Loading...
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}
1/*
2 * RTC subsystem, nvmem interface
3 *
4 * Copyright (C) 2017 Alexandre Belloni
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/err.h>
12#include <linux/types.h>
13#include <linux/nvmem-consumer.h>
14#include <linux/rtc.h>
15#include <linux/sysfs.h>
16
17/*
18 * Deprecated ABI compatibility, this should be removed at some point
19 */
20
21static const char nvram_warning[] = "Deprecated ABI, please use nvmem";
22
23static ssize_t
24rtc_nvram_read(struct file *filp, struct kobject *kobj,
25 struct bin_attribute *attr,
26 char *buf, loff_t off, size_t count)
27{
28 struct rtc_device *rtc = attr->private;
29
30 dev_warn_once(kobj_to_dev(kobj), nvram_warning);
31
32 return nvmem_device_read(rtc->nvmem, off, count, buf);
33}
34
35static ssize_t
36rtc_nvram_write(struct file *filp, struct kobject *kobj,
37 struct bin_attribute *attr,
38 char *buf, loff_t off, size_t count)
39{
40 struct rtc_device *rtc = attr->private;
41
42 dev_warn_once(kobj_to_dev(kobj), nvram_warning);
43
44 return nvmem_device_write(rtc->nvmem, off, count, buf);
45}
46
47static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
48{
49 int err;
50
51 rtc->nvram = devm_kzalloc(rtc->dev.parent,
52 sizeof(struct bin_attribute),
53 GFP_KERNEL);
54 if (!rtc->nvram)
55 return -ENOMEM;
56
57 rtc->nvram->attr.name = "nvram";
58 rtc->nvram->attr.mode = 0644;
59 rtc->nvram->private = rtc;
60
61 sysfs_bin_attr_init(rtc->nvram);
62
63 rtc->nvram->read = rtc_nvram_read;
64 rtc->nvram->write = rtc_nvram_write;
65 rtc->nvram->size = size;
66
67 err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
68 rtc->nvram);
69 if (err) {
70 devm_kfree(rtc->dev.parent, rtc->nvram);
71 rtc->nvram = NULL;
72 }
73
74 return err;
75}
76
77static void rtc_nvram_unregister(struct rtc_device *rtc)
78{
79 sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
80}
81
82/*
83 * New ABI, uses nvmem
84 */
85int rtc_nvmem_register(struct rtc_device *rtc,
86 struct nvmem_config *nvmem_config)
87{
88 if (!IS_ERR_OR_NULL(rtc->nvmem))
89 return -EBUSY;
90
91 if (!nvmem_config)
92 return -ENODEV;
93
94 nvmem_config->dev = rtc->dev.parent;
95 nvmem_config->owner = rtc->owner;
96 rtc->nvmem = nvmem_register(nvmem_config);
97 if (IS_ERR_OR_NULL(rtc->nvmem))
98 return PTR_ERR(rtc->nvmem);
99
100 /* Register the old ABI */
101 if (rtc->nvram_old_abi)
102 rtc_nvram_register(rtc, nvmem_config->size);
103
104 return 0;
105}
106EXPORT_SYMBOL_GPL(rtc_nvmem_register);
107
108void rtc_nvmem_unregister(struct rtc_device *rtc)
109{
110 if (IS_ERR_OR_NULL(rtc->nvmem))
111 return;
112
113 /* unregister the old ABI */
114 if (rtc->nvram)
115 rtc_nvram_unregister(rtc);
116
117 nvmem_unregister(rtc->nvmem);
118}