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	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	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 */
202extern int lirc_register_driver(struct lirc_driver *d);
203
204/* returns negative value on error or 0 if success
205*/
206extern 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 */
211void *lirc_get_pdata(struct file *file);
212
213/* default file operations
214 * used by drivers if they override only some operations
215 */
216int lirc_dev_fop_open(struct inode *inode, struct file *file);
217int lirc_dev_fop_close(struct inode *inode, struct file *file);
218unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait);
219long lirc_dev_fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
220ssize_t lirc_dev_fop_read(struct file *file, char __user *buffer, size_t length,
221			  loff_t *ppos);
222ssize_t lirc_dev_fop_write(struct file *file, const char __user *buffer,
223			   size_t length, loff_t *ppos);
224
225#endif