T507 PWM互补输出

[yozad]

需求：全志T507，把PI12、PI13复用为PWM2、PWM3，想要让PWM2、3互补输出。

T507手册上支持pwm互补输出

看源码需要在设备树里面配置"bind_pwm"和"dead_time"，获取死区时间和“互补输出绑定的pwm？？”，这里的bind_pwm不是很理解。

static int sunxi_pwm_get_config(struct platform_device *pdev, struct sunxi_pwm_config *config)
{
	struct device_node *np = pdev->dev.of_node;
	int ret = 0;

	/* read register config */
	pr_info("sunxi_pwm_get_config %s\n", np->name);

	ret = of_property_read_u32(np, "bind_pwm", &config->bind_pwm);
	if (ret < 0) {
		/*if there is no bind pwm,set 255, dual pwm invalid!*/
		config->bind_pwm = 255;
		ret = 0;
	}

	ret = of_property_read_u32(np, "dead_time", &config->dead_time);
	if (ret < 0) {
		/*if there is  bind pwm, but not set dead time,set bind pwm 255,dual pwm invalid!*/
		config->bind_pwm = 255;
		ret = 0;
	}

	pr_info("bind_pwm=%d,dead_time=%d\n", config->bind_pwm, config->dead_time);
	ret = of_property_read_u32(np, "clk_bypass_output", &config->clk_bypass_output);
	if (ret < 0) {
		/*if use pwm as the internal clock source!*/
		config->clk_bypass_output = 0;
		ret = 0;
	}

	of_node_put(np);

	return ret;
}

static int sunxi_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
		int duty_ns, int period_ns)
{
	int bind_num;

	struct sunxi_pwm_chip *pc = to_sunxi_pwm_chip(chip);

        //这里可以根据bind_num选择是否互补输出
	bind_num = pc->config[pwm->pwm - chip->base].bind_pwm;
	if (bind_num == 255)
		sunxi_pwm_config_single(chip, pwm, duty_ns, period_ns);
	else
		sunxi_pwm_config_dual(chip, pwm, duty_ns, period_ns, bind_num);

	return 0;
}

但是按照源码里面增加“bind_pwm”和“dead_time”

		pwm2: pwm2@0300a000 {
			pinctrl-names = "active", "sleep";
			pinctrl-0 = <&pwm2_pin_a>;
			pinctrl-1 = <&pwm2_pin_b>;
			bind_pwm = 2;
			dead_time = 1000;
			status = "okay";
		};

编译报错

Error: arch/arm64/boot/dts/sunxi/CII-Common.dtsi:543.15-16 syntax error
FATAL ERROR: Unable to parse input tree
make[2]: *** [scripts/Makefile.lib:313: arch/arm64/boot/dts/sunxi/board.dtb] Error 1
make[1]: *** [scripts/Makefile.build:648: arch/arm64/boot/dts/sunxi] Error 2
make: *** [arch/arm64/Makefile:153: dtbs] Error 2
make: *** Waiting for unfinished jobs....
  CHK     kernel/config_data.h
ERROR: build kernel Failed
INFO: mkkernel failed

请问怎么配置才能让pwm互补输出？

[jasonzhang]

@yozad d 设备树里面定义u32的数据格式时 key = <value>;
按照要求应该是
bind_pwm = <2>;
dead_time = <1000>;
你的写法不正确。