USB: dwc2: Re-use DEFINE_SHOW_ATTRIBUTE() macro

...instead of open coding file operations followed by custom ->open()
callbacks per each attribute.

Cc: John Youn <johnyoun@synopsys.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/debugfs.c

@@ -170,19 +170,7 @@ static int state_show(struct seq_file *seq, void *v)
 
 	return 0;
 }
-
-static int state_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, state_show, inode->i_private);
-}
-
-static const struct file_operations state_fops = {
-	.owner		= THIS_MODULE,
-	.open		= state_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(state);
 
 /**
  * fifo_show - debugfs: show the fifo information
@@ -219,19 +207,7 @@ static int fifo_show(struct seq_file *seq, void *v)
 
 	return 0;
 }
-
-static int fifo_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, fifo_show, inode->i_private);
-}
-
-static const struct file_operations fifo_fops = {
-	.owner		= THIS_MODULE,
-	.open		= fifo_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(fifo);
 
 static const char *decode_direction(int is_in)
 {
@@ -303,19 +279,7 @@ static int ep_show(struct seq_file *seq, void *v)
 
 	return 0;
 }
-
-static int ep_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, ep_show, inode->i_private);
-}
-
-static const struct file_operations ep_fops = {
-	.owner		= THIS_MODULE,
-	.open		= ep_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(ep);
 
 /**
  * dwc2_hsotg_create_debug - create debugfs directory and files
@@ -770,19 +734,7 @@ static int params_show(struct seq_file *seq, void *v)
 
 	return 0;
 }
-
-static int params_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, params_show, inode->i_private);
-}
-
-static const struct file_operations params_fops = {
-	.owner		= THIS_MODULE,
-	.open		= params_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(params);
 
 static int hw_params_show(struct seq_file *seq, void *v)
 {
@@ -817,19 +769,7 @@ static int hw_params_show(struct seq_file *seq, void *v)
 
 	return 0;
 }
-
-static int hw_params_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, hw_params_show, inode->i_private);
-}
-
-static const struct file_operations hw_params_fops = {
-	.owner		= THIS_MODULE,
-	.open		= hw_params_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(hw_params);
 
 static int dr_mode_show(struct seq_file *seq, void *v)
 {
@@ -840,19 +780,7 @@ static int dr_mode_show(struct seq_file *seq, void *v)
 	seq_printf(seq, "%s\n", dr_mode);
 	return 0;
 }
-
-static int dr_mode_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, dr_mode_show, inode->i_private);
-}
-
-static const struct file_operations dr_mode_fops = {
-	.owner		= THIS_MODULE,
-	.open		= dr_mode_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(dr_mode);
 
 int dwc2_debugfs_init(struct dwc2_hsotg *hsotg)
 {