V4L/DVB: IR: add lirc device interface

v2: currently unused ioctls are included, but #if 0'd out

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

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 000000000000..4afd96a38a43
--- /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