2 * RTC subsystem, nvmem interface
4 * Copyright (C) 2017 Alexandre Belloni
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.
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>
18 * Deprecated ABI compatibility, this should be removed at some point
21 static const char nvram_warning[] = "Deprecated ABI, please use nvmem";
24 rtc_nvram_read(struct file *filp, struct kobject *kobj,
25 struct bin_attribute *attr,
26 char *buf, loff_t off, size_t count)
28 struct rtc_device *rtc = attr->private;
30 dev_warn_once(kobj_to_dev(kobj), nvram_warning);
32 return nvmem_device_read(rtc->nvmem, off, count, buf);
36 rtc_nvram_write(struct file *filp, struct kobject *kobj,
37 struct bin_attribute *attr,
38 char *buf, loff_t off, size_t count)
40 struct rtc_device *rtc = attr->private;
42 dev_warn_once(kobj_to_dev(kobj), nvram_warning);
44 return nvmem_device_write(rtc->nvmem, off, count, buf);
47 static int rtc_nvram_register(struct rtc_device *rtc, size_t size)
51 rtc->nvram = devm_kzalloc(rtc->dev.parent,
52 sizeof(struct bin_attribute),
57 rtc->nvram->attr.name = "nvram";
58 rtc->nvram->attr.mode = 0644;
59 rtc->nvram->private = rtc;
61 sysfs_bin_attr_init(rtc->nvram);
63 rtc->nvram->read = rtc_nvram_read;
64 rtc->nvram->write = rtc_nvram_write;
65 rtc->nvram->size = size;
67 err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
70 devm_kfree(rtc->dev.parent, rtc->nvram);
77 static void rtc_nvram_unregister(struct rtc_device *rtc)
79 sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
85 int rtc_nvmem_register(struct rtc_device *rtc,
86 struct nvmem_config *nvmem_config)
88 if (!IS_ERR_OR_NULL(rtc->nvmem))
94 nvmem_config->dev = rtc->dev.parent;
95 nvmem_config->owner = rtc->owner;
96 rtc->nvmem = nvmem_register(nvmem_config);
97 if (IS_ERR(rtc->nvmem))
98 return PTR_ERR(rtc->nvmem);
100 /* Register the old ABI */
101 if (rtc->nvram_old_abi)
102 rtc_nvram_register(rtc, nvmem_config->size);
106 EXPORT_SYMBOL_GPL(rtc_nvmem_register);
108 void rtc_nvmem_unregister(struct rtc_device *rtc)
110 if (IS_ERR_OR_NULL(rtc->nvmem))
113 /* unregister the old ABI */
115 rtc_nvram_unregister(rtc);
117 nvmem_unregister(rtc->nvmem);