linux/include/media/lirc_dev.h at master · fabgithub/linux · GitHub

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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

#define MAX_IRCTL_DEVICES 8

#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 __user *buffer, size_t length,

loff_t *ppos);

ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,

size_t length, loff_t *ppos);

#endif

linux/include/media/lirc_dev.h at master · fabgithub/linux · GitHub

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