lpcXpresso55s16 UART configuration issue of Flexcomm7

[Arjundnsh]

Hi Team,

I am trying to configure the UART channel through Flexcomm7 in lpcXpresso55s16 board.
It is unable to configure and the program execution is stopping in the zephyr stack level. I am explaining the steps in below what we tried yet.

1. Modified the board file for enabling the UART functionality through Flexcomm7 of lpcXpresso55s16.dtsi
   `
   #include <nxp/lpc/LPC55S16JBD64-pinctrl.h>

/ {
chosen {
zephyr,console = &flexcomm0;
zephyr,shell-uart = &flexcomm0;
zephyr,rj-uart1 = &flexcomm2;
zephyr,rj-uart2= &flexcomm7;
};

aliases{
	usart-0 = &flexcomm0;
	**usart-1 = &flexcomm2; 
	usart-2 = &flexcomm7;**
};

};

&flexcomm0 {
status = "okay";
compatible = "nxp,lpc-usart";
current-speed = <115200>;
pinctrl-0 = <&pinmux_flexcomm0_usart>;
pinctrl-names = "default";
};

&flexcomm2 {
status = "okay";
compatible = "nxp,lpc-usart";
current-speed = <115200>;
pinctrl-0 = <&pinmux_flexcomm2_usart>;
pinctrl-names = "default";
};

&flexcomm7 {
status = "okay";
compatible = "nxp,lpc-usart";
current-speed = <115200>;
pinctrl-0 = <&pinmux_flexcomm7_usart>;
pinctrl-names = "default";
};

&pinctrl {

pinmux_flexcomm0_usart: pinmux_flexcomm0_usart {
	group0 {
		pinmux = <FC0_RXD_SDA_MOSI_DATA_PIO0_29>,
			<FC0_TXD_SCL_MISO_WS_PIO0_30>;
		slew-rate = "standard";
	};
};

//added the below configuration for flexcomm2
pinmux_flexcomm2_usart: pinmux_flexcomm2_usart {
group0 {
pinmux = <FC2_RXD_SDA_MOSI_DATA_PIO0_26>,
<FC2_TXD_SCL_MISO_WS_PIO0_27>;
slew-rate = "standard";
};
};

//added the below configuration for flexcomm7
pinmux_flexcomm7_usart: pinmux_flexcomm7_usart {
group0 {
pinmux = <FC7_RXD_SDA_MOSI_DATA_PIO0_20>,
<FC7_TXD_SCL_MISO_WS_PIO0_19>;
slew-rate = "standard";
};
};

};

`

2)Created api for UART Tx and Rx communication in a module file for handling it in the Stack level

3)Using a simple test function which is given below to test the transmission functionality.
`uart_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_rj_uart2));

void device_init()
{
int ret=uart_configure(uart_dev, &uart_cfg);
printk("uart_return=%d\n",ret);

if (!device_is_ready(uart_dev)) {
	printk("UART device not found!");
	ret_val= osal_rj12_err_dev_not_found;
}
else {
	printk("UART device found successfully\n");
	ret_val = osal_rj12_return_ok ;
}

}

void main()
{
uint8_t buffer[12]={1,2,3,4,5,6,7,8,9,10,11,12};
uint8_t length = 12;
device_init(); //device initialization
osal_rj12_send(buffer,length); // Uart data Transmission
}`

It is giving the following log:
<NUL>�*** Booting Zephyr OS build zephyr-v3.3.0-3441-g3154e03c454a ***<CR><LF> Main function started<CR><LF> Device initializing<CR><LF> rj12_init<CR><LF> after DT<CR><LF>

and after that the execution is halted. There is not further program run and no any log is getting printed.

The halting point is the command for configuring the flexcomm7 as UART functionality with baudrate 115200
uart_configure(uart_dev, &uart_cfg);

The same work around with configuring the UART channel with Flexcomm2 is working fine and we are able to configure and communicate the data though it. The logs for the same is attaching below:

10/15/2023 14:55:49.177 [RX] - *** Booting Zephyr OS build zephyr-v3.3.0-3441-g3154e03c454a ***<CR><LF> Main function started<CR><LF> Device initializing<CR><LF> rj12_init<CR><LF> after DT<CR><LF> uart1_return=0<CR><LF> UART device found successfully<CR><LF> Test Function<CR><LF> <CR><LF> Transmission started<CR><LF> Transmission successful<CR><LF> Transmission started<CR><LF> Transmission successful<CR><LF> Transmission started<CR><LF> Transmission successful<CR><LF> Transmission started<CR><LF> Transmission successful<CR><LF> Transmission started<CR><LF> Transmission successful<CR><LF> Transmission started<CR><LF>

Please suggest/correct me, if I need to do any additional modifications/changes for configuring Flexcomm7 to make it functional as a UART as compare to the Flexcomm2 port (which is functioning properly) in lpcXpresso55s16.

[github-actions[bot]]

Hi @Arjundnsh! We appreciate you submitting your first issue for our open-source project. 🌟

Even though I'm a bot, I can assure you that the whole community is genuinely grateful for your time and effort. 🤖💙

[decsny]

Hi,

In the zephyr tree, please check the file soc/arm/nxp_lpc/lpc55xxx/soc.c which is where currently the clock configuration is set up on this SOC platform. It looks like flexcomm2 has code to be clocked for uart but not flexcomm7.