On 29.09.2023 11:52, Luca Weiss wrote: > Enable the UFS phy and controller so that we can access the internal > storage of the phone. > > At the same time we need to bump the minimum voltage used for UFS VCC, > otherwise it doesn't initialize properly. The new range is taken from > the vcc-voltage-level property downstream. > > See also the following link for more information about the VCCQ/VCCQ2: > https://gerrit-public.fairphone.software/plugins/gitiles/kernel/msm-extra/devicetree/+/1590a3739e7dc29d2597307881553236d492f188/fp5/yupik-idp-pm7250b.dtsi#207 > > Signed-off-by: Luca Weiss <luca.weiss@xxxxxxxxxxxxx> > --- > I'm not 100% convinced about the regulator range change. For sure with > the original voltage range the UFS fails to initialize, but looking at > downstream kernel during runtime (debugfs) we see the VCC voltage > switches between 2.4V (idle?) and 2.952V (active?). But even with this > change in mainline the regulator would always stay at 2.504V which is > for sure lower than the downstream operating voltage of 2.952V. Behavior > wise I don't see a difference between ~2.5V and ~2.9V. > > Should I just constrain the regulator here to min=max=2.952V? Or just > say it's okay as-is? > > Depends on: https://lore.kernel.org/linux-arm-msm/20230927081858.15961-1-quic_nitirawa@xxxxxxxxxxx/ > --- There's a little funny hack inside the driver #if defined(CONFIG_SCSI_UFSHCD_QTI) if (vreg->low_voltage_sup && !vreg->low_voltage_active && on) min_uV = vreg->max_uV; #endif so, when the ufs is in use, it's pinned to vmax Konrad
