On I.MX6ULL, when the code is started from the SD card or nand flash , pwm is not outpt

[zhouxia]

On I.MX6ULL, when the code is solidified to the SD card or nand flash for operation, pwm is not output.

When the code runs in DDR3, the pwm output is normal.

When I use the core board of I.mx6ul to download the pwm firmware of i.mx6ull to the sd card for operation, the pwm output is also normal.

However, when the firmware is started from the sd card, it is necessary to set the PWMx_PWMCR bit23 (WAITEN) to 1 ,the pwm can be output normally.

[Sanket_Parekh]

Hi @zhouxia 

I hope you are doing well.

Please specify whether you are running the SDK_2.2_MCIM6ULL image or the Linux image.

Please provide me with more details about the PWM pin used.

Please make sure PWM pin is not muxed to any other function.

Thanks & Regards,

Sanket Parekh

[zhouxia]

I use Linux image.

II tested pwm1(GPIO1_IO08, ALT0), pwm2(GPIO1_IO09, ALT0), and pwm6 (GPIO3_IO24, ALT1)on i.mx6ull, all of which do not output pwm wave in sdcard.

the pin only used for PWM_OUT

[Sanket_Parekh]

Hi @zhouxia 

I hope you are doing well.

Please make sure that you have enabled menuconfig options for PWM as shown in 2.7.7 Menu Configuration Options in i.MX Linux Reference Manual. 

Please cross-check if your dts file contains pwm node and pinctrl as below.

&pwm1 {
	#pwm-cells = <2>;
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_pwm1>;
	status = "okay";
};

pinctrl_pwm1: pwm1grp {
	fsl,pins = <
		MX6UL_PAD_GPIO1_IO08__PWM1_OUT   0x110b0
	>;
};

Please clarify what you mean by "code is solidified to the SD card".

Please make a note that GPIO1_IO08, GPIO1_IO09, and GPIO3_IO24 are used for display backlight brightness control. SD1 RESET and LCDIF respectively in imx6ul-14x14-evk.dtsi

Please provide me with linux kernel version, device tree, and steps used to test pwm for further debugging.

Thanks & Regards,

Sanket Parekh