固件类型：官方提供的固件
固件文件名称：ROC-RK3588S-PC_Ubuntu22.04-Xfce-r31167_v1.3.0c_260
固件下载地址：百度网盘
Log日志：修改的设备树和pwm脚本.rar
我想要把UART7_TX（GPIO1_B5）复用成PWM引脚，实现LED灯做呼吸灯的功能。修改完设备树重启后，发现新的PWM设备确实是注册上了，用逻辑分析仪查看引脚，引脚一直没有输出PWM波。
我对设备树做了如下修改：
1.禁用 UART7，释放GPIO1_B4(gpio1-12) 和 GPIO1_B5(gpio1-13)，避免与 PWM3 引脚冲突
2.启动PWM3节点
3.在 pinctrl/pwm3 节点内部，添加配置
4.在 symbols 节点之前添加PWM LED节点
5.注册新节点到 `symbols
输入sudo cat /sys/kernel/debug/pinctrl/pinctrl-maps | grep"gpio1-13"
输入sudo cat /sys/kernel/debug/pinctrl/pinctrl-maps | grep"pwm3"
请问我哪个步骤弄错了，还是说要是特定的GPIO引脚才能生成PWM?
以及除了这个PWM3，还有没有其他PWM通道可以用的？
tchip_askquestions
修改的设备树和pwm脚本.rar (37.9 KB)
发现上面的图片顺序错了。重新上传的附件是问题的pdf版本，内容都是一样的
操作流程.pdf (175 KB)
That’s a tricky one! Device tree modifications can be quite finicky, especially when you’re dealing with pin multiplexing on a Rockchip RK3588. It’s great that you’ve already confirmed the PWM device is registered, but the lack of output is definitely a head-scratcher. Have you double-checked the clock source and frequency settings for your PWM3 node?
Configuring GPIO pins like GPIO1_B4 for PWM control in device tree files (DTS/DTSI) is an essential topic for anyone working with Rockchip platforms and Firefly boards! Proper multiplexing settings and kernel pin control definitions are key to getting pulse-width modulation functioning correctly for hardware projects. While taking a break from troubleshooting embedded Linux configurations and hardware drivers, I also like to check out for some casual online gaming. Thanks for sharing this forum thread!
