1 files changed, 103 insertions, 0 deletions
diff --git a/board/hardkernel/odroid_go2/go2.c b/board/hardkernel/odroid_go2/go2.c
index 29464ae63e..a0338ead3b 100644
--- a/board/hardkernel/odroid_go2/go2.c
+++ b/board/hardkernel/odroid_go2/go2.c
@@ -2,3 +2,106 @@
 /*
  * (C) Copyright 2019 Rockchip Electronics Co., Ltd
  */
+
+#include <linux/stddef.h>
+#include <adc.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <env.h>
+#include <stdlib.h>
+
+#define DTB_DIR			"rockchip/"
+
+struct oga_model {
+	const u16 adc_value;
+	const char *board;
+	const char *board_name;
+	const char *fdtfile;
+};
+
+enum oga_device_id {
+	OGA,
+	OGA_V11,
+	OGS,
+};
+
+/*
+ * All ADC values from schematic of Odroid Go Advance Black Edition.
+ * Value for OGS is inferred based on schematic and observed values.
+ */
+static const struct oga_model oga_model_details[] = {
+	[OGA] = {
+		856,
+		"rk3326-odroid-go2",
+		"ODROID-GO Advance",
+		DTB_DIR "rk3326-odroid-go2.dtb",
+	},
+	[OGA_V11] = {
+		677,
+		"rk3326-odroid-go2-v11",
+		"ODROID-GO Advance Black Edition",
+		DTB_DIR "rk3326-odroid-go2-v11.dtb",
+	},
+	[OGS] = {
+		85,
+		"rk3326-odroid-go3",
+		"ODROID-GO Super",
+		DTB_DIR "rk3326-odroid-go3.dtb",
+	},
+};
+
+/* Detect which Odroid Go Advance device we are using so as to load the
+ * correct devicetree for Linux. Set an environment variable once
+ * found. The detection depends on the value of ADC channel 0.
+ */
+int oga_detect_device(void)
+{
+	u32 adc_info;
+	int ret, i;
+	int board_id = -ENXIO;
+
+	ret = adc_channel_single_shot("saradc@ff288000", 0, &adc_info);
+	if (ret) {
+		printf("Read SARADC failed with error %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Get the correct device from the table. The ADC value is
+	 * determined by a resistor on ADC channel 0. The manufacturer
+	 * accounted for this with a 5% tolerance, so assume a +- value
+	 * of 50 should be enough.
+	 */
+	for (i = 0; i < ARRAY_SIZE(oga_model_details); i++) {
+		u32 adc_min = oga_model_details[i].adc_value - 50;
+		u32 adc_max = oga_model_details[i].adc_value + 50;
+
+		if (adc_min < adc_info && adc_max > adc_info) {
+			board_id = i;
+			break;
+		}
+	}
+
+	if (board_id < 0)
+		return board_id;
+
+	env_set("board", oga_model_details[board_id].board);
+	env_set("board_name",
+		oga_model_details[board_id].board_name);
+	env_set("fdtfile", oga_model_details[board_id].fdtfile);
+
+	return 0;
+}
+
+int rk_board_late_init(void)
+{
+	int ret;
+
+	ret = oga_detect_device();
+	if (ret) {
+		printf("Unable to detect device type: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}