Which regulator controls MMC3 IO voltage?

[Doug Springer]

We have a 3.3V SDIO card attached to the MMC3 interface:

AM33XX_PADCONF(AM335X_PIN_GPMC_CLK, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (T7) gpmc_clk.mmc2_clk */ AM33XX_PADCONF(AM335X_PIN_GPMC_CSN3, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (R7) gpmc_csn3.mmc2_cmd */ AM33XX_PADCONF(AM335X_PIN_GPMC_AD12, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (P6) gpmc_ad12.mmc2_dat0 */ AM33XX_PADCONF(AM335X_PIN_GPMC_AD13, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (R6) gpmc_ad13.mmc2_dat1 */ AM33XX_PADCONF(AM335X_PIN_GPMC_AD14, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (T6) gpmc_ad14.mmc2_dat2 */ AM33XX_PADCONF(AM335X_PIN_GPMC_AD15, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (P7) gpmc_ad15.mmc2_dat3 */ And we have copied the beaglebone black entry: wlan_en_reg: fixedregulator@2 { compatible = "regulator-fixed"; regulator-name = "wlan-en-regulator"; regulator-min-microvolt = <3300000>; regulator-max-microvolt = <3300000>; startup-delay-us= <70000>; /* WL_EN */ gpio = <&gpio3 9 0>; enable-active-high; };

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AM33XX_PADCONF(AM335X_PIN_GPMC_CLK, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (T7) gpmc_clk.mmc2_clk */   AM33XX_PADCONF(AM335X_PIN_GPMC_CSN3, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (R7) gpmc_csn3.mmc2_cmd */   AM33XX_PADCONF(AM335X_PIN_GPMC_AD12, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (P6) gpmc_ad12.mmc2_dat0 */   AM33XX_PADCONF(AM335X_PIN_GPMC_AD13, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (R6) gpmc_ad13.mmc2_dat1 */   AM33XX_PADCONF(AM335X_PIN_GPMC_AD14, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (T6) gpmc_ad14.mmc2_dat2 */   AM33XX_PADCONF(AM335X_PIN_GPMC_AD15, PIN_INPUT_PULLUP, MUX_MODE3 ) /* (P7) gpmc_ad15.mmc2_dat3 */   And we have copied the beaglebone black entry: wlan_en_reg: fixedregulator@2 { compatible = "regulator-fixed"; regulator-name = "wlan-en-regulator"; regulator-min-microvolt = <3300000>; regulator-max-microvolt = <3300000>; startup-delay-us= <70000>; /* WL_EN */ gpio = <&gpio3 9 0>; enable-active-high; };

But our signals are still driving to 5V. How do we change the VIO voltage on these pins?

Thanks

 

[Doug Springer]

It appears that not all signals are driving to 5V, only the clock is showing a 5.3V p-p voltage.

[Eshtaartha Basu]

Doug Springer,

We need some more information on your use case to help you better.

1. Are you using an official OSD335x-SM board or a custom version of it?
1.a If this is a custom board, are all the VDDSHVx pins tied to 3.3V?
1.b Do you have any pull ups on MMC3 pins?

2. It’ll be very helpful if you can share your full device tree files and at least the MMC3 interface, VDDSHV connections part of Schematics.

[Author]

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