Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware

From	Chanwoo Choi <cw00.choi@samsung.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware
Date	2016-06-29 08:30 +0200
Message-ID	<rPhax-GR-11@gated-at.bofh.it> (permalink)
References	(1 earlier) <rOgqe-2jQ-13@gated-at.bofh.it> <rP002-6Rk-23@gated-at.bofh.it> <rP002-6Rk-21@gated-at.bofh.it> <rPhax-GR-13@gated-at.bofh.it> <rPhax-GR-15@gated-at.bofh.it>
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On 2016년 06월 29일 06:59, Stephen Boyd wrote:
> Quoting Chanwoo Choi (2016-06-28 05:06:48)
>> 2016-06-28 4:11 GMT+09:00 Stephen Boyd <stephen.boyd@linaro.org>:
>>> Quoting Chanwoo Choi (2016-06-26 04:20:43)
>>>> 2016-06-26 14:56 GMT+09:00 Stephen Boyd <stephen.boyd@linaro.org>:
>>>>> +PROPERTIES
>>>>> +
>>>>> +- compatible:
>>>>> +    Usage: required
>>>>> +    Value type: <string>
>>>>> +    Definition: Should contain "qcom,pm8941-misc";
>>>>> +
>>>>> +- reg:
>>>>> +    Usage: required
>>>>> +    Value type: <u32>
>>>>> +    Definition: Should contain the offset to the misc address space
>>>>
>>>> 'reg' property is used on extcon-qcom-spmi-misc.c?
>>>> I think that you don't need to include this property.
>>>
>>> No it isn't used in the driver right now, but there is a register offset
>>> for this module and there are registers that can be read/written in this
>>> module. I'd like to keep it as required so we can easily read the
>>> registers in the future if needed.
>>
>> OK.
>> But, If you want to remain the reg property, you should add the code to get
>> the register offset by using OF functions. This patch don't include the OF
>> function to handle it.
>>
> 
> Sorry I don't follow the argument. I've put the reg property here for
> future proofing so that the binding doesn't have to change in backwards
> incompatible ways in the future if we do need to get the property later.

I don't mention that 'reg' property should be removed.
Just if you want to remain it, you should add some codes as following:
For exmaple,
- of_get_address() to get the address information from device-tree.

If documentation include the some properties, you should add the handling code
in device driver. When you add the code to get the offset from device-tree,
it doesn't influence the some behavior in the future.

Thanks,
Chanwoo Choi

Thread

[PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-26 08:00 +0200
  Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Chanwoo Choi <cwchoi00@gmail.com> - 2016-06-26 13:30 +0200
  Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Chanwoo Choi <cwchoi00@gmail.com> - 2016-06-26 13:30 +0200
    Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Chanwoo Choi <cwchoi00@gmail.com> - 2016-06-28 14:10 +0200
      Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection  hardware Chanwoo Choi <cw00.choi@samsung.com> - 2016-06-29 08:30 +0200
        Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-29 20:50 +0200
          Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection  hardware Chanwoo Choi <cw00.choi@samsung.com> - 2016-06-30 02:40 +0200
            Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-30 03:10 +0200
  Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection  hardware Roger Quadros <rogerq@ti.com> - 2016-06-27 09:50 +0200
    Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-27 21:40 +0200
      Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection  hardware Roger Quadros <rogerq@ti.com> - 2016-06-28 08:40 +0200
        Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-28 10:50 +0200
          Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection  hardware Roger Quadros <rogerq@ti.com> - 2016-06-28 11:20 +0200
            Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-29 00:10 +0200
              Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection  hardware Roger Quadros <rogerq@ti.com> - 2016-06-29 08:20 +0200
                Re: [PATCH] extcon: Add support for qcom SPMI PMIC USB id detection hardware Stephen Boyd <stephen.boyd@linaro.org> - 2016-06-29 21:00 +0200

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