[U-Boot] [PATCH v2 3/3] common: Generic loader for file system

[Marek Vasut]

On 06/07/2018 11:45 AM, Chee, Tien Fong wrote:
> On Thu, 2018-06-07 at 10:41 +0200, Marek Vasut wrote:
>> On 06/07/2018 10:36 AM, Chee, Tien Fong wrote:
>>>
>>> On Thu, 2018-06-07 at 08:51 +0200, Marek Vasut wrote:
>>>>
>>>> On 06/07/2018 06:04 AM, Chee, Tien Fong wrote:
>>>>>
>>>>>
>>>>> On Wed, 2018-06-06 at 10:39 +0200, Marek Vasut wrote:
>>>>>>
>>>>>>
>>>>>> On 05/24/2018 07:04 AM, tien.fong.chee at intel.com wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> From: Tien Fong Chee <tien.fong.chee at intel.com>
>>>>>>>
>>>>>>> This is file system generic loader which can be used to
>>>>>>> load
>>>>>>> the file image from the storage into target such as memory.
>>>>>>> The consumer driver would then use this loader to program
>>>>>>> whatever,
>>>>>>> ie. the FPGA device.
>>>>>>>
>>>>>>> Signed-off-by: Tien Fong Chee <tien.fong.chee at intel.com>
>>>>>>> ---
>>>>>> [...]
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> +static int fs_loader_probe(struct udevice *dev)
>>>>>>> +{
>>>>>>> +	return 0;
>>>>>>> +};
>>>>>>> +
>>>>>>> +static const struct udevice_id fs_loader_ids[] = {
>>>>>>> +	{ .compatible = "fs_loader"},
>>>>>> Why exactly is there a DT compatible for a firmware loader?
>>>>>>
>>>>> Correct me if i'm wrong, this is required to look the platform
>>>>> data
>>>>> from DTS, right? Details of DTS in patch 2.
>>>> How so ? The FW loader should behave as a library for other
>>>> drivers
>>>> to
>>>> use, not like a driver.
>>>>
>>> The fs_loader node in DTS just provide a way for user to tell the
>>> firmware loader what storage device and default partition to load
>>> data
>>> from. Default partition can be overriden through the variable
>>> environment.
>> So that's sitting in the chosen node ? But why do you need to match
>> on it ?
>>
> This is new device tree binding for firmware loader called fs_loader
> node. firmware loader need to know where is the storage device it need
> to load from. Those storage device would be defined in fs_loader node.

This is a configuration. You do not need (new) a DT compatible for that.
So why is the DT compatible even needed in the FW loader at all ?

>>> Caller/other drivers can create different firmware loader instance
>>> based on different fs_loader node(different storage device) for
>>> their
>>> loading purpose.
>> They can, but that could be done even without the DT compatible.
>>
> Yes, once you get dev, you can set the storage type and partiiton
> attributes through accessing dev->platdata.

Can you show me the DT patch needed for this to work ?

>>> Why this cannot be used by other driver?
>> I don't understand the question.
>>
> I means why u say this firmware loader cannot be used by other drivers.
> I have tested with FPGA Manager driver(as caller).

It must be used by other drivers, that is the point.

-- 
Best regards,
Marek Vasut