board: ti: am64x: Add support for reading eeprom data

I2C EEPROM data contains the board name and its revision.
Add support for:
- Reading EEPROM data and store a copy at end of SRAM
- Updating env variable with relevant board info
- Printing board info during boot.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/mach-k3/include/mach/am64_hardware.h

@@ -49,4 +49,7 @@
 
 #define ROM_ENTENDED_BOOT_DATA_INFO			0x701beb00
 
+/* Use Last 1K as Scratch pad */
+#define TI_SRAM_SCRATCH_BOARD_EEPROM_START		0x701bfc00
+
 #endif /* __ASM_ARCH_DRA8_HARDWARE_H */

board/ti/am64x/evm.c

@@ -10,6 +10,14 @@
 #include <common.h>
 #include <asm/io.h>
 #include <spl.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/sys_proto.h>
+#include <env.h>
+
+#include "../common/board_detect.h"
+
+#define board_is_am64x_gpevm()	board_ti_k3_is("AM64-GPEVM")
+#define board_is_am64x_skevm()	board_ti_k3_is("AM64-SKEVM")
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -46,3 +54,87 @@ int board_fit_config_name_match(const char *name)
 	return -1;
 }
 #endif
+
+#ifdef CONFIG_TI_I2C_BOARD_DETECT
+int do_board_detect(void)
+{
+	int ret;
+
+	ret = ti_i2c_eeprom_am6_get_base(CONFIG_EEPROM_BUS_ADDRESS,
+					 CONFIG_EEPROM_CHIP_ADDRESS);
+	if (ret) {
+		printf("EEPROM not available at 0x%02x, trying to read at 0x%02x\n",
+			CONFIG_EEPROM_CHIP_ADDRESS, CONFIG_EEPROM_CHIP_ADDRESS + 1);
+		ret = ti_i2c_eeprom_am6_get_base(CONFIG_EEPROM_BUS_ADDRESS,
+						 CONFIG_EEPROM_CHIP_ADDRESS + 1);
+		if (ret)
+			pr_err("Reading on-board EEPROM at 0x%02x failed %d\n",
+			       CONFIG_EEPROM_CHIP_ADDRESS + 1, ret);
+	}
+
+	return ret;
+}
+
+int checkboard(void)
+{
+	struct ti_am6_eeprom *ep = TI_AM6_EEPROM_DATA;
+
+	if (!do_board_detect())
+		printf("Board: %s rev %s\n", ep->name, ep->version);
+
+	return 0;
+}
+
+#ifdef CONFIG_BOARD_LATE_INIT
+static void setup_board_eeprom_env(void)
+{
+	char *name = "am64x_gpevm";
+
+	if (do_board_detect())
+		goto invalid_eeprom;
+
+	if (board_is_am64x_gpevm())
+		name = "am64x_gpevm";
+	else if (board_is_am64x_skevm())
+		name = "am64x_skevm";
+	else
+		printf("Unidentified board claims %s in eeprom header\n",
+		       board_ti_get_name());
+
+invalid_eeprom:
+	set_board_info_env_am6(name);
+}
+
+static void setup_serial(void)
+{
+	struct ti_am6_eeprom *ep = TI_AM6_EEPROM_DATA;
+	unsigned long board_serial;
+	char *endp;
+	char serial_string[17] = { 0 };
+
+	if (env_get("serial#"))
+		return;
+
+	board_serial = simple_strtoul(ep->serial, &endp, 16);
+	if (*endp != '\0') {
+		pr_err("Error: Can't set serial# to %s\n", ep->serial);
+		return;
+	}
+
+	snprintf(serial_string, sizeof(serial_string), "%016lx", board_serial);
+	env_set("serial#", serial_string);
+}
+#endif
+#endif
+
+#ifdef CONFIG_BOARD_LATE_INIT
+int board_late_init(void)
+{
+	if (IS_ENABLED(CONFIG_TI_I2C_BOARD_DETECT)) {
+		setup_board_eeprom_env();
+		setup_serial();
+	}
+
+	return 0;
+}
+#endif