4 files changed, 131 insertions, 0 deletions

diff --git a/board/ti/common/Kconfig b/board/ti/common/Kconfig
index 9ead7ca..49edd98 100644
--- a/board/ti/common/Kconfig
+++ b/board/ti/common/Kconfig
@@ -16,6 +16,12 @@ config EEPROM_CHIP_ADDRESS
 	default 0x50
 	depends on TI_I2C_BOARD_DETECT
 
+config CAPE_EEPROM_BUS_NUM
+	int "Cape EEPROM's I2C bus address"
+	range 0 8
+	default 2
+	depends on CMD_EXTENSION
+
 config TI_COMMON_CMD_OPTIONS
 	bool "Enable cmd options on TI platforms"
 	imply CMD_ASKENV
diff --git a/board/ti/common/Makefile b/board/ti/common/Makefile
index cb97f22..3172d87 100644
--- a/board/ti/common/Makefile
+++ b/board/ti/common/Makefile
@@ -2,3 +2,4 @@
 # Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
 
 obj-${CONFIG_TI_I2C_BOARD_DETECT} += board_detect.o
+obj-${CONFIG_CMD_EXTENSION} += cape_detect.o
diff --git a/board/ti/common/cape_detect.c b/board/ti/common/cape_detect.c
new file mode 100644
index 0000000..2e6105c
--- /dev/null
+++ b/board/ti/common/cape_detect.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2021
+ * Köry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <i2c.h>
+#include <extension_board.h>
+
+#include "cape_detect.h"
+
+static void sanitize_field(char *text, size_t size)
+{
+	char *c = NULL;
+
+	for (c = text; c < text + (int)size; c++) {
+		if (*c == 0xFF)
+			*c = 0;
+	}
+}
+
+int extension_board_scan(struct list_head *extension_list)
+{
+	struct extension *cape;
+	struct am335x_cape_eeprom_id eeprom_header;
+
+	int num_capes = 0;
+	int ret, i;
+	struct udevice *dev;
+	unsigned char addr;
+
+	char process_cape_part_number[17] = {'0'};
+	char process_cape_version[5] = {'0'};
+	uint8_t cursor = 0;
+
+	for (addr = CAPE_EEPROM_FIRST_ADDR; addr <= CAPE_EEPROM_LAST_ADDR; addr++) {
+		ret = i2c_get_chip_for_busnum(CONFIG_CAPE_EEPROM_BUS_NUM, addr, 1, &dev);
+		if (ret)
+			continue;
+
+		/* Move the read cursor to the beginning of the EEPROM */
+		dm_i2c_write(dev, 0, &cursor, 1);
+		ret = dm_i2c_read(dev, 0, (uint8_t *)&eeprom_header,
+				  sizeof(struct am335x_cape_eeprom_id));
+		if (ret) {
+			printf("Cannot read i2c EEPROM\n");
+			continue;
+		}
+
+		if (eeprom_header.header != CAPE_MAGIC)
+			continue;
+
+		sanitize_field(eeprom_header.board_name, sizeof(eeprom_header.board_name));
+		sanitize_field(eeprom_header.version, sizeof(eeprom_header.version));
+		sanitize_field(eeprom_header.manufacturer, sizeof(eeprom_header.manufacturer));
+		sanitize_field(eeprom_header.part_number, sizeof(eeprom_header.part_number));
+
+		/* Process cape part_number */
+		memset(process_cape_part_number, 0, sizeof(process_cape_part_number));
+		strncpy(process_cape_part_number, eeprom_header.part_number, 16);
+		/* Some capes end with '.' */
+		for (i = 15; i >= 0; i--) {
+			if (process_cape_part_number[i] == '.')
+				process_cape_part_number[i] = '\0';
+			else
+				break;
+		}
+
+		/* Process cape version */
+		memset(process_cape_version, 0, sizeof(process_cape_version));
+		strncpy(process_cape_version, eeprom_header.version, 4);
+		for (i = 0; i < 4; i++) {
+			if (process_cape_version[i] == 0)
+				process_cape_version[i] = '0';
+		}
+
+		printf("BeagleBone Cape: %s (0x%x)\n", eeprom_header.board_name, addr);
+
+		cape = calloc(1, sizeof(struct extension));
+		if (!cape) {
+			printf("Error in memory allocation\n");
+			return num_capes;
+		}
+
+		snprintf(cape->overlay, sizeof(cape->overlay), "%s-%s.dtbo",
+			 process_cape_part_number, process_cape_version);
+		strncpy(cape->name, eeprom_header.board_name, 32);
+		strncpy(cape->version, process_cape_version, 4);
+		strncpy(cape->owner, eeprom_header.manufacturer, 16);
+		list_add_tail(&cape->list, extension_list);
+		num_capes++;
+	}
+	return num_capes;
+}
diff --git a/board/ti/common/cape_detect.h b/board/ti/common/cape_detect.h
new file mode 100644
index 0000000..b0d5c9f
--- /dev/null
+++ b/board/ti/common/cape_detect.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2021
+ * Köry Maincent, Bootlin, <kory.maincent@bootlin.com>
+ */
+
+#ifndef __CAPE_DETECT_H
+#define __CAPE_DETECT_H
+
+struct am335x_cape_eeprom_id {
+	unsigned int header;
+	char eeprom_rev[2];
+	char board_name[32];
+	char version[4];
+	char manufacturer[16];
+	char part_number[16];
+};
+
+#define CAPE_EEPROM_FIRST_ADDR	0x54
+#define CAPE_EEPROM_LAST_ADDR	0x57
+
+#define CAPE_EEPROM_ADDR_LEN 0x10
+
+#define CAPE_MAGIC 0xEE3355AA
+
+int extension_board_scan(struct list_head *extension_list);
+
+#endif /* __CAPE_DETECT_H */