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
 121/**
 122 * struct lirc_driver - Defines the parameters on a LIRC driver
 123 *
 124 * @name:               this string will be used for logs
 125 *
 126 * @minor:              indicates minor device (/dev/lirc) number for
 127 *                      registered driver if caller fills it with negative
 128 *                      value, then the first free minor number will be used
 129 *                      (if available).
 130 *
 131 * @code_length:        length of the remote control key code expressed in bits.
 132 *
 133 * @buffer_size:        Number of FIFO buffers with @chunk_size size. If zero,
 134 *                      creates a buffer with BUFLEN size (16 bytes).
 135 *
 136 * @sample_rate:        if zero, the device will wait for an event with a new
 137 *                      code to be parsed. Otherwise, specifies the sample
 138 *                      rate for polling. Value should be between 0
 139 *                      and HZ. If equal to HZ, it would mean one polling per
 140 *                      second.
 141 *
 142 * @features:           lirc compatible hardware features, like LIRC_MODE_RAW,
 143 *                      LIRC_CAN_*, as defined at include/media/lirc.h.
 144 *
 145 * @chunk_size:         Size of each FIFO buffer.
 146 *
 147 * @data:               it may point to any driver data and this pointer will
 148 *                      be passed to all callback functions.
 149 *
 150 * @min_timeout:        Minimum timeout for record. Valid only if
 151 *                      LIRC_CAN_SET_REC_TIMEOUT is defined.
 152 *
 153 * @max_timeout:        Maximum timeout for record. Valid only if
 154 *                      LIRC_CAN_SET_REC_TIMEOUT is defined.
 155 *
 156 * @add_to_buf:         add_to_buf will be called after specified period of the
 157 *                      time or triggered by the external event, this behavior
 158 *                      depends on value of the sample_rate this function will
 159 *                      be called in user context. This routine should return
 160 *                      0 if data was added to the buffer and -ENODATA if none
 161 *                      was available. This should add some number of bits
 162 *                      evenly divisible by code_length to the buffer.
 163 *
 164 * @rbuf:               if not NULL, it will be used as a read buffer, you will
 165 *                      have to write to the buffer by other means, like irq's
 166 *                      (see also lirc_serial.c).
 167 *
 168 * @set_use_inc:        set_use_inc will be called after device is opened
 169 *
 170 * @set_use_dec:        set_use_dec will be called after device is closed
 171 *
 172 * @rdev:               Pointed to struct rc_dev associated with the LIRC
 173 *                      device.
 174 *
 175 * @fops:               file_operations for drivers which don't fit the current
 176 *                      driver model.
 177 *                      Some ioctl's can be directly handled by lirc_dev if the
 178 *                      driver's ioctl function is NULL or if it returns
 179 *                      -ENOIOCTLCMD (see also lirc_serial.c).
 180 *
 181 * @dev:                pointer to the struct device associated with the LIRC
 182 *                      device.
 183 *
 184 * @owner:              the module owning this struct
 185 */
 186struct lirc_driver {
 187        char name[40];
 188        int minor;
 189        __u32 code_length;
 190        unsigned int buffer_size; /* in chunks holding one code each */
 191        int sample_rate;
 192        __u32 features;
 193
 194        unsigned int chunk_size;
 195
 196        void *data;
 197        int min_timeout;
 198        int max_timeout;
 199        int (*add_to_buf)(void *data, struct lirc_buffer *buf);
 200        struct lirc_buffer *rbuf;
 201        int (*set_use_inc)(void *data);
 202        void (*set_use_dec)(void *data);
 203        struct rc_dev *rdev;
 204        const struct file_operations *fops;
 205        struct device *dev;
 206        struct module *owner;
 207};
 208
 209/* following functions can be called ONLY from user context
 210 *
 211 * returns negative value on error or minor number
 212 * of the registered device if success
 213 * contents of the structure pointed by p is copied
 214 */
 215extern int lirc_register_driver(struct lirc_driver *d);
 216
 217/* returns negative value on error or 0 if success
 218*/
 219extern int lirc_unregister_driver(int minor);
 220
 221/* Returns the private data stored in the lirc_driver
 222 * associated with the given device file pointer.
 223 */
 224void *lirc_get_pdata(struct file *file);
 225
 226/* default file operations
 227 * used by drivers if they override only some operations
 228 */
 229int lirc_dev_fop_open(struct inode *inode, struct file *file);
 230int lirc_dev_fop_close(struct inode *inode, struct file *file);
 231unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
 232long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 233ssize_t lirc_dev_fop_read(struct file *file, char __user *buffer, size_t length,
 234                          loff_t *ppos);
 235ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
 236                           size_t length, loff_t *ppos);
 237
 238#endif
 239