[linux-2.6-block.git] / drivers / rtc / nvmem.c

// 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_t
rtc_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_t
rtc_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);
}
Commit	Line	Data
cdf7545a	1	// SPDX-License-Identifier: GPL-2.0
697e5a47 AB	2	/*
	3	* RTC subsystem, nvmem interface
	4	*
	5	* Copyright (C) 2017 Alexandre Belloni
697e5a47 AB	6	*/
	7
	8	#include <linux/err.h>
	9	#include <linux/types.h>
	10	#include <linux/nvmem-consumer.h>
	11	#include <linux/rtc.h>
bba3d2da	12	#include <linux/slab.h>
697e5a47 AB	13	#include <linux/sysfs.h>
697e5a47 AB	14
697e5a47 AB	15	/*
	16	* Deprecated ABI compatibility, this should be removed at some point
	17	*/
	18
	19	static const char nvram_warning[] = "Deprecated ABI, please use nvmem";
	20
	21	static ssize_t
	22	rtc_nvram_read(struct file filp, struct kobject kobj,
	23	struct bin_attribute *attr,
	24	char *buf, loff_t off, size_t count)
	25	{
697e5a47 AB	26	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
697e5a47 AB	27
41c9e132	28	return nvmem_device_read(attr->private, off, count, buf);
697e5a47 AB	29	}
	30
	31	static ssize_t
	32	rtc_nvram_write(struct file filp, struct kobject kobj,
	33	struct bin_attribute *attr,
	34	char *buf, loff_t off, size_t count)
	35	{
697e5a47 AB	36	dev_warn_once(kobj_to_dev(kobj), nvram_warning);
697e5a47 AB	37
41c9e132	38	return nvmem_device_write(attr->private, off, count, buf);
697e5a47 AB	39	}
697e5a47 AB	40
41c9e132 AB	41	static int rtc_nvram_register(struct rtc_device *rtc,
41c9e132 AB	42	struct nvmem_device *nvmem, size_t size)
697e5a47 AB	43	{
	44	int err;
	45
606cc43c	46	rtc->nvram = kzalloc(sizeof(*rtc->nvram), GFP_KERNEL);
697e5a47 AB	47	if (!rtc->nvram)
	48	return -ENOMEM;
	49
	50	rtc->nvram->attr.name = "nvram";
	51	rtc->nvram->attr.mode = 0644;
41c9e132	52	rtc->nvram->private = nvmem;
697e5a47 AB	53
	54	sysfs_bin_attr_init(rtc->nvram);
	55
	56	rtc->nvram->read = rtc_nvram_read;
	57	rtc->nvram->write = rtc_nvram_write;
4cce9d39	58	rtc->nvram->size = size;
697e5a47 AB	59
	60	err = sysfs_create_bin_file(&rtc->dev.parent->kobj,
	61	rtc->nvram);
	62	if (err) {
bba3d2da	63	kfree(rtc->nvram);
697e5a47 AB	64	rtc->nvram = NULL;
	65	}
	66
	67	return err;
	68	}
	69
	70	static void rtc_nvram_unregister(struct rtc_device *rtc)
	71	{
	72	sysfs_remove_bin_file(&rtc->dev.parent->kobj, rtc->nvram);
bba3d2da AB	73	kfree(rtc->nvram);
bba3d2da AB	74	rtc->nvram = NULL;
697e5a47 AB	75	}
	76
	77	/*
	78	* New ABI, uses nvmem
	79	*/
2cc82121 AB	80	int rtc_nvmem_register(struct rtc_device *rtc,
2cc82121 AB	81	struct nvmem_config *nvmem_config)
697e5a47	82	{
41c9e132	83	struct nvmem_device *nvmem;
ab3ea36e	84
4cce9d39	85	if (!nvmem_config)
2cc82121	86	return -ENODEV;
697e5a47	87
ac75779b	88	nvmem_config->dev = rtc->dev.parent;
4cce9d39	89	nvmem_config->owner = rtc->owner;
41c9e132 AB	90	nvmem = devm_nvmem_register(rtc->dev.parent, nvmem_config);
	91	if (IS_ERR(nvmem))
	92	return PTR_ERR(nvmem);
697e5a47 AB	93
	94	/* Register the old ABI */
	95	if (rtc->nvram_old_abi)
41c9e132	96	rtc_nvram_register(rtc, nvmem, nvmem_config->size);
2cc82121 AB	97
2cc82121 AB	98	return 0;
697e5a47	99	}
fd5cd21d	100	EXPORT_SYMBOL_GPL(rtc_nvmem_register);
697e5a47 AB	101
	102	void rtc_nvmem_unregister(struct rtc_device *rtc)
	103	{
697e5a47 AB	104	/* unregister the old ABI */
	105	if (rtc->nvram)
	106	rtc_nvram_unregister(rtc);
697e5a47	107	}