uart4 rx not working sololite

[kondaveetiarung]

Hi,

Iam working on imx6 sololite evk boards.in my board i configured  uart4 as in my dtsi

uart4: serial@02038000 {
                                        compatible = "fsl,imx6sl-uart", "fsl,imx21-uart";
                                        reg = <0x02038000 0x4000>;
                                        interrupts = <0 29 0x04>;
                                        clocks = <&clks IMX6SL_CLK_UART>,
                                                 <&clks IMX6SL_CLK_UART_SERIAL>;
                                        clock-names = "ipg", "per";
                                        dmas = <&sdma 31 4 0>, <&sdma 32 4 0>;
                                        dma-names = "rx", "tx";
                                        status = "disabled";
                                };

 uart4 {
                pinctrl_uart4_4:uart4grp-4 {
                        fsl,pins =<
                                MX6SL_PAD_KEY_COL6__UART4_RX_DATA   0x81701 /*pad Value i configured as the  0x1b0b1*/

                               My receive Pin Pad Value ( 0x184 0x48c 0x814 0x1 0x2)
                                MX6SL_PAD_KEY_COL6__UART4_TX_DATA   0x1b0b1

}

when iam trying to write data to uart port i got write return Value is equal to the my data length.but iam unable to receive the data from the module.i tried loop back also in my processor but iam unable to read the data from the processor.

My Tx pin Voltage is 3.3 v and my rx pin voltage is it is showing as the 2.15 volts only.

But i configured other uarts it is working fine but it is showing some problem on uart4 only.

Please tell me any modifications i need in uart.

[igorpadykov]

Hi kondaveeti 

please verify that there is record for enabling uart4 in dts files

status = "okay";

Best regards
igor
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[kondaveetiarung]

Hi igor,

Thank you for Reply.

&uart4 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_uart4_4>;
        status = "okay";
};

My dts file.

Any Modifications in the kernel source code for uart4

[igorpadykov]

Hi kondaveeti 

could you check uart4 imx6sl-evk-uart.dts example

linux-imx.git - i.MX Linux Kernel 

~igor

[kondaveetiarung]

Hi igor,

Thank you for your reply.

In My uart iam not using RTS and CTS Pins.Iam using only rxd and txd pins only.

and how to enable DTE mode?for previous uarts iam not using DTE MODE.

it is working fine.is there any hardware difference for uart4 compare to other uarts in imx6

[kondaveetiarung]

Hi,

How to tell to imx6 processor uart4 should be disable with RTS and CTS pins.

In my Previous kernels we are using some flags like

        static const struct imxuart_platform_data mx6sl_evk_ifd_uart4_data __initconst = {
//      .flags      = IMXUART_HAVE_RTSCTS,
        .dma_req_rx = MX6Q_DMA_REQ_UART4_RX,
        .dma_req_tx = MX6Q_DMA_REQ_UART4_TX,
};      

Here we have commented to disbale RTS and CTS functionality.

How to approch this technique in Device tree kernels.

[kondaveetiarung]

Hi,

Any update about my question?

[igorpadykov]

please refer to description in linux/Documentation/devicetree/bindings/serial/fsl-imx-uart.txt

~igor

[kondaveetiarung]

Hi igor,

Thank you.

it s working Thank you for your Valuable reply.