u-boot-brain/arch/arm/dts/am572x-idk.dts
Faiz Abbas 6b66d2ee47 ARM: dts: am57xx: Disable voltage switching for SD card
If UHS speed modes are enabled, a compatible SD card switches down to 1.8V
during enumeration. If after this a software reboot/crash takes place and
on-chip ROM tries to enumerate the SD card, the difference in
IO voltages (host @ 3.3V and card @ 1.8V) may end up damaging the card.

The fix for this is to have support for power cycling the card in
hardware (with a PORz/soft-reset line causing a power cycle of the card).
Because the beaglebone X15 (rev A,B and C), am57xx-evms and am57xx-idks don't
have this capability, disable voltage switching for these boards.

The major effect of this is that the maximum supported speed mode is now
high speed(50 MHz) down from SDR104(200 MHz).

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
2019-07-26 22:24:11 -04:00

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/*
* Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/dts-v1/;
#include "dra74x.dtsi"
#include "am572x-idk-common.dtsi"
#include "am57xx-idk-common.dtsi"
#include "dra7-mmc-iodelay.dtsi"
#include "dra74x-mmc-iodelay.dtsi"
/ {
model = "TI AM5728 IDK";
compatible = "ti,am5728-idk", "ti,am5728", "ti,dra742", "ti,dra74",
"ti,dra7";
};
&mmc1 {
pinctrl-names = "default", "hs";
pinctrl-0 = <&mmc1_pins_default_no_clk_pu>;
pinctrl-1 = <&mmc1_pins_hs>;
};
&mmc2 {
pinctrl-names = "default", "hs", "ddr_1_8v";
pinctrl-0 = <&mmc2_pins_default>;
pinctrl-1 = <&mmc2_pins_hs>;
pinctrl-2 = <&mmc2_pins_ddr_rev20>;
};