Re: [PATCH v6 3/3] mfd: max14577: Add device tree bindings document

[Chanwoo Choi <cw00.choi@samsung.com>]

On 12/04/2013 07:56 PM, Krzysztof Kozlowski wrote:
> On Wed, 2013-12-04 at 19:50 +0900, Chanwoo Choi wrote:
>> Hi Krzysztof,
>>
>> On 12/04/2013 07:40 PM, Krzysztof Kozlowski wrote:
>>> Add document describing device tree bindings for MAX14577 MFD driver.
>>>
>>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>>> ---
>>>  Documentation/devicetree/bindings/mfd/max14577.txt |   48 ++++++++++++++++++++
>>>  1 file changed, 48 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/mfd/max14577.txt
>>>
>>> diff --git a/Documentation/devicetree/bindings/mfd/max14577.txt b/Documentation/devicetree/bindings/mfd/max14577.txt
>>> new file mode 100644
>>> index 000000000000..f4fd16360b6b
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/mfd/max14577.txt
>>> @@ -0,0 +1,48 @@
>>> +MAXIM MAX14577 multi-function device
>>> +
>>> +MAX14577 is a Multi-function device with Micro-USB Interface Circuit, Li+
>>> +Battery Charger and SFOUT LDO output for powering USB devices. It is
>>> +interfaced to host controller using I2C.
>>> +
>>> +Required properties:
>>> +- compatible : Must be "maxim,max14577".
>>> +- reg : I2C slave address for the max14577 chip.
>>> +- interrupts : IRQ line for the max14577 chip.
>>> +- interrupt-parent :  The parent interrupt controller.
>>> +
>>> +Optional nodes:
>>> +- regulators :
>>> +  Required child node properties:
>>> +  - compatible : "maxim,max14577-regulator"
>>> +
>>> +  Optional child nodes:
>>> +    Each child node representing a regulator, following standard regulator
>>> +    bindings. Valid names for a regulator are: "CHARGER" and "SAFEOUT".
>>> +    The SAFEOUT is a constant voltage regulator so there is no need to specify
>>> +    voltages for it.
>>> +
>>> +	[*] refer Documentation/devicetree/bindings/regulator/regulator.txt
>>> +
>>> +Example:
>>> +	max14577@25 {
>>> +		compatible = "maxim,max14577";
>>> +		reg = <0x25>;
>>> +		interrupt-parent = <&gpx1>;
>>> +		interrupts = <5 0>;
>>> +
>>> +		regulators {
>>> +			compatible = "maxim,max14577-regulator";
>>> +
>>> +			safeout_reg: safeout@1 {
>>> +				regulator-compatible = "SAFEOUT";
>>> +				regulator-name = "SAFEOUT";
>>> +			};
>>> +			charger_reg: charger@0 {
>>> +				regulator-compatible = "CHARGER";
>>> +				regulator-name = "CHARGER";
>>> +				regulator-min-microamp = <90000>;
>>> +				regulator-max-microamp = <950000>;
>>> +				regulator-boot-on;
>>> +			};
>>> +		};
>>
>> I prefer to add dt data about max14577-muic on following:
>> If extcon consumer driver need to use muic device, dts should provide following dt data.
>>
>> 		muic: max14577-muic {
>> 			compatible = "maxim, max14577-muic";
>> 		};
>>> +	};
>>>
>> For example,
>> If fuel-gauge want to use extcon subsystem, dt data of fuel-gauge add 'extcon' property as following:
>>
>> 	fuel-gague@ {
>> 		compatible = "...";
>> 		extcon = <&muic>;
>> 	}
>>
> Hi,
> 
> The extcon driver itself does not use the binding. It is only needed for
> consumers. Is it a common practice to add to documentation such notice
> for consumers only?

As you comment, It is only for extcon consumer.
But extcon provider driver always is operated with extcon consumer driver.
If dts file don't support upper dt data about extcon provider driver,
all of extcon consumer drivers could not use extcon subsystem.

I thinks it is common dt data for muic device.

Thanks,
Chanwoo Choi