imx8mn: support get_cpu_rev

Add a dummy cpu type and support get_cpu_rev for i.MX8MN

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/include/asm/arch-imx/cpu.h b/arch/arm/include/asm/arch-imx/cpu.h
index 3a85492..b0f4dd0 100644
--- a/arch/arm/include/asm/arch-imx/cpu.h
+++ b/arch/arm/include/asm/arch-imx/cpu.h
@@ -32,6 +32,7 @@
 #define MXC_CPU_IMX8MMDL	0x88 /* dummy ID */
 #define MXC_CPU_IMX8MMS		0x89 /* dummy ID */
 #define MXC_CPU_IMX8MMSL	0x8a /* dummy ID */
+#define MXC_CPU_IMX8MN		0x8b /* dummy ID */
 #define MXC_CPU_IMX8QXP_A0	0x90 /* dummy ID */
 #define MXC_CPU_IMX8QM		0x91 /* dummy ID */
 #define MXC_CPU_IMX8QXP		0x92 /* dummy ID */
diff --git a/arch/arm/include/asm/mach-imx/sys_proto.h b/arch/arm/include/asm/mach-imx/sys_proto.h
index 1e627c8..459d73d 100644
--- a/arch/arm/include/asm/mach-imx/sys_proto.h
+++ b/arch/arm/include/asm/mach-imx/sys_proto.h
@@ -53,6 +53,8 @@
 #define is_imx8mmdl() (is_cpu_type(MXC_CPU_IMX8MMDL))
 #define is_imx8mms() (is_cpu_type(MXC_CPU_IMX8MMS))
 #define is_imx8mmsl() (is_cpu_type(MXC_CPU_IMX8MMSL))
+#define is_imx8mn() (is_cpu_type(MXC_CPU_IMX8MN))
+
 #define is_imx8qxp() (is_cpu_type(MXC_CPU_IMX8QXP))
 
 #ifdef CONFIG_MX6
diff --git a/arch/arm/mach-imx/cpu.c b/arch/arm/mach-imx/cpu.c
index d39f607..4db37c7 100644
--- a/arch/arm/mach-imx/cpu.c
+++ b/arch/arm/mach-imx/cpu.c
@@ -92,6 +92,8 @@
 const char *get_imx_type(u32 imxtype)
 {
 	switch (imxtype) {
+	case MXC_CPU_IMX8MN:
+		return "8MNano";/* Quad-core version of the imx8mn */
 	case MXC_CPU_IMX8MM:
 		return "8MMQ";	/* Quad-core version of the imx8mm */
 	case MXC_CPU_IMX8MML:
diff --git a/arch/arm/mach-imx/imx8m/soc.c b/arch/arm/mach-imx/imx8m/soc.c
index a924af4..82fa7ae 100644
--- a/arch/arm/mach-imx/imx8m/soc.c
+++ b/arch/arm/mach-imx/imx8m/soc.c
@@ -197,7 +197,9 @@
 	reg &= 0xff;
 
 	/* i.MX8MM */
-	if (major_low == 0x41) {
+	if (major_low == 0x42) {
+		return (MXC_CPU_IMX8MN << 12) | reg;
+	} else if (major_low == 0x41) {
 		type = get_cpu_variant_type(MXC_CPU_IMX8MM);
 	} else {
 		if (reg == CHIP_REV_1_0) {