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| − | [[PWM/zh|查看中文]] | + | [[PWM/zh|查看中文]]<br> |
| − | ===H3上配置SYS_PWM===
| + | TODO |
| − | ====先确定内核已经打了这个补丁====
| + | |
| − | <syntaxhighlight lang="bash"> | + | |
| − | https://github.com/torvalds/linux/commit/179a79fd740b6b2f66b64bae5cb6ecd483987d20
| + | |
| − | </syntaxhighlight>
| + | |
| − | 注: FriendlyELEC的内核源代码分支 https://github.com/friendlyarm/linux/tree/sunxi-4.14.y 已包含此提交。
| + | |
| − | ====修改内核dts配置, 启用SYS_PWM (在NanoPi NEO上, 引脚与POWER LED复用)====
| + | |
| − | 参考以下补丁, 配置POWER LED对应的引脚为PWM功能，然后编译并测试:
| + | |
| − | <syntaxhighlight lang="bash">
| + | |
| − | diff --git a/arch/arm/boot/dts/sun8i-h3-nanopi-neo.dts b/arch/arm/boot/dts/sun8i-h3-nanopi-neo.dts
| + | |
| − | index b9826c150c0a..ca62502ad9a3 100644
| + | |
| − | --- a/arch/arm/boot/dts/sun8i-h3-nanopi-neo.dts
| + | |
| − | +++ b/arch/arm/boot/dts/sun8i-h3-nanopi-neo.dts
| + | |
| − | @@ -45,6 +45,10 @@
| + | |
| − | / {
| + | |
| − | model = "FriendlyElec NanoPi-NEO";
| + | |
| − | compatible = "friendlyelec,nanopi-neo", "allwinner,sun8i-h3";
| + | |
| − | +
| + | |
| − | + aliases {
| + | |
| − | + pwm1 = &r_pwm;
| + | |
| − | + };
| + | |
| − | };
| + | |
| − |
| + | |
| − | &emac {
| + | |
| − | @@ -52,4 +56,14 @@
| + | |
| − | phy-mode = "mii";
| + | |
| − | allwinner,leds-active-low;
| + | |
| − | status = "okay";
| + | |
| − | -};
| + | |
| − | \ No newline at end of file
| + | |
| − | +};
| + | |
| − | +
| + | |
| − | +&gpio_leds {
| + | |
| − | + pinctrl-0 = <&leds_npi>;
| + | |
| − | +
| + | |
| − | + /delete-node/ pwr;
| + | |
| − | +};
| + | |
| − | +
| + | |
| − | +&r_pwm {
| + | |
| − | + status = "okay";
| + | |
| − | +};
| + | |
| − | diff --git a/arch/arm/boot/dts/sun8i-h3-nanopi.dtsi b/arch/arm/boot/dts/sun8i-h3-nanopi.dtsi
| + | |
| − | index 5eeb41744735..1802f8ca2c56 100644
| + | |
| − | --- a/arch/arm/boot/dts/sun8i-h3-nanopi.dtsi
| + | |
| − | +++ b/arch/arm/boot/dts/sun8i-h3-nanopi.dtsi
| + | |
| − | @@ -89,7 +89,7 @@
| + | |
| − | };
| + | |
| − | };
| + | |
| − |
| + | |
| − | - leds {
| + | |
| − | + gpio_leds: leds {
| + | |
| − | compatible = "gpio-leds";
| + | |
| − | pinctrl-names = "default";
| + | |
| − | pinctrl-0 = <&leds_npi>, <&leds_r_npi>;
| + | |
| − | </syntaxhighlight>
| + | |
| − | ====测试脚本====
| + | |
| − | 在NanoPi NEO上测试, 可看到POWER LED以淡出效果闪烁10次:
| + | |
| − | <syntaxhighlight lang="bash">
| + | |
| − | #!/bin/bash
| + | |
| − | | + | |
| − | sys_pwm=/sys/class/pwm/pwmchip0
| + | |
| − | | + | |
| − | [ -d $sys_pwm ] || exit 1
| + | |
| − | | + | |
| − | if [ ! -d $sys_pwm/pwm0 ]; then
| + | |
| − | echo 0 > $sys_pwm/export
| + | |
| − | fi
| + | |
| − | | + | |
| − | echo 1000 > $sys_pwm/pwm0/period
| + | |
| − | echo 1 > $sys_pwm/pwm0/enable
| + | |
| − | | + | |
| − | for n in $(seq 10); do
| + | |
| − | for d in $(seq 0 50 1000); do
| + | |
| − | echo $d > $sys_pwm/pwm0/duty_cycle
| + | |
| − | sleep .02
| + | |
| − | done
| + | |
| − | sleep 1
| + | |
| − | done
| + | |
| − | </syntaxhighlight>
| + | |
