diff mbox

[v2,1/3] v4l: Add support for multi-plane buffers to V4L2 API.

Message ID 1268146183-2018-2-git-send-email-p.osciak@samsung.com (mailing list archive)
State RFC
Headers show

Commit Message

Pawel Osciak March 9, 2010, 2:49 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 4b11257..b89b73f 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -172,6 +172,8 @@  static const char *v4l2_memory_names[] = {
 	[V4L2_MEMORY_MMAP]    = "mmap",
 	[V4L2_MEMORY_USERPTR] = "userptr",
 	[V4L2_MEMORY_OVERLAY] = "overlay",
+	[V4L2_MEMORY_MULTI_USERPTR]	= "multi-userptr",
+	[V4L2_MEMORY_MULTI_MMAP]	= "multi-mmap",
 };
 
 #define prt_names(a, arr) ((((a) >= 0) && ((a) < ARRAY_SIZE(arr))) ? \
@@ -1975,7 +1977,7 @@  static unsigned long cmd_input_size(unsigned int cmd)
 	switch (cmd) {
 		CMDINSIZE(ENUM_FMT,		fmtdesc,	type);
 		CMDINSIZE(G_FMT,		format,		type);
-		CMDINSIZE(QUERYBUF,		buffer,		type);
+		CMDINSIZE(QUERYBUF,		buffer,		length);
 		CMDINSIZE(G_PARM,		streamparm,	type);
 		CMDINSIZE(ENUMSTD,		standard,	index);
 		CMDINSIZE(ENUMINPUT,		input,		index);
@@ -2000,6 +2002,46 @@  static unsigned long cmd_input_size(unsigned int cmd)
 	}
 }
 
+static int check_array_args(unsigned int cmd, void *parg, size_t *array_size,
+			    void * __user *user_ptr, void ***kernel_ptr)
+{
+	int ret = 0;
+
+	switch(cmd) {
+	case VIDIOC_QUERYBUF:
+	case VIDIOC_QBUF:
+	case VIDIOC_DQBUF: {
+		struct v4l2_buffer *buf = parg;
+
+		if ((buf->memory == V4L2_MEMORY_MULTI_USERPTR
+		     || buf->memory == V4L2_MEMORY_MULTI_MMAP)) {
+			*user_ptr = (void __user *)buf->m.planes;
+			*kernel_ptr = (void **)&buf->m.planes;
+			*array_size = sizeof(struct v4l2_plane) * buf->length;
+			ret = 1;
+		}
+		break;
+	}
+
+	case VIDIOC_S_EXT_CTRLS:
+	case VIDIOC_G_EXT_CTRLS:
+	case VIDIOC_TRY_EXT_CTRLS: {
+		struct v4l2_ext_controls *ctrls = parg;
+
+		if (ctrls->count != 0) {
+			*user_ptr = (void __user *)ctrls->controls;
+			*kernel_ptr = (void **)&ctrls->controls;
+			*array_size = sizeof(struct v4l2_ext_control)
+				    * ctrls->count;
+			ret = 1;
+		}
+		break;
+	}
+	}
+
+	return ret;
+}
+
 long video_ioctl2(struct file *file,
 	       unsigned int cmd, unsigned long arg)
 {
@@ -2007,15 +2049,16 @@  long video_ioctl2(struct file *file,
 	void    *mbuf = NULL;
 	void	*parg = NULL;
 	long	err  = -EINVAL;
-	int     is_ext_ctrl;
-	size_t  ctrls_size = 0;
+	int	has_array_args;
+	size_t  array_size = 0;
 	void __user *user_ptr = NULL;
+	void	**kernel_ptr = NULL;
 
 #ifdef __OLD_VIDIOC_
 	cmd = video_fix_command(cmd);
 #endif
-	is_ext_ctrl = (cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_G_EXT_CTRLS ||
-		       cmd == VIDIOC_TRY_EXT_CTRLS);
+	/*is_ext_ctrl = (cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_G_EXT_CTRLS ||
+		       cmd == VIDIOC_TRY_EXT_CTRLS);*/
 
 	/*  Copy arguments into temp kernel buffer  */
 	if (_IOC_DIR(cmd) != _IOC_NONE) {
@@ -2045,43 +2088,39 @@  long video_ioctl2(struct file *file,
 		}
 	}
 
-	if (is_ext_ctrl) {
-		struct v4l2_ext_controls *p = parg;
+	has_array_args = check_array_args(cmd, parg, &array_size,
+					  &user_ptr, &kernel_ptr);
 
-		/* In case of an error, tell the caller that it wasn't
-		   a specific control that caused it. */
-		p->error_idx = p->count;
-		user_ptr = (void __user *)p->controls;
-		if (p->count) {
-			ctrls_size = sizeof(struct v4l2_ext_control) * p->count;
-			/* Note: v4l2_ext_controls fits in sbuf[] so mbuf is still NULL. */
-			mbuf = kmalloc(ctrls_size, GFP_KERNEL);
-			err = -ENOMEM;
-			if (NULL == mbuf)
-				goto out_ext_ctrl;
-			err = -EFAULT;
-			if (copy_from_user(mbuf, user_ptr, ctrls_size))
-				goto out_ext_ctrl;
-			p->controls = mbuf;
-		}
+	if (has_array_args) {
+		/* When adding new types of array args, make sure that the
+		 * parent argument to ioctl, which contains the array, fits into
+		 * sbuf (so that mbuf will still remain unused up to here).
+		 */
+		mbuf = kmalloc(array_size, GFP_KERNEL);
+		err = -ENOMEM;
+		if (NULL == mbuf)
+			goto out_array_args;
+		err = -EFAULT;
+		if (copy_from_user(mbuf, user_ptr, array_size))
+			goto out_array_args;
+		*kernel_ptr = mbuf;
 	}
 
 	/* Handles IOCTL */
 	err = __video_do_ioctl(file, cmd, parg);
 	if (err == -ENOIOCTLCMD)
 		err = -EINVAL;
-	if (is_ext_ctrl) {
-		struct v4l2_ext_controls *p = parg;
 
-		p->controls = (void *)user_ptr;
-		if (p->count && err == 0 && copy_to_user(user_ptr, mbuf, ctrls_size))
+	if (has_array_args) {
+		*kernel_ptr = user_ptr;
+		if (copy_to_user(user_ptr, mbuf, array_size))
 			err = -EFAULT;
-		goto out_ext_ctrl;
+		goto out_array_args;
 	}
 	if (err < 0)
 		goto out;
 
-out_ext_ctrl:
+out_array_args:
 	/*  Copy results into user buffer  */
 	switch (_IOC_DIR(cmd)) {
 	case _IOC_READ:
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index d4962a7..bf3f33d 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -70,6 +70,7 @@ 
  * Moved from videodev.h
  */
 #define VIDEO_MAX_FRAME               32
+#define VIDEO_MAX_PLANES		3
 
 #ifndef __KERNEL__
 
@@ -180,6 +181,10 @@  enum v4l2_memory {
 	V4L2_MEMORY_MMAP             = 1,
 	V4L2_MEMORY_USERPTR          = 2,
 	V4L2_MEMORY_OVERLAY          = 3,
+
+	/* Discontiguous buffer types */
+	V4L2_MEMORY_MULTI_USERPTR    = 4,
+	V4L2_MEMORY_MULTI_MMAP       = 5,
 };
 
 /* see also http://vektor.theorem.ca/graphics/ycbcr/ */
@@ -519,6 +524,29 @@  struct v4l2_requestbuffers {
 	__u32			reserved[2];
 };
 
+/* struct v4l2_plane - a multi-plane buffer plane.
+ *
+ * Multi-plane buffers consist of two or more planes, e.g. an YCbCr buffer
+ * with two planes has one plane for Y, and another for interleaved CbCr
+ * components. Each plane can reside in a separate memory buffer, or in
+ * a completely separate memory chip even (e.g. in embedded devices).
+ */
+struct v4l2_plane {
+	__u32			bytesused;
+
+	union {
+		__u32		offset;
+		unsigned long	userptr;
+	} m;
+	__u32			length;
+	__u32			reserved[5];
+};
+
+/* struct v4l2_buffer - a video buffer (frame)
+ * @length:	size of the buffer (not its payload) for single-plane buffers,
+ * 		number of planes (and number of elements in planes array)
+ * 		for multi-plane
+ */
 struct v4l2_buffer {
 	__u32			index;
 	enum v4l2_buf_type      type;
@@ -532,8 +560,9 @@  struct v4l2_buffer {
 	/* memory location */
 	enum v4l2_memory        memory;
 	union {
-		__u32           offset;
-		unsigned long   userptr;
+		__u32			offset;
+		unsigned long		userptr;
+		struct v4l2_plane	*planes;
 	} m;
 	__u32			length;
 	__u32			input;