From ca2618b5d5b04a1e2e96244b00b54479cb6cf2b6 Mon Sep 17 00:00:00 2001 From: Kishon Vijay Abraham I Date: Fri, 27 Apr 2018 17:38:54 +0530 Subject: 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: Kishon Vijay Abraham I Signed-off-by: Tony Lindgren --- arch/arm/boot/dts/dra7-mmc-iodelay.dtsi | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 arch/arm/boot/dts/dra7-mmc-iodelay.dtsi (limited to 'arch/arm/boot/dts/dra7-mmc-iodelay.dtsi') diff --git a/arch/arm/boot/dts/dra7-mmc-iodelay.dtsi b/arch/arm/boot/dts/dra7-mmc-iodelay.dtsi new file mode 100644 index 000000000000..aa0947266526 --- /dev/null +++ b/arch/arm/boot/dts/dra7-mmc-iodelay.dtsi @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MMC IOdelay values for TI's DRA7xx SoCs. + * Copyright (C) 2018 Texas Instruments + * Author: Kishon Vijay Abraham I + */ + +&dra7_pmx_core { + mmc1_pins_default_no_clk_pu: mmc1_pins_default_no_clk_pu { + pinctrl-single,pins = < + DRA7XX_CORE_IOPAD(0x3754, PIN_INPUT_PULLDOWN | MUX_MODE0) /* mmc1_clk.clk */ + DRA7XX_CORE_IOPAD(0x3758, PIN_INPUT_PULLUP | MUX_MODE0) /* mmc1_cmd.cmd */ + DRA7XX_CORE_IOPAD(0x375c, PIN_INPUT_PULLUP | MUX_MODE0) /* mmc1_dat0.dat0 */ + DRA7XX_CORE_IOPAD(0x3760, PIN_INPUT_PULLUP | MUX_MODE0) /* mmc1_dat1.dat1 */ + DRA7XX_CORE_IOPAD(0x3764, PIN_INPUT_PULLUP | MUX_MODE0) /* mmc1_dat2.dat2 */ + DRA7XX_CORE_IOPAD(0x3768, PIN_INPUT_PULLUP | MUX_MODE0) /* mmc1_dat3.dat3 */ + >; + }; +}; -- cgit v1.2.3-59-g8ed1b