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/*
* LIRC base driver
*
* by Artur Lipowski <alipowski@interia.pl>
* This code is licensed under GNU GPL
*
*/
#ifndef _LINUX_LIRC_DEV_H
#define _LINUX_LIRC_DEV_H
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/poll.h>
#include <linux/kfifo.h>
#include <media/lirc.h>
#include <linux/device.h>
#include <linux/cdev.h>
struct lirc_buffer {
wait_queue_head_t wait_poll;
spinlock_t fifo_lock;
unsigned int chunk_size;
unsigned int size; /* in chunks */
/* Using chunks instead of bytes pretends to simplify boundary checking
* And should allow for some performance fine tunning later */
struct kfifo fifo;
};
static inline void lirc_buffer_clear(struct lirc_buffer *buf)
{
unsigned long flags;
if (kfifo_initialized(&buf->fifo)) {
spin_lock_irqsave(&buf->fifo_lock, flags);
kfifo_reset(&buf->fifo);
spin_unlock_irqrestore(&buf->fifo_lock, flags);
} else
WARN(1, "calling %s on an uninitialized lirc_buffer\n",
__func__);
}
static inline int lirc_buffer_init(struct lirc_buffer *buf,
unsigned int chunk_size,
unsigned int size)
{
int ret;
init_waitqueue_head(&buf->wait_poll);
spin_lock_init(&buf->fifo_lock);
buf->chunk_size = chunk_size;
buf->size = size;
ret = kfifo_alloc(&buf->fifo, size * chunk_size, GFP_KERNEL);
return ret;
}
static inline void lirc_buffer_free(struct lirc_buffer *buf)
{
if (kfifo_initialized(&buf->fifo)) {
kfifo_free(&buf->fifo);
} else
WARN(1, "calling %s on an uninitialized lirc_buffer\n",
__func__);
}
static inline int lirc_buffer_len(struct lirc_buffer *buf)
{
int len;
unsigned long flags;
spin_lock_irqsave(&buf->fifo_lock, flags);
len = kfifo_len(&buf->fifo);
spin_unlock_irqrestore(&buf->fifo_lock, flags);
return len;
}
static inline int lirc_buffer_full(struct lirc_buffer *buf)
{
return lirc_buffer_len(buf) == buf->size * buf->chunk_size;
}
static inline int lirc_buffer_empty(struct lirc_buffer *buf)
{
return !lirc_buffer_len(buf);
}
static inline unsigned int lirc_buffer_read(struct lirc_buffer *buf,
unsigned char *dest)
{
unsigned int ret = 0;
if (lirc_buffer_len(buf) >= buf->chunk_size)
ret = kfifo_out_locked(&buf->fifo, dest, buf->chunk_size,
&buf->fifo_lock);
return ret;
}
static inline unsigned int lirc_buffer_write(struct lirc_buffer *buf,
unsigned char *orig)
{
unsigned int ret;
ret = kfifo_in_locked(&buf->fifo, orig, buf->chunk_size,
&buf->fifo_lock);
return ret;
}
/**
* struct lirc_dev - represents a LIRC device
*
* @name: used for logging
* @minor: the minor device (/dev/lircX) number for the device
* @features: lirc compatible hardware features, like LIRC_MODE_RAW,
* LIRC_CAN\_\*, as defined at include/media/lirc.h.
* @buffer_size: Number of FIFO buffers with @chunk_size size.
* Only used if @rbuf is NULL.
* @chunk_size: Size of each FIFO buffer.
* Only used if @rbuf is NULL.
* @buf: if %NULL, lirc_dev will allocate and manage the buffer,
* otherwise allocated by the caller which will
* have to write to the buffer by other means, like irq's
* (see also lirc_serial.c).
* @buf_internal: whether lirc_dev has allocated the read buffer or not
* @rdev: &struct rc_dev associated with the device
* @fops: &struct file_operations for the device
* @owner: the module owning this struct
* @attached: if the device is still live
* @open: open count for the device's chardev
* @mutex: serialises file_operations calls
* @dev: &struct device assigned to the device
* @cdev: &struct cdev assigned to the device
*/
struct lirc_dev {
char name[40];
unsigned int minor;
__u32 features;
unsigned int buffer_size; /* in chunks holding one code each */
unsigned int chunk_size;
struct lirc_buffer *buf;
bool buf_internal;
struct rc_dev *rdev;
const struct file_operations *fops;
struct module *owner;
bool attached;
int open;
struct mutex mutex; /* protect from simultaneous accesses */
struct device dev;
struct cdev cdev;
};
struct lirc_dev *lirc_allocate_device(void);
void lirc_free_device(struct lirc_dev *d);
int lirc_register_device(struct lirc_dev *d);
void lirc_unregister_device(struct lirc_dev *d);
/* default file operations
* used by drivers if they override only some operations
*/
int lirc_dev_fop_open(struct inode *inode, struct file *file);
int lirc_dev_fop_close(struct inode *inode, struct file *file);
unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
ssize_t lirc_dev_fop_read(struct file *file, char __user *buffer, size_t length,
loff_t *ppos);
#endif
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