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