Hi, On 18.12.24 4:27 PM, Frieder Schrempf wrote: > From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> > > This is a follow-up of [1]. > > The main objective of this is to fix the PCA9450 driver to > use the correct control register for the LDO5 regulator. > > Currently the control register to use for LDO5 is hardcoded to > LDO5CTRL_H. This is wrong for two reasons: > > 1. LDO5CTRL_H doesn't contain the bits for enabling/disabling > the regulator. Only LDO5CTRL_L does. > > 2. The actual output voltage of the regulator is determined by > the LDO5CTRL_H only if the SD_VSEL input is HIGH. If it is > low, then LDO5CTRL_L is used. The driver does not take this > into account. > > This can cause several problems: > > 1. LDO5 can not be turned on/off and we rely on the bootloader > to leave it turned on. On the other hand we can't save > power if LDO5 is unused. > > 2. There is a potential for corner-cases where switching > SD_VSEL via USDHC_VSELECT and writing to the (wrong) > control register can cause wrong output voltage and therfore > SD card failures (not observed yet). > > 3. Reading the current voltage of the LDO5 regulator (e. g. via > sysfs can yield the wrong value as the voltage is read from > the wrong control register. > > At the same time there is now hardware that hardwires SD_VSEL > to a fixed LOW level and therefore relies on switching the > voltage only via a single control register. We add support for > this through an additional property "nxp,sd-vsel-fixed-low" in > the LDO5 node. > > Summary of binding changes (patch 1): > > 1. Adjust the bindings to remove the old and abandoned use of > sd-vsel-gpios property. > > 2. Adjust the bindings to use sd-vsel-gpios in the LDO5 node to > retrieve an input that can be used to sample the SD_VSEL > status. > > 3. Adjust bindings to allow "nxp,sd-vsel-fixed-low" to be used > for boards that have SD_VSEL hardwired to low level. > > Summary of driver changes (patch 2-6): > > 1. Remove the old sd-vsel-gpios handling. > > 2. Use the new sd-vsel-gpios property to determine the correct > control register for LDO5. > > 3. Fix the enable register for LDO5. > > 4. Support hardware with fixed low level of SD_VSEL. > > Summary of devicetree changes (patch 7-9): > > Implement the changes in the devicetrees for Kontron hardware > (i.MX8MM, i.MX8MP and i.MX93). > > Changelog: > > v2 -> v3: > > * Merge binding patches into one and extend commit message > * Rebase to next-20241218 > > v1 -> v2: > > * Split binding patch > * Add solution for hardwired SD_VSEL > * Leave regulator core untouched as requested by Mark > * Add devicetree changes for i.MX8MP and i.MX93 > > [1] https://lore.kernel.org/lkml/20230213155833.1644366-1-frieder@xxxxxxx/ > > Frieder Schrempf (9): > dt-bindings: regulator: pca9450: Add properties for handling LDO5 > arm64: dts: imx8mp-skov-reva: Use hardware signal for SD card VSELECT > Revert "regulator: pca9450: Add SD_VSEL GPIO for LDO5" > regulator: pca9450: Fix control register for LDO5 > regulator: pca9450: Fix enable register for LDO5 > regulator: pca9450: Handle hardware with fixed SD_VSEL for LDO5 > arm64: dts: imx8mm-kontron: Add support for reading SD_VSEL signal > arm64: dts: imx93-kontron: Fix SD card IO voltage control > arm64: dts: imx8mp-kontron: Add support for reading SD_VSEL signal > > .../regulator/nxp,pca9450-regulator.yaml | 29 ++++- > .../boot/dts/freescale/imx8mm-kontron-bl.dts | 10 +- > .../dts/freescale/imx8mm-kontron-osm-s.dtsi | 7 +- > .../dts/freescale/imx8mp-kontron-osm-s.dtsi | 7 +- > .../boot/dts/freescale/imx8mp-skov-reva.dtsi | 5 +- > .../dts/freescale/imx93-kontron-osm-s.dtsi | 5 +- > drivers/regulator/pca9450-regulator.c | 103 +++++++++++++++--- > 7 files changed, 133 insertions(+), 33 deletions(-) > I just want to ask kindly if there is any feedback for the driver and devicetree changes in this set? Thanks Frieder
