>From the HPG: In some platform, SDCC controller can be connected to either an eMMC device or an SD card. The PADs for SD card are dual-voltage that support 3v/1.8v. Those PADs have a control signal (io_pad_pwr_switch/mode18 ) that indicates whether the PAD works in 3v or 1.8v. For SD usage the default value of this signal is ‘0’, and SD driver changes it to ‘1’ as a part of voltage switching sequence. For eMMC usage, SW should configure this signal to ‘1’ and supply 1.8v to PADs before starting any activity on the eMMC BUS. To set this signal, write the following in the SDC1_SDCC_HC_VENDOR_SPECIFIC_FUNC register: HC_IO_PAD_PWR_SWITCH: bit 16 HC_IO_PAD_PWR_SWITCH_EN: bit 15 Changes since v1: Modified comments on io_pad related changes. Split some read+modify+write commands to multiple lines Changes since v2: IO_PAD_PWR_SWITCH_EN will be set only if we have info regarding what voltage is supported by the regulators. Replaced regulator_list_voltage() API with regulator_is_supported_voltage(). Changes since v3: Removed unnecessary prints and extra lines. Changes since v4: Removed unnecessary mb() within sdhci_msm_handle_pwr_irq() since wakeup calls have implicit write barriers. Krishna Konda (1): mmc: sdhci-msm: support voltage pad switching Vijay Viswanath (1): mmc: sdhci-msm: Add support to store supported vdd-io voltages drivers/mmc/host/sdhci-msm.c | 99 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 97 insertions(+), 2 deletions(-) -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
