/*
* 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
#define MAX_IRCTL_DEVICES 4
#define BUFLEN 16
#define mod(n, div) ((n) % (div))
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/poll.h>
#include <linux/kfifo.h>
#include <media/lirc.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;
u8 fifo_initialized;
};
static inline void lirc_buffer_clear(struct lirc_buffer *buf)
{
unsigned long flags;
if (buf->fifo_initialized) {
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);
if (ret == 0)
buf->fifo_initialized = 1;
return ret;
}
static inline void lirc_buffer_free(struct lirc_buffer *buf)
{
if (buf->fifo_initialized) {
kfifo_free(&buf->fifo);
buf->fifo_initialized = 0;
} 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 int lirc_buffer_available(struct lirc_buffer *buf)
{
return buf->size - (lirc_buffer_len(buf) / buf->chunk_size);
}
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_driver {
char name[40];
int minor;
__u32 code_length;
unsigned int buffer_size; /* in chunks holding one code each */
int sample_rate;
__u32 features;
unsigned int chunk_size;
void *data;
int min_timeout;
int max_timeout;
int (*add_to_buf) (void *data, struct lirc_buffer *buf);
struct lirc_buffer *rbuf;
int (*set_use_inc) (void *data);
void (*set_use_dec) (void *data);
const struct file_operations *fops;
struct device *dev;
struct module *owner;
};
/* name:
* this string will be used for logs
*
* minor:
* indicates minor device (/dev/lirc) number for registered driver
* if caller fills it with negative value, then the first free minor
* number will be used (if available)
*
* code_length:
* length of the remote control key code expressed in bits
*
* sample_rate:
*
* data:
* it may point to any driver data and this pointer will be passed to
* all callback functions
*
* add_to_buf:
* add_to_buf will be called after specified period of the time or
* triggered by the external event, this behavior depends on value of
* the sample_rate this function will be called in user context. This
* routine should return 0 if data was added to the buffer and
* -ENODATA if none was available. This should add some number of bits
* evenly divisible by code_length to the buffer
*
* rbuf:
* if not NULL, it will be used as a read buffer, you will have to
* write to the buffer by other means, like irq's (see also
* lirc_serial.c).
*
* set_use_inc:
* set_use_inc will be called after device is opened
*
* set_use_dec:
* set_use_dec will be called after device is closed
*
* fops:
* file_operations for drivers which don't fit the current driver model.
*
* Some ioctl's can be directly handled by lirc_dev if the driver's
* ioctl function is NULL or if it returns -ENOIOCTLCMD (see also
* lirc_serial.c).
*
* owner:
* the module owning this struct
*
*/
/* following functions can be called ONLY from user context
*
* returns negative value on error or minor number
* of the registered device if success
* contents of the structure pointed by p is copied
*/
extern int lirc_register_driver(struct lirc_driver *d);
/* returns negative value on error or 0 if success
*/
extern int lirc_unregister_driver(int minor);
/* Returns the private data stored in the lirc_driver
* associated with the given device file pointer.
*/
void *lirc_get_pdata(struct file *file);
/* 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 *buffer, size_t length,
loff_t *ppos);
ssize_t lirc_dev_fop_write(struct file *file, const char *buffer, size_t length,
loff_t *ppos);
#endif
