Enable other uart in imx6 sololite evk

[eugenephua]

Hi all, on the imx6 sololite evk board, there is only 1 uart enabled and is used for the USB to UART debugging port. I saw the schematic and there are several UARTs but they are connected to other pins. How do i enable the other UARTs in order to use them? Do i need to recompile the kernel? I am just starting to use the imx6 board so any advise is good!

[eugenephua]

Hi all, just to consolidate the question, i saw that pin KEY_COL6 and KEY_ROW6 corresponds to uart4.RXD_MUX and uart4.TXD_MUX in the ALT1 mux mode. In its original mux mode, they are used as the push buttons if i am not wrong.

Now i want to use these 2 pins KEY_COL6 and KEY_ROW6 to act as UART4 instead of push buttons. I read and think i will need to change the u-boot to support this?

In u-boot, i saw this inside the file mx6slevk.c

static void setup_iomux_uart(void)

{

    imx_iomux_v3_setup_multiple_pads(uart1_pads, ARRAY_SIZE(uart1_pads));

}

Do i just add one line -> imx_iomux_v3_setup_multiple_pads(uart4_pads, ARRAY_SIZE(uart4_pads)); ??

thanks for helping out this newbie here

[igorpadykov]

Hi Eugene

please look at attached document

Chapter 3 Registering a New UART Driver

Best regards

igor

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[eugenephua]

Hi igorpadykov, thanks for the manual. In the manual Chapter 3.1.4 it mentioned the relevant uart files, but i cannot find the directory plat-max : linux/arch/arm/mach-imx at master · torvalds/linux · GitHub . Has the directory been updated to this mach-imx?

Regards

Eugene

[igorpadykov]

Hi Eugene

please look at another attached file Chapter 3.

Best regards

igor

[eugenephua]

Hi igor,

For the BSP porting guide chapter 3, the serial devices are enabled. This is a screenshot of the dev, only ttymxc0 is displayed. How do i get the ttymxc1,2 or 3 to show?

I also did a dmesg | grep tty and the result is:

Kernel command line: console=ttymxc0,115200 root=/dev/mmcblk1p2 rootwait rw

2020000.serial: ttymxc0 at MMIO 0x2020000 (irq = 58) is a IMX

console [ttymxc0] enabled

[jayaramks]

HI,

1.Configuring UART Pads on IOMUX as described in  i.MX_6SoloLite_BSP_Porting_Guide.pdf.

2.in board.c file add UART usining imx6q_add_imx_uart() function.

Regards,

Jayaram

[eugenephua]

Hi Jayaram, thanks for the information. However, I am confused as to which linux kernel i should use:

(1) linux-2.6-imx.git - Freescale i.MX Linux Tree

(2) https://github.com/torvalds/linux

For both of these, they do not have the /arch/arm/mach-mx6/board-mx6sl_evk.c file. Could you share the link to get the correct kernel?

Thanks!
Eugene

[jayaramks]

You can find i.MX 6 Series Software and Development Tool Resources @

i.MX 6 Series Software and Development Tool R|Freescale

Regards,

Jayaram

[eugenephua]

I have already downloaded the L3.10.53_1.1.0_iMX6SL_Bundle. But it does not contain any source code for the kernel inside... Please help link me to the board.c file... I have tried looking and found one at https://gitorious.org/utilite/utilite/source/923d109379cfcca3e69251aa4d2100fbd5c0b208:arch/arm/mach-....

But looking at the directory structure, it looks so much different from Freescale's. E.g. it has the mach-mx6 directory but Freescale does not have and instead, the closest is mach-imx. Inside, the files are not the same...

[jayaramks]

Try:

L3.10.17_1.0.0_IMX6SL_BUNDLE : Source Code Download Steps Documentation and Demo Images.
Size (K): 714420 Format: gz Rev #: L3.10.17_1.0.0 Modified: 2/24/2015

[eugenephua]

Hi Jayaram,

The bundle contains only the images, it does not contain any source codes. After some reading, the mx6slevk.c file can be found inside the git.denx.de Git instead of the Freescale git..

A question here is for enabling the additional uart, we need to change u-boot and kernel?

Thanks!

Eugene