imx8mm-cl-iot-gate: Retrieve the serial number from EEPROM
The serial number is located at offset 0x14 of the EEPROM
under i2c0 bus at address 0x54.
To print the serial number in Linux:
SERNUM=$(cat /proc/device-tree/serial-number)
echo $SERNUM
Signed-off-by: Fabio Estevam <festevam@denx.de>
diff --git a/board/compulab/imx8mm-cl-iot-gate/imx8mm-cl-iot-gate.c b/board/compulab/imx8mm-cl-iot-gate/imx8mm-cl-iot-gate.c
index 779b64b..27200f7 100644
--- a/board/compulab/imx8mm-cl-iot-gate/imx8mm-cl-iot-gate.c
+++ b/board/compulab/imx8mm-cl-iot-gate/imx8mm-cl-iot-gate.c
@@ -463,6 +463,52 @@
return 0;
}
+static int read_serial_number(void)
+{
+ unsigned char serialnumber[6];
+ unsigned char reversed[6];
+ char serial_string[12];
+ struct udevice *dev;
+ int ret, off, i;
+
+ off = fdt_path_offset(gd->fdt_blob, "eeprom0");
+ if (off < 0) {
+ printf("No eeprom0 path offset found in DT\n");
+ return off;
+ }
+
+ ret = uclass_get_device_by_of_offset(UCLASS_I2C_EEPROM, off, &dev);
+ if (ret) {
+ printf("%s: Could not find EEPROM\n", __func__);
+ return ret;
+ }
+
+ ret = i2c_set_chip_offset_len(dev, 1);
+ if (ret)
+ return ret;
+
+ ret = i2c_eeprom_read(dev, 0x14, serialnumber, sizeof(serialnumber));
+ if (ret) {
+ printf("%s: Could not read EEPROM\n", __func__);
+ return ret;
+ }
+
+ for (i = sizeof(serialnumber) - 1; i >= 0; i--)
+ reversed[i] = serialnumber[sizeof(serialnumber) - 1 - i];
+
+ for (i = 0; i < sizeof(reversed); i++) {
+ serial_string[i * 2] = (reversed[i] >> 4) & 0xf;
+ serial_string[i * 2 + 1] = reversed[i] & 0xf;
+ }
+
+ for (i = 0; i < sizeof(serial_string); i++)
+ serial_string[i] += '0';
+
+ env_set("serial#", serial_string);
+
+ return 0;
+}
+
int board_late_init(void)
{
int ret;
@@ -476,5 +522,9 @@
if (ret < 0)
printf("Cannot set MAC address from EEPROM\n");
+ ret = read_serial_number();
+ if (ret < 0)
+ printf("Cannot read serial number from EEPROM\n");
+
return 0;
}