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
24 struct 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
lirc_buffer_clear(struct lirc_buffer * buf)35 static 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
lirc_buffer_init(struct lirc_buffer * buf,unsigned int chunk_size,unsigned int size)48 static 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
lirc_buffer_free(struct lirc_buffer * buf)65 static 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
lirc_buffer_len(struct lirc_buffer * buf)75 static 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
lirc_buffer_full(struct lirc_buffer * buf)87 static inline int lirc_buffer_full(struct lirc_buffer *buf)
88 {
89 return lirc_buffer_len(buf) == buf->size * buf->chunk_size;
90 }
91
lirc_buffer_empty(struct lirc_buffer * buf)92 static inline int lirc_buffer_empty(struct lirc_buffer *buf)
93 {
94 return !lirc_buffer_len(buf);
95 }
96
lirc_buffer_available(struct lirc_buffer * buf)97 static inline int lirc_buffer_available(struct lirc_buffer *buf)
98 {
99 return buf->size - (lirc_buffer_len(buf) / buf->chunk_size);
100 }
101
lirc_buffer_read(struct lirc_buffer * buf,unsigned char * dest)102 static 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
lirc_buffer_write(struct lirc_buffer * buf,unsigned char * orig)114 static 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
125 struct 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 const struct file_operations *fops;
143 struct device *dev;
144 struct module *owner;
145 };
146
147 /* name:
148 * this string will be used for logs
149 *
150 * minor:
151 * indicates minor device (/dev/lirc) number for registered driver
152 * if caller fills it with negative value, then the first free minor
153 * number will be used (if available)
154 *
155 * code_length:
156 * length of the remote control key code expressed in bits
157 *
158 * sample_rate:
159 *
160 * data:
161 * it may point to any driver data and this pointer will be passed to
162 * all callback functions
163 *
164 * add_to_buf:
165 * add_to_buf will be called after specified period of the time or
166 * triggered by the external event, this behavior depends on value of
167 * the sample_rate this function will be called in user context. This
168 * routine should return 0 if data was added to the buffer and
169 * -ENODATA if none was available. This should add some number of bits
170 * evenly divisible by code_length to the buffer
171 *
172 * rbuf:
173 * if not NULL, it will be used as a read buffer, you will have to
174 * write to the buffer by other means, like irq's (see also
175 * lirc_serial.c).
176 *
177 * set_use_inc:
178 * set_use_inc will be called after device is opened
179 *
180 * set_use_dec:
181 * set_use_dec will be called after device is closed
182 *
183 * fops:
184 * file_operations for drivers which don't fit the current driver model.
185 *
186 * Some ioctl's can be directly handled by lirc_dev if the driver's
187 * ioctl function is NULL or if it returns -ENOIOCTLCMD (see also
188 * lirc_serial.c).
189 *
190 * owner:
191 * the module owning this struct
192 *
193 */
194
195
196 /* following functions can be called ONLY from user context
197 *
198 * returns negative value on error or minor number
199 * of the registered device if success
200 * contents of the structure pointed by p is copied
201 */
202 extern int lirc_register_driver(struct lirc_driver *d);
203
204 /* returns negative value on error or 0 if success
205 */
206 extern int lirc_unregister_driver(int minor);
207
208 /* Returns the private data stored in the lirc_driver
209 * associated with the given device file pointer.
210 */
211 void *lirc_get_pdata(struct file *file);
212
213 /* default file operations
214 * used by drivers if they override only some operations
215 */
216 int lirc_dev_fop_open(struct inode *inode, struct file *file);
217 int lirc_dev_fop_close(struct inode *inode, struct file *file);
218 unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
219 long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
220 ssize_t lirc_dev_fop_read(struct file *file, char __user *buffer, size_t length,
221 loff_t *ppos);
222 ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
223 size_t length, loff_t *ppos);
224
225 #endif
226