topic Re: Enabling console using LPUART8 for imx93 in i.MX Processors

Enabling console using LPUART8 for imx93

Robbi — Thu, 03 Apr 2025 13:56:29 GMT

Hi team,

I'm trying to boot a board which uses LPUART8 as console but LPUART1 default console in i.MX93 EVK kit. So I had done the changes in u-boot dts, linux-imx dts,imx93_evk.c and imx93_evk.h.

But unable to watch serial logs and same I checked using EVK kit J1001 header pin32&33 which are ALT modes of LPUART8. This configuration also doesn't work. Please let me know the changes need to be applied and also let me know the path.

Thanks

Robbi

Re: Enabling console using LPUART8 for imx93

Robbi — Mon, 07 Apr 2025 08:31:15 GMT

Please help on this issue modified all paths.

Re: Enabling console using LPUART8 for imx93

AldoG — Tue, 08 Apr 2025 00:18:32 GMT

Hello,

Could you share the changes you have made, so I could check those are made correctly?
Also, please share the Linux version you are working with.

Best regards/Saludos,
Aldo.

Re: Enabling console using LPUART8 for imx93

Robbi — Tue, 08 Apr 2025 04:30:49 GMT

Thanks @AldoG ,

For the response, i.MX93 EVK uses LPUART1 as default console port, but as my custom board is configured for LPUART8. I need to change my console from LPUART1 to LPUART8 and check in Header J1001. For that the modifications I had done:

u-boot-imx:

Added lpuart8 node and disabled lpuart1 along with iomux.
changed "console=ttyLP7,115200 earlycon\0" \ from ttyLP0" in /configs/imx93_evk.h file.
Added
static iomux_v3_cfg_t const uart_pads[] = {
// MX93_PAD_UART1_RXD__LPUART1_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
// MX93_PAD_UART1_TXD__LPUART1_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
MX93_PAD_GPIO_IO13__LPUART8_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
MX93_PAD_GPIO_IO12__LPUART8_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
}; in /imx93_evk/imx93_evk.c file.

linux-imx:

Added lpuart8 node and disabled lpuart1 along with iomux.

imx-atf:

changed IMX_LPUART_BASE U(0x426a0000) from U(0x44380000) in /include/platform_def.h file.

meta-fresscale:

changed SERIAL_CONSOLES = "115200;ttyLP7" in /conf/machine/imx93-11x11-lpddr4x-evk.conf which includes header /conf/machine/include/imx93-evk.inc file.

optee-os:

changed set(CFG_UART_BASE UART1_BASE) to set(CFG_UART_BASE UART8_BASE).

For more info add zip folder which contains images of changes done. Please go through it and let me know update.

Thanks

Robbi

Thanks

Robbi

Re: Enabling console using LPUART8 for imx93

AldoG — Tue, 08 Apr 2025 23:18:02 GMT

Hello,

All your changes are correct, you're missing some configuration for the clock to be enabled on the peripheral, since at boot time this is not being on by default.

at /arch/arm/mach-imx/imx9/native/clock.c
in mxc_get_clock(enum mxc_clock clk) function add:
return ccm_clk_root_get_rate(LPUART8_CLK_ROOT);

in void init_uart_clk(u32 index) function add:
case LPUART8_CLK_ROOT:
/* 24M */
ccm_lpcg_on(CCGR_URT8, false);
ccm_clk_root_cfg(LPUART8_CLK_ROOT, OSC_24M_CLK, 1);
ccm_lpcg_on(CCGR_URT8, true);
break;

Also at /board/freescale/imx93_evk/imx93_evk.c
in function int board_early_init_f(void) add:
init_uart_clk(LPUART8_CLK_ROOT);

This changes have been made and tested by a colleague and are working correctly on the EVK.

Best regards/Saludos,
Aldo.

Re: Enabling console using LPUART8 for imx93

Robbi — Wed, 09 Apr 2025 06:00:27 GMT

Thanks @AldoG ,

It is working now. Is i.mx93 Image compactible for imx91.

Thanks

Robbi.

Re: Enabling console using LPUART8 for imx93

AldoG — Wed, 09 Apr 2025 16:49:55 GMT

Hello,

Glad that it is working now, regarding image compatibility I would say no, since even if the processor is practically a downgrade of the other it would require to create your own image for the i.MX91 but you may reuse almost all of your changes.

Best regards/Saludos,
Aldo.