Re: [PATCH] ARM: dts: imx: imx6q uart2 pin mux correction

[Vladimir Zapolskiy <vz@mleia.com>]

Hi Robert,

On 10.03.2015 15:45, Robert Smigielski wrote:
> This patch contains a correction to the file imx6q-pinfunc.h for the
> definition of the UART2 GPIO pin mux setting.
> 
> Issue found when testing UART2 configured as the console in Linux
> GPIO_7 is a transmit pin not a transmit and receive pin
> GPIO_8 is a receive pin not a transmit and receive pin
> 
> Verified the correction with Freescale in posting to the Freescale
> forum https://community.freescale.com/thread/343349
> 
> commit c383bbb4d17037435305858f488db7ae17dc1c85
> Author: robert.smigielski <robert.smigielski@timesys.com>
> Date:   Fri Mar 6 11:53:20 2015 -0500
> 
>     UART2 Tx and Rx values corrected based on IMX6Q datasheet
> 
> diff --git a/arch/arm/boot/dts/imx6q-pinfunc.h
> b/arch/arm/boot/dts/imx6q-pinfunc.h
> index c68c21d..4d4cc49 100644
> --- a/arch/arm/boot/dts/imx6q-pinfunc.h
> +++ b/arch/arm/boot/dts/imx6q-pinfunc.h
> @@ -696,8 +696,7 @@
>  #define MX6QDL_PAD_GPIO_7__ECSPI5_RDY               0x240 0x610 0x000 0x1 0x0
>  #define MX6QDL_PAD_GPIO_7__EPIT1_OUT                0x240 0x610 0x000 0x2 0x0
>  #define MX6QDL_PAD_GPIO_7__FLEXCAN1_TX              0x240 0x610 0x000 0x3 0x0
> -#define MX6QDL_PAD_GPIO_7__UART2_TX_DATA            0x240 0x610 0x000 0x4 0x0
> -#define MX6QDL_PAD_GPIO_7__UART2_RX_DATA            0x240 0x610 0x928 0x4 0x2
> +#define MX6QDL_PAD_GPIO_7__UART2_TX_DATA            0x240 0x610 0x928 0x4 0x2

the introduction of non-zero input register for UART TX pin is valid
only for UART2 in DTE mode, so in my opinion only removal of
MX6QDL_PAD_GPIO_7__UART2_RX_DATA and MX6QDL_PAD_GPIO_8__UART2_TX_DATA is
needed here. Otherwise you get a conflict within
IOMUXC_UART2_UART_RX_DATA_SELECT_INPUT between invalid in DCE
UART2_TX_DATA and valid in DCE UART2_RX_DATA configuration.

FWIW even currently defined MX6QDL_PAD_GPIO_7__UART2_RX_DATA and
MX6QDL_PAD_GPIO_8__UART2_TX_DATA are correct in DTE mode, but I think it
is better to preserve the proper pin function names, so no objections if
these two definitions are removed for sake of clarity.

>  #define MX6QDL_PAD_GPIO_7__GPIO1_IO07               0x240 0x610 0x000 0x5 0x0
>  #define MX6QDL_PAD_GPIO_7__SPDIF_LOCK               0x240 0x610 0x000 0x6 0x0
>  #define MX6QDL_PAD_GPIO_7__USB_OTG_HOST_MODE        0x240 0x610 0x000 0x7 0x0
> @@ -706,7 +705,6 @@
>  #define MX6QDL_PAD_GPIO_8__EPIT2_OUT                0x244 0x614 0x000 0x2 0x0
>  #define MX6QDL_PAD_GPIO_8__FLEXCAN1_RX              0x244 0x614 0x7e4 0x3 0x1
>  #define MX6QDL_PAD_GPIO_8__UART2_RX_DATA            0x244 0x614 0x928 0x4 0x3
> -#define MX6QDL_PAD_GPIO_8__UART2_TX_DATA            0x244 0x614 0x000 0x4 0x0
>  #define MX6QDL_PAD_GPIO_8__GPIO1_IO08               0x244 0x614 0x000 0x5 0x0
>  #define MX6QDL_PAD_GPIO_8__SPDIF_SR_CLK             0x244 0x614 0x000 0x6 0x0
>  #define MX6QDL_PAD_GPIO_8__USB_OTG_PWR_CTL_WAKE     0x244 0x614 0x000 0x7 0x0
> 

--
With best wishes,
Vladimir