AM625: use WKUP_UART0 as BT connect port

Hi Daniel,

Does the customer use the Processor SDK Linux package? Can you please explain how "it can not work"?

Hi Bin

Only one byte of data can be sent, and then it cannot be sent.

Thanks

Daniel

Daniel,

You still didn't provide enough details for me to understand the issue. Please explain:

- you hardware setup, do you use AM62x EVM or your custom board? how is the BT device connected to WKUP UART0 port?

- any kernel change to support this BT device?

- what program and how did you run the test?

- any Linux log showing the issue?

Hi Bin

- you hardware setup, do you use AM62x EVM or your custom board? how is the BT device connected to WKUP UART0 port?

custom board.

- any kernel change to support this BT device?

Only the device tree has been modified.

/ {

    bt_reg_on: regulator-5 {

        compatible = "gpio-reset";

        pinctrl-names = "default";

        pinctrl-0 = <&main_bt_en_pins_default>;

        reset-gpios = <&main_gpio0 42 GPIO_ACTIVE_LOW>;

        reset-delay-us = <2000>;

        reset-post-delay-ms = <200>;

        #reset-cells = <0>;

    };

  main_bt_en_pins_default: main-bt-en-pins-default {

        pinctrl-single,pins = <

            AM62X_IOPAD(0x00ac, PIN_OUTPUT_PULLUP, 7) /* (L21) GPMC0_CSn1.GPIO0_42 */

            AM62X_IOPAD(0x0244, PIN_OUTPUT_PULLUP, 7) /* (C17) MMC1_SDWP.GPIO1_49 */

        >;

    };

/* BT */

&wkup_uart0 {

    /* WKUP UART0 is used by DM firmware */

    //status = "reserved";

    pinctrl-names = "default";

    pinctrl-0 = <&wkup_uart0_pins_default>;

    resets = <&bt_reg_on>;

};

- what program and how did you run the test?

Loading firmware fails when using the hciattch command.

- any Linux log showing the issue?

Thanks

Daniel

Hi Daniel,

I think first we need to determine the issue is in UART or the BT device. Can you please bypass the BT device and connect the TXD RXD pins directly, then run UART external loopback test. If you can send and receive UART characters, then issue is not in UART. Otherwise, we need to look at the UART configuration first.

Hi Bin

Remove BT device, but UART only can send one byte data.

So the issue maybe the UART configuration.

Thanks

Daniel

Daniel,

Please explain how you tested the UART.

Hi Bin

Connect TXD and RXD to loopback test, send at most 2 bytes and the system will hang

Thanks

Daniel

Hi Daniel,

Daniel Cheng1 said:

  pinctrl-names = "default";

    pinctrl-0 = <&wkup_uart0_pins_default>;

How is this pinmux configured in device tree?

Hi Bin

&mcu_pmx0 {

    wkup_uart0_pins_default: wkup-uart0-pins-default {

        pinctrl-single,pins = <

            AM62X_MCU_IOPAD(0x002c, PIN_INPUT, 0) /* (C6) WKUP_UART0_CTSn */

            AM62X_MCU_IOPAD(0x0030, PIN_OUTPUT, 0) /* (A4) WKUP_UART0_RTSn */

            AM62X_MCU_IOPAD(0x0024, PIN_INPUT, 0) /* (B4) WKUP_UART0_RXD */

            AM62X_MCU_IOPAD(0x0028, PIN_OUTPUT, 0) /* (C5) WKUP_UART0_TXD */

        >;

    };

Thanks

Daniel

Hi Daniel,

The pinmux looks correct.

Have you tried to enable the wkup uart0 on AM625 SK EVM and test to see if it has the same issue?

Hi Bin

Yes, it has the same issue.

The modified device tree is as follows:

--------------------------------------------------------------------------------------------

diff --git a/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi b/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi

index 054a41caa0c5..c9cb995d25bb 100644

--- a/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi

+++ b/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi

@@ -8,6 +8,7 @@

/ {

        aliases {

                serial2 = &main_uart0;

+               serial1 = &wkup_uart0;

                mmc0 = &sdhci0;

                mmc1 = &sdhci1;

                mmc2 = &sdhci2;

@@ -247,6 +248,17 @@ hdmi_connector_in: endpoint {

        };

};

+&mcu_pmx0 {

+       wkup_uart0_pins_default: wkup-uart0-pins-default {

+               pinctrl-single,pins = <

+                       AM62X_MCU_IOPAD(0x002c, PIN_INPUT, 0) /* (C6) WKUP_UART0_CTSn */

+                       AM62X_MCU_IOPAD(0x0030, PIN_OUTPUT, 0) /* (A4) WKUP_UART0_RTSn */

+                       AM62X_MCU_IOPAD(0x0024, PIN_INPUT, 0) /* (B4) WKUP_UART0_RXD */

+                       AM62X_MCU_IOPAD(0x0028, PIN_OUTPUT, 0) /* (C5) WKUP_UART0_TXD */

+               >;

+       };

+};

+

&main_pmx0 {

        main_uart0_pins_default: main-uart0-pins-default {

                pinctrl-single,pins = <

@@ -453,7 +465,8 @@ AM62X_IOPAD(0x0084, PIN_INPUT, 2) /* (L23) GPMC0_ADVN_ALE.MCASP1_AXR2 */

 &wkup_uart0 {

        /* WKUP UART0 is used by DM firmware */

-       status = "reserved";

+       pinctrl-names = "default";

+       pinctrl-0 = <&wkup_uart0_pins_default>;

};

Thanks

Daniel

Hi Bin

Customer used this modification on AM625 SK EVM, but the problem still exists. Maybe he took one of the wrong steps. Can you help to provide his binaries to test?

Thanks

Daniel

Hi Daniel,

Attached below are the uboot binaries with WKUP UART0 disabled.

u-boot-wkup-uart.zip

Hi Bin

Customer uses the binary file to test on the SK-AM625 evm, puts the three files into the first partition of the SD card, and then uses the SD card to boot, the test result WKUP_UART0 still only sends one byte

Is the DM firmware the file ipc_echo_testb_mcu1_0_release_strip.xer5f?

but can't find the source code

Is DM firmware included when making u-boot?

How do I verify this file?

Thanks

Daniel

Hi Daniel,

Daniel Cheng1 said:

Is the DM firmware the file ipc_echo_testb_mcu1_0_release_strip.xer5f?

Yes.

Daniel Cheng1 said:

but can't find the source code

Its source code is not provided.

Daniel Cheng1 said:

Is DM firmware included when making u-boot?

Yes.

Daniel Cheng1 said:

How do I verify this file?

U-Boot won't boot if the DM firmware is missing in the U-Boot binary.

Hi Daniel,

I could echo string multiple times, but transmission failed in my stress test. I will look into it to understand why wkup uart fails.

Next week is a holiday in US, so please expect my delayed update.