LXR linux/include/media/lirc

   1/*
   2 * LIRC base driver
   3 *
   4 * by Artur Lipowski <alipowski@interia.pl>
   5 *        This code is licensed under GNU GPL
   6 *
   7 */
   8
   9#ifndef _LINUX_LIRC_DEV_H
  10#define _LINUX_LIRC_DEV_H
  11
  12#define MAX_IRCTL_DEVICES 8
  13#define BUFLEN            16
  14
  15#define mod(n, div) ((n) % (div))
  16
  17#include <linux/slab.h>
  18#include <linux/fs.h>
  19#include <linux/ioctl.h>
  20#include <linux/poll.h>
  21#include <linux/kfifo.h>
  22#include <media/lirc.h>
  23
  24struct lirc_buffer {
  25        wait_queue_head_t wait_poll;
  26        spinlock_t fifo_lock;
  27        unsigned int chunk_size;
  28        unsigned int size; /* in chunks */
  29        /* Using chunks instead of bytes pretends to simplify boundary checking
  30         * And should allow for some performance fine tunning later */
  31        struct kfifo fifo;
  32};
  33
  34static inline void lirc_buffer_clear(struct lirc_buffer *buf)
  35{
  36        unsigned long flags;
  37
  38        if (kfifo_initialized(&buf->fifo)) {
  39                spin_lock_irqsave(&buf->fifo_lock, flags);
  40                kfifo_reset(&buf->fifo);
  41                spin_unlock_irqrestore(&buf->fifo_lock, flags);
  42        } else
  43                WARN(1, "calling %s on an uninitialized lirc_buffer\n",
  44                     __func__);
  45}
  46
  47static inline int lirc_buffer_init(struct lirc_buffer *buf,
  48                                    unsigned int chunk_size,
  49                                    unsigned int size)
  50{
  51        int ret;
  52
  53        init_waitqueue_head(&buf->wait_poll);
  54        spin_lock_init(&buf->fifo_lock);
  55        buf->chunk_size = chunk_size;
  56        buf->size = size;
  57        ret = kfifo_alloc(&buf->fifo, size * chunk_size, GFP_KERNEL);
  58
  59        return ret;
  60}
  61
  62static inline void lirc_buffer_free(struct lirc_buffer *buf)
  63{
  64        if (kfifo_initialized(&buf->fifo)) {
  65                kfifo_free(&buf->fifo);
  66        } else
  67                WARN(1, "calling %s on an uninitialized lirc_buffer\n",
  68                     __func__);
  69}
  70
  71static inline int lirc_buffer_len(struct lirc_buffer *buf)
  72{
  73        int len;
  74        unsigned long flags;
  75
  76        spin_lock_irqsave(&buf->fifo_lock, flags);
  77        len = kfifo_len(&buf->fifo);
  78        spin_unlock_irqrestore(&buf->fifo_lock, flags);
  79
  80        return len;
  81}
  82
  83static inline int lirc_buffer_full(struct lirc_buffer *buf)
  84{
  85        return lirc_buffer_len(buf) == buf->size * buf->chunk_size;
  86}
  87
  88static inline int lirc_buffer_empty(struct lirc_buffer *buf)
  89{
  90        return !lirc_buffer_len(buf);
  91}
  92
  93static inline int lirc_buffer_available(struct lirc_buffer *buf)
  94{
  95        return buf->size - (lirc_buffer_len(buf) / buf->chunk_size);
  96}
  97
  98static inline unsigned int lirc_buffer_read(struct lirc_buffer *buf,
  99                                            unsigned char *dest)
 100{
 101        unsigned int ret = 0;
 102
 103        if (lirc_buffer_len(buf) >= buf->chunk_size)
 104                ret = kfifo_out_locked(&buf->fifo, dest, buf->chunk_size,
 105                                       &buf->fifo_lock);
 106        return ret;
 107
 108}
 109
 110static inline unsigned int lirc_buffer_write(struct lirc_buffer *buf,
 111                                             unsigned char *orig)
 112{
 113        unsigned int ret;
 114
 115        ret = kfifo_in_locked(&buf->fifo, orig, buf->chunk_size,
 116                              &buf->fifo_lock);
 117
 118        return ret;
 119}
 120
 121struct lirc_driver {
 122        char name[40];
 123        int minor;
 124        __u32 code_length;
 125        unsigned int buffer_size; /* in chunks holding one code each */
 126        int sample_rate;
 127        __u32 features;
 128
 129        unsigned int chunk_size;
 130
 131        void *data;
 132        int min_timeout;
 133        int max_timeout;
 134        int (*add_to_buf) (void *data, struct lirc_buffer *buf);
 135        struct lirc_buffer *rbuf;
 136        int (*set_use_inc) (void *data);
 137        void (*set_use_dec) (void *data);
 138        struct rc_dev *rdev;
 139        const struct file_operations *fops;
 140        struct device *dev;
 141        struct module *owner;
 142};
 143
 144/* name:
 145 * this string will be used for logs
 146 *
 147 * minor:
 148 * indicates minor device (/dev/lirc) number for registered driver
 149 * if caller fills it with negative value, then the first free minor
 150 * number will be used (if available)
 151 *
 152 * code_length:
 153 * length of the remote control key code expressed in bits
 154 *
 155 * sample_rate:
 156 *
 157 * data:
 158 * it may point to any driver data and this pointer will be passed to
 159 * all callback functions
 160 *
 161 * add_to_buf:
 162 * add_to_buf will be called after specified period of the time or
 163 * triggered by the external event, this behavior depends on value of
 164 * the sample_rate this function will be called in user context. This
 165 * routine should return 0 if data was added to the buffer and
 166 * -ENODATA if none was available. This should add some number of bits
 167 * evenly divisible by code_length to the buffer
 168 *
 169 * rbuf:
 170 * if not NULL, it will be used as a read buffer, you will have to
 171 * write to the buffer by other means, like irq's (see also
 172 * lirc_serial.c).
 173 *
 174 * set_use_inc:
 175 * set_use_inc will be called after device is opened
 176 *
 177 * set_use_dec:
 178 * set_use_dec will be called after device is closed
 179 *
 180 * fops:
 181 * file_operations for drivers which don't fit the current driver model.
 182 *
 183 * Some ioctl's can be directly handled by lirc_dev if the driver's
 184 * ioctl function is NULL or if it returns -ENOIOCTLCMD (see also
 185 * lirc_serial.c).
 186 *
 187 * owner:
 188 * the module owning this struct
 189 *
 190 */
 191
 192
 193/* following functions can be called ONLY from user context
 194 *
 195 * returns negative value on error or minor number
 196 * of the registered device if success
 197 * contents of the structure pointed by p is copied
 198 */
 199extern int lirc_register_driver(struct lirc_driver *d);
 200
 201/* returns negative value on error or 0 if success
 202*/
 203extern int lirc_unregister_driver(int minor);
 204
 205/* Returns the private data stored in the lirc_driver
 206 * associated with the given device file pointer.
 207 */
 208void *lirc_get_pdata(struct file *file);
 209
 210/* default file operations
 211 * used by drivers if they override only some operations
 212 */
 213int lirc_dev_fop_open(struct inode *inode, struct file *file);
 214int lirc_dev_fop_close(struct inode *inode, struct file *file);
 215unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
 216long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 217ssize_t lirc_dev_fop_read(struct file *file, char __user *buffer, size_t length,
 218                          loff_t *ppos);
 219ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
 220                           size_t length, loff_t *ppos);
 221
 222#endif
 223