【tina_nezha】【求助】pwm无法启用/或寻其他途径控制舵机

The_Qiang LV 4

我尝试使用字符驱动和/sys/class/pwm/pwmchip0/export 启用pwm，驱动和用户层操作都是类似下面这种错误pinctrl_get failed

[  868.035098] platform 2000c17.pwm7: pinctrl_get failed

这是/sys/class下的pwm7(pwm1也是如此)

root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# ls
capture               output_type           power
duty_cycle            period                uevent
enable                polarity              waiting_for_supplier
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# echo 2000000 >period
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# echo 1000000 >duty_cycle
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# echo normal >polarity
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# echo 1 > enable
[  868.035098] platform 2000c17.pwm7: pinctrl_get failed
ash: write error: No such device
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# cat capture
[  885.724275] platform 2000c17.pwm7: pinctrl_get failed
[  885.730046] time out is 1000
[  894.621166] platform 2000c17.pwm7: pinctrl_get failed
[  894.627001] sunxi_pwm_capture: pwm capture timeout !
[  894.632728] platform 2000c17.pwm7: pinctrl_get failed
[  894.638491] time out is 1000
[  903.529004] platform 2000c17.pwm7: pinctrl_get failed
[  903.534865] sunxi_pwm_capture: pwm capture timeout !
cat: read error: Operation not permitted
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7# cat /sys/kernel/debug/pwm
platform/2000c00.pwm, 8 PWM devices
 pwm-0   (vdd-cpu             ): requested period: 0 ns duty: 0 ns polarity: inverse
 pwm-1   (sysfs               ): requested period: 2000000 ns duty: 0 ns polarity: inverse
 pwm-2   (lcd                 ): requested enabled period: 1000000 ns duty: 390625 ns polarity: normal
 pwm-3   ((null)              ): period: 0 ns duty: 0 ns polarity: inverse
 pwm-4   ((null)              ): period: 0 ns duty: 0 ns polarity: inverse
 pwm-5   ((null)              ): period: 0 ns duty: 0 ns polarity: inverse
 pwm-6   ((null)              ): period: 0 ns duty: 0 ns polarity: inverse
 pwm-7   (sysfs               ): requested period: 2000000 ns duty: 1000000 ns polarity: normal
root@TinaLinux:/sys/devices/platform/soc@3000000/2000c00.pwm/pwm/pwmchip0/pwm7#

下面是修改过的设备树

 	pwm1_pin_a: pwm1@0 {
		pins = "PB6";
           // allwinner,muxsel = <5>;//这个地方尝试过，也是pinctrl_get failed
		function = "pwm1";
		drive-strength = <10>;
		bias-pull-up;
	};

	pwm1_pin_b: pwm1@1 {
		pins = "PB6";
		function = "gpio_in";
	};
&pwm1 {
	pinctrl-names = "active", "sleep";
	pinctrl-0 = <&pwm1_pin_a>;
	pinctrl-1 = <&pwm1_pin_b>;
	status = "okay";
};

我还把设备树中PB6相关的其他设备都“disable”了（TWI3和daudio2）（i2s2的我没找到）结果和上面相同

allwinner,muxsel = <5>;我试着加在了pwm1_pin_a: pwm1@0 {} 里，也没效果