The Amlogic Meson SoC Secure Monitor implements a call to retrieve an
unique CHIP ID with CPU ID (128 bits length) starting from the GX
Family and all new families.
The chipid string is simply exposed as a sysfs entry under the firmware
sysfs directory.
Signed-off-by: Viacheslav Bocharov <adeep@xxxxxxxxx>
---
drivers/firmware/meson/meson_sm.c | 54 ++++++++++++++++++++++++++++++-
1 file changed, 53 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
index c1c694b485ee..2820f4ac871b 100644
--- a/drivers/firmware/meson/meson_sm.c
+++ b/drivers/firmware/meson/meson_sm.c
@@ -240,9 +240,10 @@ struct meson_sm_firmware *meson_sm_get(struct device_node *sm_node)
}
EXPORT_SYMBOL_GPL(meson_sm_get);
-#define SM_CHIP_ID_LENGTH 119
+#define SM_CHIP_ID_LENGTH 128
#define SM_CHIP_ID_OFFSET 4
#define SM_CHIP_ID_SIZE 12
+#define SM_CHIP_IDv2_SIZE 16
static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
char *buf)
@@ -274,8 +275,59 @@ static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR_RO(serial);
+static ssize_t chipid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct meson_sm_firmware *fw;
+ uint8_t *id_buf;
+ int ret;
+
+ fw = platform_get_drvdata(pdev);
+
+ id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);
+ if (!id_buf)
+ return -ENOMEM;
+
+ ret = meson_sm_call_read(fw, id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID,
+ 2, 0, 0, 0, 0);
+ if (ret < 0) {
+ kfree(id_buf);
+ return ret;
+ }
+
+ int version = *((unsigned int *)id_buf);
+
+ if (version == 2)
+ ret = scnprintf(buf, PAGE_SIZE, "%16phN\n", &id_buf[SM_CHIP_ID_OFFSET]);
+ else {
+ /**
+ * Legacy 12-byte chip ID read out, transform data
+ * to expected order format.
+ */
+ uint8_t *buff;
+
+ buff = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);
+ if (!buff)
+ return -ENOMEM;
+ ((uint32_t *)buff)[0] = 0; // CPU_ID is empty
+ /* Transform into expected order for display */
+ ch = (uint8_t *)(id_buf + 4);
+ for (i = 0; i < 12; i++)
+ buff[i + 4] = ch[11 - i];
+ ret = scnprintf(buf, PAGE_SIZE, "%16phN\n", &buff);
+ kfree(buff);
+ }
+
+ kfree(id_buf);
+ return ret;
+}
+
+static DEVICE_ATTR_RO(chipid);
+
static struct attribute *meson_sm_sysfs_attributes[] = {
&dev_attr_serial.attr,
+ &dev_attr_chipid.attr,
NULL,
};
--
2.34.1
