[PATCH 4/4] imx: kontron-sl-mx8mm: 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-mx8mm/Kconfig     |  2 ++
 board/kontron/sl-mx8mm/sl-mx8mm.c  | 32 ++++++++++++++++++++++++++++++
 configs/kontron-sl-mx8mm_defconfig |  1 +
 3 files changed, 35 insertions(+)

diff --git a/board/kontron/sl-mx8mm/Kconfig b/board/kontron/sl-mx8mm/Kconfig
index 1597bcf894d..0a5123d2979 100644
--- a/board/kontron/sl-mx8mm/Kconfig
+++ b/board/kontron/sl-mx8mm/Kconfig
@@ -9,4 +9,6 @@ config SYS_VENDOR
 config SYS_CONFIG_NAME
 	default "kontron-sl-mx8mm"
 
+source "board/kontron/common/Kconfig"
+
 endif
diff --git a/board/kontron/sl-mx8mm/sl-mx8mm.c b/board/kontron/sl-mx8mm/sl-mx8mm.c
index df92765cb2d..d24d5286e45 100644
--- a/board/kontron/sl-mx8mm/sl-mx8mm.c
+++ b/board/kontron/sl-mx8mm/sl-mx8mm.c
@@ -18,8 +18,37 @@
 #include <mmc.h>
 #include <net.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 + 0x7A0),
+		.len = 2,
+		.format = UID_OTP_FORMAT_DEC,
+		.desc = "BOARD"
+	},
+	{
+		.addr = (u32 *)(OCOTP_BASE_ADDR + 0x780),
+		.len = 2,
+		.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 */
+
 #if IS_ENABLED(CONFIG_EFI_HAVE_CAPSULE_SUPPORT)
 struct efi_fw_image fw_images[] = {
 	{
@@ -167,6 +196,9 @@ int board_late_init(void)
 		env_set("touch_rst_gpio", "87");
 	}
 
+	if (IS_ENABLED(CONFIG_KONTRON_HW_UID))
+		get_serial_number(uid_otp_locations, ARRAY_SIZE(uid_otp_locations));
+
 	if (is_usb_boot()) {
 		env_set("bootcmd", "fastboot 0");
 		env_set("bootdelay", "0");
diff --git a/configs/kontron-sl-mx8mm_defconfig b/configs/kontron-sl-mx8mm_defconfig
index 42346a305f9..ed60d3b9ce4 100644
--- a/configs/kontron-sl-mx8mm_defconfig
+++ b/configs/kontron-sl-mx8mm_defconfig
@@ -11,6 +11,7 @@ CONFIG_ENV_OFFSET=0x1E0000
 CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_IMX_CONFIG="board/kontron/sl-mx8mm/imximage.cfg"
 CONFIG_DM_GPIO=y
+CONFIG_KONTRON_HW_UID=y
 CONFIG_SPL_DM_SPI=y
 CONFIG_DEFAULT_DEVICE_TREE="freescale/imx8mm-kontron-bl"
 CONFIG_TARGET_KONTRON_MX8MM=y
-- 
2.51.0