board: ti: am654: Use EEPROM-based board detection

The TI AM654x EVM base board and the associated daughtercards have on-
board I2C-based EEPROMs containing board configuration data. Use the
board detection infrastructure introduced earlier to do the following:

1) Parse the AM654x EVM base board EEPROM and populate items like board
   name and MAC addresses into the TI common EEPROM data structure
   residing in SRAM scratch space
2) Check for presence of daughter card(s) by probing the associated
   presence signals via an I2C-based GPIO expander. Then, if such a
   card is found, parse the data such as additional Ethernet MAC
   addresses from its on-board EEPROM and populate into U-Boot
   accordingly
3) Dynamically create an U-Boot ENV variable called overlay_files
   containing a list of daugherboard-specific DTB overlays based on
   daughercards found.

This patch adds support for the AM654x base board ("AM6-COMPROCEVM")
as well as for the IDK ("AM6-IDKAPPEVM"), OLDI LCD ("OLDI-LCD1EVM")
PCIe/USB3.0 ("SER-PCIEUSBEVM"), 2 Lane PCIe/USB2.0 ("SER-PCIE2LEVM"),
and general purpuse ("AM6-GPAPPEVM") daughtercards.

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

2 files changed, 248 insertions, 0 deletions

diff --git a/board/ti/am65x/Kconfig b/board/ti/am65x/Kconfig
index 60bb834acae..47b41cd6afe 100644
--- a/board/ti/am65x/Kconfig
+++ b/board/ti/am65x/Kconfig
@@ -12,6 +12,8 @@ config TARGET_AM654_A53_EVM
 	select ARM64
 	select SOC_K3_AM6
 	select SYS_DISABLE_DCACHE_OPS
+	select BOARD_LATE_INIT
+	imply TI_I2C_BOARD_DETECT
 
 config TARGET_AM654_R5_EVM
 	bool "TI K3 based AM654 EVM running on R5"
@@ -21,6 +23,7 @@ config TARGET_AM654_R5_EVM
 	select K3_LOAD_SYSFW
 	select K3_AM654_DDRSS
 	imply SYS_K3_SPL_ATF
+	imply TI_I2C_BOARD_DETECT
 
 endchoice
 
@@ -35,6 +38,8 @@ config SYS_VENDOR
 config SYS_CONFIG_NAME
        default "am65x_evm"
 
+source "board/ti/common/Kconfig"
+
 endif
 
 if TARGET_AM654_R5_EVM
@@ -51,4 +56,6 @@ config SYS_CONFIG_NAME
 config SPL_LDSCRIPT
 	default "arch/arm/mach-omap2/u-boot-spl.lds"
 
+source "board/ti/common/Kconfig"
+
 endif
diff --git a/board/ti/am65x/evm.c b/board/ti/am65x/evm.c
index 52f5d6b11e3..7bd8c4fa665 100644
--- a/board/ti/am65x/evm.c
+++ b/board/ti/am65x/evm.c
@@ -8,10 +8,31 @@
  */
 
 #include <common.h>
+#include <dm.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/hardware.h>
+#include <asm/gpio.h>
 #include <asm/io.h>
+#include <asm/omap_common.h>
 #include <spl.h>
 #include <asm/arch/sys_proto.h>
 
+#include "../common/board_detect.h"
+
+#define board_is_am65x_base_board()	board_ti_is("AM6-COMPROCEVM")
+
+/* Daughter card presence detection signals */
+enum {
+	AM65X_EVM_APP_BRD_DET,
+	AM65X_EVM_LCD_BRD_DET,
+	AM65X_EVM_SERDES_BRD_DET,
+	AM65X_EVM_HDMI_GPMC_BRD_DET,
+	AM65X_EVM_BRD_DET_COUNT,
+};
+
+/* 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)
@@ -80,3 +101,223 @@ 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 = "am65x";
+
+	if (do_board_detect())
+		goto invalid_eeprom;
+
+	if (board_is_am65x_base_board())
+		name = "am65x";
+	else
+		printf("Unidentified board claims %s in eeprom header\n",
+		       board_ti_get_name());
+
+invalid_eeprom:
+	set_board_info_env_am6(name);
+}
+
+static int init_daughtercard_det_gpio(char *gpio_name, struct gpio_desc *desc)
+{
+	int ret;
+
+	memset(desc, 0, sizeof(*desc));
+
+	ret = dm_gpio_lookup_name(gpio_name, desc);
+	if (ret < 0)
+		return ret;
+
+	/* Request GPIO, simply re-using the name as label */
+	ret = dm_gpio_request(desc, gpio_name);
+	if (ret < 0)
+		return ret;
+
+	return dm_gpio_set_dir_flags(desc, GPIOD_IS_IN);
+}
+
+static int probe_daughtercards(void)
+{
+	struct ti_am6_eeprom ep;
+	struct gpio_desc board_det_gpios[AM65X_EVM_BRD_DET_COUNT];
+	char mac_addr[DAUGHTER_CARD_NO_OF_MAC_ADDR][TI_EEPROM_HDR_ETH_ALEN];
+	u8 mac_addr_cnt;
+	char name_overlays[1024] = { 0 };
+	int i, j;
+	int ret;
+
+	/*
+	 * Daughter card presence detection signal name to GPIO (via I2C I/O
+	 * expander @ address 0x38) name and EEPROM I2C address mapping.
+	 */
+	const struct {
+		char *gpio_name;
+		u8 i2c_addr;
+	} slot_map[AM65X_EVM_BRD_DET_COUNT] = {
+		{ "gpio@38_0", 0x52, },	/* AM65X_EVM_APP_BRD_DET */
+		{ "gpio@38_1", 0x55, },	/* AM65X_EVM_LCD_BRD_DET */
+		{ "gpio@38_2", 0x54, },	/* AM65X_EVM_SERDES_BRD_DET */
+		{ "gpio@38_3", 0x53, },	/* AM65X_EVM_HDMI_GPMC_BRD_DET */
+	};
+
+	/* Declaration of daughtercards to probe */
+	const struct {
+		u8 slot_index;		/* Slot the card is installed */
+		char *card_name;	/* EEPROM-programmed card name */
+		char *dtbo_name;	/* Device tree overlay to apply */
+		u8 eth_offset;		/* ethXaddr MAC address index offset */
+	} cards[] = {
+		{
+			AM65X_EVM_APP_BRD_DET,
+			"AM6-GPAPPEVM",
+			"k3-am654-gp.dtbo",
+			0,
+		},
+		{
+			AM65X_EVM_APP_BRD_DET,
+			"AM6-IDKAPPEVM",
+			"k3-am654-idk.dtbo",
+			3,
+		},
+		{
+			AM65X_EVM_SERDES_BRD_DET,
+			"SER-PCIE2LEVM",
+			"k3-am654-pcie-usb2.dtbo",
+			0,
+		},
+		{
+			AM65X_EVM_SERDES_BRD_DET,
+			"SER-PCIEUSBEVM",
+			"k3-am654-pcie-usb3.dtbo",
+			0,
+		},
+		{
+			AM65X_EVM_LCD_BRD_DET,
+			"OLDI-LCD1EVM",
+			"k3-am654-evm-oldi-lcd1evm.dtbo",
+			0,
+		},
+	};
+
+	/*
+	 * Initialize GPIO used for daughtercard slot presence detection and
+	 * keep the resulting handles in local array for easier access.
+	 */
+	for (i = 0; i < AM65X_EVM_BRD_DET_COUNT; i++) {
+		ret = init_daughtercard_det_gpio(slot_map[i].gpio_name,
+						 &board_det_gpios[i]);
+		if (ret < 0)
+			return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(cards); i++) {
+		/* Obtain card-specific slot index and associated I2C address */
+		u8 slot_index = cards[i].slot_index;
+		u8 i2c_addr = slot_map[slot_index].i2c_addr;
+
+		/*
+		 * The presence detection signal is active-low, hence skip
+		 * over this card slot if anything other than 0 is returned.
+		 */
+		ret = dm_gpio_get_value(&board_det_gpios[slot_index]);
+		if (ret < 0)
+			return ret;
+		else if (ret)
+			continue;
+
+		/* 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) {
+			pr_err("Reading daughtercard EEPROM at 0x%02x failed %d\n",
+			       i2c_addr, ret);
+			/*
+			 * Even this is pretty serious let's just skip over
+			 * this particular daughtercard, rather than ending
+			 * the probing process altogether.
+			 */
+			continue;
+		}
+
+		/* Only process the parsed data if we found a match */
+		if (strncmp(ep.name, cards[i].card_name, sizeof(ep.name)))
+			continue;
+
+		printf("detected %s\n", cards[i].card_name);
+
+		/*
+		 * Populate any MAC addresses from daughtercard into the U-Boot
+		 * environment, starting with a card-specific offset so we can
+		 * have multiple 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",
+						      cards[i].eth_offset + j,
+						      (uchar *)mac_addr[j]);
+		}
+
+		/* Skip if no overlays are to be added */
+		if (!strlen(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(cards[i].dtbo_name) + 2 >
+		    sizeof(name_overlays))
+			return -ENOMEM;
+
+		/* Append to our list of overlays */
+		strcat(name_overlays, 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);
+
+	return 0;
+}
+
+int board_late_init(void)
+{
+	struct ti_am6_eeprom *ep = TI_AM6_EEPROM_DATA;
+
+	setup_board_eeprom_env();
+
+	/*
+	 * The first MAC address for ethernet a.k.a. ethernet0 comes from
+	 * efuse populated via the am654 gigabit eth switch subsystem driver.
+	 * All the other ones are populated via EEPROM, hence continue with
+	 * an index of 1.
+	 */
+	board_ti_am6_set_ethaddr(1, ep->mac_addr_cnt);
+
+	/* Check for and probe any plugged-in daughtercards */
+	probe_daughtercards();
+
+	return 0;
+}