Using the serial port on Sabre lite board

[cliftonjones]

I am currently trying to output data from my android app running on Sabre lite board through the serial port. Can i enable that port through the U-boot and if so which command do I use?

[sandeshgowda]

Eric,

We are using imx6 sabrelite rev-2 board running Android Lollipop(Linux kernel 3.10).  DTS file we are using is imx6q-nitrogen6x.dts. By default UART2(ttymxc1) is configured for console. We are trying to bring up bluetooth (BCM4339) which  uses UART as the interface. As per the sabre_lite-revD.pdf schematic, we configured the UART1(ttymxc0) in imx6qdl-nitrogen6x.dtsi and commented the similar lines(SD3_DAT6 and SD3_DAT7) which were configured for MMC in imx6qdl.dtsi.  Please find the UART1 configuration below,

the below configurations are based on http://boundarydevices.com/sabre_lite-revD.pdf

uart1 {

                pinctrl_uart1_2: uart1grp-2 {

                        fsl,pins = <

                                MX6QDL_PAD_SD3_DAT7__UART1_TX_DATA 0x1b0b1

                                MX6QDL_PAD_SD3_DAT6__UART1_RX_DATA 0x1b0b1

                        >;

                };

        };

&uart1 {

        pinctrl-names = "default";

        pinctrl-0 = <&pinctrl_uart1_2>;

        status = "okay";

};

We are using BCM murata chip(http://wireless.murata.com/eng/products/rf-modules-1/wi-fi-bluetooth/type-zp.html) for Bluetooth and WiFi . To load the blueooth firmware, we are using brcm_patchram_plus tool. When we run this tool from our PC, we are able to load the firmware to the BT chip. But when we try the same from the console, sabrelite board is not able to communicate with the BT chip.

Regards,

Sandesh D

[cliftonjones]

The problem I am having is that I cannot open the the uart port 0 which is the serial port on this device.I also cannot access the root so that i can check to see if that port is enabled.

[EricNelson]

Hi Clifton,

Which serial port? The second (non-console) serial port is available as /dev/ttymxc0, and should be world readable/writeable:

android_device_boundary/ueventd.boundary.rc at boundary-kk4.4.2_1.0.0-ga · boundarydevices/android_d...

We've tested this on various occasions using off-the-shelf terminal emulator apps.

You may have some contention for the console port (/dev/ttymxc1) because it's configured as a console by

default in our boot script. You can change that by removing the references to "ttymxc1" here:

     android_device_boundary/6x_bootscript.txt at boundary-kk4.4.2_1.0.0-ga · boundarydevices/android_dev...

[chum]

after changing the uart how to use it for serial application.

my android serial application should send the data imx6q hardware to host machine serial console

[cliftonjones]

I am trying to use the non console serial port. The problem I am having is that i still can't acess to the port. Do you know the boot command  to enable ttymxc0? also the board I have is using 08-09 U-boot , does that matter?

[EricNelson]

Hi Clifton,

I'm not sure what you mean by "cannot access". Are you having trouble opening the device, or does the device not communicate as expected.

I just tested things out on one of our boards using this simple console program (via ADB).

U-Boot should have nothing to do with access to the serial port once Linux is booted, but I encourage you to update to the latest.

     http://boundarydevices.com/u-boot-2014-07-release-mx6-boards/

[cliftonjones]

The problem I am having is that I cannot open the the uart port 0 which is the serial port on this device.I also cannot access the root so that i can check to see if that port is enabled