[U-Boot] [PATCH v1 3/5] apalis/colibri_t30: avoid uart input from floating pins

[Igor Opaniuk]

On Thu, Sep 12, 2019 at 12:15 PM Marcel Ziswiler <marcel at ziswiler.com> wrote:
>
> From: Marcel Ziswiler <marcel.ziswiler at toradex.com>
>
> Avoid UART input from floating RX pins on UARTB and UARTC (Colibri T30)
> and UARTB, UARTC and UARTD (Apalis T30).
>
> Note: Floating pins may cause spurious break conditions potentially
> interrupting U-Boot's autoboot.
>
> Signed-off-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>
>
> ---
>
>  board/toradex/apalis_t30/pinmux-config-apalis_t30.h   | 9 ++++++---
>  board/toradex/colibri_t30/pinmux-config-colibri_t30.h | 7 ++++---
>  2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/board/toradex/apalis_t30/pinmux-config-apalis_t30.h b/board/toradex/apalis_t30/pinmux-config-apalis_t30.h
> index 8d6696aaad..3a2cf4606e 100644
> --- a/board/toradex/apalis_t30/pinmux-config-apalis_t30.h
> +++ b/board/toradex/apalis_t30/pinmux-config-apalis_t30.h
> @@ -120,7 +120,8 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
>         DEFAULT_PINMUX(ULPI_DATA6_PO7, UARTA, NORMAL, NORMAL, INPUT),
>         DEFAULT_PINMUX(ULPI_DATA7_PO0, UARTA, NORMAL, NORMAL, OUTPUT),
>         DEFAULT_PINMUX(ULPI_CLK_PY0, UARTD, NORMAL, NORMAL, OUTPUT),
> -       DEFAULT_PINMUX(ULPI_DIR_PY1, UARTD, NORMAL, NORMAL, INPUT),
> +       /* UARTD RX, make sure we don't get input form a floating Pin */
> +       DEFAULT_PINMUX(ULPI_DIR_PY1, UARTD, UP, NORMAL, INPUT),
>         DEFAULT_PINMUX(ULPI_NXT_PY2, UARTD, NORMAL, NORMAL, INPUT),
>         DEFAULT_PINMUX(ULPI_STP_PY3, UARTD, NORMAL, NORMAL, OUTPUT),
>         DEFAULT_PINMUX(DAP3_FS_PP0, I2S2, NORMAL, NORMAL, INPUT),
> @@ -189,12 +190,14 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
>         LV_PINMUX(VI_MCLK_PT1, VI, NORMAL, NORMAL, OUTPUT, DISABLE, DISABLE),
>         LV_PINMUX(VI_PCLK_PT0, VI, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
>         LV_PINMUX(VI_VSYNC_PD6, VI, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
> -       DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, NORMAL, NORMAL, INPUT),
> +       /* UARTB RX, make sure we don't get input form a floating Pin */
> +       DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, UP, NORMAL, INPUT),
>         DEFAULT_PINMUX(UART2_TXD_PC2, UARTB, NORMAL, NORMAL, OUTPUT),
>         DEFAULT_PINMUX(UART2_RTS_N_PJ6, UARTB, DOWN, TRISTATE, OUTPUT), /* NC */
>         DEFAULT_PINMUX(UART2_CTS_N_PJ5, UARTB, DOWN, TRISTATE, OUTPUT), /* NC */
>         DEFAULT_PINMUX(UART3_TXD_PW6, UARTC, NORMAL, NORMAL, OUTPUT),
> -       DEFAULT_PINMUX(UART3_RXD_PW7, UARTC, NORMAL, NORMAL, INPUT),
> +       /* UARTC RX, make sure we don't get input form a floating Pin */
> +       DEFAULT_PINMUX(UART3_RXD_PW7, UARTC, UP, NORMAL, INPUT),
>         DEFAULT_PINMUX(UART3_CTS_N_PA1, UARTC, NORMAL, NORMAL, INPUT),
>         DEFAULT_PINMUX(UART3_RTS_N_PC0, PWM0, NORMAL, NORMAL, OUTPUT),
>         DEFAULT_PINMUX(PU0, RSVD1, DOWN, TRISTATE, OUTPUT),
> diff --git a/board/toradex/colibri_t30/pinmux-config-colibri_t30.h b/board/toradex/colibri_t30/pinmux-config-colibri_t30.h
> index c583583b3f..5ac1a6da97 100644
> --- a/board/toradex/colibri_t30/pinmux-config-colibri_t30.h
> +++ b/board/toradex/colibri_t30/pinmux-config-colibri_t30.h
> @@ -180,7 +180,8 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
>         LV_PINMUX(VI_D7_PL5, SDMMC2, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
>         LV_PINMUX(VI_D10_PT2, RSVD1, NORMAL, NORMAL, INPUT, DISABLE, DISABLE),
>         LV_PINMUX(VI_MCLK_PT1, VI, UP, NORMAL, INPUT, DISABLE, DISABLE),
> -       DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, NORMAL, NORMAL, INPUT),
> +       /* UARTC RX, make sure we don't get input form a floating Pin */
> +       DEFAULT_PINMUX(UART2_RXD_PC3, UARTB, UP, NORMAL, INPUT),
>         DEFAULT_PINMUX(UART2_TXD_PC2, UARTB, NORMAL, NORMAL, INPUT),
>         DEFAULT_PINMUX(UART2_RTS_N_PJ6, GMI, NORMAL, NORMAL, INPUT),
>         DEFAULT_PINMUX(UART2_CTS_N_PJ5, GMI, NORMAL, NORMAL, INPUT),
> @@ -207,11 +208,11 @@ static struct pmux_pingrp_config tegra3_pinmux_common[] = {
>         DEFAULT_PINMUX(GMI_AD8_PH0, PWM0, NORMAL, NORMAL, OUTPUT), /* LCD1_BL_PWM */
>         DEFAULT_PINMUX(GMI_AD10_PH2, NAND, NORMAL, NORMAL, OUTPUT), /* LCD1_BL_EN */
>         DEFAULT_PINMUX(GMI_A16_PJ7, UARTD, NORMAL, NORMAL, INPUT),
> -       DEFAULT_PINMUX(GMI_A17_PB0, UARTD, NORMAL, NORMAL, INPUT),
> +       /* UARTB RX, make sure we don't get input form a floating Pin */
> +       DEFAULT_PINMUX(GMI_A17_PB0, UARTD, UP, NORMAL, INPUT),
>         DEFAULT_PINMUX(GMI_A18_PB1, UARTD, NORMAL, NORMAL, INPUT),
>         DEFAULT_PINMUX(GMI_A19_PK7, UARTD, NORMAL, NORMAL, INPUT),
>
> -
>         /* Multiplexed with KB_ROW10/KB_ROW11/KB_ROW12/KB_ROW15 */
>         DEFAULT_PINMUX(CAM_MCLK_PCC0, VI_ALT2, UP, TRISTATE, INPUT),
>         DEFAULT_PINMUX(PCC1, RSVD1, NORMAL, TRISTATE, INPUT),
> --
> 2.21.0
>
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Reviewed-by: Igor Opaniuk <igor.opaniuk at toradex.com>

-- 
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Igor Opaniuk

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