diff --git a/arch/arm/mach-clps7500/core.c b/arch/arm/mach-clps7500/core.c
index 112f1d68..e216ab8 100644
--- a/arch/arm/mach-clps7500/core.c
+++ b/arch/arm/mach-clps7500/core.c
@@ -354,7 +354,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-ebsa110/core.c b/arch/arm/mach-ebsa110/core.c
index 23c4da1..5aeadfd 100644
--- a/arch/arm/mach-ebsa110/core.c
+++ b/arch/arm/mach-ebsa110/core.c
@@ -219,7 +219,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-epxa10db/arch.c b/arch/arm/mach-epxa10db/arch.c
index 7daa021..44c5657 100644
--- a/arch/arm/mach-epxa10db/arch.c
+++ b/arch/arm/mach-epxa10db/arch.c
@@ -52,7 +52,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-footbridge/isa.c b/arch/arm/mach-footbridge/isa.c
index aa3a1fe..28846c7 100644
--- a/arch/arm/mach-footbridge/isa.c
+++ b/arch/arm/mach-footbridge/isa.c
@@ -34,7 +34,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-h720x/cpu-h7202.c b/arch/arm/mach-h720x/cpu-h7202.c
index 4b31993..a4a7c01 100644
--- a/arch/arm/mach-h720x/cpu-h7202.c
+++ b/arch/arm/mach-h720x/cpu-h7202.c
@@ -90,7 +90,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-ixp2000/core.c b/arch/arm/mach-ixp2000/core.c
index 098c817..74bd2fd 100644
--- a/arch/arm/mach-ixp2000/core.c
+++ b/arch/arm/mach-ixp2000/core.c
@@ -174,7 +174,7 @@
 
 static struct platform_device ixp2000_serial_device = {
 	.name		= "serial8250",
-	.id		= 0,
+	.id		= PLAT8250_DEV_PLATFORM,
 	.dev		= {
 		.platform_data		= ixp2000_serial_port,
 	},
diff --git a/arch/arm/mach-ixp4xx/coyote-setup.c b/arch/arm/mach-ixp4xx/coyote-setup.c
index 8b2f253..050c927 100644
--- a/arch/arm/mach-ixp4xx/coyote-setup.c
+++ b/arch/arm/mach-ixp4xx/coyote-setup.c
@@ -66,7 +66,7 @@
 
 static struct platform_device coyote_uart = {
 	.name		= "serial8250",
-	.id		= 0,
+	.id		= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= coyote_uart_data,
 	},
diff --git a/arch/arm/mach-ixp4xx/gtwx5715-setup.c b/arch/arm/mach-ixp4xx/gtwx5715-setup.c
index 3fd92c5..29a6d02 100644
--- a/arch/arm/mach-ixp4xx/gtwx5715-setup.c
+++ b/arch/arm/mach-ixp4xx/gtwx5715-setup.c
@@ -93,7 +93,7 @@
 
 static struct platform_device gtwx5715_uart_device = {
 	.name		= "serial8250",
-	.id		= 0,
+	.id		= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= gtwx5715_uart_platform_data,
 	},
diff --git a/arch/arm/mach-ixp4xx/ixdp425-setup.c b/arch/arm/mach-ixp4xx/ixdp425-setup.c
index 6c14ff3..ae1fa09 100644
--- a/arch/arm/mach-ixp4xx/ixdp425-setup.c
+++ b/arch/arm/mach-ixp4xx/ixdp425-setup.c
@@ -96,7 +96,7 @@
 
 static struct platform_device ixdp425_uart = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev.platform_data	= ixdp425_uart_data,
 	.num_resources		= 2,
 	.resource		= ixdp425_uart_resources
diff --git a/arch/arm/mach-omap1/board-voiceblue.c b/arch/arm/mach-omap1/board-voiceblue.c
index e422819..76176dd 100644
--- a/arch/arm/mach-omap1/board-voiceblue.c
+++ b/arch/arm/mach-omap1/board-voiceblue.c
@@ -74,7 +74,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 1,
+	.id			= PLAT8250_DEV_PLATFORM1,
 	.dev			= {
 		.platform_data	= voiceblue_ports,
 	},
diff --git a/arch/arm/mach-omap1/serial.c b/arch/arm/mach-omap1/serial.c
index 214e5d1..1446bf3 100644
--- a/arch/arm/mach-omap1/serial.c
+++ b/arch/arm/mach-omap1/serial.c
@@ -94,7 +94,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-rpc/riscpc.c b/arch/arm/mach-rpc/riscpc.c
index a102686..e3587ef 100644
--- a/arch/arm/mach-rpc/riscpc.c
+++ b/arch/arm/mach-rpc/riscpc.c
@@ -140,7 +140,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-s3c2410/mach-bast.c b/arch/arm/mach-s3c2410/mach-bast.c
index e918224..1a3367d 100644
--- a/arch/arm/mach-s3c2410/mach-bast.c
+++ b/arch/arm/mach-s3c2410/mach-bast.c
@@ -381,7 +381,7 @@
 
 static struct platform_device bast_sio = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= &bast_sio_data,
 	},
diff --git a/arch/arm/mach-s3c2410/mach-vr1000.c b/arch/arm/mach-s3c2410/mach-vr1000.c
index 924e846..8f9ab28 100644
--- a/arch/arm/mach-s3c2410/mach-vr1000.c
+++ b/arch/arm/mach-s3c2410/mach-vr1000.c
@@ -221,7 +221,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/arm/mach-shark/core.c b/arch/arm/mach-shark/core.c
index e737eae..946c0d1 100644
--- a/arch/arm/mach-shark/core.c
+++ b/arch/arm/mach-shark/core.c
@@ -41,7 +41,7 @@
 
 static struct platform_device serial_device = {
 	.name			= "serial8250",
-	.id			= 0,
+	.id			= PLAT8250_DEV_PLATFORM,
 	.dev			= {
 		.platform_data	= serial_platform_data,
 	},
diff --git a/arch/ppc/syslib/mpc10x_common.c b/arch/ppc/syslib/mpc10x_common.c
index 87065e2..3e03970 100644
--- a/arch/ppc/syslib/mpc10x_common.c
+++ b/arch/ppc/syslib/mpc10x_common.c
@@ -140,12 +140,12 @@
 	},
 	[MPC10X_UART0] = {
 		.name = "serial8250",
-		.id	= 0,
+		.id	= PLAT8250_DEV_PLATFORM,
 		.dev.platform_data = serial_plat_uart0,
 	},
 	[MPC10X_UART1] = {
 		.name = "serial8250",
-		.id	= 1,
+		.id	= PLAT8250_DEV_PLATFORM1,
 		.dev.platform_data = serial_plat_uart1,
 	},
 
diff --git a/arch/ppc/syslib/mpc83xx_devices.c b/arch/ppc/syslib/mpc83xx_devices.c
index 5aaf0e5..95b3b8a 100644
--- a/arch/ppc/syslib/mpc83xx_devices.c
+++ b/arch/ppc/syslib/mpc83xx_devices.c
@@ -165,7 +165,7 @@
 	},
 	[MPC83xx_DUART] = {
 		.name = "serial8250",
-		.id	= 0,
+		.id	= PLAT8250_DEV_PLATFORM,
 		.dev.platform_data = serial_platform_data,
 	},
 	[MPC83xx_SEC2] = {
diff --git a/arch/ppc/syslib/mpc85xx_devices.c b/arch/ppc/syslib/mpc85xx_devices.c
index 8af322d..bbc5ac0 100644
--- a/arch/ppc/syslib/mpc85xx_devices.c
+++ b/arch/ppc/syslib/mpc85xx_devices.c
@@ -282,7 +282,7 @@
 	},
 	[MPC85xx_DUART] = {
 		.name = "serial8250",
-		.id	= 0,
+		.id	= PLAT8250_DEV_PLATFORM,
 		.dev.platform_data = serial_platform_data,
 	},
 	[MPC85xx_PERFMON] = {
diff --git a/arch/ppc64/kernel/setup.c b/arch/ppc64/kernel/setup.c
index d0bb68a..bfa8791c 100644
--- a/arch/ppc64/kernel/setup.c
+++ b/arch/ppc64/kernel/setup.c
@@ -1283,7 +1283,7 @@
 
 static struct platform_device serial_device = {
 	.name	= "serial8250",
-	.id	= 0,
+	.id	= PLAT8250_DEV_PLATFORM,
 	.dev	= {
 		.platform_data = serial_ports,
 	},
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 30a0a3d..5b65e20 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2536,7 +2536,7 @@
 		goto out;
 
 	serial8250_isa_devs = platform_device_register_simple("serial8250",
-							      -1, NULL, 0);
+					 PLAT8250_DEV_LEGACY, NULL, 0);
 	if (IS_ERR(serial8250_isa_devs)) {
 		ret = PTR_ERR(serial8250_isa_devs);
 		goto unreg;
diff --git a/drivers/serial/8250_accent.c b/drivers/serial/8250_accent.c
index 1f2c276..9c10262 100644
--- a/drivers/serial/8250_accent.c
+++ b/drivers/serial/8250_accent.c
@@ -29,7 +29,7 @@
 
 static struct platform_device accent_device = {
 	.name			= "serial8250",
-	.id			= 2,
+	.id			= PLAT8250_DEV_ACCENT,
 	.dev			= {
 		.platform_data	= accent_data,
 	},
diff --git a/drivers/serial/8250_boca.c b/drivers/serial/8250_boca.c
index 465c9ea..3bfe0f7 100644
--- a/drivers/serial/8250_boca.c
+++ b/drivers/serial/8250_boca.c
@@ -43,7 +43,7 @@
 
 static struct platform_device boca_device = {
 	.name			= "serial8250",
-	.id			= 3,
+	.id			= PLAT8250_DEV_BOCA,
 	.dev			= {
 		.platform_data	= boca_data,
 	},
diff --git a/drivers/serial/8250_fourport.c b/drivers/serial/8250_fourport.c
index e9b4d90..6375d68 100644
--- a/drivers/serial/8250_fourport.c
+++ b/drivers/serial/8250_fourport.c
@@ -35,7 +35,7 @@
 
 static struct platform_device fourport_device = {
 	.name			= "serial8250",
-	.id			= 1,
+	.id			= PLAT8250_DEV_FOURPORT,
 	.dev			= {
 		.platform_data	= fourport_data,
 	},
diff --git a/drivers/serial/8250_hub6.c b/drivers/serial/8250_hub6.c
index 77f396f..daf569c 100644
--- a/drivers/serial/8250_hub6.c
+++ b/drivers/serial/8250_hub6.c
@@ -40,7 +40,7 @@
 
 static struct platform_device hub6_device = {
 	.name			= "serial8250",
-	.id			= 4,
+	.id			= PLAT8250_DEV_HUB6,
 	.dev			= {
 		.platform_data	= hub6_data,
 	},
diff --git a/drivers/serial/8250_mca.c b/drivers/serial/8250_mca.c
index f0c40d6..ac20525 100644
--- a/drivers/serial/8250_mca.c
+++ b/drivers/serial/8250_mca.c
@@ -44,7 +44,7 @@
 
 static struct platform_device mca_device = {
 	.name			= "serial8250",
-	.id			= 5,
+	.id			= PLAT8250_DEV_MCA,
 	.dev			= {
 		.platform_data	= mca_data,
 	},
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index d8a023d..317a979 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -30,6 +30,21 @@
 };
 
 /*
+ * Allocate 8250 platform device IDs.  Nothing is implied by
+ * the numbering here, except for the legacy entry being -1.
+ */
+enum {
+	PLAT8250_DEV_LEGACY = -1,
+	PLAT8250_DEV_PLATFORM,
+	PLAT8250_DEV_PLATFORM1,
+	PLAT8250_DEV_FOURPORT,
+	PLAT8250_DEV_ACCENT,
+	PLAT8250_DEV_BOCA,
+	PLAT8250_DEV_HUB6,
+	PLAT8250_DEV_MCA,
+};
+
+/*
  * This should be used by drivers which want to register
  * their own 8250 ports without registering their own
  * platform device.  Using these will make your driver