1 files changed, 109 insertions, 0 deletions
diff --git a/arch/arm/boards/novena/board.c b/arch/arm/boards/novena/board.c
new file mode 100644
index 0000000000..b6c59aff44
--- /dev/null
+++ b/arch/arm/boards/novena/board.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 John Watts <contact@jookia.org>
+
+#include <common.h>
+#include <deep-probe.h>
+#include <fs.h>
+#include <libfile.h>
+#include <net.h>
+
+struct novena_eeprom {
+	uint8_t signature[6]; /* 'Novena' */
+	uint8_t version; /* 1 or 2, not checked */
+	uint8_t page_size; /* v2 only: EEPROM read/write page */
+	uint32_t serial; /* 32-bit serial number */
+	uint8_t mac[6]; /* Gigabit MAC address */
+	uint16_t features; /* features */
+	/* ... extra fields omitted ... */
+} __packed;
+
+static void power_on_audio_codec(void)
+{
+	int rc = of_devices_ensure_probed_by_name("regulator-audio-codec");
+
+	if (rc < 0)
+		pr_err("Unable to power on audio codec: %s\n", strerror(-rc));
+}
+
+static struct novena_eeprom *novena_read_eeprom(void)
+{
+	size_t read;
+	loff_t max = sizeof(struct novena_eeprom);
+	void *eeprom;
+	int rc;
+
+	/*
+	 * When powered off the audio codec pulls down the EEPROM's I2C line.
+	 * Power it on so we can actually read data.
+	 */
+	power_on_audio_codec();
+
+	rc = of_device_ensure_probed_by_alias("eeprom0");
+	if (rc < 0) {
+		pr_err("Unable to probe eeprom0: %s\n", strerror(-rc));
+		return NULL;
+	}
+
+	rc = read_file_2("/dev/eeprom0", &read, &eeprom, max);
+
+	if (rc < 0 && rc != -EFBIG) {
+		pr_err("Unable to read Novena EEPROM: %s\n", strerror(-rc));
+		return NULL;
+	} else if (read != max) {
+		pr_err("Short read from Novena EEPROM?\n");
+		free(eeprom);
+		return NULL;
+	}
+
+	return eeprom;
+}
+
+static bool novena_check_eeprom(struct novena_eeprom *eeprom)
+{
+	char *sig = eeprom->signature;
+	size_t size = sizeof(eeprom->signature);
+
+	if (memcmp("Novena", sig, size) != 0) {
+		pr_err("Unknown Novena EEPROM signature\n");
+		return false;
+	}
+
+	return true;
+}
+
+static void novena_set_mac(struct novena_eeprom *eeprom)
+{
+	struct device_node *dnode;
+
+	dnode = of_find_node_by_alias(of_get_root_node(), "ethernet0");
+	if (dnode)
+		of_eth_register_ethaddr(dnode, eeprom->mac);
+	else
+		pr_err("Unable to find ethernet node\n");
+}
+
+static int novena_probe(struct device *dev)
+{
+	struct novena_eeprom *eeprom = novena_read_eeprom();
+
+	if (eeprom && novena_check_eeprom(eeprom))
+		novena_set_mac(eeprom);
+
+	free(eeprom);
+
+	return 0;
+}
+
+static const struct of_device_id novena_of_match[] = {
+	{ .compatible = "kosagi,imx6q-novena", },
+	{ /* sentinel */ }
+};
+
+static struct driver novena_board_driver = {
+	.name = "board-novena",
+	.probe = novena_probe,
+	.of_compatible = novena_of_match,
+};
+coredevice_platform_driver(novena_board_driver);
+
+BAREBOX_DEEP_PROBE_ENABLE(novena_of_match);