u-boot-brain/arch/arm/dts/am572x-idk.dts
Faiz Abbas 461918d7df ARM: dts: dra7-mmc-iodelay: Add a new pinctrl group for clk line without pullup
During a short period when the bus voltage is switched from 3.3v to 1.8v,
(to enumerate UHS mode), the mmc module is disabled and the mmc IO lines
are kept in a state according to the programmed pad mux pull type.

According to 4.2.4.2 Timing to Switch Signal Voltage in "SD Specifications
Part 1 Physical Layer Specification Version 5.00 February 22, 2016", the
host should hold CLK low for at least 5ms.

In order to keep the card line low during voltage switch, the pad mux of
mmc1_clk line should be configured to pull down.

Add a new pinctrl group for clock line without pullup to be used in boards
where mmc1_clk line is not connected to an external pullup.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
2019-07-26 22:24:10 -04:00

40 lines
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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", "sdr12", "sdr25", "sdr50", "ddr50", "sdr104";
pinctrl-0 = <&mmc1_pins_default_no_clk_pu>;
pinctrl-1 = <&mmc1_pins_hs>;
pinctrl-2 = <&mmc1_pins_sdr12>;
pinctrl-3 = <&mmc1_pins_sdr25>;
pinctrl-4 = <&mmc1_pins_sdr50>;
pinctrl-5 = <&mmc1_pins_ddr50 &mmc1_iodelay_ddr_rev20_conf>;
pinctrl-6 = <&mmc1_pins_sdr104 &mmc1_iodelay_sdr104_rev20_conf>;
};
&mmc2 {
pinctrl-names = "default", "hs", "ddr_1_8v";
pinctrl-0 = <&mmc2_pins_default>;
pinctrl-1 = <&mmc2_pins_hs>;
pinctrl-2 = <&mmc2_pins_ddr_rev20>;
};