[PATCH 2/2] soc: imx8: Add i.MX8MM UID(unique identifier) support

[Anson . Huang]

From: Anson Huang <anson.hu...@nxp.com>

Add i.MX8MM SoC UID(unique identifier) support, user
can read it from sysfs:

root@imx8mmevk:~# cat /sys/devices/soc0/soc_uid
B365FA0A5C85D6EE

Signed-off-by: Anson Huang <anson.hu...@nxp.com>
---
 drivers/soc/imx/soc-imx8.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
index c19ef4b..b9831576 100644
--- a/drivers/soc/imx/soc-imx8.c
+++ b/drivers/soc/imx/soc-imx8.c
@@ -66,6 +66,26 @@ static u32 __init imx8mq_soc_revision(void)
        return rev;
 }
 
+static void __init imx8mm_soc_uid(void)
+{
+       void __iomem *ocotp_base;
+       struct device_node *np;
+
+       np = of_find_compatible_node(NULL, NULL, "fsl,imx8mm-ocotp");
+       if (!np)
+               return;
+
+       ocotp_base = of_iomap(np, 0);
+       WARN_ON(!ocotp_base);
+
+       soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH);
+       soc_uid <<= 32;
+       soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW);
+
+       iounmap(ocotp_base);
+       of_node_put(np);
+}
+
 static u32 __init imx8mm_soc_revision(void)
 {
        struct device_node *np;
@@ -83,6 +103,9 @@ static u32 __init imx8mm_soc_revision(void)
 
        iounmap(anatop_base);
        of_node_put(np);
+
+       imx8mm_soc_uid();
+
        return rev;
 }
 
-- 
2.7.4