[PATCH 3/4] imx: kontron-sl-mx6ul: Add support for reading HW UIDs

[Frieder Schrempf]

From: Frieder Schrempf <frieder.schrempf at kontron.de>

The factory provides a CPU UID in the OTPs and the SoM module
and the carrier board might provide additional UIDs in the GP
registers of the OTPs. Load these values in the following order
and create a serial number string:

* Board UID (GP2)
* SoM UID (GP1)
* CPU UID (UNIQUE_ID)

The string is stored in the "serial#" env variable and
exported to Linux. Further this prints the used UID to the
console which looks like this

  ID:    0042152331 (Board)

or:

  ID:    0030124840 (SoM)

or:

  ID:    4696668CD9516886 (CPU)

Signed-off-by: Frieder Schrempf <frieder.schrempf at kontron.de>
---
 board/kontron/sl-mx6ul/Kconfig     |  2 ++
 board/kontron/sl-mx6ul/sl-mx6ul.c  | 32 ++++++++++++++++++++++++++++++
 configs/kontron-sl-mx6ul_defconfig |  1 +
 3 files changed, 35 insertions(+)

diff --git a/board/kontron/sl-mx6ul/Kconfig b/board/kontron/sl-mx6ul/Kconfig
index 7a4ffbed289..a6d3fa49778 100644
--- a/board/kontron/sl-mx6ul/Kconfig
+++ b/board/kontron/sl-mx6ul/Kconfig
@@ -9,4 +9,6 @@ config SYS_VENDOR
 config SYS_CONFIG_NAME
 	default "kontron-sl-mx6ul"
 
+source "board/kontron/common/Kconfig"
+
 endif
diff --git a/board/kontron/sl-mx6ul/sl-mx6ul.c b/board/kontron/sl-mx6ul/sl-mx6ul.c
index 65f9b75c1a0..9dda8822ef9 100644
--- a/board/kontron/sl-mx6ul/sl-mx6ul.c
+++ b/board/kontron/sl-mx6ul/sl-mx6ul.c
@@ -14,8 +14,37 @@
 
 #include "sl-mx6ul-common.h"
 
+#include "../common/hw-uid.h"
+
 DECLARE_GLOBAL_DATA_PTR;
 
+#if IS_ENABLED(CONFIG_KONTRON_HW_UID)
+
+struct uid_otp_loc uid_otp_locations[] = {
+	{
+		.addr = (u32 *)(OCOTP_BASE_ADDR + 0x670),
+		.len = 1,
+		.format = UID_OTP_FORMAT_DEC,
+		.desc = "BOARD"
+	},
+	{
+		.addr = (u32 *)(OCOTP_BASE_ADDR + 0x660),
+		.len = 1,
+		.format = UID_OTP_FORMAT_DEC,
+		.desc = "SOM"
+	},
+#if IS_ENABLED(CONFIG_KONTRON_HW_UID_USE_SOC_FALLBACK)
+	{
+		.addr = (u32 *)(OCOTP_BASE_ADDR + 0x410),
+		.len = 2,
+		.format = UID_OTP_FORMAT_HEX,
+		.desc = "SOC"
+	}
+#endif
+};
+
+#endif /* CONFIG_KONTRON_HW_UID */
+
 int dram_init(void)
 {
 	gd->ram_size = imx_ddr_size();
@@ -91,6 +120,9 @@ int board_init(void)
 
 int board_late_init(void)
 {
+	if (IS_ENABLED(CONFIG_KONTRON_HW_UID))
+		get_serial_number(uid_otp_locations, ARRAY_SIZE(uid_otp_locations));
+
 	if (is_boot_from_usb()) {
 		env_set("bootdelay", "0");
 		env_set("bootcmd", "fastboot 0");
diff --git a/configs/kontron-sl-mx6ul_defconfig b/configs/kontron-sl-mx6ul_defconfig
index 9f7003bf54c..c6d450419cc 100644
--- a/configs/kontron-sl-mx6ul_defconfig
+++ b/configs/kontron-sl-mx6ul_defconfig
@@ -13,6 +13,7 @@ CONFIG_ENV_SECT_SIZE=0x4000
 CONFIG_MX6UL=y
 CONFIG_TARGET_KONTRON_MX6UL=y
 CONFIG_DM_GPIO=y
+CONFIG_KONTRON_HW_UID=y
 CONFIG_DEFAULT_DEVICE_TREE="nxp/imx/imx6ul-kontron-bl"
 CONFIG_SPL_MMC=y
 CONFIG_SPL_SERIAL=y
-- 
2.51.0