fusb302的pd驱动代码

以下是fusb302的PD驱动代码示例，参考自Linux内核的驱动代码（fusb302.c）：

static int fusb302_pd_send_message(struct fusb302_chip *chip,
				    enum tcpm_transmit_type type,
				    uint16_t header, const void *data,
				    size_t count)
{
	int ret;
	u8 buf[PDO_MAX_OBJECT_SIZE];
	struct pd_message msg = {
		.header = header,
		.count = count,
		.obj = buf,
	};
	struct tcpm_message tcpm_msg = {
		.header = type,
		.tx_data = &msg,
	};

	if (count > PDO_MAX_OBJECT_SIZE) {
		dev_err(chip->dev, "message too long\n");
		return -EINVAL;
	}

	memcpy(buf, data, count);

	ret = chip->phy_ops->tcpm_transmit(chip, &tcpm_msg);
	if (ret < 0)
		dev_err(chip->dev, "failed to send message: %d\n", ret);

	return ret;
}

此代码片段中，`fusb302_pd_send_message()`函数用于向FUSB302发送PD消息。该函数将消息打包为TCPM消息格式并传递给`tcpm_transmit()`函数以进行发送。`tcpm_transmit()`函数是由FUSB302 PHY驱动程序提供的函数，用于将TCPM消息传递给FUSB302芯片进行发送。