arm: mach-k3: j721e: Add detection for j721e

Add an api soc_is_j721e(), and use it to enable certain functionality
that is available only on j721e. This detection is needed when DT is not
available.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>

arch/arm/mach-k3/common.c

@@ -345,6 +345,16 @@ int print_cpuinfo(void)
 }
 #endif
 
+bool soc_is_j721e(void)
+{
+	u32 soc;
+
+	soc = (readl(CTRLMMR_WKUP_JTAG_ID) &
+		JTAG_ID_PARTNO_MASK) >> JTAG_ID_PARTNO_SHIFT;
+
+	return soc == J721E;
+}
+
 #ifdef CONFIG_ARM64
 void board_prep_linux(bootm_headers_t *images)
 {

arch/arm/mach-k3/common.h

@@ -8,6 +8,8 @@
 
 #include <asm/armv7_mpu.h>
 
+#define J721E  0xbb64
+
 struct fwl_data {
 	const char *name;
 	u16 fwl_id;

arch/arm/mach-k3/include/mach/hardware.h

@@ -15,6 +15,7 @@
 #endif
 
 /* Assuming these addresses and definitions stay common across K3 devices */
+#define CTRLMMR_WKUP_JTAG_ID	0x43000014
 #define JTAG_ID_VARIANT_SHIFT	28
 #define JTAG_ID_VARIANT_MASK	(0xf << 28)
 #define JTAG_ID_PARTNO_SHIFT	12

arch/arm/mach-k3/include/mach/sys_proto.h

@@ -16,4 +16,6 @@ int do_board_detect(void);
 void release_resources_for_core_shutdown(void);
 int fdt_disable_node(void *blob, char *node_path);
 
+bool soc_is_j721e(void);
+
 #endif

arch/arm/mach-k3/j721e_init.c

@@ -361,6 +361,9 @@ void start_non_linux_remote_cores(void)
 	int size = 0, ret;
 	u32 loadaddr = 0;
 
+	if (!soc_is_j721e())
+		return;
+
 	size = load_firmware("name_mainr5f0_0fw", "addr_mainr5f0_0load",
 			     &loadaddr);
 	if (size <= 0)