1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * RTC subsystem, nvmem interface
 4 *
 5 * Copyright (C) 2017 Alexandre Belloni
 6 */
 7
 8#include <linux/err.h>
 9#include <linux/types.h>
10#include <linux/nvmem-consumer.h>
11#include <linux/rtc.h>
 
 
12
13int devm_rtc_nvmem_register(struct rtc_device *rtc,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
14		       struct nvmem_config *nvmem_config)
15{
16	struct device *dev = rtc->dev.parent;
17	struct nvmem_device *nvmem;
18
19	if (!nvmem_config)
20		return -ENODEV;
21
22	nvmem_config->dev = dev;
23	nvmem_config->owner = rtc->owner;
24	nvmem_config->add_legacy_fixed_of_cells = true;
25	nvmem = devm_nvmem_register(dev, nvmem_config);
26	if (IS_ERR(nvmem))
27		dev_err(dev, "failed to register nvmem device for RTC\n");
 
 
 
 
28
29	return PTR_ERR_OR_ZERO(nvmem);
 
 
 
 
 
 
 
 
30}
31EXPORT_SYMBOL_GPL(devm_rtc_nvmem_register);

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * RTC subsystem, nvmem interface
  4 *
  5 * Copyright (C) 2017 Alexandre Belloni
  6 */
  7
  8#include <linux/err.h>
  9#include <linux/types.h>
 10#include <linux/nvmem-consumer.h>
 11#include <linux/rtc.h>
 12#include <linux/slab.h>
 13#include <linux/sysfs.h>
 14
 15/*
 16 * Deprecated ABI compatibility, this should be removed at some point
 17 */
 18
 19static const char nvram_warning[] = "Deprecated ABI, please use nvmem";
 20
 21static ssize_t
 22rtc_nvram_read(struct file *filp, struct kobject *kobj,
 23	       struct bin_attribute *attr,
 24	       char *buf, loff_t off, size_t count)
 25{
 26	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 27
 28	return nvmem_device_read(attr->private, off, count, buf);
 29}
 30
 31static ssize_t
 32rtc_nvram_write(struct file *filp, struct kobject *kobj,
 33		struct bin_attribute *attr,
 34		char *buf, loff_t off, size_t count)
 35{
 36	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
 37
 38	return nvmem_device_write(attr->private, off, count, buf);
 39}
 40
 41static int rtc_nvram_register(struct rtc_device *rtc,
 42			      struct nvmem_device *nvmem, size_t size)
 43{
 44	int err;
 45
 46	rtc->nvram = kzalloc(sizeof(*rtc->nvram), GFP_KERNEL);
 47	if (!rtc->nvram)
 48		return -ENOMEM;
 49
 50	rtc->nvram->attr.name = "nvram";
 51	rtc->nvram->attr.mode = 0644;
 52	rtc->nvram->private = nvmem;
 53
 54	sysfs_bin_attr_init(rtc->nvram);
 55
 56	rtc->nvram->read = rtc_nvram_read;
 57	rtc->nvram->write = rtc_nvram_write;
 58	rtc->nvram->size = size;
 59
 60	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
 61				    rtc->nvram);
 62	if (err) {
 63		kfree(rtc->nvram);
 64		rtc->nvram = NULL;
 65	}
 66
 67	return err;
 68}
 69
 70static void rtc_nvram_unregister(struct rtc_device *rtc)
 71{
 72	sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
 73	kfree(rtc->nvram);
 74	rtc->nvram = NULL;
 75}
 76
 77/*
 78 * New ABI, uses nvmem
 79 */
 80int rtc_nvmem_register(struct rtc_device *rtc,
 81		       struct nvmem_config *nvmem_config)
 82{
 
 83	struct nvmem_device *nvmem;
 84
 85	if (!nvmem_config)
 86		return -ENODEV;
 87
 88	nvmem_config->dev = rtc->dev.parent;
 89	nvmem_config->owner = rtc->owner;
 90	nvmem = devm_nvmem_register(rtc->dev.parent, nvmem_config);
 
 91	if (IS_ERR(nvmem))
 92		return PTR_ERR(nvmem);
 93
 94	/* Register the old ABI */
 95	if (rtc->nvram_old_abi)
 96		rtc_nvram_register(rtc, nvmem, nvmem_config->size);
 97
 98	return 0;
 99}
100EXPORT_SYMBOL_GPL(rtc_nvmem_register);
101
102void rtc_nvmem_unregister(struct rtc_device *rtc)
103{
104	/* unregister the old ABI */
105	if (rtc->nvram)
106		rtc_nvram_unregister(rtc);
107}