[U-Boot] [PATCH 07/10] clk: imx8: add i.MX8QM clk driver

[Stefano Babic]

Hi Fabio,

On 28/01/19 15:23, Fabio Estevam wrote:
> Hi Stefano,
> 
> On Mon, Jan 28, 2019 at 12:04 PM Stefano Babic <sbabic at denx.de> wrote:
> 
>> Ok - I see you decide to split the code on depend of the SOC type.
>> Nevertheless, even if defines are different, it seems to me that there
>> is still a lot of common code (_imx8_clk_enable is very similar). Do we
>> need really a separate file for each MX8 variant ? Which are the
>> blocking points that avoid to do this ? I am looking at the patch, but I
>> do not find such as issue. Can you explain it ?
> 
> I am also concerned about the current i.MX clock driver status in
> U-Boot and I expressed this during my review of Lukasz's patch that
> added a imx6 clock driver.
> 

Nice we are sharing the sa me opinion. I am currently checking all
patches from oldest to neweset, I have not yet catched Lukasz', but they
are on my sight, too.

> It does not scale well as we can see by the huge switch statement in
> this patch. Of course this would need to grow when new peripherals
> clocks are added.

I fully agree. Yes, it is simple now to do in this way, but it does not
scale very well.

> 
> I think a better approach would be to use the same scheme as done in
> the kernel with common clock framework.
> 
> Barebox folows this same approach. For example:
> 
> i.MX8M clock driver:
> https://git.pengutronix.de/cgit/barebox/tree/drivers/clk/imx/clk-imx8mq.c
> 
> i.MX6Q clock driver:
> https://git.pengutronix.de/cgit/barebox/tree/drivers/clk/imx/clk-imx6.c
> 
> It allows syncing with the kernel clock driver more easily 

This is also a great benefit.

> and it
> makes it easier to maintain several i.MX SoCs in the long term.
> 

Best regards,
Stefano

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