Re: [PATCHv2 1/3] phy: Add exynos-simple-phy driver

From: Rahul Sharma <rahul.sharma@samsung.com>
To: Tomasz Stanislawski <t.stanislaws@samsung.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	linux-samsung-soc <linux-samsung-soc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Andrzej Hajda <a.hajda@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Rob Herring <robh+dt@kernel.org>,
	Sylwester Nawrocki <s.nawrocki@samsung.com>,
	Grant Likely <grant.likely@linaro.org>,
	Kukjin Kim <kgene.kim@samsung.com>,
	sunil joshi <joshi@samsung.com>,
	"linux-media@vger.kernel.org" <linux-media@vger.kernel.org>
Subject: Re: [PATCHv2 1/3] phy: Add exynos-simple-phy driver
Date: Wed, 7 May 2014 19:49:10 +0530	[thread overview]
Message-ID: <CAPdUM4M6uk2KN_L487_cRkOqbgJrhhMRx9zpczA6-3LzSM3FSg@mail.gmail.com> (raw)
In-Reply-To: <536A36F5.5080303@samsung.com>

On 7 May 2014 19:06, Tomasz Stanislawski <t.stanislaws@samsung.com> wrote:
> On 05/07/2014 12:38 PM, Rahul Sharma wrote:
>> On 5 May 2014 15:14, Kishon Vijay Abraham I <kishon@ti.com> wrote:
>>> Hi,
>>>
>>> On Wednesday 09 April 2014 03:31 PM, Sylwester Nawrocki wrote:
>>>> Hi,
>>>>
>>>> On 09/04/14 11:12, Rahul Sharma wrote:
>>>>> Idea looks good. How about keeping compatible which is independent
>>>>> of SoC, something like "samsung,exynos-simple-phy" and provide Reg
>>>>> and Bit through phy provider node. This way we can avoid SoC specific
>>>>> hardcoding in phy driver and don't need to look into dt bindings for
>>>>> each new SoC.
>>>>
>>>> I believe it is a not recommended approach.
>>>
>>> Why not? We should try to avoid hard coding in the driver code. Moreover by
>>> avoiding hardcoding we can make it a generic driver for single bit PHYs.
>>>
>>
>> +1.
>>
>> @Tomasz, any plans to consider this approach for simple phy driver?
>>
>> Regards,
>> Rahul Sharma.
>>
>
> Hi Rahul,
> Initially, I wanted to make a very generic driver and to add bit and
> register (or its offset) attribute to the PHY node.
> However, there was a very strong opposition from DT maintainers
> to adding any bit related configuration to DT.
> The current solution was designed to be a trade-off between
> being generic and being accepted :).
>

Thanks Tomasz,
Ok got it. lets discuss it again and conclude it.

@Kishon, DT-folks,

The original RFC patch from Tomasz (at https://lkml.org/lkml/2013/10/21/313)
added simple phy driver as "Generic-simple-phy" with these properties:

+ of_property_read_u32(dev->of_node, "mask", &sphy->mask);
+ of_property_read_u32(dev->of_node, "on-value", &sphy->on_value);
+ of_property_read_u32(dev->of_node, "off-value", &sphy->off_value);

Shall we consider the same solution again for generic simple phy
driver which just expose on/off control through register bit.

Regards,
Rahul Sharma

> Regards,
> Tomasz Stanislawski
>
>
>
>>> Cheers
>>> Kishon
>>
>
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