Hi,

On Tue, Dec 17, 2024 at 02:51:47PM +0800, Sandor Yu wrote:

+static ssize_t firmware_version_show(struct device *dev,
+				     struct device_attribute *attr, char *buf);
+static struct device_attribute firmware_version = __ATTR_RO(firmware_version);
+
+ssize_t firmware_version_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct cdns_mhdp8501_device *mhdp = dev_get_drvdata(dev);
+
+	u32 version = readl(mhdp->base.regs + VER_L) | readl(mhdp->base.regs + VER_H) << 8;
+	u32 lib_version = readl(mhdp->base.regs + VER_LIB_L_ADDR) |
+			  readl(mhdp->base.regs + VER_LIB_H_ADDR) << 8;
+
+	return sprintf(buf, "FW version %d, Lib version %d\n", version, lib_version);
+}
+
+static void cdns_mhdp8501_create_device_files(struct cdns_mhdp8501_device *mhdp)
+{
+	if (device_create_file(mhdp->dev, &firmware_version)) {
+		DRM_ERROR("Unable to create firmware_version sysfs\n");
+		device_remove_file(mhdp->dev, &firmware_version);
+	}
+}

sysfs files are part of the uABI, and need to be stable and documented.

For these kind of things, you should use debugfs.

Maxime