Make /dev/port conditional on config symbol

Instead of having /dev/port support dependent in multiple places on a
string of preprocessor symbols, define a new configuration directive for
it.  This ensures that all four places remain consistent with each other.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/Kconfig

@@ -1071,5 +1071,11 @@ config TELCLOCK
 	  /sys/devices/platform/telco_clock, with a number of files for
 	  controlling the behavior of this hardware.
 
+config DEVPORT
+	bool
+	depends on !M68K
+	depends on ISA || PCI
+	default y
+
 endmenu
 

drivers/char/mem.c

@@ -551,7 +551,7 @@ static ssize_t write_kmem(struct file * file, const char __user * buf,
  	return virtr + wrote;
 }
 
-#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
+#ifdef CONFIG_DEVPORT
 static ssize_t read_port(struct file * file, char __user * buf,
 			 size_t count, loff_t *ppos)
 {
@@ -834,7 +834,7 @@ static const struct file_operations null_fops = {
 	.splice_write	= splice_write_null,
 };
 
-#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
+#ifdef CONFIG_DEVPORT
 static const struct file_operations port_fops = {
 	.llseek		= memory_lseek,
 	.read		= read_port,
@@ -912,7 +912,7 @@ static int memory_open(struct inode * inode, struct file * filp)
 		case 3:
 			filp->f_op = &null_fops;
 			break;
-#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
+#ifdef CONFIG_DEVPORT
 		case 4:
 			filp->f_op = &port_fops;
 			break;
@@ -959,7 +959,7 @@ static const struct {
 	{1, "mem",     S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
 	{2, "kmem",    S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
 	{3, "null",    S_IRUGO | S_IWUGO,           &null_fops},
-#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)
+#ifdef CONFIG_DEVPORT
 	{4, "port",    S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
 #endif
 	{5, "zero",    S_IRUGO | S_IWUGO,           &zero_fops},