diff options
Diffstat (limited to 'drivers/media/IR/lirc_dev.h')
| -rw-r--r-- | drivers/media/IR/lirc_dev.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/media/IR/lirc_dev.h b/drivers/media/IR/lirc_dev.h new file mode 100644 index 00000000000..4afd96a38a4 --- /dev/null +++ b/drivers/media/IR/lirc_dev.h @@ -0,0 +1,226 @@ +/* + * LIRC base driver + * + * by Artur Lipowski <alipowski@interia.pl> + * This code is licensed under GNU GPL + * + */ + +#ifndef _LINUX_LIRC_DEV_H +#define _LINUX_LIRC_DEV_H + +#define MAX_IRCTL_DEVICES 4 +#define BUFLEN 16 + +#define mod(n, div) ((n) % (div)) + +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/ioctl.h> +#include <linux/poll.h> +#include <linux/kfifo.h> +#include <media/lirc.h> + +struct lirc_buffer { + wait_queue_head_t wait_poll; + spinlock_t fifo_lock; + unsigned int chunk_size; + unsigned int size; /* in chunks */ + /* Using chunks instead of bytes pretends to simplify boundary checking + * And should allow for some performance fine tunning later */ + struct kfifo fifo; + u8 fifo_initialized; +}; + +static inline void lirc_buffer_clear(struct lirc_buffer *buf) +{ + unsigned long flags; + + if (buf->fifo_initialized) { + spin_lock_irqsave(&buf->fifo_lock, flags); + kfifo_reset(&buf->fifo); + spin_unlock_irqrestore(&buf->fifo_lock, flags); + } else + WARN(1, "calling %s on an uninitialized lirc_buffer\n", + __func__); +} + +static inline int lirc_buffer_init(struct lirc_buffer *buf, + unsigned int chunk_size, + unsigned int size) +{ + int ret; + + init_waitqueue_head(&buf->wait_poll); + spin_lock_init(&buf->fifo_lock); + buf->chunk_size = chunk_size; + buf->size = size; + ret = kfifo_alloc(&buf->fifo, size * chunk_size, GFP_KERNEL); + if (ret == 0) + buf->fifo_initialized = 1; + + return ret; +} + +static inline void lirc_buffer_free(struct lirc_buffer *buf) +{ + if (buf->fifo_initialized) { + kfifo_free(&buf->fifo); + buf->fifo_initialized = 0; + } else + WARN(1, "calling %s on an uninitialized lirc_buffer\n", + __func__); +} + +static inline int lirc_buffer_len(struct lirc_buffer *buf) +{ + int len; + unsigned long flags; + + spin_lock_irqsave(&buf->fifo_lock, flags); + len = kfifo_len(&buf->fifo); + spin_unlock_irqrestore(&buf->fifo_lock, flags); + + return len; +} + +static inline int lirc_buffer_full(struct lirc_buffer *buf) +{ + return lirc_buffer_len(buf) == buf->size * buf->chunk_size; +} + +static inline int lirc_buffer_empty(struct lirc_buffer *buf) +{ + return !lirc_buffer_len(buf); +} + +static inline int lirc_buffer_available(struct lirc_buffer *buf) +{ + return buf->size - (lirc_buffer_len(buf) / buf->chunk_size); +} + +static inline unsigned int lirc_buffer_read(struct lirc_buffer *buf, + unsigned char *dest) +{ + unsigned int ret = 0; + + if (lirc_buffer_len(buf) >= buf->chunk_size) + ret = kfifo_out_locked(&buf->fifo, dest, buf->chunk_size, + &buf->fifo_lock); + return ret; + +} + +static inline unsigned int lirc_buffer_write(struct lirc_buffer *buf, + unsigned char *orig) +{ + unsigned int ret; + + ret = kfifo_in_locked(&buf->fifo, orig, buf->chunk_size, + &buf->fifo_lock); + + return ret; +} + +struct lirc_driver { + char name[40]; + int minor; + unsigned long code_length; + unsigned int buffer_size; /* in chunks holding one code each */ + int sample_rate; + unsigned long features; + + unsigned int chunk_size; + + void *data; + int min_timeout; + int max_timeout; + int (*add_to_buf) (void *data, struct lirc_buffer *buf); + struct lirc_buffer *rbuf; + int (*set_use_inc) (void *data); + void (*set_use_dec) (void *data); + struct file_operations *fops; + struct device *dev; + struct module *owner; +}; + +/* name: + * this string will be used for logs + * + * minor: + * indicates minor device (/dev/lirc) number for registered driver + * if caller fills it with negative value, then the first free minor + * number will be used (if available) + * + * code_length: + * length of the remote control key code expressed in bits + * + * sample_rate: + * + * data: + * it may point to any driver data and this pointer will be passed to + * all callback functions + * + * add_to_buf: + * add_to_buf will be called after specified period of the time or + * triggered by the external event, this behavior depends on value of + * the sample_rate this function will be called in user context. This + * routine should return 0 if data was added to the buffer and + * -ENODATA if none was available. This should add some number of bits + * evenly divisible by code_length to the buffer + * + * rbuf: + * if not NULL, it will be used as a read buffer, you will have to + * write to the buffer by other means, like irq's (see also + * lirc_serial.c). + * + * set_use_inc: + * set_use_inc will be called after device is opened + * + * set_use_dec: + * set_use_dec will be called after device is closed + * + * fops: + * file_operations for drivers which don't fit the current driver model. + * + * Some ioctl's can be directly handled by lirc_dev if the driver's + * ioctl function is NULL or if it returns -ENOIOCTLCMD (see also + * lirc_serial.c). + * + * owner: + * the module owning this struct + * + */ + + +/* following functions can be called ONLY from user context + * + * returns negative value on error or minor number + * of the registered device if success + * contents of the structure pointed by p is copied + */ +extern int lirc_register_driver(struct lirc_driver *d); + +/* returns negative value on error or 0 if success +*/ +extern int lirc_unregister_driver(int minor); + +/* Returns the private data stored in the lirc_driver + * associated with the given device file pointer. + */ +void *lirc_get_pdata(struct file *file); + +/* default file operations + * used by drivers if they override only some operations + */ +int lirc_dev_fop_open(struct inode *inode, struct file *file); +int lirc_dev_fop_close(struct inode *inode, struct file *file); +unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait); +int lirc_dev_fop_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg); +ssize_t lirc_dev_fop_read(struct file *file, char *buffer, size_t length, + loff_t *ppos); +ssize_t lirc_dev_fop_write(struct file *file, const char *buffer, size_t length, + loff_t *ppos); + +#endif |