Re: [RFC PATCH 0/4] power_supply: Add DT helper function to get power-supply dev from dt

From: Chanwoo Choi
Date: Tue Mar 18 2014 - 02:06:23 EST

Hi Sebastian,

On 03/18/2014 09:38 AM, sre@xxxxxxxx wrote:
> Hi,
> On Mon, Mar 17, 2014 at 09:43:43PM +0900, Chanwoo Choi wrote:
>> This patchset add DT helper function to get power-supply device from devicetree.
>> - of_power_supply_get_dev(struct device *dev, enum power_supply_dev_type type,
>> int index)
>> Power-supply class provides 'power_supply_get_by_name()' to users who want to
>> find power-supply device with the name of power-supply device.
>> If CONFIG_OF is enabled, device drivers which want to get power-supply device
>> would directly get the power-supply device from devicetree by using of_power_
>> supply_get_dev(). This function can be used instead of power_supply_get_by_name().
>> For example,
>> [...]
> include/linux/power_supply.h provides the following function already:
> struct power_supply *
> power_supply_get_by_phandle(struct device_node *np, const char *property);

I checked power_supply_get_by_phandle().
But power_supply_get_by_phandle() is different from of_power_supply_get_dev()

So, I expalin the difference between "power_supply_get_by_phandle()" and "of_power_supply_get_dev()".

Existing "power_supply_get_by_phandle()"
- Need correct the name of power_supply property.
some device driver using power_supply_get_by_phandle() has the dependecy of
the name of power_supply property.

If the name of power_supply property is modified,
have to modify some device driver using power_supply_get_by_phandle().

Proposed "of_power_supply_get_dev()"
- of_power_supply_get_dev() has not dependency of specific name.
of_power_supply_get_dev() only need device type of power_supply device among following device type:
we can do addtional device type of power_supply device.

If some device driver use of_poewr_supply_get_dev(),
don't need to consider the name of power_supply device.

Chanwoo Choi

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