нд, 30 бер. 2025 р. о 22:27 Artur Kowalski <[email protected]> пише: > > Tegra20 has mux allowing to repurpose microSD as UART on boards which > use sdmmc3 controller for microSD. Add TEGRA_UARTA_MICROSD to enable > this feature. It is currently supported on Transformer T20, support for > other boards may require Device Tree changes. > > Update Transformer T20 DTS to select correct pinmux and stdout-path > based on TEGRA_UARTA_MICROSD. > > Signed-off-by: Artur Kowalski <[email protected]> > --- > > Changes in v2: > - added TEGRA_UARTA_MICROSD Kconfig option > - removed .dtsi for enabling UART over microSD > - modified transformer DT to use UARTA and correct pinmux when > TEGRA_UARTA_MICROSD is enabled; it is enough to flip a single > switch to enable/disable UART over microSD > > arch/arm/dts/tegra20-asus-transformer.dtsi | 24 ++++++++++++++++++++++ > arch/arm/mach-tegra/tegra20/Kconfig | 15 ++++++++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/arch/arm/dts/tegra20-asus-transformer.dtsi > b/arch/arm/dts/tegra20-asus-transformer.dtsi > index 49efabbfd92..9ea323c81f3 100644 > --- a/arch/arm/dts/tegra20-asus-transformer.dtsi > +++ b/arch/arm/dts/tegra20-asus-transformer.dtsi > @@ -5,7 +5,13 @@ > > / { > chosen { > +#if CONFIG_IS_ENABLED(TEGRA_ENABLE_UARTA) > + stdout-path = &uarta; > +#elif CONFIG_IS_ENABLED(TEGRA_ENABLE_UARTD) > stdout-path = &uartd; > +#else > +#error Unsupported UART > +#endif > }; > > aliases { > @@ -195,10 +201,17 @@ > nvidia,function = "i2c1"; > }; > > +#if CONFIG_IS_ENABLED(TEGRA_UARTA_SDB_SDD) > + dbguart { > + nvidia,pins = "sdb", "sdd"; > + nvidia,function = "uarta"; > + }; > +#else > sdb { > nvidia,pins = "sdb", "sdc", "sdd", "slxc", > "slxk"; > nvidia,function = "sdio3"; > }; > +#endif > > sdio1 { > nvidia,pins = "sdio1"; > @@ -376,7 +389,13 @@ > }; > }; > > +#if CONFIG_IS_ENABLED(TEGRA_ENABLE_UARTA) > + uarta: serial@70006000 { > +#elif CONFIG_IS_ENABLED(TEGRA_ENABLE_UARTD) > uartd: serial@70006300 { > +#else > +#error Unsupported UART > +#endif > status = "okay"; > clock-frequency = <216000000>; > }; > @@ -434,7 +453,12 @@ > }; > > sdmmc3: sdhci@c8000400 { > +#if CONFIG_IS_ENABLED(TEGRA_UARTA_MICROSD) > + /* Can't use both at the same time */ > + status = "disabled"; > +#else > status = "okay"; > +#endif > bus-width = <4>; > > cd-gpios = <&gpio TEGRA_GPIO(I, 5) GPIO_ACTIVE_LOW>; > diff --git a/arch/arm/mach-tegra/tegra20/Kconfig > b/arch/arm/mach-tegra/tegra20/Kconfig > index 3349f1e2786..c2c51660216 100644 > --- a/arch/arm/mach-tegra/tegra20/Kconfig > +++ b/arch/arm/mach-tegra/tegra20/Kconfig > @@ -77,6 +77,21 @@ endchoice > config SYS_SOC > default "tegra20" > > +config TEGRA_UARTA_MICROSD > + bool "UARTA on MicroSD breakout board" > + default n > + depends on TEGRA_ENABLE_UARTA && TARGET_TRANSFORMER_T20 > + select TEGRA_UARTA_SDB_SDD > + help > + Repurpose the SD card slot for getting access to the UARTA serial > + console. Primarily useful only for low level u-boot debugging on > + tablets, where normal UARTD is difficult to access and requires > + device disassembly and/or soldering. Enabling this option causes > + UARTA TX to become exposed on SDD and RX on SDB pins which > correspond > + to microSD CLK and CMD pins respectively. Currently this is > supported > + only on Transformer T20, support for other platforms may require DT > + and configs (from include/configs/*) updates. > + > source "board/nvidia/harmony/Kconfig" > source "board/avionic-design/medcom-wide/Kconfig" > source "board/compal/paz00/Kconfig" > -- > 2.48.1 >
This is not applicable since this is a hack by nature, BUT if you contain this in the transformer t20 board and Kconfig (no dts changes), this may be applied.
