Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c
index 36ab183..4312096 100644
--- a/drivers/rtc/nvmem.c
+++ b/drivers/rtc/nvmem.c
@@ -1,17 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * RTC subsystem, nvmem interface
  *
  * Copyright (C) 2017 Alexandre Belloni
- *
- * 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.
  */
 
 #include <linux/err.h>
 #include <linux/types.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/rtc.h>
+#include <linux/slab.h>
 #include <linux/sysfs.h>
 
 /*
@@ -25,11 +23,9 @@
 	       struct bin_attribute *attr,
 	       char *buf, loff_t off, size_t count)
 {
-	struct rtc_device *rtc = attr->private;
-
 	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 
-	return nvmem_device_read(rtc->nvmem, off, count, buf);
+	return nvmem_device_read(attr->private, off, count, buf);
 }
 
 static ssize_t
@@ -37,26 +33,23 @@
 		struct bin_attribute *attr,
 		char *buf, loff_t off, size_t count)
 {
-	struct rtc_device *rtc = attr->private;
-
 	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 
-	return nvmem_device_write(rtc->nvmem, off, count, buf);
+	return nvmem_device_write(attr->private, off, count, buf);
 }
 
-static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
+static int rtc_nvram_register(struct rtc_device *rtc,
+			      struct nvmem_device *nvmem, size_t size)
 {
 	int err;
 
-	rtc->nvram = devm_kzalloc(rtc->dev.parent,
-				sizeof(struct bin_attribute),
-				GFP_KERNEL);
+	rtc->nvram = kzalloc(sizeof(*rtc->nvram), GFP_KERNEL);
 	if (!rtc->nvram)
 		return -ENOMEM;
 
 	rtc->nvram->attr.name = "nvram";
 	rtc->nvram->attr.mode = 0644;
-	rtc->nvram->private = rtc;
+	rtc->nvram->private = nvmem;
 
 	sysfs_bin_attr_init(rtc->nvram);
 
@@ -67,7 +60,7 @@
 	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
 				    rtc->nvram);
 	if (err) {
-		devm_kfree(rtc->dev.parent, rtc->nvram);
+		kfree(rtc->nvram);
 		rtc->nvram = NULL;
 	}
 
@@ -77,6 +70,8 @@
 static void rtc_nvram_unregister(struct rtc_device *rtc)
 {
 	sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
+	kfree(rtc->nvram);
+	rtc->nvram = NULL;
 }
 
 /*
@@ -85,21 +80,20 @@
 int rtc_nvmem_register(struct rtc_device *rtc,
 		       struct nvmem_config *nvmem_config)
 {
-	if (!IS_ERR_OR_NULL(rtc->nvmem))
-		return -EBUSY;
+	struct nvmem_device *nvmem;
 
 	if (!nvmem_config)
 		return -ENODEV;
 
 	nvmem_config->dev = rtc->dev.parent;
 	nvmem_config->owner = rtc->owner;
-	rtc->nvmem = nvmem_register(nvmem_config);
-	if (IS_ERR(rtc->nvmem))
-		return PTR_ERR(rtc->nvmem);
+	nvmem = devm_nvmem_register(rtc->dev.parent, nvmem_config);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
 
 	/* Register the old ABI */
 	if (rtc->nvram_old_abi)
-		rtc_nvram_register(rtc, nvmem_config->size);
+		rtc_nvram_register(rtc, nvmem, nvmem_config->size);
 
 	return 0;
 }
@@ -107,12 +101,7 @@
 
 void rtc_nvmem_unregister(struct rtc_device *rtc)
 {
-	if (IS_ERR_OR_NULL(rtc->nvmem))
-		return;
-
 	/* unregister the old ABI */
 	if (rtc->nvram)
 		rtc_nvram_unregister(rtc);
-
-	nvmem_unregister(rtc->nvmem);
 }