Re: [PATCH v1 2/2] usb: dwc3: eic7700: Add EIC7700 usb driver

[Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>]

On 5/16/2025 3:24 PM, zhangsenchuan@eswincomputing.com wrote:
> From: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
> 
> Add the eic7700 usb driver, which is responsible for
> identifying,configuring and connecting usb devices,and
> provides interfaces for accessing these devices.
> 
> Co-developed-by: Wei Yang <yangwei1@eswincomputing.com>
> Signed-off-by: Wei Yang <yangwei1@eswincomputing.com>
> Signed-off-by: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
> ---

[...]

> +static ssize_t dwc3_mode_show(struct device *device,
> +			      struct device_attribute *attr, char *buf)
> +{
> +	struct dwc3_eswin *eswin = dev_get_drvdata(device);
> +	struct dwc3 *dwc = eswin->dwc;
> +	int ret;
> +
> +	switch (dwc->current_dr_role) {
> +	case USB_DR_MODE_HOST:
> +		ret = sprintf(buf, "host\n");
> +		break;
> +	case USB_DR_MODE_PERIPHERAL:
> +		ret = sprintf(buf, "peripheral\n");
> +		break;
> +	case USB_DR_MODE_OTG:
> +		ret = sprintf(buf, "otg\n");
> +		break;
> +	default:
> +		ret = sprintf(buf, "UNKNOWN\n");
> +	}
> +

Use sysfs_emit instead [1].

> +	return ret;
> +}
> +
> +static ssize_t dwc3_mode_store(struct device *device,
> +			       struct device_attribute *attr, const char *buf,
> +			       size_t count)
> +{
> +	struct dwc3_eswin *eswin = dev_get_drvdata(device);
> +	struct dwc3 *dwc = eswin->dwc;
> +	enum usb_role new_role;
> +	struct usb_role_switch *role_sw = dwc->role_sw;
> +
> +	if (!strncmp(buf, "1", 1) || !strncmp(buf, "host", 4)) {
> +		new_role = USB_ROLE_HOST;
> +	} else if (!strncmp(buf, "0", 1) || !strncmp(buf, "peripheral", 10)) {
> +		new_role = USB_ROLE_DEVICE;
> +	} else {
> +		dev_info(eswin->dev, "illegal dr_mode\n");
> +		return count;
> +	}
> +	eswin->force_mode = true;
> +
> +	mutex_lock(&eswin->lock);
> +	usb_role_switch_set_role(role_sw, new_role);
> +	mutex_unlock(&eswin->lock);
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR_RW(dwc3_mode);
> +
> +static ssize_t dwc3_hub_rst_show(struct device *device,
> +				 struct device_attribute *attr, char *buf)
> +{
> +	struct dwc3_eswin *eswin = dev_get_drvdata(device);
> +
> +	if (!IS_ERR(eswin->hub_gpio))
> +		return sprintf(buf, "%d", gpiod_get_raw_value(eswin->hub_gpio));
> +
> +	return sprintf(buf, "UNKONWN");

Here too, Use sysfs_emit instead [1].

> +}
> +
> +static ssize_t dwc3_hub_rst_store(struct device *device,
> +				  struct device_attribute *attr,
> +				  const char *buf, size_t count)
> +{
> +	struct dwc3_eswin *eswin = dev_get_drvdata(device);
> +
> +	if (!IS_ERR(eswin->hub_gpio)) {
> +		if (!strncmp(buf, "0", 1))
> +			gpiod_set_raw_value(eswin->hub_gpio, 0);
> +		else
> +			gpiod_set_raw_value(eswin->hub_gpio, 1);
> +	}
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR_RW(dwc3_hub_rst);
> +
> +static struct attribute *dwc3_eswin_attrs[] = {
> +	&dev_attr_dwc3_mode.attr,
> +	&dev_attr_dwc3_hub_rst.attr,
> +	NULL,
> +};
> +
> +static struct attribute_group dwc3_eswin_attr_group = {
> +	.name = NULL, /* we want them in the same directory */
> +	.attrs = dwc3_eswin_attrs,
> +};
> +

[...]

> +static int dwc3_eswin_probe(struct platform_device *pdev)
> +{
> +	struct dwc3_eswin *eswin;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node, *child;
> +	struct platform_device *child_pdev;
> +	unsigned int count;
> +	int ret;
> +	int i;
> +	int err_desc = 0;
> +

[...]

> +	child = of_get_child_by_name(np, "dwc3");
> +	if (!child) {
> +		dev_err(dev, "failed to find dwc3 core node\n");
> +		ret = -ENODEV;
> +		goto err1;
> +	}
> +	/* Allocate and initialize the core */
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret) {
> +		dev_err(dev, "failed to create dwc3 core\n");
> +		goto err1;
> +	}
> +
> +	INIT_WORK(&eswin->otg_work, dwc3_eswin_otg_extcon_evt_work);
> +	child_pdev = of_find_device_by_node(child);
> +	if (!child_pdev) {
> +		dev_err(dev, "failed to find dwc3 core device\n");
> +		ret = -ENODEV;
> +		goto err2;
> +	}
> +	eswin->dwc = platform_get_drvdata(child_pdev);
> +	if (!eswin->dwc) {
> +		dev_err(dev, "failed to get drvdata dwc3\n");
> +		ret = -EPROBE_DEFER;
> +		goto err2;
> +	}

Try using falttened implementation if possible.

Regards,
Krishna,