On Mon, Jul 06, 2020 at 09:23:49PM +0530, Alim Akhtar wrote: > Hi Krzysztof, > > > -----Original Message----- > > From: Krzysztof Kozlowski <k...@kernel.org> > > Sent: 05 July 2020 23:53 > > To: Alim Akhtar <alim.akh...@samsung.com> > > Cc: devicet...@vger.kernel.org; linux-arm-ker...@lists.infradead.org; linux- > > samsung-...@vger.kernel.org; linux-kernel@vger.kernel.org; > > robh...@kernel.org > > Subject: Re: [PATCH v1 2/2] arm64: dts: exynos: keep LDO12 always-on > > > > On Sun, Jul 05, 2020 at 12:39:18PM +0530, Alim Akhtar wrote: > > > LDO12 on exynos7 supply power to VDDQ_UFS20_RESET, in case this > > > regulator is OFF, UFS host controller can not send command to UFS > > > device. To keep this supply ON, set regulator-always-on property for > > > this ldo. > > > > Why UFS does not take any supplies? This looks like a workaround for the > > case > > of not implementing any consumer. > > > This particular supply is not part of UFS HCI spec and binding documentation, > as per binding only one supply for host controller and three others for UFS > device are needed. My best guess is, VDDQ_UFS20_RESET supply to reset logic > block inside HCI, which might be specific to this controller version (I did > not find any such supply in the latest host controller though).
The bindings specific to Exynos7 UFS are then incomplete. Anyway it's nothing worth revisiting so I applied both patches. Best regards, Krzysztof
