Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
index 0ec2ca8..8d908a8 100644
--- a/drivers/firmware/meson/meson_sm.c
+++ b/drivers/firmware/meson/meson_sm.c
@@ -1,15 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Amlogic Secure Monitor driver
  *
  * Copyright (C) 2016 Endless Mobile, Inc.
  * Author: Carlo Caione <carlo@endlessm.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * version 2 as published by the Free Software Foundation.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 #define pr_fmt(fmt) "meson-sm: " fmt
@@ -24,6 +18,7 @@
 #include <linux/printk.h>
 #include <linux/types.h>
 #include <linux/sizes.h>
+ #include <linux/slab.h>
 
 #include <linux/firmware/meson/meson_sm.h>
 
@@ -48,6 +43,7 @@
 		CMD(SM_EFUSE_READ,	0x82000030),
 		CMD(SM_EFUSE_WRITE,	0x82000031),
 		CMD(SM_EFUSE_USER_MAX,	0x82000033),
+		CMD(SM_GET_CHIP_ID,	0x82000044),
 		{ /* sentinel */ },
 	},
 };
@@ -214,6 +210,57 @@
 }
 EXPORT_SYMBOL(meson_sm_call_write);
 
+#define SM_CHIP_ID_LENGTH	119
+#define SM_CHIP_ID_OFFSET	4
+#define SM_CHIP_ID_SIZE		12
+
+static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	uint8_t *id_buf;
+	int ret;
+
+	id_buf = kmalloc(SM_CHIP_ID_LENGTH, GFP_KERNEL);
+	if (!id_buf)
+		return -ENOMEM;
+
+	ret = meson_sm_call_read(id_buf, SM_CHIP_ID_LENGTH, SM_GET_CHIP_ID,
+				 0, 0, 0, 0, 0);
+	if (ret < 0) {
+		kfree(id_buf);
+		return ret;
+	}
+
+	ret = sprintf(buf, "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
+			id_buf[SM_CHIP_ID_OFFSET + 0],
+			id_buf[SM_CHIP_ID_OFFSET + 1],
+			id_buf[SM_CHIP_ID_OFFSET + 2],
+			id_buf[SM_CHIP_ID_OFFSET + 3],
+			id_buf[SM_CHIP_ID_OFFSET + 4],
+			id_buf[SM_CHIP_ID_OFFSET + 5],
+			id_buf[SM_CHIP_ID_OFFSET + 6],
+			id_buf[SM_CHIP_ID_OFFSET + 7],
+			id_buf[SM_CHIP_ID_OFFSET + 8],
+			id_buf[SM_CHIP_ID_OFFSET + 9],
+			id_buf[SM_CHIP_ID_OFFSET + 10],
+			id_buf[SM_CHIP_ID_OFFSET + 11]);
+
+	kfree(id_buf);
+
+	return ret;
+}
+
+static DEVICE_ATTR_RO(serial);
+
+static struct attribute *meson_sm_sysfs_attributes[] = {
+	&dev_attr_serial.attr,
+	NULL,
+};
+
+static const struct attribute_group meson_sm_sysfs_attr_group = {
+	.attrs = meson_sm_sysfs_attributes,
+};
+
 static const struct of_device_id meson_sm_ids[] = {
 	{ .compatible = "amlogic,meson-gxbb-sm", .data = &gxbb_chip },
 	{ /* sentinel */ },
@@ -242,6 +289,9 @@
 	fw.chip = chip;
 	pr_info("secure-monitor enabled\n");
 
+	if (sysfs_create_group(&pdev->dev.kobj, &meson_sm_sysfs_attr_group))
+		goto out_in_base;
+
 	return 0;
 
 out_in_base: