[U-Boot] [PATCH 02/15][v4] imx: usb: ehci-mx7 add usb driver for i.MX7D

[Stefano Babic]

Hi Adrian,

On 24/07/2015 17:34, Alonso Adrian wrote:
> Hi Marek,
> 
>> -----Original Message-----
>> From: Marek Vasut [mailto:marex at denx.de]
>> Sent: Friday, July 24, 2015 4:44 AM
>> To: Alonso Lazcano Adrian-B38018
>> Cc: u-boot at lists.denx.de; sbabic at denx.de; otavio at ossystems.com.br;
>> Estevam Fabio-R49496; Li Frank-B20596; Garg Nitin-B37173
>> Subject: Re: [PATCH 02/15][v4] imx: usb: ehci-mx7 add usb driver for i.MX7D
>>
>> On Thursday, July 23, 2015 at 09:25:17 PM, Adrian Alonso wrote:
>>> Add support for usb driver for i.MX7D SoC
>>>
>>> Signed-off-by: Adrian Alonso <aalonso at freescale.com>
>>> Signed-off-by: Ye.Li <B37916 at freescale.com>
>>> Signed-off-by: Peng Fan <Peng.Fan at freescale.com>
>>
>> So errr, why exactly can ehci-mx6 not be used here ? The code looks almost like
>> a copy of ehci-mx6 with minor tweaks here and there.
>>
>> Best regards,
>> Marek Vasut
> 
> [Adrian] We can definitely have a single driver to support imx7 and imx6, but we mainly decide
> to have a driver for each SoC to try to make easier to maintain, there are so many variants of imx6
> (Quad/Dual/Solo/SoloX/QuadPlus/UL) and imx7 (Dual/Solo);

This is exactly we do not want to have in U-Boot mainline. We try as
much as püossible to duplicate code, and when it is possible to have a
single driver across more platforms or event architectures.

> while there are several similarities in
> USB IP for iMX6 and iMX7, USB PHY Control and clock settings differ slightly making code harder to
> Understand and maintain in a single driver for imx7 and imx6.

This could mean that some parts should be extracted and move into a
separate SOC specific file, but it is not a reson for duplicating code.

Best regards,
Stefano Babic

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