[PATCH v2 1/1] media: common: Add v4l2_find_nearest_size_conditional()

[Sakari Ailus <sakari.ailus@linux.intel.com>]

v4l2_find_nearest_size() returns a mode from sensor driver's mode list
that is a best match width and height wise for the sensor. Some drivers
have different set of available modes depending on the number of lanes.
While this could be handled within a driver by providing different lists
of modes, provide a helper v4l2_find_nearest_size_conditional() to ignore
modes that aren't available.

Also use size_t for the array index and remove extra commas while at it.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
since v1:

- Fix function naming in v4l2-common.c to make it compile.

 drivers/media/v4l2-core/v4l2-common.c | 18 ++++++---
 include/media/v4l2-common.h           | 58 +++++++++++++++++++++------
 2 files changed, 59 insertions(+), 17 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index e4b2de3833ee..06d2f468e1af 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -154,13 +154,18 @@ void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax,
 EXPORT_SYMBOL_GPL(v4l_bound_align_image);
 
 const void *
-__v4l2_find_nearest_size(const void *array, size_t array_size,
-			 size_t entry_size, size_t width_offset,
-			 size_t height_offset, s32 width, s32 height)
+__v4l2_find_nearest_size_conditional(const void *array, size_t array_size,
+				     size_t entry_size, size_t width_offset,
+				     size_t height_offset, s32 width,
+				     s32 height,
+				     bool (*func)(const void *array,
+						  size_t index,
+						  const void *context),
+				     const void *context)
 {
 	u32 error, min_error = U32_MAX;
 	const void *best = NULL;
-	unsigned int i;
+	size_t i;
 
 	if (!array)
 		return NULL;
@@ -169,6 +174,9 @@ __v4l2_find_nearest_size(const void *array, size_t array_size,
 		const u32 *entry_width = array + width_offset;
 		const u32 *entry_height = array + height_offset;
 
+		if (func && !func(array, i, context))
+			continue;
+
 		error = abs(*entry_width - width) + abs(*entry_height - height);
 		if (error > min_error)
 			continue;
@@ -181,7 +189,7 @@ __v4l2_find_nearest_size(const void *array, size_t array_size,
 
 	return best;
 }
-EXPORT_SYMBOL_GPL(__v4l2_find_nearest_size);
+EXPORT_SYMBOL_GPL(__v4l2_find_nearest_size_conditional);
 
 int v4l2_g_parm_cap(struct video_device *vdev,
 		    struct v4l2_subdev *sd, struct v4l2_streamparm *a)
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index fda903bb3674..df59f291a9b8 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -390,38 +390,72 @@ void v4l_bound_align_image(unsigned int *width, unsigned int wmin,
 			   unsigned int salign);
 
 /**
- * v4l2_find_nearest_size - Find the nearest size among a discrete
- *	set of resolutions contained in an array of a driver specific struct.
+ * v4l2_find_nearest_size_conditional - Find the nearest size among a discrete
+ *	set of resolutions contained in an array of a driver specific struct,
+ *	with conditionally exlusion of certain modes
  *
  * @array: a driver specific array of image sizes
  * @array_size: the length of the driver specific array of image sizes
  * @width_field: the name of the width field in the driver specific struct
  * @height_field: the name of the height field in the driver specific struct
- * @width: desired width.
- * @height: desired height.
+ * @width: desired width
+ * @height: desired height
+ * @func: ignores mode if returns false
+ * @context: context for the function
  *
  * Finds the closest resolution to minimize the width and height differences
  * between what requested and the supported resolutions. The size of the width
  * and height fields in the driver specific must equal to that of u32, i.e. four
- * bytes.
+ * bytes. @func is called for each mode considered, a mode is ignored if @func
+ * returns false for it.
  *
  * Returns the best match or NULL if the length of the array is zero.
  */
-#define v4l2_find_nearest_size(array, array_size, width_field, height_field, \
-			       width, height)				\
+#define v4l2_find_nearest_size_conditional(array, array_size, width_field, \
+					   height_field, width, height, \
+					   func, context) \
 	({								\
 		BUILD_BUG_ON(sizeof((array)->width_field) != sizeof(u32) || \
 			     sizeof((array)->height_field) != sizeof(u32)); \
-		(typeof(&(array)[0]))__v4l2_find_nearest_size(		\
+		(typeof(&(array)[0]))__v4l2_find_nearest_size_conditional( \
 			(array), array_size, sizeof(*(array)),		\
 			offsetof(typeof(*(array)), width_field),	\
 			offsetof(typeof(*(array)), height_field),	\
-			width, height);					\
+			width, height, func, context);			\
 	})
 const void *
-__v4l2_find_nearest_size(const void *array, size_t array_size,
-			 size_t entry_size, size_t width_offset,
-			 size_t height_offset, s32 width, s32 height);
+__v4l2_find_nearest_size_conditional(const void *array, size_t array_size,
+				     size_t entry_size, size_t width_offset,
+				     size_t height_offset, s32 width,
+				     s32 height,
+				     bool (*func)(const void *array,
+						  size_t index,
+						  const void *context),
+				     const void *context);
+
+/**
+ * v4l2_find_nearest_size - Find the nearest size among a discrete set of
+ *	resolutions contained in an array of a driver specific struct
+ *
+ * @array: a driver specific array of image sizes
+ * @array_size: the length of the driver specific array of image sizes
+ * @width_field: the name of the width field in the driver specific struct
+ * @height_field: the name of the height field in the driver specific struct
+ * @width: desired width
+ * @height: desired height
+ *
+ * Finds the closest resolution to minimize the width and height differences
+ * between what requested and the supported resolutions. The size of the width
+ * and height fields in the driver specific must equal to that of u32, i.e. four
+ * bytes.
+ *
+ * Returns the best match or NULL if the length of the array is zero.
+ */
+#define v4l2_find_nearest_size(array, array_size, width_field,		\
+			       height_field, width, height)		\
+	v4l2_find_nearest_size_conditional(array, array_size, width_field, \
+					   height_field, width, height, NULL, \
+					   NULL);
 
 /**
  * v4l2_g_parm_cap - helper routine for vidioc_g_parm to fill this in by
-- 
2.39.5