On qcom SD host controllers voltage switching be done after the HW is ready for it. The HW informs its readiness through power irq. The voltage switching should happen only then. So added support to register voltage regulators from the msm driver and use them. This patchset was posted long back but not actively pursued https://lore.kernel.org/linux-arm-msm/1539004739-32060-1-git-send-email-vbadigan@xxxxxxxxxxxxxx/ So posting it as fresh patchset. Changes since V1: - Removed setting load for Vmmc regulator while turning it on/off. Instead setting the active load once during probe. - Simplified handlng of supplies for BUS_ON/OFF cases in shci_msm_handle_pwr_irq(). - Moved common code out of switch case in sdhci_msm_start_signal_voltage_switch(). - Updated variable name to sdhci_core_to_disable_vqmmc. - Updated pr_err logs to dev_err logs. Veerabhadrarao Badiganti (1): dt-bindings: mmc: Supply max load for mmc supplies mmc: sdhci-msm: Use internal voltage control Vijay Viswanath (1): mmc: sdhci: Allow platform controlled voltage switching .../devicetree/bindings/mmc/mmc-controller.yaml | 16 ++ drivers/mmc/host/sdhci-msm.c | 207 ++++++++++++++++++++- drivers/mmc/host/sdhci.c | 32 ++-- drivers/mmc/host/sdhci.h | 1 + 4 files changed, 234 insertions(+), 22 deletions(-) -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project