Commit | Line | Data |
---|---|---|
697e5a47 AB |
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 | ||
697e5a47 AB |
17 | /* |
18 | * Deprecated ABI compatibility, this should be removed at some point | |
19 | */ | |
20 | ||
21 | static const char nvram_warning[] = "Deprecated ABI, please use nvmem"; | |
22 | ||
23 | static ssize_t | |
24 | rtc_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 | ||
35 | static ssize_t | |
36 | rtc_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 | ||
4cce9d39 | 47 | static int rtc_nvram_register(struct rtc_device *rtc, size_t size) |
697e5a47 AB |
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; | |
4cce9d39 | 65 | rtc->nvram->size = size; |
697e5a47 AB |
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 | ||
77 | static 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 | */ | |
2cc82121 AB |
85 | int rtc_nvmem_register(struct rtc_device *rtc, |
86 | struct nvmem_config *nvmem_config) | |
697e5a47 | 87 | { |
ab3ea36e AB |
88 | if (!IS_ERR_OR_NULL(rtc->nvmem)) |
89 | return -EBUSY; | |
90 | ||
4cce9d39 | 91 | if (!nvmem_config) |
2cc82121 | 92 | return -ENODEV; |
697e5a47 | 93 | |
ac75779b | 94 | nvmem_config->dev = rtc->dev.parent; |
4cce9d39 AB |
95 | nvmem_config->owner = rtc->owner; |
96 | rtc->nvmem = nvmem_register(nvmem_config); | |
046dbb24 | 97 | if (IS_ERR(rtc->nvmem)) |
2cc82121 | 98 | return PTR_ERR(rtc->nvmem); |
697e5a47 AB |
99 | |
100 | /* Register the old ABI */ | |
101 | if (rtc->nvram_old_abi) | |
4cce9d39 | 102 | rtc_nvram_register(rtc, nvmem_config->size); |
2cc82121 AB |
103 | |
104 | return 0; | |
697e5a47 | 105 | } |
fd5cd21d | 106 | EXPORT_SYMBOL_GPL(rtc_nvmem_register); |
697e5a47 AB |
107 | |
108 | void 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 | } |