[U-Boot] [PATCH v2 1/2] core: add uclass_get_device_by_phandle_id() api

[Kever Yang]

Hi Simon,


On 02/25/2018 11:54 PM, Simon Glass wrote:
> Hi Kever,
>
> On 23 February 2018 at 19:08, Kever Yang <kever.yang at rock-chips.com> wrote:
>> Hi Simon,
>>
>>
>> On 02/12/2018 10:35 PM, Simon Glass wrote:
>>> Hi Kever,
>>>
>>> On 8 February 2018 at 19:56, Kever Yang <kever.yang at rock-chips.com> wrote:
>>>> Add api for who can not get phandle from a device property.
>>> Can you please add a motivation to the commit message? It is not
>>> obvious to me when this function would be used.
>> Here is the example why I need this, see the dts node here:
>> lvds at ff2e0000 {
>>     ...
>>     rockchip,grf = <&grf>;
>>     port {
>>         port at 0 {
>>             endpoint at 0 {
>>                 remote-endpoint = <&vopl_out_lvds>;
>>             }
>>         }
>>     }
>> }
>>
>> We can only get 'grf' udevice by uclass_get_device_by_phandle(),
>> but we not able to get udevice 'vopl_out_lvds', other driver like
>> rockchip pinctrl
>> also need to get udevice by a phandle which is not one of direct property of
>> another device node.
> OK I see. This sort of info is useful in the commit message. It helps
> to know two things about a patch:
>
> - why it is needed
> - what it does
>
> In this case see rk_display_init() for how it handles the
> 'remote-endpoint' property. I think it would be better to have
> something like:
>
> ofnode ofnode_lookup_phandle(ofnode node, const char *prop_name);
Yes, this is enough for "remote-endpoint" case, but not for pinctrl case:
1199         pinctrl: pinctrl {
2095                 pwm0
{                                                         
2096                         pwm0_pin: pwm0-pin
{                                   
2097                                 rockchip,pins
=                                
2098                                         <0 RK_PB7 RK_FUNC_1
&pcfg_pull_none>;  
2099                        
};                                                     
2100                 };    

    I think ofnode_lookup_phandle() still not able to find node for
'pcfg_pull_none'.

Thanks,
- Kever
>
> This should meet your needs without needing to decoding the phandle
> property in the caller.
>
> Regards,
> Simon
>