board: ti: j721e: Use EEPROM-based board detection

The TI J721E EVM system on module (SOM), the common processor board, and
the associated daughtercards have on-board I2C-based EEPROMs containing
board config data. Use the board detection infrastructure to do the
following:

1) Parse the J721E SOM EEPROM and populate items like board name, board
   HW and SW revision as well as board serial number into the TI common
   EEPROM data structure residing in SRAM scratch space
2) Check for presence of daughter card(s) by probing associated I2C
   addresses used for on-board EEPROMs containing daughter card-specific
   data. If such a card is found, parse the EEPROM data such as for
   additional Ethernet MAC addresses and populate those into U-Boot
   accordingly
3) Dynamically apply daughter card DTB overlays to the U-Boot (proper)
   DTB during SPL execution
4) Dynamically create an U-Boot ENV variable called name_overlays
   during U-Boot execution containing a list of daugherboard-specific
   DTB overlays based on daughercards found to be used during Kernel
   boot.

This patch adds support for the J721E system on module boards containing
the actual SoC ("J721EX-PM2-SOM", accessed via CONFIG_EEPROM_CHIP_ADDRESS),
the common processor board ("J7X-BASE-CPB"), the Quad-Port Ethernet
Expansion Board ("J7X-VSC8514-ETH"), the infotainment board
("J7X-INFOTAN-EXP") as well as for the gateway/Ethernet switch/industrial
expansion board ("J7X-GESI-EXP").

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

arch/arm/mach-k3/include/mach/j721e_hardware.h

@@ -46,4 +46,7 @@
 #define CTRLMMR_LOCK_KICK1				0x0100c
 #define CTRLMMR_LOCK_KICK1_UNLOCK_VAL			0xd172bc5a
 
+/* MCU SCRATCHPAD usage */
+#define TI_SRAM_SCRATCH_BOARD_EEPROM_START	CONFIG_SYS_K3_MCU_SCRATCHPAD_BASE
+
 #endif /* __ASM_ARCH_J721E_HARDWARE_H */

arch/arm/mach-k3/j721e_init.c

@@ -119,6 +119,9 @@ void board_init_f(ulong dummy)
 	preloader_console_init();
 #endif
 
+	/* Perform EEPROM-based board detection */
+	do_board_detect();
+
 #if defined(CONFIG_CPU_V7R) && defined(CONFIG_K3_AVS0)
 	ret = uclass_get_device_by_driver(UCLASS_MISC, DM_GET_DRIVER(k3_avs),
 					  &dev);

board/ti/common/board_detect.c

@@ -548,6 +548,15 @@ int __maybe_unused ti_i2c_eeprom_am6_get_base(int bus_addr, int dev_addr)
 	return ret;
 }
 
+bool __maybe_unused board_ti_k3_is(char *name_tag)
+{
+	struct ti_am6_eeprom *ep = TI_AM6_EEPROM_DATA;
+
+	if (ep->header == TI_DEAD_EEPROM_MAGIC)
+		return false;
+	return !strncmp(ep->name, name_tag, AM6_EEPROM_HDR_NAME_LEN);
+}
+
 bool __maybe_unused board_ti_is(char *name_tag)
 {
 	struct ti_common_eeprom *ep = TI_EEPROM_DATA;

board/ti/common/board_detect.h

@@ -319,6 +319,15 @@ int __maybe_unused ti_i2c_eeprom_am6_get_base(int bus_addr, int dev_addr);
  */
 bool board_ti_is(char *name_tag);
 
+/**
+ * board_ti_k3_is() - Board detection logic for TI K3 EVMs
+ * @name_tag:	Tag used in eeprom for the board
+ *
+ * Return: false if board information does not match OR eeprom wasn't read.
+ *	   true otherwise
+ */
+bool board_ti_k3_is(char *name_tag);
+
 /**
  * board_ti_rev_is() - Compare board revision for TI EVMs
  * @rev_tag:	Revision tag to check in eeprom

board/ti/j721e/Kconfig

@@ -11,6 +11,8 @@ config TARGET_J721E_A72_EVM
 	bool "TI K3 based J721E EVM running on A72"
 	select ARM64
 	select SOC_K3_J721E
+	select BOARD_LATE_INIT
+	imply TI_I2C_BOARD_DETECT
 	select SYS_DISABLE_DCACHE_OPS
 
 config TARGET_J721E_R5_EVM
@@ -23,6 +25,7 @@ config TARGET_J721E_R5_EVM
 	select SPL_RAM
 	select K3_J721E_DDRSS
 	imply SYS_K3_SPL_ATF
+	imply TI_I2C_BOARD_DETECT
 
 endchoice
 
@@ -37,6 +40,8 @@ config SYS_VENDOR
 config SYS_CONFIG_NAME
        default "j721e_evm"
 
+source "board/ti/common/Kconfig"
+
 endif
 
 if TARGET_J721E_R5_EVM
@@ -53,4 +58,6 @@ config SYS_CONFIG_NAME
 config SPL_LDSCRIPT
 	default "arch/arm/mach-omap2/u-boot-spl.lds"
 
+source "board/ti/common/Kconfig"
+
 endif

board/ti/j721e/evm.c

@@ -9,10 +9,21 @@
 
 #include <common.h>
 #include <init.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/hardware.h>
+#include <asm/gpio.h>
 #include <asm/io.h>
 #include <spl.h>
 #include <asm/arch/sys_proto.h>
 
+#include "../common/board_detect.h"
+
+#define board_is_j721e_som()	(board_ti_k3_is("J721EX-PM1-SOM") || \
+				 board_ti_k3_is("J721EX-PM2-SOM"))
+
+/* Max number of MAC addresses that are parsed/processed per daughter card */
+#define DAUGHTER_CARD_NO_OF_MAC_ADDR	8
+
 DECLARE_GLOBAL_DATA_PTR;
 
 int board_init(void)
@@ -81,3 +92,243 @@ int ft_board_setup(void *blob, bd_t *bd)
 	return ret;
 }
 #endif
+
+int do_board_detect(void)
+{
+	int ret;
+
+	ret = ti_i2c_eeprom_am6_get_base(CONFIG_EEPROM_BUS_ADDRESS,
+					 CONFIG_EEPROM_CHIP_ADDRESS);
+	if (ret)
+		pr_err("Reading on-board EEPROM at 0x%02x failed %d\n",
+		       CONFIG_EEPROM_CHIP_ADDRESS, ret);
+
+	return ret;
+}
+
+static void setup_board_eeprom_env(void)
+{
+	char *name = "j721e";
+
+	if (do_board_detect())
+		goto invalid_eeprom;
+
+	if (board_is_j721e_som())
+		name = "j721e";
+	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);
+}
+
+/*
+ * Declaration of daughtercards to probe. Note that when adding more
+ * cards they should be grouped by the 'i2c_addr' field to allow for a
+ * more efficient probing process.
+ */
+static const struct {
+	u8 i2c_addr;		/* I2C address of card EEPROM */
+	char *card_name;	/* EEPROM-programmed card name */
+	char *dtbo_name;	/* Device tree overlay to apply */
+	u8 eth_offset;		/* ethXaddr MAC address index offset */
+} ext_cards[] = {
+	{
+		0x51,
+		"J7X-BASE-CPB",
+		"",		/* No dtbo for this board */
+		0,
+	},
+	{
+		0x52,
+		"J7X-INFOTAN-EXP",
+		"",		/* No dtbo for this board */
+		0,
+	},
+	{
+		0x52,
+		"J7X-GESI-EXP",
+		"",		/* No dtbo for this board */
+		5,		/* Start populating from eth5addr */
+	},
+	{
+		0x54,
+		"J7X-VSC8514-ETH",
+		"",		/* No dtbo for this board */
+		1,		/* Start populating from eth1addr */
+	},
+};
+
+static bool daughter_card_detect_flags[ARRAY_SIZE(ext_cards)];
+
+const char *board_fit_get_additionnal_images(int index, const char *type)
+{
+	int i, j;
+
+	if (strcmp(type, FIT_FDT_PROP))
+		return NULL;
+
+	j = 0;
+	for (i = 0; i < ARRAY_SIZE(ext_cards); i++) {
+		if (daughter_card_detect_flags[i]) {
+			if (j == index) {
+				/*
+				 * Return dtbo name only if populated,
+				 * otherwise stop parsing here.
+				 */
+				if (strlen(ext_cards[i].dtbo_name))
+					return ext_cards[i].dtbo_name;
+				else
+					return NULL;
+			};
+
+			j++;
+		}
+	}
+
+	return NULL;
+}
+
+static int probe_daughtercards(void)
+{
+	char mac_addr[DAUGHTER_CARD_NO_OF_MAC_ADDR][TI_EEPROM_HDR_ETH_ALEN];
+	bool eeprom_read_success;
+	struct ti_am6_eeprom ep;
+	u8 previous_i2c_addr;
+	u8 mac_addr_cnt;
+	int i;
+	int ret;
+
+	/* Mark previous I2C address variable as not populated */
+	previous_i2c_addr = 0xff;
+
+	/* No EEPROM data was read yet */
+	eeprom_read_success = false;
+
+	/* Iterate through list of daughtercards */
+	for (i = 0; i < ARRAY_SIZE(ext_cards); i++) {
+		/* Obtain card-specific I2C address */
+		u8 i2c_addr = ext_cards[i].i2c_addr;
+
+		/* Read card EEPROM if not already read previously */
+		if (i2c_addr != previous_i2c_addr) {
+			/* Store I2C address so we can avoid reading twice */
+			previous_i2c_addr = i2c_addr;
+
+			/* Get and parse the daughter card EEPROM record */
+			ret = ti_i2c_eeprom_am6_get(CONFIG_EEPROM_BUS_ADDRESS,
+						    i2c_addr,
+						    &ep,
+						    (char **)mac_addr,
+						    DAUGHTER_CARD_NO_OF_MAC_ADDR,
+						    &mac_addr_cnt);
+			if (ret) {
+				debug("%s: No daughtercard EEPROM at 0x%02x found %d\n",
+				      __func__, i2c_addr, ret);
+				eeprom_read_success = false;
+				/* Skip to the next daughtercard to probe */
+				continue;
+			}
+
+			/* EEPROM read successful, okay to further process. */
+			eeprom_read_success = true;
+		}
+
+		/* Only continue processing if EEPROM data was read */
+		if (!eeprom_read_success)
+			continue;
+
+		/* Only process the parsed data if we found a match */
+		if (strncmp(ep.name, ext_cards[i].card_name, sizeof(ep.name)))
+			continue;
+
+		printf("Detected: %s rev %s\n", ep.name, ep.version);
+		daughter_card_detect_flags[i] = true;
+
+#ifndef CONFIG_SPL_BUILD
+		int j;
+		/*
+		 * Populate any MAC addresses from daughtercard into the U-Boot
+		 * environment, starting with a card-specific offset so we can
+		 * have multiple ext_cards contribute to the MAC pool in a well-
+		 * defined manner.
+		 */
+		for (j = 0; j < mac_addr_cnt; j++) {
+			if (!is_valid_ethaddr((u8 *)mac_addr[j]))
+				continue;
+
+			eth_env_set_enetaddr_by_index("eth",
+						      ext_cards[i].eth_offset + j,
+						      (uchar *)mac_addr[j]);
+		}
+#endif
+	}
+#ifndef CONFIG_SPL_BUILD
+	char name_overlays[1024] = { 0 };
+
+	for (i = 0; i < ARRAY_SIZE(ext_cards); i++) {
+		if (!daughter_card_detect_flags[i])
+			continue;
+
+		/* Skip if no overlays are to be added */
+		if (!strlen(ext_cards[i].dtbo_name))
+			continue;
+
+		/*
+		 * Make sure we are not running out of buffer space by checking
+		 * if we can fit the new overlay, a trailing space to be used
+		 * as a separator, plus the terminating zero.
+		 */
+		if (strlen(name_overlays) + strlen(ext_cards[i].dtbo_name) + 2 >
+		    sizeof(name_overlays))
+			return -ENOMEM;
+
+		/* Append to our list of overlays */
+		strcat(name_overlays, ext_cards[i].dtbo_name);
+		strcat(name_overlays, " ");
+	}
+
+	/* Apply device tree overlay(s) to the U-Boot environment, if any */
+	if (strlen(name_overlays))
+		return env_set("name_overlays", name_overlays);
+#endif
+
+	return 0;
+}
+
+int board_late_init(void)
+{
+	setup_board_eeprom_env();
+	setup_serial();
+
+	/* Check for and probe any plugged-in daughtercards */
+	probe_daughtercards();
+
+	return 0;
+}
+
+void spl_board_init(void)
+{
+	probe_daughtercards();
+}