projects/linux·blob 04480094 · refs

226 lines · 5.7 KiB

1/*
2 * LIRC base driver
3 *
4 * by Artur Lipowski <[email protected]>
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 u8 fifo_initialized;
33};
34
35static inline void lirc_buffer_clear(struct lirc_buffer *buf)
36{
37 unsigned long flags;
38
39 if (buf->fifo_initialized) {
40 spin_lock_irqsave(&buf->fifo_lock, flags);
41 kfifo_reset(&buf->fifo);
42 spin_unlock_irqrestore(&buf->fifo_lock, flags);
43 } else
44 WARN(1, "calling %s on an uninitialized lirc_buffer\n",
45 __func__);
46}
47
48static inline int lirc_buffer_init(struct lirc_buffer *buf,
49 unsigned int chunk_size,
50 unsigned int size)
51{
52 int ret;
53
54 init_waitqueue_head(&buf->wait_poll);
55 spin_lock_init(&buf->fifo_lock);
56 buf->chunk_size = chunk_size;
57 buf->size = size;
58 ret = kfifo_alloc(&buf->fifo, size * chunk_size, GFP_KERNEL);
59 if (ret == 0)
60 buf->fifo_initialized = 1;
61
62 return ret;
63}
64
65static inline void lirc_buffer_free(struct lirc_buffer *buf)
66{
67 if (buf->fifo_initialized) {
68 kfifo_free(&buf->fifo);
69 buf->fifo_initialized = 0;
70 } else
71 WARN(1, "calling %s on an uninitialized lirc_buffer\n",
72 __func__);
73}
74
75static inline int lirc_buffer_len(struct lirc_buffer *buf)
76{
77 int len;
78 unsigned long flags;
79
80 spin_lock_irqsave(&buf->fifo_lock, flags);
81 len = kfifo_len(&buf->fifo);
82 spin_unlock_irqrestore(&buf->fifo_lock, flags);
83
84 return len;
85}
86
87static inline int lirc_buffer_full(struct lirc_buffer *buf)
88{
89 return lirc_buffer_len(buf) == buf->size * buf->chunk_size;
90}
91
92static inline int lirc_buffer_empty(struct lirc_buffer *buf)
93{
94 return !lirc_buffer_len(buf);
95}
96
97static inline int lirc_buffer_available(struct lirc_buffer *buf)
98{
99 return buf->size - (lirc_buffer_len(buf) / buf->chunk_size);
100}
101
102static inline unsigned int lirc_buffer_read(struct lirc_buffer *buf,
103 unsigned char *dest)
104{
105 unsigned int ret = 0;
106
107 if (lirc_buffer_len(buf) >= buf->chunk_size)
108 ret = kfifo_out_locked(&buf->fifo, dest, buf->chunk_size,
109 &buf->fifo_lock);
110 return ret;
111
112}
113
114static inline unsigned int lirc_buffer_write(struct lirc_buffer *buf,
115 unsigned char *orig)
116{
117 unsigned int ret;
118
119 ret = kfifo_in_locked(&buf->fifo, orig, buf->chunk_size,
120 &buf->fifo_lock);
121
122 return ret;
123}
124
125struct lirc_driver {
126 char name[40];
127 int minor;
128 __u32 code_length;
129 unsigned int buffer_size; /* in chunks holding one code each */
130 int sample_rate;
131 __u32 features;
132
133 unsigned int chunk_size;
134
135 void *data;
136 int min_timeout;
137 int max_timeout;
138 int (*add_to_buf) (void *data, struct lirc_buffer *buf);
139 struct lirc_buffer *rbuf;
140 int (*set_use_inc) (void *data);
141 void (*set_use_dec) (void *data);
142 struct rc_dev *rdev;
143 const struct file_operations *fops;
144 struct device *dev;
145 struct module *owner;
146};
147
148/* name:
149 * this string will be used for logs
150 *
151 * minor:
152 * indicates minor device (/dev/lirc) number for registered driver
153 * if caller fills it with negative value, then the first free minor
154 * number will be used (if available)
155 *
156 * code_length:
157 * length of the remote control key code expressed in bits
158 *
159 * sample_rate:
160 *
161 * data:
162 * it may point to any driver data and this pointer will be passed to
163 * all callback functions
164 *
165 * add_to_buf:
166 * add_to_buf will be called after specified period of the time or
167 * triggered by the external event, this behavior depends on value of
168 * the sample_rate this function will be called in user context. This
169 * routine should return 0 if data was added to the buffer and
170 * -ENODATA if none was available. This should add some number of bits
171 * evenly divisible by code_length to the buffer
172 *
173 * rbuf:
174 * if not NULL, it will be used as a read buffer, you will have to
175 * write to the buffer by other means, like irq's (see also
176 * lirc_serial.c).
177 *
178 * set_use_inc:
179 * set_use_inc will be called after device is opened
180 *
181 * set_use_dec:
182 * set_use_dec will be called after device is closed
183 *
184 * fops:
185 * file_operations for drivers which don't fit the current driver model.
186 *
187 * Some ioctl's can be directly handled by lirc_dev if the driver's
188 * ioctl function is NULL or if it returns -ENOIOCTLCMD (see also
189 * lirc_serial.c).
190 *
191 * owner:
192 * the module owning this struct
193 *
194 */
195
196
197/* following functions can be called ONLY from user context
198 *
199 * returns negative value on error or minor number
200 * of the registered device if success
201 * contents of the structure pointed by p is copied
202 */
203extern int lirc_register_driver(struct lirc_driver *d);
204
205/* returns negative value on error or 0 if success
206*/
207extern int lirc_unregister_driver(int minor);
208
209/* Returns the private data stored in the lirc_driver
210 * associated with the given device file pointer.
211 */
212void *lirc_get_pdata(struct file *file);
213
214/* default file operations
215 * used by drivers if they override only some operations
216 */
217int lirc_dev_fop_open(struct inode *inode, struct file *file);
218int lirc_dev_fop_close(struct inode *inode, struct file *file);
219unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
220long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
221ssize_t lirc_dev_fop_read(struct file *file, char __user *buffer, size_t length,
222 loff_t *ppos);
223ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
224 size_t length, loff_t *ppos);
225
226#endif