[PATCH V3] soc: imx-scu: Add SoC UID(unique identifier) support

From: Anson . Huang
Date: Tue Jul 02 2019 - 03:54:53 EST


From: Anson Huang <Anson.Huang@xxxxxxx>

Add i.MX SCU SoC's UID(unique identifier) support, user
can read it from sysfs:

root@imx8qxpmek:~# cat /sys/devices/soc0/soc_uid
7B64280B57AC1898

Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
Reviewed-by: Daniel Baluta <daniel.baluta@xxxxxxx>
---
Change since V2:
- The SCU FW API for getting UID does NOT have response, so we should set
imx_scu_call_rpc()'s 3rd parameter as false and still can check the returned
value, and comment is no needed any more.
---
drivers/soc/imx/soc-imx-scu.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/drivers/soc/imx/soc-imx-scu.c b/drivers/soc/imx/soc-imx-scu.c
index 676f612..50831eb 100644
--- a/drivers/soc/imx/soc-imx-scu.c
+++ b/drivers/soc/imx/soc-imx-scu.c
@@ -27,6 +27,40 @@ struct imx_sc_msg_misc_get_soc_id {
} data;
} __packed;

+struct imx_sc_msg_misc_get_soc_uid {
+ struct imx_sc_rpc_msg hdr;
+ u32 uid_low;
+ u32 uid_high;
+} __packed;
+
+static ssize_t soc_uid_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct imx_sc_msg_misc_get_soc_uid msg;
+ struct imx_sc_rpc_msg *hdr = &msg.hdr;
+ u64 soc_uid;
+ int ret;
+
+ hdr->ver = IMX_SC_RPC_VERSION;
+ hdr->svc = IMX_SC_RPC_SVC_MISC;
+ hdr->func = IMX_SC_MISC_FUNC_UNIQUE_ID;
+ hdr->size = 1;
+
+ ret = imx_scu_call_rpc(soc_ipc_handle, &msg, false);
+ if (ret) {
+ pr_err("%s: get soc uid failed, ret %d\n", __func__, ret);
+ return ret;
+ }
+
+ soc_uid = msg.uid_high;
+ soc_uid <<= 32;
+ soc_uid |= msg.uid_low;
+
+ return sprintf(buf, "%016llX\n", soc_uid);
+}
+
+static DEVICE_ATTR_RO(soc_uid);
+
static int imx_scu_soc_id(void)
{
struct imx_sc_msg_misc_get_soc_id msg;
@@ -102,6 +136,11 @@ static int imx_scu_soc_probe(struct platform_device *pdev)
goto free_revision;
}

+ ret = device_create_file(soc_device_to_device(soc_dev),
+ &dev_attr_soc_uid);
+ if (ret)
+ goto free_revision;
+
return 0;

free_revision:
--
2.7.4