V4L/DVB: add memory-to-memory device helper framework for videobuf

A mem-to-mem device is a device that uses memory buffers passed by
userspace applications for both their source and destination data. This
is different from existing drivers, which utilize memory buffers for either
input or output, but not both.

In terms of V4L2 such a device would be both of OUTPUT and CAPTURE type.

Examples of such devices would be: image 'resizers', 'rotators',
'colorspace converters', etc.

This patch adds a separate Kconfig sub-menu for mem-to-mem devices as well.

Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Vaibhav Hiremath <hvaibhav@ti.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 201 insertions, 0 deletions

diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
new file mode 100644
index 0000000..8d149f1
--- /dev/null
+++ b/include/media/v4l2-mem2mem.h
@@ -0,0 +1,201 @@
+/*
+ * Memory-to-memory device framework for Video for Linux 2.
+ *
+ * Helper functions for devices that use memory buffers for both source
+ * and destination.
+ *
+ * Copyright (c) 2009 Samsung Electronics Co., Ltd.
+ * Pawel Osciak, <p.osciak@samsung.com>
+ * Marek Szyprowski, <m.szyprowski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version
+ */
+
+#ifndef _MEDIA_V4L2_MEM2MEM_H
+#define _MEDIA_V4L2_MEM2MEM_H
+
+#include <media/videobuf-core.h>
+
+/**
+ * struct v4l2_m2m_ops - mem-to-mem device driver callbacks
+ * @device_run:	required. Begin the actual job (transaction) inside this
+ *		callback.
+ *		The job does NOT have to end before this callback returns
+ *		(and it will be the usual case). When the job finishes,
+ *		v4l2_m2m_job_finish() has to be called.
+ * @job_ready:	optional. Should return 0 if the driver does not have a job
+ *		fully prepared to run yet (i.e. it will not be able to finish a
+ *		transaction without sleeping). If not provided, it will be
+ *		assumed that one source and one destination buffer are all
+ *		that is required for the driver to perform one full transaction.
+ *		This method may not sleep.
+ * @job_abort:	required. Informs the driver that it has to abort the currently
+ *		running transaction as soon as possible (i.e. as soon as it can
+ *		stop the device safely; e.g. in the next interrupt handler),
+ *		even if the transaction would not have been finished by then.
+ *		After the driver performs the necessary steps, it has to call
+ *		v4l2_m2m_job_finish() (as if the transaction ended normally).
+ *		This function does not have to (and will usually not) wait
+ *		until the device enters a state when it can be stopped.
+ */
+struct v4l2_m2m_ops {
+	void (*device_run)(void *priv);
+	int (*job_ready)(void *priv);
+	void (*job_abort)(void *priv);
+};
+
+struct v4l2_m2m_dev;
+
+struct v4l2_m2m_queue_ctx {
+/* private: internal use only */
+	struct videobuf_queue	q;
+
+	/* Queue for buffers ready to be processed as soon as this
+	 * instance receives access to the device */
+	struct list_head	rdy_queue;
+	u8			num_rdy;
+};
+
+struct v4l2_m2m_ctx {
+/* private: internal use only */
+	struct v4l2_m2m_dev		*m2m_dev;
+
+	/* Capture (output to memory) queue context */
+	struct v4l2_m2m_queue_ctx	cap_q_ctx;
+
+	/* Output (input from memory) queue context */
+	struct v4l2_m2m_queue_ctx	out_q_ctx;
+
+	/* For device job queue */
+	struct list_head		queue;
+	unsigned long			job_flags;
+
+	/* Instance private data */
+	void				*priv;
+};
+
+void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
+
+struct videobuf_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
+				       enum v4l2_buf_type type);
+
+void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
+			 struct v4l2_m2m_ctx *m2m_ctx);
+
+int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		     struct v4l2_requestbuffers *reqbufs);
+
+int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		      struct v4l2_buffer *buf);
+
+int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		  struct v4l2_buffer *buf);
+int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		   struct v4l2_buffer *buf);
+
+int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		      enum v4l2_buf_type type);
+int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		       enum v4l2_buf_type type);
+
+unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+			   struct poll_table_struct *wait);
+
+int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+		  struct vm_area_struct *vma);
+
+struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops);
+void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);
+
+struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(void *priv, struct v4l2_m2m_dev *m2m_dev,
+			void (*vq_init)(void *priv, struct videobuf_queue *,
+					enum v4l2_buf_type));
+void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
+
+void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct videobuf_queue *vq,
+			struct videobuf_buffer *vb);
+
+/**
+ * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
+ * use
+ */
+static inline
+unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return m2m_ctx->cap_q_ctx.num_rdy;
+}
+
+/**
+ * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
+ * ready for use
+ */
+static inline
+unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return m2m_ctx->out_q_ctx.num_rdy;
+}
+
+void *v4l2_m2m_next_buf(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type);
+
+/**
+ * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
+ * buffers
+ */
+static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return v4l2_m2m_next_buf(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+
+/**
+ * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
+ * ready buffers
+ */
+static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return v4l2_m2m_next_buf(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+}
+
+/**
+ * v4l2_m2m_get_src_vq() - return videobuf_queue for source buffers
+ */
+static inline
+struct videobuf_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+
+/**
+ * v4l2_m2m_get_dst_vq() - return videobuf_queue for destination buffers
+ */
+static inline
+struct videobuf_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+}
+
+void *v4l2_m2m_buf_remove(struct v4l2_m2m_ctx *m2m_ctx,
+			  enum v4l2_buf_type type);
+
+/**
+ * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
+ * buffers and return it
+ */
+static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return v4l2_m2m_buf_remove(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+
+/**
+ * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
+ * ready buffers and return it
+ */
+static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
+{
+	return v4l2_m2m_buf_remove(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+}
+
+#endif /* _MEDIA_V4L2_MEM2MEM_H */
+