diff --git a/drivers/acpi/ibm_acpi.c b/drivers/acpi/ibm_acpi.c
index 36e2667..8bb41bd 100644
--- a/drivers/acpi/ibm_acpi.c
+++ b/drivers/acpi/ibm_acpi.c
@@ -78,9 +78,11 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/string.h>
+
 #include <linux/proc_fs.h>
 #include <linux/backlight.h>
 #include <asm/uaccess.h>
+
 #include <linux/dmi.h>
 #include <linux/jiffies.h>
 #include <linux/workqueue.h>
@@ -121,28 +123,6 @@
 	static char        *object##_path;			\
 	static char        *object##_paths[] = { paths }
 
-/*
- * The following models are supported to various degrees:
- *
- * 570, 600e, 600x, 770e, 770x
- * A20m, A21e, A21m, A21p, A22p, A30, A30p, A31, A31p
- * G40, G41
- * R30, R31, R32, R40, R40e, R50, R50e, R50p, R51
- * T20, T21, T22, T23, T30, T40, T40p, T41, T41p, T42, T42p, T43
- * X20, X21, X22, X23, X24, X30, X31, X40
- *
- * The following models have no supported features:
- *
- * 240, 240x, i1400
- *
- * Still missing DSDTs for the following models:
- *
- * A20p, A22e, A22m
- * R52
- * S31
- * T43p
- */
-
 IBM_HANDLE(ec, root, "\\_SB.PCI0.ISA.EC0",	/* 240, 240x */
 	   "\\_SB.PCI.ISA.EC",	/* 570 */
 	   "\\_SB.PCI0.ISA0.EC0",	/* 600e/x, 770e, 770x */
@@ -785,12 +765,15 @@
 	return 0;
 }
 
-static int video_supported;
-static int video_orig_autosw;
+enum video_access_mode {
+	IBMACPI_VIDEO_NONE = 0,
+	IBMACPI_VIDEO_570,	/* 570 */
+	IBMACPI_VIDEO_770,	/* 600e/x, 770e, 770x */
+	IBMACPI_VIDEO_NEW,	/* all others */
+};
 
-#define VIDEO_570 1
-#define VIDEO_770 2
-#define VIDEO_NEW 3
+static enum video_access_mode video_supported;
+static int video_orig_autosw;
 
 static int video_init(void)
 {
@@ -802,16 +785,16 @@
 
 	if (!vid_handle)
 		/* video switching not supported on R30, R31 */
-		video_supported = 0;
+		video_supported = IBMACPI_VIDEO_NONE;
 	else if (acpi_evalf(vid_handle, &video_orig_autosw, "SWIT", "qd"))
 		/* 570 */
-		video_supported = VIDEO_570;
+		video_supported = IBMACPI_VIDEO_570;
 	else if (acpi_evalf(vid_handle, &video_orig_autosw, "^VADL", "qd"))
 		/* 600e/x, 770e, 770x */
-		video_supported = VIDEO_770;
+		video_supported = IBMACPI_VIDEO_770;
 	else
 		/* all others */
-		video_supported = VIDEO_NEW;
+		video_supported = IBMACPI_VIDEO_NEW;
 
 	return 0;
 }
@@ -821,15 +804,15 @@
 	int status = 0;
 	int i;
 
-	if (video_supported == VIDEO_570) {
+	if (video_supported == IBMACPI_VIDEO_570) {
 		if (acpi_evalf(NULL, &i, "\\_SB.PHS", "dd", 0x87))
 			status = i & 3;
-	} else if (video_supported == VIDEO_770) {
+	} else if (video_supported == IBMACPI_VIDEO_770) {
 		if (acpi_evalf(NULL, &i, "\\VCDL", "d"))
 			status |= 0x01 * i;
 		if (acpi_evalf(NULL, &i, "\\VCDC", "d"))
 			status |= 0x02 * i;
-	} else if (video_supported == VIDEO_NEW) {
+	} else if (video_supported == IBMACPI_VIDEO_NEW) {
 		acpi_evalf(NULL, NULL, "\\VUPS", "vd", 1);
 		if (acpi_evalf(NULL, &i, "\\VCDC", "d"))
 			status |= 0x02 * i;
@@ -848,9 +831,10 @@
 {
 	int autosw = 0;
 
-	if (video_supported == VIDEO_570)
+	if (video_supported == IBMACPI_VIDEO_570)
 		acpi_evalf(vid_handle, &autosw, "SWIT", "d");
-	else if (video_supported == VIDEO_770 || video_supported == VIDEO_NEW)
+	else if (video_supported == IBMACPI_VIDEO_770 ||
+		 video_supported == IBMACPI_VIDEO_NEW)
 		acpi_evalf(vid_handle, &autosw, "^VDEE", "d");
 
 	return autosw & 1;
@@ -870,12 +854,12 @@
 	len += sprintf(p + len, "status:\t\tsupported\n");
 	len += sprintf(p + len, "lcd:\t\t%s\n", enabled(status, 0));
 	len += sprintf(p + len, "crt:\t\t%s\n", enabled(status, 1));
-	if (video_supported == VIDEO_NEW)
+	if (video_supported == IBMACPI_VIDEO_NEW)
 		len += sprintf(p + len, "dvi:\t\t%s\n", enabled(status, 3));
 	len += sprintf(p + len, "auto:\t\t%s\n", enabled(autosw, 0));
 	len += sprintf(p + len, "commands:\tlcd_enable, lcd_disable\n");
 	len += sprintf(p + len, "commands:\tcrt_enable, crt_disable\n");
-	if (video_supported == VIDEO_NEW)
+	if (video_supported == IBMACPI_VIDEO_NEW)
 		len += sprintf(p + len, "commands:\tdvi_enable, dvi_disable\n");
 	len += sprintf(p + len, "commands:\tauto_enable, auto_disable\n");
 	len += sprintf(p + len, "commands:\tvideo_switch, expand_toggle\n");
@@ -890,7 +874,7 @@
 
 	if (!acpi_evalf(vid_handle, NULL, "_DOS", "vd", 1))
 		return -EIO;
-	ret = video_supported == VIDEO_570 ?
+	ret = video_supported == IBMACPI_VIDEO_570 ?
 	    acpi_evalf(ec_handle, NULL, "_Q16", "v") :
 	    acpi_evalf(vid_handle, NULL, "VSWT", "v");
 	acpi_evalf(vid_handle, NULL, "_DOS", "vd", autosw);
@@ -900,9 +884,9 @@
 
 static int video_expand(void)
 {
-	if (video_supported == VIDEO_570)
+	if (video_supported == IBMACPI_VIDEO_570)
 		return acpi_evalf(ec_handle, NULL, "_Q17", "v");
-	else if (video_supported == VIDEO_770)
+	else if (video_supported == IBMACPI_VIDEO_770)
 		return acpi_evalf(vid_handle, NULL, "VEXP", "v");
 	else
 		return acpi_evalf(NULL, NULL, "\\VEXP", "v");
@@ -912,10 +896,10 @@
 {
 	int ret;
 
-	if (video_supported == VIDEO_570) {
+	if (video_supported == IBMACPI_VIDEO_570) {
 		ret = acpi_evalf(NULL, NULL,
 				 "\\_SB.PHS2", "vdd", 0x8b, status | 0x80);
-	} else if (video_supported == VIDEO_770) {
+	} else if (video_supported == IBMACPI_VIDEO_770) {
 		int autosw = video_autosw();
 		if (!acpi_evalf(vid_handle, NULL, "_DOS", "vd", 1))
 			return -EIO;
@@ -951,10 +935,10 @@
 			enable |= 0x02;
 		} else if (strlencmp(cmd, "crt_disable") == 0) {
 			disable |= 0x02;
-		} else if (video_supported == VIDEO_NEW &&
+		} else if (video_supported == IBMACPI_VIDEO_NEW &&
 			   strlencmp(cmd, "dvi_enable") == 0) {
 			enable |= 0x08;
-		} else if (video_supported == VIDEO_NEW &&
+		} else if (video_supported == IBMACPI_VIDEO_NEW &&
 			   strlencmp(cmd, "dvi_disable") == 0) {
 			disable |= 0x08;
 		} else if (strlencmp(cmd, "auto_enable") == 0) {
@@ -1253,26 +1237,28 @@
 	return 0;
 }
 
-static int led_supported;
-
-#define LED_570 1
-#define LED_OLD 2
-#define LED_NEW 3
+enum led_access_mode {
+	IBMACPI_LED_NONE = 0,
+	IBMACPI_LED_570,	/* 570 */
+	IBMACPI_LED_OLD,	/* 600e/x, 770e, 770x, A21e, A2xm/p, T20-22, X20-21 */
+	IBMACPI_LED_NEW,	/* all others */
+};
+static enum led_access_mode led_supported;
 
 static int led_init(void)
 {
 	if (!led_handle)
 		/* led not supported on R30, R31 */
-		led_supported = 0;
+		led_supported = IBMACPI_LED_NONE;
 	else if (strlencmp(led_path, "SLED") == 0)
 		/* 570 */
-		led_supported = LED_570;
+		led_supported = IBMACPI_LED_570;
 	else if (strlencmp(led_path, "SYSL") == 0)
 		/* 600e/x, 770e, 770x, A21e, A2xm/p, T20-22, X20-21 */
-		led_supported = LED_OLD;
+		led_supported = IBMACPI_LED_OLD;
 	else
 		/* all others */
-		led_supported = LED_NEW;
+		led_supported = IBMACPI_LED_NEW;
 
 	return 0;
 }
@@ -1289,7 +1275,7 @@
 	}
 	len += sprintf(p + len, "status:\t\tsupported\n");
 
-	if (led_supported == LED_570) {
+	if (led_supported == IBMACPI_LED_570) {
 		/* 570 */
 		int i, status;
 		for (i = 0; i < 8; i++) {
@@ -1338,13 +1324,13 @@
 		} else
 			return -EINVAL;
 
-		if (led_supported == LED_570) {
+		if (led_supported == IBMACPI_LED_570) {
 			/* 570 */
 			led = 1 << led;
 			if (!acpi_evalf(led_handle, NULL, NULL, "vdd",
 					led, led_sled_arg1[ind]))
 				return -EIO;
-		} else if (led_supported == LED_OLD) {
+		} else if (led_supported == IBMACPI_LED_OLD) {
 			/* 600e/x, 770e, 770x, A21e, A2xm/p, T20-22, X20 */
 			led = 1 << led;
 			ret = ec_write(EC_HLMS, led);