[U-Boot] [PATCH] w1: fix build without CONFIG_W1_EEPROM

[Eugen.Hristev at microchip.com <Eugen.Hristev@microchip.com>]

On 23.10.2018 11:31, Martin Fuzzey wrote:
> On 23/10/18 09:07, Eugen.Hristev at microchip.com wrote:
>>
>> On 22.10.2018 19:51, Martin Fuzzey wrote:
>>> Building with CONFIG_W1 and CONFIG_CMD_W1 but without CONFIG_W1_EEPROM
>>> fails with
>>>     drivers/w1/w1-uclass.c:104: undefined reference to 
>>> `w1_eeprom_register_new_device'
>>>     cmd/w1.c:93: undefined reference to `w1_eeprom_read_buf'
>>>
>>> Fix this.
>> I would prefer if you let the w1 read command to be accessible
>> regardless if CONFIG_W1_EEPROM is defined or not. Hence have only the w1
>> eeprom reads under the ifdef...
>> The w1_read checks for devices anyway and for the bus, so it should
>> print invalid bus/device if nothing is present there.
>> Any opinion on this ?
> 
> I don't really have a strong opinion on this.
> 
> Completely removing non implemented commands seems to be a common thing 
> to do in u-boot (cmd/i2c.c for instance) presumably to keep the image 
> size as small as possible.
> But for the one wire case the code space saving is likely to be small 
> and, currently at least, there is little point buiding without 
> CONFIG_W1_EEPROM, not sure if that will change some day - of course 
> there are other types of one wire devices like various sensors but they 
> are probably of less interest in the context of a bootloader.
> 
> Let's wait a bit and see what Maxime or anyone else has to say about this.

I tried as much as possible to decouple the W1 bus from the W1 EEPROM 
memories. It is possible that we will have a different framework for 
EEPROMs that will include both 1wire and i2c eeproms, and then the 
interfacing would be pretty easy to change to.

That's why I am thinking that w1 bus read should not be much affected if 
the 1w EEPROMs are unknown to U-boot

> 
> Regards,
> 
> Martin
> 
>