// SPDX-License-Identifier: GPL-2.0/* * RTC subsystem, nvmem interface * * Copyright (C) 2017 Alexandre Belloni */ #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> /* * Deprecated ABI compatibility, this should be removed at some point */ static const char nvram_warning[] = "Deprecated ABI, please use nvmem"; static ssize_trtc_nvram_read(struct file *filp, struct kobject *kobj,	       struct bin_attribute *attr,	       char *buf, loff_t off, size_t count){	dev_warn_once(kobj_to_dev(kobj), nvram_warning); 	return nvmem_device_read(attr->private, off, count, buf);} static ssize_trtc_nvram_write(struct file *filp, struct kobject *kobj,		struct bin_attribute *attr,		char *buf, loff_t off, size_t count){	dev_warn_once(kobj_to_dev(kobj), nvram_warning); 	return nvmem_device_write(attr->private, off, count, buf);} static int rtc_nvram_register(struct rtc_device *rtc,			      struct nvmem_device *nvmem, size_t size){	int err; 	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 = nvmem; 	sysfs_bin_attr_init(rtc->nvram); 	rtc->nvram->read = rtc_nvram_read;	rtc->nvram->write = rtc_nvram_write;	rtc->nvram->size = size; 	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,				    rtc->nvram);	if (err) {		kfree(rtc->nvram);		rtc->nvram = NULL;	} 	return err;} 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;} /* * New ABI, uses nvmem */int rtc_nvmem_register(struct rtc_device *rtc,		       struct nvmem_config *nvmem_config){	struct nvmem_device *nvmem; 	if (!nvmem_config)		return -ENODEV; 	nvmem_config->dev = rtc->dev.parent;	nvmem_config->owner = rtc->owner;	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, nvmem_config->size); 	return 0;}EXPORT_SYMBOL_GPL(rtc_nvmem_register); void rtc_nvmem_unregister(struct rtc_device *rtc){	/* unregister the old ABI */	if (rtc->nvram)		rtc_nvram_unregister(rtc);}