On Mon 13 Dec 2021 at 19:50, "rong.chen@xxxxxxxxxxx" <rong.chen@xxxxxxxxxxx> wrote: > Hello, > If 3.3V always-on power source for vmmc is supplied by hardware boards fixed, don't need regulator in software, so .dts unnecessary the link between regulator > and MMC controller vmmc/vqmmc. Controllable or not, your vmmc/vqmmc regulators should be described in DT. There are several examples of this in arch/arm64/boot/dts/amlogic/*.dts > > ------------------------------------------------------------------------------------------------------------------------------------------------------ > rong.chen@xxxxxxxxxxx > > > From: Martin Blumenstingl > Date: 2021-12-13 16:00 > To: Rong Chen > CC: Ulf Hansson; Neil Armstrong; Kevin Hilman; Jerome Brunet; --to=1131046452; 45581586; linux-mmc; linux-arm-kernel; linux-amlogic; linux-kernel > Subject: Re: [PATCH] mmc: meson: initial ocr available by default value > [ EXTERNAL EMAIL ] > > Hello, > > On Mon, Dec 13, 2021 at 8:03 AM Rong Chen <rong.chen@xxxxxxxxxxx> wrote: > > > > The patch will add a value of ocr supported by the controller, > > to specify some of voltage values are supported. > Can you please share some details on this topic? > > We already have many boards upstreamed which work fine without > manually setting ocr_avail in the driver. > In general there's two types of boards: > 1) boards where the regulator can switch between different voltages. > One example is the Odroid-C2, see meson-gxbb-odroidc2.dts [0] > Here we specify: > vmmc-supply = <&tflash_vdd>; > vqmmc-supply = <&tf_io>; > &tflash_vdd is either turned off or at 3.3V when turned on. > &tf_io can be either turned off, 1.8V or 3.3V. > > 2) boards where the voltages are fixed. > One example is Radxa Zero, see meson-g12a-radxa-zero.dts [1] > For the SD card the board uses: > vmmc-supply = <&vddao_3v3>; > vqmmc-supply = <&vddao_3v3>; > (meaning fixed 3.3V always-on power source for both VMMC and VQMMC) > and for eMMC the board uses: > vmmc-supply = <&vcc_3v3>; > vqmmc-supply = <&vcc_1v8>; > (meaning: 3.3V always-on power source for vmmc and 1.8V always-on > power source for VQMMC) > > With the information from the regulators the MMC core will > automatically detect ocr_avail in Linux. > Or in other words: your .dts may be missing the link between regulator > and MMC controller vmmc/vqmmc. > Can you please double-check this? > > > Best regards, > Martin > > > [0] > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts?id=2585cf9dfaaddf00b069673f27bb3f8530e2039c#n354 > > [1] > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/amlogic/meson-g12a-radxa-zero.dts?id=2585cf9dfaaddf00b069673f27bb3f8530e2039c#n333
