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