path: root/drivers/counter/counter.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Generic Counter interface
 * Copyright (C) 2018 William Breathitt Gray
 */
#include <linux/counter.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/types.h>

const char *const counter_count_direction_str[2] = {
	[COUNTER_COUNT_DIRECTION_FORWARD] = "forward",
	[COUNTER_COUNT_DIRECTION_BACKWARD] = "backward"
};
EXPORT_SYMBOL_GPL(counter_count_direction_str);

const char *const counter_count_mode_str[4] = {
	[COUNTER_COUNT_MODE_NORMAL] = "normal",
	[COUNTER_COUNT_MODE_RANGE_LIMIT] = "range limit",
	[COUNTER_COUNT_MODE_NON_RECYCLE] = "non-recycle",
	[COUNTER_COUNT_MODE_MODULO_N] = "modulo-n"
};
EXPORT_SYMBOL_GPL(counter_count_mode_str);

ssize_t counter_signal_enum_read(struct counter_device *counter,
				 struct counter_signal *signal, void *priv,
				 char *buf)
{
	const struct counter_signal_enum_ext *const e = priv;
	int err;
	size_t index;

	if (!e->get)
		return -EINVAL;

	err = e->get(counter, signal, &index);
	if (err)
		return err;

	if (index >= e->num_items)
		return -EINVAL;

	return sprintf(buf, "%s\n", e->items[index]);
}
EXPORT_SYMBOL_GPL(counter_signal_enum_read);

ssize_t counter_signal_enum_write(struct counter_device *counter,
				  struct counter_signal *signal, void *priv,
				  const char *buf, size_t len)
{
	const struct counter_signal_enum_ext *const e = priv;
	ssize_t index;
	int err;

	if (!e->set)
		return -EINVAL;

	index = __sysfs_match_string(e->items, e->num_items, buf);
	if (index < 0)
		return index;

	err = e->set(counter, signal, index);
	if (err)
		return err;

	return len;
}
EXPORT_SYMBOL_GPL(counter_signal_enum_write);

ssize_t counter_signal_enum_available_read(struct counter_device *counter,
					   struct counter_signal *signal,
					   void *priv, char *buf)
{
	const struct counter_signal_enum_ext *const e = priv;
	size_t i;
	size_t len = 0;

	if (!e->num_items)
		return 0;

	for (i = 0; i < e->num_items; i++)
		len += sprintf(buf + len, "%s\n", e->items[i]);

	return len;
}
EXPORT_SYMBOL_GPL(counter_signal_enum_available_read);

ssize_t counter_count_enum_read(struct counter_device *counter,
				struct counter_count *count, void *priv,
				char *buf)
{
	const struct counter_count_enum_ext *const e = priv;
	int err;
	size_t index;

	if (!e->get)
		return -EINVAL;

	err = e->get(counter, count, &index);
	if (err)
		return err;

	if (index >= e->num_items)
		return -EINVAL;

	return sprintf(buf, "%s\n", e->items[index]);
}
EXPORT_SYMBOL_GPL(counter_count_enum_read);

ssize_t counter_count_enum_write(struct counter_device *counter,
				 struct counter_count *count, void *priv,
				 const char *buf, size_t len)
{
	const struct counter_count_enum_ext *const e = priv;
	ssize_t index;
	int err;

	if (!e->set)
		return -EINVAL;

	index = __sysfs_match_string(e->items, e->num_items, buf);
	if (index < 0)
		return index;

	err = e->set(counter, count, index);
	if (err)
		return err;

	return len;
}
EXPORT_SYMBOL_GPL(counter_count_enum_write);

ssize_t counter_count_enum_available_read(struct counter_device *counter,
					  struct counter_count *count,
					  void *priv, char *buf)
{
	const struct counter_count_enum_ext *const e = priv;
	size_t i;
	size_t len = 0;

	if (!e->num_items)
		return 0;

	for (i = 0; i < e->num_items; i++)
		len += sprintf(buf + len, "%s\n", e->items[i]);

	return len;
}
EXPORT_SYMBOL_GPL(counter_count_enum_available_read);

ssize_t counter_device_enum_read(struct counter_device *counter, void *priv,
				 char *buf)
{
	const struct counter_device_enum_ext *const e = priv;
	int err;
	size_t index;

	if (!e->get)
		return -EINVAL;

	err = e->get(counter, &index);
	if (err)
		return err;

	if (index >= e->num_items)
		return -EINVAL;

	return sprintf(buf, "%s\n", e->items[index]);
}
EXPORT_SYMBOL_GPL(counter_device_enum_read);

ssize_t counter_device_enum_write(struct counter_device *counter, void *priv,
				  const char *buf, size_t len)
{
	const struct counter_device_enum_ext *const e = priv;
	ssize_t index;
	int err;

	if (!e->set)
		return -EINVAL;

	index = __sysfs_match_string(e->items, e->num_items, buf);
	if (index < 0)
		return index;

	err = e->set(counter, index);
	if (err)
		return err;

	return len;
}
EXPORT_SYMBOL_GPL(counter_device_enum_write);

ssize_t counter_device_enum_available_read(struct counter_device *counter,
					   void *priv, char *buf)
{
	const struct counter_device_enum_ext *const e = priv;
	size_t i;
	size_t len = 0;

	if (!e->num_items)
		return 0;

	for (i = 0; i < e->num_items; i++)
		len += sprintf(buf + len, "%s\n", e->items[i]);

	return len;
}
EXPORT_SYMBOL_GPL(counter_device_enum_available_read);

static const char *const counter_signal_level_str[] = {
	[COUNTER_SIGNAL_LEVEL_LOW] = "low",
	[COUNTER_SIGNAL_LEVEL_HIGH] = "high"
};

/**
 * counter_signal_read_value_set - set counter_signal_read_value data
 * @val:	counter_signal_read_value structure to set
 * @type:	property Signal data represents
 * @data:	Signal data
 *
 * This function sets an opaque counter_signal_read_value structure with the
 * provided Signal data.
 */
void counter_signal_read_value_set(struct counter_signal_read_value *const val,
				   const enum counter_signal_value_type type,
				   void *const data)
{
	if (type == COUNTER_SIGNAL_LEVEL)
		val->len = sprintf(val->buf, "%s\n",
				   counter_signal_level_str[*(enum counter_signal_level *)data]);
	else
		val->len = 0;
}
EXPORT_SYMBOL_GPL(counter_signal_read_value_set);

/**
 * counter_count_read_value_set - set counter_count_read_value data
 * @val:	counter_count_read_value structure to set
 * @type:	property Count data represents
 * @data:	Count data
 *
 * This function sets an opaque counter_count_read_value structur