Hello!
I am now working on a custom i.MX6Q board with Yocto(3.10.17_1.0.2),and I want to enable HW
flow control for UART2(Which is used for BT module).
When I worked with LTIB(3.0.35),I set the UART2 as below.
1)pin config
MX6Q_PAD_GPIO_7__UART2_TXD,
MX6Q_PAD_GPIO_8__UART2_RXD,
MX6Q_PAD_EIM_D28__UART2_CTS,
MX6Q_PAD_EIM_D29__UART2_RTS,
2)set CTSRTS flag.
static const struct imxuart_platform_data mx6_xxxx_uart2_data __initconst = {
.flags = IMXUART_HAVE_RTSCTS,
};
static inline void mx6q_xxxx_init_uart(void)
{
......
imx6q_add_imx_uart(1, &mx6_xxxx_uart2_data); /* UART2:BT */
.......
}
Then I test the UART2 with /unit_test/mxc_uart_xmit_test
./mxc_uart_xmit_test.out /dev/ttymxc1 -B 115200 -HW
The terminal output logs sent 10000 bytes with speed 105540.897098bps
According to the logs, the hardware flow control is enabled for UART2.
-------------------------------------------------------------------------------------------------------------------
Now I am working with Yocto, and I set the UART2 in device tree files as below.
1)pin config.
pinctrl_uart2_3: uart2grp-3 {
fsl,pins = <
MX6QDL_PAD_GPIO_8__UART2_RX_DATA 0x1b0b1
MX6QDL_PAD_GPIO_7__UART2_TX_DATA 0x1b0b1
MX6QDL_PAD_EIM_D28__UART2_CTS_B 0x1b0b1
MX6QDL_PAD_EIM_D29__UART2_RTS_B 0x1b0b1
>;
};
2)uart2
/*BT*/
&uart2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart2_3>;
status = "okay";
fsl,uart-has-rtscts;
};
Then I run the /unit_test/mxc_uart_xmit_test
./mxc_uart_xmit_test.out /dev/ttymxc1 -B 115200 -HW
There is no message like 'sent 10000 bytes with speed .....' output.
------------------------------------------------------------------------------------------------------------------------
In the LTIB case,when it is running mxc_uart_xmit_test, the UART2_RTS pin is always low.
But in the Yocto case,the UART2_RTS pin is always high.
I don't know whether is there something wrong with L3.10.17?
Could you help me.Thank you.
Best Regards,
ZongbiaoLiao
