topic Re: [iMX8QM-MEK] LPUART2 setting in i.MX Processors

[iMX8QM-MEK] LPUART2 setting

sushi_happy — Tue, 09 Aug 2022 09:27:48 GMT

Hi, all.

I want to know how to use LPUART2 from coreA.
By default, LPUART2 is assigned to the coreM4, and I think that access is prohibited from the coreA.

I used scfw_tcm.bin which was built by changing the SCFW setting.
・board.c (/imx-scfw-porting-kit-1.12.1/src/scfw_export_mx8qm_b0/platform/board/mx8qm_mek)
- changed the following code.

/* List of pads */
static const sc_pad_t pad_list[6U] =
{
RM_RANGE(SC_P_M41_I2C0_SCL, SC_P_M41_GPIO0_01),
// RM_RANGE(SC_P_UART0_CTS_B, SC_P_UART0_RTS_B),
RM_RANGE(SC_P_FLEXCAN0_RX, SC_P_FLEXCAN2_TX),
RM_RANGE(SC_P_QSPI0A_DATA0, SC_P_COMP_CTL_GPIO_1V8_3V3_QSPI0)
};

Also, I made the following changes.

environment
・Android-11.0.0_2.6.0
・MCIMX8QM-CPU + MCIMX8-8X-BB

changes
・init.rc (/device/nxp/imx8q/mek_8q)
- Added the following code before "on boot".

chmod 0777 /dev/ttyLP2

・imx8qm-mek.dts (/vendor/nxp-opensource/kernel-imx/arch/arm64/boot/dts/freescale)
- changed the following code.

&lpuart2 {
pinctrl-0 = <&pinctrl_lpuart2>;
status = "okay";
};

However, LPUART2 is not enabled.
The ttyLP2 device file is not added.
What other settings do I need?

Re: [iMX8QM-MEK] LPUART2 setting

joanxie — Fri, 19 Aug 2022 10:17:17 GMT

try to set this in the uboot

setenv console ttyLP2

setenv mmcargs setenv bootargs console=${console},${baudrate} root=${mmcroot}

when board boot up, use command " dmesg | grep -i console", what do you get?

Re: [iMX8QM-MEK] LPUART2 setting

sushi_happy — Mon, 22 Aug 2022 08:04:17 GMT

@joanxie

Is this okay?
ttyLP2 is not registered yet.

Re: [iMX8QM-MEK] LPUART2 setting

joanxie — Wed, 31 Aug 2022 08:45:56 GMT

could you share the logfile with me?

Re: [iMX8QM-MEK] LPUART2 setting

sushi_happy — Thu, 01 Sep 2022 01:44:40 GMT

@joanxie

I sent you the log file by private message.

Could you please check?

Re: [iMX8QM-MEK] LPUART2 setting

sushi_happy — Tue, 04 Oct 2022 00:12:39 GMT

I was able to enable ttyLP2 with the following changes:

1.
Change the boot setting
・BoardConfig.mk(/device/nxp/imx8q/mek_8q)
　Added the following code.
# SELinux
BOARD_KERNEL_CMDLINE += androidboot.selinux=permissive

・init.rc (/device/nxp/imx8q/mek_8q)
　Added the following code before "on boot".
chmod 0777 /dev/ttyLP2

2.
Change the device tree.
・imx8qm-mek.dts(vendor/nxp-opensource/kernel_imx/arch/arm64/boot/dts/freescale)
　Changed the following code.
&lpuart2 {
pinctrl-0 = <&pinctrl_lpuart2>;
status = "okay";
};

・imx8qm-mek-rpmsg.dts(vendor/nxp-opensource/kernel_imx/arch/arm64/boot/dts/freescale)
　Changed the following code.
&lpuart2 {
status = "okay";
};

&uart2_lpcg {
status = "okay";
};

3.
Remove pin assignment of M4 core
・Base on board-imx8qm.c (vendor/nxp/fsl-property/uboot-firmware/imx8q), change as follows.
/* Create M4 1 partition */
if (rm_is_resource_avail(SC_R_M4_1_PID0) != SC_FALSE)
{
sc_rm_mr_t mr;

/* List of resources */
static const sc_rsrc_t rsrc_list[8U] =
{
SC_R_IRQSTR_M4_1,
// SC_R_UART_2,
SC_R_MU_6B,
SC_R_MU_7B,
SC_R_MU_9B,
SC_R_GPT_3,
RM_RANGE(SC_R_CAN_0, SC_R_CAN_2),
SC_R_FSPI_0
};

/* List of pads */
static const sc_pad_t pad_list[6U] =
{
RM_RANGE(SC_P_M41_I2C0_SCL, SC_P_M41_GPIO0_01),
// RM_RANGE(SC_P_UART0_CTS_B, SC_P_UART0_RTS_B),
RM_RANGE(SC_P_FLEXCAN0_RX, SC_P_FLEXCAN2_TX),
RM_RANGE(SC_P_QSPI0A_DATA0, SC_P_COMP_CTL_GPIO_1V8_3V3_QSPI0)
};
・Build with gcc-toolchain and place the generated binary file in vendor/nxp-opensource/imx-mkimage/iMX8QM.
　Refer：https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/System-Controller-Firmware-101-Getting-started/ta-p/1121153
・At this time, change the name of the binary file.
Also, change the code of "scfw-tcm.bin" in the following makefile as above.
(soc.mak, android.mak, autobuild.mak, m4.mak, misc.mak)