Re: [PATCH v3 0/4] Restore ULPI USB on Tegra20

[Thierry Reding]

On Tue, May 08, 2018 at 07:26:02PM +0300, Dmitry Osipenko wrote:
> Hello,
> 
> This series of patches fixes ULPI USB on Tegra20. The original problem
> was reported by Marcel Ziswiler, he found that "ulpi-link" clock was
> incorrectly set to CDEV2 instead of PLL_P_OUT4. Marcel made a patch
> that changed the "ulpi-link" clock to PLL_P_OUT4 and that fixed issue
> with the USB for the devices that have CDEV2 being enabled by bootloader.
> The patch got into the kernel and later Marc Dietrich found that USB
> stopped working on the "paz00" Tegra20 board. After a bit of discussion
> was revealed that PLL_P_OUT4 is the parent clock of the CDEV2 and clock
> driver was setting CDEV2's parent incorrectly. The parent clock is actually
> determined by the pinmuxing config of CDEV2 pingroup. This patchset fixes
> the parent of CDEV2 clock by making Tegra's pinctrl driver a clock provider,
> providing CDEV1/2 clock muxes (thanks to Peter De Schrijver for the
> suggestion), and then setting these clock muxes as parents for the CDEV1/2
> clocks. In the end Marcel's CDEV2->PLL_P_OUT4 change is reverted since CDEV2
> (aka MCLK2) is the actual clock source for "ulpi-link".
> 
> Changelog:
> 
> v3:
> 	- Use clk DT ID's instead of comparing clk names and make
> 	  custom of_src_onecell_get specific to Tegra20 clk provider
> 	  in the "Add quirk for getting CDEV1/2 clocks on Tegra20" patch
> 	  as was suggested by Peter De Schrijver for v2.
> 
> v2:
> 	- Added new patch "Add quirk for getting CDEV1/2 clocks", assuring
> 	  that clk user won't get CDEV1/2 clocks until parent clk muxes
> 	  are available, i.e. resolves potential issue with CDEV-user driver
> 	  vs pinctrl driver probe order.
> 
> 	- Factored out "pinctrl" patch from the patchset as was requested by
> 	  Linus Walleij.
> 
> 	- Addressed v1 review comments: fixed swapped DEV1/2 clk div bits,
> 	  made DEV1/2 divs read-only, etc minor changes.
> 
> Dmitry Osipenko (4):
>   clk: tegra20: Add DEV1/DEV2 OSC dividers
>   clk: tegra20: Correct parents of CDEV1/2 clocks
>   clk: tegra: Add quirk for getting CDEV1/2 clocks on Tegra20
>   ARM: dts: tegra20: Revert "Fix ULPI regression on Tegra20"

Patches 1-3 applied, thanks.

Thierry

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