.

The BD72720 is designed to support using the BUCK10 as a supply for the LDOs 1 to 4. When the BUCK10 is used for this, it can be set to a LDON_HEAD mode. In this mode, the BUCK10 voltage can't be controlled by software, but the voltage is adjusted by PMIC to match the LDO1 .. LDO4 voltages with a given offset. Offset can be 50mV .. 300mV and is changeable at 50mV steps.

Add 'ldon-head-millivolt' property to denote a board which is designed to utilize the LDON_HEAD mode.

All other properties are already existing.

Add dt-binding doc for ROHM BD72720 regulators to make it usable.

Signed-off-by Matti Vaittinen <[email protected]>

---
Revision history:
RFCv1 =>:
- No changes

---
 .../regulator/rohm,bd72720-regulator.yaml     | 153 ++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/rohm,bd72720-regulator.yaml

Documentation/devicetree/bindings/regulator/rohm,bd72720-regulator.yaml new file +25 -0

new file mode 100644
index 000000000000..665086f56928
@@ -0,0 +1,153 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/rohm,bd72720-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD72720 Power Management Integrated Circuit regulators
+
+maintainers:
+  - Matti Vaittinen <[email protected]>
+
+description: |
+  This module is part of the ROHM BD72720 MFD device. For more details
+  see Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml.
+
+  The regulator controller is represented as a sub-node of the PMIC node
+  on the device tree.
+
+  Regulator nodes should be named to BUCK_<number> and LDO_<number>.
+  The valid names for BD72720 regulator nodes are
+  buck1, buck2, buck3, buck4, buck5, buck6, buck7, buck8, buck9, buck10
+  ldo1, ldo2, ldo3, ldo4, ldo5, ldo6, ldo7, ldo8, ldo9, ldo10, ldo11
+
+patternProperties:
+  "^ldo[1-11]$":

Documentation/devicetree/bindings/regulator/rohm,bd72720-regulator.yaml new file +48 -0

+
+      rohm,dvs-run-voltage:
+        description:
+          PMIC default "RUN" state voltage in uV. See below table for
+          LDOs which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+      rohm,dvs-idle-voltage:
+        description:
+          PMIC default "IDLE" state voltage in uV. See below table for
+          LDOs which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+      rohm,dvs-suspend-voltage:
+        description:
+          PMIC default "SUSPEND" state voltage in uV. See below table for
+          LDOs which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+      rohm,dvs-lpsr-voltage:
+        description:
+          PMIC default "deep-idle" state voltage in uV. See below table for
+          LDOs which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+        # Supported default DVS states:
+        #     ldo        |    run     |   idle    | suspend   | lpsr
+        # --------------------------------------------------------------
+        # 1, 2, 3, and 4 | supported  | supported | supported | supported
+        # --------------------------------------------------------------
+        # 5 - 11         |                    supported (*)
+        # --------------------------------------------------------------
+        #
+        # (*) All states use same voltage but have own enable / disable
+        #      settings. Voltage 0 can be specified for a state to make
+        #      regulator disabled on that state.
+
+    unevaluatedProperties: false
+
+  "^buck[1-10]$":

Documentation/devicetree/bindings/regulator/rohm,bd72720-regulator.yaml new file +58 -0

+        description:
+          Set this on boards where BUCK10 is used to supply LDOs 1-4. The bucki
+          voltage will be changed by the PMIC to follow the LDO output voltages
+          with the offset voltage given here. This will improve the LDO efficiency.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 50
+        maximum: 300
+
+      rohm,dvs-run-voltage:
+        description:
+          PMIC default "RUN" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+      rohm,dvs-idle-voltage:
+        description:
+          PMIC default "IDLE" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+      rohm,dvs-suspend-voltage:
+        description:
+          PMIC default "SUSPEND" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+      rohm,dvs-lpsr-voltage:
+        description:
+          PMIC default "deep-idle" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 3300000
+
+        # Supported default DVS states:
+        #     buck       |    run     |   idle    | suspend   | lpsr
+        # --------------------------------------------------------------
+        # 1, 2, 3, and 4 | supported  | supported | supported | supported
+        # --------------------------------------------------------------
+        # 5 - 10    |                    supported (*)
+        # --------------------------------------------------------------
+        #
+        # (*) All states use same voltage but have own enable / disable
+        #      settings. Voltage 0 can be specified for a state to make
+        #      regulator disabled on that state.
+
+    required:
+      - regulator-name
+
+    unevaluatedProperties: false
+
+additionalProperties: false

Signature · 1 line

2.51.0

Some of the chargers for lithium-ion batteries use a trickle-charging as a first charging phase for very empty batteries, to "wake-up" the battery.

Trickle-charging is a low current, constant current phase. After the voltage of the very empty battery has reached an upper limit for trickle charging, the pre-charge phase is started with a higher current.

Allow defining the upper limit for trickle charging voltage, after which the charging should be changed to the pre-charging.

Signed-off-by Matti Vaittinen <[email protected]>

Reviewed-by Linus Walleij <[email protected]>

---
Revision history:
RFCv1 =>:
- No changes

---
 Documentation/devicetree/bindings/power/supply/battery.yaml | 3 +++
 1 file changed, 3 insertions(+)

Documentation/devicetree/bindings/power/supply/battery.yaml +0 -0

index 491488e7b970..66bed24b3dee 100644

Quoted 2 lines · Matti Vaittinen

Some of the chargers for lithium-ion batteries use a trickle-charging as a first charging phase for very empty batteries, to "wake-up" the battery.

In the few cases I was dealing with charging circuits, trickle charging was used in context of top-off charging, so when battery is 100%. It's also documented at Wiki like that:
https://en.wikipedia.org/wiki/Trickle_charging

Quoted 4 lines

Trickle-charging is a low current, constant current phase. After the voltage of the very empty battery has reached an upper limit for trickle charging, the pre-charge phase is started with a higher current.

Quoted 2 lines

Allow defining the upper limit for trickle charging voltage, after which the charging should be changed to the pre-charging.

pre-charging is the trickle charging, no? Or you want to say that trickle-charging is pre-pre-charging? But then what is pre-charging in this binding?

Quoted 13 lines · Krzysztof Kozlowski

Quoted 2 lines · Matti Vaittinen

Some of the chargers for lithium-ion batteries use a trickle-charging as a first charging phase for very empty batteries, to "wake-up" the battery.

In the few cases I was dealing with charging circuits, trickle charging was used in context of top-off charging, so when battery is 100%. It's also documented at Wiki like that:
https://en.wikipedia.org/wiki/Trickle_charging

Quoted 4 lines

Trickle-charging is a low current, constant current phase. After the voltage of the very empty battery has reached an upper limit for trickle charging, the pre-charge phase is started with a higher current.

Quoted 6 lines

Quoted 2 lines

Allow defining the upper limit for trickle charging voltage, after which the charging should be changed to the pre-charging.

pre-charging is the trickle charging, no? Or you want to say that trickle-charging is pre-pre-charging? But then what is pre-charging in this binding?

Now I see that you added initial trickle-charging in commit e3420b49949c79d6182dd8128fa7a3958da01b07. I looked at TI chargers for LiIon/LiPo batteries and few popular models use the same meaning/cycles as you here. Probably in LiIon/LiPo you cannot or should not use trickle for top-off charging (CV phase).

For NiMh these TI chargers use term "Trickle Maintenance Charge" (e.g. bq24400), so in separate or this patch please also clarify the description of properties that this is trickle-charging for LiIon/LiPo batteries, so the pre-pre charging.

Best regards,
Krzysztof

Quoted 2 lines · Matti Vaittinen

Some of the chargers for lithium-ion batteries use a trickle-charging as a first charging phase for very empty batteries, to "wake-up" the battery.

In the few cases I was dealing with charging circuits, trickle charging was used in context of top-off charging, so when battery is 100%. It's also documented at Wiki like that:
https://en.wikipedia.org/wiki/Trickle_charging

Quoted 4 lines

Trickle-charging is a low current, constant current phase. After the voltage of the very empty battery has reached an upper limit for trickle charging, the pre-charge phase is started with a higher current.

Quoted 2 lines

Allow defining the upper limit for trickle charging voltage, after which the charging should be changed to the pre-charging.

pre-charging is the trickle charging, no? Or you want to say that trickle-charging is pre-pre-charging? But then what is pre-charging in this binding?

Quoted 21 lines

Signed-off-by Matti Vaittinen <[email protected]>

Reviewed-by Linus Walleij <[email protected]>

---
Revision history:
RFCv1 =>:
- No changes

---
  Documentation/devicetree/bindings/power/supply/battery.yaml | 3 +++
  1 file changed, 3 insertions(+)

Documentation/devicetree/bindings/power/supply/battery.yaml +0 -0

index 491488e7b970..66bed24b3dee 100644
@@ -66,6 +66,9 @@ properties:
    trickle-charge-current-microamp:
      description: current for trickle-charge phase
 

Documentation/devicetree/bindings/power/supply/battery.yaml properties: · line 69

Quoted 1 line

Documentation/devicetree/bindings/power/supply/battery.yaml +1 -0

+  tricklecharge-upper-limit-microvolt:

Please keep existing format, look three lines above. trickle-charge-....

But I believe this is wrong. Trickle charging does not switch to anything more, there is no fast charging after trickle. You have some sort of pre-pre-charging, which is just pre-charging.

Quoted 4 lines · Matti Vaittinen

Quoted 2 lines

Some of the chargers for lithium-ion batteries use a trickle-charging as a first charging phase for very empty batteries, to "wake-up" the battery.

This is already reflected by existing bindings:
trickle-charge-current-microamp, Please, see:
bbcecd1b9335 ("dt-bindings: Add trickle-charge upper limit")

Quoted 3 lines

But I believe this is wrong. Trickle charging does not switch to anything more, there is no fast charging after trickle. You have some sort of pre-pre-charging, which is just pre-charging.

There is trickle, pre and fast-charge phases. Furthermore, the fast-charge is further divided to CC and CV. Finally, if my memory serves me well, Linus W did explain me that some chargers use 'trickle-charging' as a _last_ charging phase for a full battery. Thus the term 'trickle-charging' is slightly confusing - but it is already used by the existing bindings...

https://lore.kernel.org/all/[email protected]/

Quoted 4 lines · Matti Vaittinen

Quoted 3 lines

But I believe this is wrong. Trickle charging does not switch to anything more, there is no fast charging after trickle. You have some sort of pre-pre-charging, which is just pre-charging.

Quoted 8 lines

There is trickle, pre and fast-charge phases. Furthermore, the fast-charge is further divided to CC and CV. Finally, if my memory serves me well, Linus W did explain me that some chargers use 'trickle-charging' as a _last_ charging phase for a full battery. Thus the term 'trickle-charging' is slightly confusing - but it is already used by the existing bindings...

https://lore.kernel.org/all/[email protected]/

I think we need to refer to a textbook or IEEE articles to get this terminology right.

As you say it appears "trickle-charging" is ambiguous.

Maybe what Krzysztof suggest to use: "pre-pre-charging" or "empty-battery-charging" or something like this is needed.

But we really need a trustworthy academic source here.

The BD72720 PMIC has a battery charger + coulomb counter block. These can be used to manage charging of a lithium-ion battery and to do fuel gauging.

ROHM has developed a so called "zero-correction" -algorithm to improve the fuel-gauging accuracy close to the point where battery is depleted. This relies on battery specific "VDR" tables, which are measured from the battery, and which describe the voltage drop rate. More thorough explanation about the "zero correction" and "VDR" parameters is here:
https://lore.kernel.org/all/[email protected]/

Document the VDR zero-correction specific battery properties used by the BD72720 and some other ROHM chargers.

Signed-off-by Matti Vaittinen <[email protected]>

---
Revision history:
RFCv1 => v2:
- Add units to rohm,volt-drop-soc (tenths of %)
- Give real temperatures matching the VDR tables, instead of vague 'high', 'normal', 'low', 'very low'. (Add table of temperatures and use number matching the right temperature index in the VDR table name).
- Fix typoed 'algorithm' in commit message.

The parameters are describing the battery voltage drop rates - so they are properties of the battery, not the charger. Thus they do not belong in the charger node.

The right place for them is the battery node, which is described by the generic "battery.yaml". I was not comfortable with adding these properties to the generic battery.yaml because they are:
- Meaningful only for those charger drivers which have the VDR algorithm implemented. (And even though the algorithm is not charger specific, AFAICS, it is currently only used by some ROHM PMIC drivers).
- Technique of measuring the VDR tables for a battery is not widely known. AFAICS, only folks at ROHM are measuring those for some customer products. We do have those tables available for some of the products though (Kobo?).

---
 .../power/supply/rohm,vdr-battery.yaml        | 80 +++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/supply/rohm,vdr-battery.yaml

Documentation/devicetree/bindings/power/supply/rohm,vdr-battery.yaml new file +10 -0

new file mode 100644
index 000000000000..1ab3418d4338
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/rohm,vdr-battery.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Battery managed by the BD72720 PMIC
+
+maintainers:
+  - Matti Vaittinen <[email protected]>

Documentation/devicetree/bindings/power/supply/rohm,vdr-battery.yaml new file +56 -0

+    $ref: /schemas/types.yaml#/definitions/uint32-array
+
+  rohm,volt-drop-temperatures-millicelsius:
+    description: An array containing the temperature in milli celsius, for each
+      of the VDR lookup table.
+
+patternProperties:
+  '^rohm,volt-drop-[0-9]-microvolt':
+    description: Table of the voltage drop rate (VDR) values. Each entry in the
+      table should match a capacity value in the rohm,volt-drop-soc table.
+      Furthermore, the values should be obtained for the temperature given in
+      rohm,volt-drop-temperatures-millicelsius table at index matching the
+      number in this table's name.
+
+additionalProperties: false
+
+examples:
+  - |
+    power {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      battery: battery {
+        compatible = "simple-battery";
+
+        ocv-capacity-celsius = <25>;
+        ocv-capacity-table-0 = <4200000 100 4184314 100 4140723 95 4099487 90
+          4060656 85 4024350 80 3991121 75 3954379 70 3913265 65 3877821 60
+          3855577 55 3837466 50 3822194 45 3809012 40 3795984 35 3780647 30
+          3760505 25 3741532 20 3718837 15 3696698 10 3690594 5 3581427 0>;
+
+        rohm,volt-drop-soc = <1000 1000 950 900 850 800 750 700 650 600 550 500
+          450 400 350 300 250 200 150 100 50 00 (-50)>;
+
+        rohm,volt-drop-temperatures-millicelsius = <45000 25000 5000 0>;
+
+        rohm,volt-drop-0-microvolt =  <100 100 102 104 106 109 114 124
+          117 107 107 109 112 116 117 108 109 109 108 109 122 126 130>;
+
+        rohm,volt-drop-1-microvolt = <100 100 102 105 98 100 105 102
+          101 99 98 100 103 105 109 117 111 109 110 114 128 141 154>;
+
+        rohm,volt-drop-2-microvolt = <100 100 98 107 112 114 118 118 112
+          108 108 110 111 113 117 123 131 144 157 181 220 283 399>;
+
+        rohm,volt-drop-3-temp-microvolt = <86 86 105 109 114 110 115 115
+          110 108 110 112 114 118 124 134 136 160 177 201 241 322 403>;
+
+        rohm,voltage-vdr-thresh-microvolt = <4150000>;
+
+        charge-full-design-microamp-hours = <1799000>;
+        voltage-max-design-microvolt = <4200000>;
+        voltage-min-design-microvolt = <3500000>;
+        degrade-cycle-microamp-hours = <131>;
+      };
+    };

Signature · 1 line

2.51.0

The BD72720 PMIC has a battery charger + coulomb counter block. These can be used to manage charging of a lithium-ion battery and to do fuel gauging.

ROHM has developed a so called "zero-correction" -algorithm to improve the fuel-gauging accuracy close to the point where battery is depleted. This relies on battery specific "VDR" tables, which are measured from the battery, and which describe the voltage drop rate. More thorough explanation about the "zero correction" and "VDR" parameters is here:
https://lore.kernel.org/all/[email protected]/

Document the VDR zero-correction specific battery properties used by the BD72720 and some other ROHM chargers.

Signed-off-by Matti Vaittinen <[email protected]>

The ROHM BD72720 is a power management IC integrating regulators, GPIOs, charger, LEDs, RTC and a clock gate.

Add dt-binding doc for ROHM BD72720.

Signed-off-by Matti Vaittinen <[email protected]>

---
Revision history:
RFCv1 => v2:
- Typofixes

---
 .../bindings/mfd/rohm,bd72720-pmic.yaml       | 269 ++++++++++++++++++
 1 file changed, 269 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +10 -0

new file mode 100644
index 000000000000..b0d4bc01d199
@@ -0,0 +1,269 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/rohm,bd72720-pmic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD72720 Power Management Integrated Circuit
+
+maintainers:
+  - Matti Vaittinen <[email protected]>

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +34 -0

+#
+# Following properties are used
+# when present:
+#
+# charge-full-design-microamp-hours: Battry capacity in mAh
+# voltage-max-design-microvolt:      Maximum voltage
+# voltage-min-design-microvolt:      Minimum voltage system is still operating.
+# degrade-cycle-microamp-hours:      Capacity lost due to aging at each full
+#                                    charge cycle.
+# ocv-capacity-celsius:              Array of OCV table temperatures. 1/table.
+# ocv-capacity-table-<N>:            Table of OCV voltage/SOC pairs. Corresponds
+#                                    N.th temperature in ocv-capacity-celsius
+#
+# ROHM specific properties:
+# rohm,voltage-vdr-thresh-microvolt: Threshold for starting the VDR correction
+# rohm,volt-drop-soc:                Table of capacity values matching the
+#                                    values in VDR tables.
+# rohm,volt-drop-high-temp-microvolt: VDR table for high temperature
+# rohm,volt-drop-normal-temp-microvolt: VDR table for normal temperature
+# rohm,volt-drop-low-temp-microvolt:  VDR table for low temperature
+# rohm,volt-drop-very-low-temp-microvolt: VDR table for very low temperature
+#
+# VDR tables are (usually) determined for a specific battery by ROHM.
+# The battery node would then be referred from the charger node:
+#
+# monitored-battery = <&battery>;
+
+properties:
+  compatible:
+    const: rohm,bd72720
+
+  reg:
+    description:
+      I2C slave address.

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +4 -0

+
+  clocks:
+    maxItems: 1
+

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +13 -0

+
+  rohm,pin-dvs0:
+    $ref: /schemas/types.yaml#/definitions/string
+    description:
+      BD72720 has 4 different OTP options to determine the use of dvs0-pin.
+      OTP0 - regulator RUN state control.
+      OTP1 - GPI.
+      OTP2 - GPO.
+      OTP3 - Power sequencer output.
+      This property specifies the use of the pin.
+    enum:
+      - dvs-input
+      - gpi

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +13 -0

+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - "#clock-cells"
+  - regulators
+  - gpio-controller
+  - "#gpio-cells"
+
+additionalProperties: false
+

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +107 -0

+
+            interrupt-parent = <&gpio1>;
+            interrupts = <29 IRQ_TYPE_LEVEL_LOW>;
+
+            clocks = <&osc 0>;
+            #clock-cells = <0>;
+            clock-output-names = "bd71828-32k-out";
+
+            gpio-controller;
+            #gpio-cells = <2>;
+            gpio-reserved-ranges = <0 1>, <2 1>;
+
+            rohm,charger-sense-resistor-ohms = <10000000>;
+
+            regulators {
+                buck1: BUCK1 {
+                    regulator-name = "buck1";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <2000000>;
+                    regulator-ramp-delay = <2500>;
+                };
+                buck2: BUCK2 {
+                    regulator-name = "buck2";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <2000000>;
+                    regulator-ramp-delay = <2500>;
+                };
+                buck3: BUCK3 {
+                    regulator-name = "buck3";
+                    regulator-min-microvolt = <1200000>;
+                    regulator-max-microvolt = <2000000>;
+                };
+                buck4: BUCK4 {
+                    regulator-name = "buck4";
+                    regulator-min-microvolt = <1000000>;
+                    regulator-max-microvolt = <1800000>;
+                };
+                buck5: BUCK5 {
+                    regulator-name = "buck5";
+                    regulator-min-microvolt = <2500000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+                buck6: BUCK6 {
+                    regulator-name = "buck6";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <2000000>;
+                    regulator-ramp-delay = <2500>;
+                };
+                buck7: BUCK7 {
+                    regulator-name = "buck7";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <2000000>;
+                    regulator-ramp-delay = <2500>;
+                };
+                ldo1: LDO1 {
+                    regulator-name = "ldo1";
+                    regulator-min-microvolt = <800000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+                ldo2: LDO2 {
+                    regulator-name = "ldo2";
+                    regulator-min-microvolt = <800000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+                ldo3: LDO3 {
+                    regulator-name = "ldo3";
+                    regulator-min-microvolt = <800000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+                ldo4: LDO4 {
+                    regulator-name = "ldo4";
+                    regulator-min-microvolt = <800000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+                ldo5: LDO5 {
+                    regulator-name = "ldo5";
+                    regulator-min-microvolt = <800000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+                ldo6: LDO6 {
+                    regulator-name = "ldo6";
+                    regulator-min-microvolt = <1800000>;
+                    regulator-max-microvolt = <1800000>;
+                };
+                ldo7_reg: LDO7 {
+                    regulator-name = "ldo7";
+                    regulator-min-microvolt = <800000>;
+                    regulator-max-microvolt = <3300000>;
+                };
+            };
+
+            leds {
+                compatible = "rohm,bd71828-leds";
+
+                led-1 {
+                    rohm,led-compatible = "bd71828-grnled";
+                    function = LED_FUNCTION_INDICATOR;
+                    color = <LED_COLOR_ID_GREEN>;
+                };
+                led-2 {
+                    rohm,led-compatible = "bd71828-ambled";
+                    function = LED_FUNCTION_CHARGING;
+                    color = <LED_COLOR_ID_AMBER>;
+                };
+            };
+        };
+    };

Signature · 1 line

2.51.0

Quoted 36 lines · Matti Vaittinen

The ROHM BD72720 is a power management IC integrating regulators, GPIOs, charger, LEDs, RTC and a clock gate.

Add dt-binding doc for ROHM BD72720.

Signed-off-by Matti Vaittinen <[email protected]>

---
Revision history:
RFCv1 => v2:
- Typofixes

---
  .../bindings/mfd/rohm,bd72720-pmic.yaml       | 269 ++++++++++++++++++
  1 file changed, 269 insertions(+)

create mode 100644 Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +14 -0

new file mode 100644
index 000000000000..b0d4bc01d199
@@ -0,0 +1,269 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/rohm,bd72720-pmic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD72720 Power Management Integrated Circuit
+
+maintainers:
+  - Matti Vaittinen <[email protected]>
+
+description: |
+  BD72720 is a single-chip power management IC for battery-powered portable
+  devices. The BD72720 integrates 10 bucks and 11 LDOs, and a 3000 mA

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 20

Quoted 6 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +6 -0

+  switching charger. The IC also includes a Coulomb counter, a real-time
+  clock (RTC), GPIOs and a 32.768 kHz clock gate.
+
+# In addition to the properties found from the charger node, the ROHM BD72720
+# uses properties from a static battery node. Please see the:
+# Documentation/devicetree/bindings/power/supply/rohm,vdr-battery.yaml

Why is all of this a comment?

Quoted 37 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +36 -0

+#
+# Following properties are used
+# when present:
+#
+# charge-full-design-microamp-hours: Battry capacity in mAh
+# voltage-max-design-microvolt:      Maximum voltage
+# voltage-min-design-microvolt:      Minimum voltage system is still operating.
+# degrade-cycle-microamp-hours:      Capacity lost due to aging at each full
+#                                    charge cycle.
+# ocv-capacity-celsius:              Array of OCV table temperatures. 1/table.
+# ocv-capacity-table-<N>:            Table of OCV voltage/SOC pairs. Corresponds
+#                                    N.th temperature in ocv-capacity-celsius
+#
+# ROHM specific properties:
+# rohm,voltage-vdr-thresh-microvolt: Threshold for starting the VDR correction
+# rohm,volt-drop-soc:                Table of capacity values matching the
+#                                    values in VDR tables.
+# rohm,volt-drop-high-temp-microvolt: VDR table for high temperature
+# rohm,volt-drop-normal-temp-microvolt: VDR table for normal temperature
+# rohm,volt-drop-low-temp-microvolt:  VDR table for low temperature
+# rohm,volt-drop-very-low-temp-microvolt: VDR table for very low temperature
+#
+# VDR tables are (usually) determined for a specific battery by ROHM.
+# The battery node would then be referred from the charger node:
+#
+# monitored-battery = <&battery>;
+
+properties:
+  compatible:
+    const: rohm,bd72720
+
+  reg:
+    description:
+      I2C slave address.
+    maxItems: 1
+

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 64

Quoted 8 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +8 -0

+  interrupts:
+    maxItems: 1
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+    description: |

Quoted 13 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +13 -0

+
+  rohm,pin-dvs0:
+    $ref: /schemas/types.yaml#/definitions/string
+    description:
+      BD72720 has 4 different OTP options to determine the use of dvs0-pin.
+      OTP0 - regulator RUN state control.
+      OTP1 - GPI.
+      OTP2 - GPO.
+      OTP3 - Power sequencer output.
+      This property specifies the use of the pin.
+    enum:
+      - dvs-input
+      - gpi

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 121

Quoted 10 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +10 -0

+      - gpo
+
+  rohm,pin-dvs1:
+    $ref: /schemas/types.yaml#/definitions/string
+    description:
+      see rohm,pin-dvs0
+    enum:
+      - dvs-input
+      - gpi
+      - gpo

These 2 could be combined into a single entry in patternProperties.

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 133

Quoted 12 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +12 -0

+
+  rohm,pin-exten0:
+    $ref: /schemas/types.yaml#/definitions/string
+    description: BD72720 has an OTP option to use exten0-pin for different
+      purposes. Set this property accordingly.
+    const: gpo
+
+  rohm,pin-exten1:
+    $ref: /schemas/types.yaml#/definitions/string
+    description: BD72720 has an OTP option to use exten1-pin for different
+      purposes. Set this property accordingly.
+    const: gpo

And these 2 also.

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 139

Quoted 6 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +6 -0

+
+  rohm,pin-fault_b:
+    $ref: /schemas/types.yaml#/definitions/string
+    description: BD72720 has an OTP option to use fault_b-pin for different
+      purposes. Set this property accordingly.
+    const: gpo

Seems like different purposes would have more than 1 option.

Quoted 18 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +17 -0

+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - "#clock-cells"
+  - regulators
+  - gpio-controller
+  - "#gpio-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/leds/common.h>

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 162

Quoted 6 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +6 -0

+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        pmic: pmic@4b {
+            compatible = "rohm,bd71828";
+            reg = <0x4b>;

Just 1 complete example in the mfd schema and drop this example.

The ROHM BD72720 is a power management IC integrating regulators, GPIOs, charger, LEDs, RTC and a clock gate.

Add dt-binding doc for ROHM BD72720.

Signed-off-by Matti Vaittinen <[email protected]>

Quoted 7 lines · On Mon, 27 Oct 2025 13:45:46 +0200 Matti Vaittinen <[email protected]>…

The ROHM BD72720 is a power management IC integrating regulators, GPIOs, charger, LEDs, RTC and a clock gate.

Add dt-binding doc for ROHM BD72720.

Signed-off-by Matti Vaittinen <[email protected]>

[...]

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 91

Quoted 10 lines

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +10 -0

+
+  rohm,charger-sense-resistor-milli-ohms:
+    minimum: 10
+    maximum: 50
+    description: |
+      BD72720 has a SAR ADC for measuring charging currents. External sense
+      resistor (RSENSE in data sheet) should be used. If some other but
+      30 mOhm resistor is used the resistance value should be given here in
+      milli Ohms.
+

rohm,bd71828.yaml has rohm,charger-sense-resistor-micro-ohms, lets keep that unified.

+examples:

Hi Matti,

thanks for your patch!

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 81

Quoted 5 lines · Matti Vaittinen

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +5 -0

+  rohm,clkout-open-drain:
+    description: clk32kout mode. Set to 1 for "open-drain" or 0 for "cmos".
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 1

I think CMOS is the same as "push-pull" ( I could be wrong, but I think I've seen that before) so I would probably try to use the pin config standard names as strings here but I'm not sure.

rohm,clkout-bias-open-drain;
rohm,clkout-bias-push-pull;

Mutually exclusive.

Or maybe use the pattern from rohm,pin-dvs0
with string enumerators?

rohm,clkout-bias = "open-drain";
rohm,clkout-bias = "push-pull";

Quoted 20 lines · Linus Walleij

Hi Matti,

thanks for your patch!

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml line 81

Quoted 5 lines · Matti Vaittinen

Documentation/devicetree/bindings/mfd/rohm,bd72720-pmic.yaml new file +5 -0

+  rohm,clkout-open-drain:
+    description: clk32kout mode. Set to 1 for "open-drain" or 0 for "cmos".
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 1

I think CMOS is the same as "push-pull" ( I could be wrong, but I think I've seen that before) so I would probably try to use the pin config standard names as strings here but I'm not sure.

rohm,clkout-bias-open-drain;
rohm,clkout-bias-push-pull;

Quoted 8 lines

Mutually exclusive.

Or maybe use the pattern from rohm,pin-dvs0
with string enumerators?

rohm,clkout-bias = "open-drain";
rohm,clkout-bias = "push-pull";

Hmm. I kind of agree with you. Still, the way it was done in this patch is used by the other existing ROHM PMICs (bd71815, bd71828, bd71879). I am kind of reluctant to support another way in the same driver - and I am also reluctant to change the existing bindings as that sounds a bit like asking for a nose-bleed :) (I've in the past worked with some devices which didn't update the device-trees when kernel was updated...)

Do you think you could live with using this existing convention? :)

Add the ROHM BD72720 documentation to the binding documents.

Signed-off-by Matti Vaittinen <[email protected]>

---

The new ROHM BD72720 PMIC has similarities with the BD71828. It makes sense to support the regulator control for both PMICs using the same driver. It is often more clear to have the IC specific functions and globals named starting with the chip-name. So, as a preparatory step, prefix the BD71828 specific functions and globals with the bd71828.

ROHM BD72720 is a power management IC which integrates 10 buck and 11 LDO regulators. This PMIC has plenty of commonalities with the BD71828 and BD71879.

The BD72720 has similar RTC block as a few other ROHM PMICs.

Add support for BD72720 RTC.

Signed-off-by Matti Vaittinen <[email protected]>

---
Revision history:
RFCv1 =>:
- No changes

---
 drivers/rtc/Kconfig       |  3 ++-
 drivers/rtc/rtc-bd70528.c | 21 ++++++++++++++-------
 2 files changed, 16 insertions(+), 8 deletions(-)

drivers/rtc/Kconfig +2 -1

index 2933c41c77c8..418f6c28847a 100644
@@ -561,7 +561,8 @@ config RTC_DRV_BD70528
 	depends on MFD_ROHM_BD71828
 	help
 	  If you say Y here you will get support for the RTC
-	  block on ROHM BD71815 and BD71828 Power Management IC.
+	  block on ROHM BD71815, BD71828 and BD72720 Power
+	  Management ICs.
 
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-bd70528.

drivers/rtc/rtc-bd70528.c +14 -7

index 954ac4ef53e8..4c8599761b2e 100644
@@ -7,6 +7,7 @@
 #include <linux/bcd.h>
 #include <linux/mfd/rohm-bd71815.h>
 #include <linux/mfd/rohm-bd71828.h>
+#include <linux/mfd/rohm-bd72720.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>

@@ -262,13 +263,13 @@ static int bd70528_probe(struct platform_device *pdev)
 
 		/*
 		 * See also BD718XX_ALM_EN_OFFSET:
-		 * This works for BD71828 and BD71815 as they have same offset
-		 * between ALM0 start and ALM0_MASK. If new ICs are to be
-		 * added this requires proper check as ALM0_MASK is not located
-		 * at the end of ALM0 block - but after all ALM blocks so if
-		 * amount of ALMs differ the offset to enable/disable is likely
-		 * to be incorrect and enable/disable must be given as own
-		 * reg address here.
+		 * This works for BD71828, BD71815, and BD72720 as they all
+		 * have same offset between the ALM0 start and the ALM0_MASK.
+		 * If new ICs are to be added this requires proper check as
+		 * the  ALM0_MASK is not located at the end of ALM0 block -
+		 * but after all ALM blocks. If amount of ALMs differ, the
+		 * offset to enable/disable is likely to be incorrect and
+		 * enable/disable must be given as own reg address here.
 		 */
 		bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START;
 		hour_reg = BD71815_REG_HOUR;

@@ -278,6 +279,11 @@ static int bd70528_probe(struct platform_device *pdev)
 		bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START;
 		hour_reg = BD71828_REG_RTC_HOUR;
 		break;
+	case ROHM_CHIP_TYPE_BD72720:
+		bd_rtc->reg_time_start = BD72720_REG_RTC_START;
+		bd_rtc->bd718xx_alm_block_start = BD72720_REG_RTC_ALM_START;
+		hour_reg = BD72720_REG_RTC_HOUR;
+		break;
 	default:
 		dev_err(&pdev->dev, "Unknown chip\n");
 		return -ENOENT;

@@ -337,6 +343,7 @@ static int bd70528_probe(struct platform_device *pdev)
 static const struct platform_device_id bd718x7_rtc_id[] = {
 	{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
 	{ "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
+	{ "bd72720-rtc", ROHM_CHIP_TYPE_BD72720 },
 	{ },
 };
 MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);

Signature · 1 line

2.51.0

Quoted 4 lines · Matti Vaittinen

The BD72720 has similar RTC block as a few other ROHM PMICs.

Add support for BD72720 RTC.

Quoted 2 lines

Signed-off-by Matti Vaittinen <[email protected]>

Acked-by Alexandre Belloni <[email protected]>

Note that we didn't get 07/15 that adds linux/mfd/rohm-bd72720.h which this patch depends on.

The ROHM BD72720 is a new power management IC for portable, battery powered devices. It integrates 10 BUCKs and 11 LDOs, RTC, charger, LEDs, GPIOs and a clock gate. To me the BD72720 seems like a successor to the BD71828 and BD71815 PMICs.

This series depends on the series: "[PATCH v5 0/3] power: supply: add charger for BD71828":
https://lore.kernel.org/all/[email protected]/
sent by Andreas. The power-supplly and MAINTAINERs patches (2/3 and 3/3) from that serties aren't merged yet.

Revision history:
RFCv1 => v2:
- Drop RFC status
- Use stacked regmaps to hide secondary map from the sub-drivers
- Quite a few styling fixes and improvements as suggested by reviewers. More accurate changelog in individual patches.
- Link to v1:

     https://lore.kernel.org/all/[email protected]/