wifi: rtl8xxxu: expose efuse via debugfs

The efuse contains the mac address and calibration data. During
manufacturing and testing it can be necessary to read and check this
data.

Add a debugfs interface to make it available to userspace.

Signed-off-by: Martin Kaistra <martin.kaistra@linutronix.de>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250901121613.1876109-1-martin.kaistra@linutronix.de

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/core.c b/drivers/net/wireless/realtek/rtl8xxxu/core.c
index 9e00dc020e30e0e2c3d7a5a22e1710df0968b11a..3ded5952729fc6917f1b46fe9de222a77bdf28f7 100644 (file)
--- a/drivers/net/wireless/realtek/rtl8xxxu/core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/core.c
@@ -1901,6 +1901,27 @@ static void rtl8xxxu_dump_efuse(struct rtl8xxxu_priv *priv)
                       priv->efuse_wifi.raw, EFUSE_MAP_LEN, true);
 }
 
+static ssize_t read_file_efuse(struct file *file, char __user *user_buf,
+                              size_t count, loff_t *ppos)
+{
+       struct rtl8xxxu_priv *priv = file_inode(file)->i_private;
+
+       return simple_read_from_buffer(user_buf, count, ppos,
+                                      priv->efuse_wifi.raw, EFUSE_MAP_LEN);
+}
+
+static const struct debugfs_short_fops fops_efuse = {
+       .read = read_file_efuse,
+};
+
+static void rtl8xxxu_debugfs_init(struct rtl8xxxu_priv *priv)
+{
+       struct dentry *phydir;
+
+       phydir = debugfs_create_dir("rtl8xxxu", priv->hw->wiphy->debugfsdir);
+       debugfs_create_file("efuse", 0400, phydir, priv, &fops_efuse);
+}
+
 void rtl8xxxu_reset_8051(struct rtl8xxxu_priv *priv)
 {
        u8 val8;
@@ -7975,6 +7996,7 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
        }
 
        rtl8xxxu_init_led(priv);
+       rtl8xxxu_debugfs_init(priv);
 
        return 0;