mfd: aat2870: Use per-client debugfs directory

The I2C core now provides a debugfs entry for each client. Let this
driver use it instead of the custom directory in debugfs root. Further
improvements by this change: automatic clean up on removal, support of
multiple instances.

Signed-off-by: Wolfram Sang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/aat2870-core.c

···
 
 static void aat2870_init_debugfs(struct aat2870_data *aat2870)
 {
-	aat2870->dentry_root = debugfs_create_dir("aat2870", NULL);
-
-	debugfs_create_file("regs", 0644, aat2870->dentry_root, aat2870,
+	debugfs_create_file("regs", 0644, aat2870->client->debugfs, aat2870,
 			    &aat2870_reg_fops);
 }
 

include/linux/mfd/aat2870.h

···
 	int (*read)(struct aat2870_data *aat2870, u8 addr, u8 *val);
 	int (*write)(struct aat2870_data *aat2870, u8 addr, u8 val);
 	int (*update)(struct aat2870_data *aat2870, u8 addr, u8 mask, u8 val);
-
-	/* for debugfs */
-	struct dentry *dentry_root;
 };
 
 struct aat2870_subdev_info {