[PATCH v2] driver: pwm: pwm-imx: fix probing on imx6

[Tom Rini]

On Wed, Aug 14, 2024 at 06:07:52AM +0200, Heiko Schocher wrote:
> Hello Tom,
> 
> On 13.08.24 18:16, Tom Rini wrote:
> > On Tue, Aug 13, 2024 at 03:57:08PM +0200, Heiko Schocher wrote:
> > > Hello Fabio, Tom,
> > > 
> > > On 13.08.24 14:27, Fabio Estevam wrote:
> > > > Hi Heiko,
> > > > 
> > > > On Wed, Aug 7, 2024 at 12:53 PM Heiko Schocher <hs at denx.de> wrote:
> > > > > 
> > > > > U-Boot 2024.07 drops on aristainetos2 board the following
> > > > > warning:
> > > > > 
> > > > >           Failed to enable per_clk
> > > > > 
> > > > > and bootlogo is not seen on LVDS display.
> > > > > 
> > > > > This patch uses old behaviour for systems without clock framework
> > > > > if CONFIG_CLK is not enabled.
> > > > > 
> > > > > Fixes: bfc778cb93a3 ("driver: pwm: pwm-imx: get and enable per/ipg clock using dm")
> > > > > 
> > > > > Signed-off-by: Heiko Schocher <hs at denx.de>
> > > > > ---
> > > > > 
> > > > > Changes in v2:
> > > > > use CONFIG_IS_ENABLED instead of IS_ENABLED
> > > > > as Anatolij suggested.
> > > > 
> > > > This causes build failures:
> > > > 
> > > > https://source.denx.de/u-boot/custodians/u-boot-imx/-/jobs/887503
> > > > 
> > > > Please fix and resend.
> > > 
> > > Hmm... yes ... I work/worked on aristainetos2 board update for 2024.07
> > > (or later)  ... and saw this
> > > 
> > >    Failed to enable per_clk
> > > 
> > > warning when 2024.07 boots ... and bootlogo did not work anymore, as
> > > backlight is pwm driven on this hardware...
> > > 
> > > I bet, for all the boards which fail in the azure run with this patch,
> > > PWM do not work anymore... because CONFIG_CLK is not enabled for them!
> > > 
> > > I am really unhappy, that I have no automated U-Boot runtime tests anymore
> > > running on real hardware... setup with tbot was very easy, but had no
> > > time for looking at the bugs poping up...
> > > 
> > > Hmm... looking in git history, there comes this commit in my eyes:
> > > 
> > > commit 4eea76574062e9079b6a267229962d6ec0be910a
> > > Author: Tom Rini <trini at konsulko.com>
> > > Date:   Sat Nov 19 18:45:18 2022 -0500
> > > 
> > >      pwm: imx: Remove unused references to CONFIG_IMX6_PWM_PER_CLK
> > > 
> > >      On platforms that use DM_PWM, we do not need to define this value
> > >      anymore, so remove it from config files.
> > > 
> > >      Signed-off-by: Tom Rini <trini at konsulko.com>
> > > 
> > > which exactly removes for all breaking boards this define...
> > > 
> > > Should we revert this patch?
> > > 
> > > I just can say for the aristianetos2 board, that I readded exactly this
> > > define in my work for the port to currentmainline ... and with my patch,
> > > pwm and so bootlogo works again ...
> > 
> > We can't do a strict revert, no, the symbol is now CFG_IMX6_PWM_PER_CLK.
> > But also, isn't this board using DM_PWM? And if so, that value isn't
> > used?
> 
> Yes, of course, simple revert does not work.
> 
> Yes, the failing boards are converted to DM_PWM, but they do not work
> anymore as bfc778cb93a3 intrdocued clk framework functions, and the
> failing boards have no clk framwork enabled. So my patch simply
> readded the define for DM_PWM case.

OK. And why don't we just fix the missing clock migration next?

-- 
Tom
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