mtd: use DEFINE_SHOW_ATTRIBUTE() instead of open-coding it

DEFINE_SHOW_ATTRIBUTE macro can help us simplify the code, so change
to it. And change the DEBUGFS_RO_ATTR macro defined in some file to a
standard macro.

Signed-off-by: Yangtao Li <[e-mail]>
Signed-off-by: Boris Brezillon <[e-mail]>

drivers/mtd/devices/docg3.c

···
 /*
  * Debug sysfs entries
  */
-static int dbg_flashctrl_show(struct seq_file *s, void *p)
+static int flashcontrol_show(struct seq_file *s, void *p)
 {
 	struct docg3 *docg3 = (struct docg3 *)s->private;
 
···
 
 	return 0;
 }
-DEBUGFS_RO_ATTR(flashcontrol, dbg_flashctrl_show);
+DEFINE_SHOW_ATTRIBUTE(flashcontrol);
 
-static int dbg_asicmode_show(struct seq_file *s, void *p)
+static int asic_mode_show(struct seq_file *s, void *p)
 {
 	struct docg3 *docg3 = (struct docg3 *)s->private;
 
···
 	seq_puts(s, ")\n");
 	return 0;
 }
-DEBUGFS_RO_ATTR(asic_mode, dbg_asicmode_show);
+DEFINE_SHOW_ATTRIBUTE(asic_mode);
 
-static int dbg_device_id_show(struct seq_file *s, void *p)
+static int device_id_show(struct seq_file *s, void *p)
 {
 	struct docg3 *docg3 = (struct docg3 *)s->private;
 	int id;
···
 	seq_printf(s, "DeviceId = %d\n", id);
 	return 0;
 }
-DEBUGFS_RO_ATTR(device_id, dbg_device_id_show);
+DEFINE_SHOW_ATTRIBUTE(device_id);
 
-static int dbg_protection_show(struct seq_file *s, void *p)
+static int protection_show(struct seq_file *s, void *p)
 {
 	struct docg3 *docg3 = (struct docg3 *)s->private;
 	int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;
···
 		   !!(dps1 & DOC_DPS_KEY_OK));
 	return 0;
 }
-DEBUGFS_RO_ATTR(protection, dbg_protection_show);
+DEFINE_SHOW_ATTRIBUTE(protection);
 
 static void __init doc_dbg_register(struct mtd_info *floor)
 {

drivers/mtd/devices/docg3.h

···
 #define doc_info(fmt, arg...) dev_info(docg3->dev, (fmt), ## arg)
 #define doc_dbg(fmt, arg...) dev_dbg(docg3->dev, (fmt), ## arg)
 #define doc_vdbg(fmt, arg...) dev_vdbg(docg3->dev, (fmt), ## arg)
-
-#define DEBUGFS_RO_ATTR(name, show_fct) \
-	static int name##_open(struct inode *inode, struct file *file) \
-	{ return single_open(file, show_fct, inode->i_private); }      \
-	static const struct file_operations name##_fops = { \
-		.owner = THIS_MODULE, \
-		.open = name##_open, \
-		.llseek = seq_lseek, \
-		.read = seq_read, \
-		.release = single_release \
-	};
 #endif
 
 /*

drivers/mtd/mtdswap.c

···
 
 	return 0;
 }
-
-static int mtdswap_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, mtdswap_show, inode->i_private);
-}
-
-static const struct file_operations mtdswap_fops = {
-	.open		= mtdswap_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(mtdswap);
 
 static int mtdswap_add_debugfs(struct mtdswap_dev *d)
 {

drivers/mtd/nand/raw/nandsim.c

···
 /* MTD structure for NAND controller */
 static struct mtd_info *nsmtd;
 
-static int nandsim_debugfs_show(struct seq_file *m, void *private)
+static int nandsim_show(struct seq_file *m, void *private)
 {
 	unsigned long wmin = -1, wmax = 0, avg;
 	unsigned long deciles[10], decile_max[10], tot = 0;
···
 
 	return 0;
 }
-
-static int nandsim_debugfs_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, nandsim_debugfs_show, inode->i_private);
-}
-
-static const struct file_operations dfs_fops = {
-	.open		= nandsim_debugfs_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(nandsim);
 
 /**
  * nandsim_debugfs_create - initialize debugfs
···
 	}
 
 	dent = debugfs_create_file("nandsim_wear_report", S_IRUSR,
-				   root, dev, &dfs_fops);
+				   root, dev, &nandsim_fops);
 	if (IS_ERR_OR_NULL(dent)) {
 		NS_ERR("cannot create \"nandsim_wear_report\" debugfs entry\n");
 		return -1;