media: pisp_be: Use clamp() and define max sizes

Use the clamp() function from minmax.h and provide a define for the max
sizes as they will be used in subsequent patches.

Reviewed-by: Daniel Scally <[e-mail]>
Reviewed-by: Stefan Klug <[e-mail]>
Signed-off-by: Jacopo Mondi <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/platform/raspberrypi/pisp_be/pisp_be.c

···
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/lockdep.h>
+#include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
···
 	f->fmt.pix_mp.pixelformat = fmt->fourcc;
 	f->fmt.pix_mp.num_planes = fmt->num_planes;
 	f->fmt.pix_mp.field = V4L2_FIELD_NONE;
-	f->fmt.pix_mp.width = max(min(f->fmt.pix_mp.width, 65536u),
-				  PISP_BACK_END_MIN_TILE_WIDTH);
-	f->fmt.pix_mp.height = max(min(f->fmt.pix_mp.height, 65536u),
-				   PISP_BACK_END_MIN_TILE_HEIGHT);
+	f->fmt.pix_mp.width = clamp(f->fmt.pix_mp.width,
+				    PISP_BACK_END_MIN_TILE_WIDTH,
+				    PISP_BACK_END_MAX_TILE_WIDTH);
+	f->fmt.pix_mp.height = clamp(f->fmt.pix_mp.height,
+				     PISP_BACK_END_MIN_TILE_HEIGHT,
+				     PISP_BACK_END_MAX_TILE_HEIGHT);
 
 	/*
 	 * Fill in the actual colour space when the requested one was

include/uapi/linux/media/raspberrypi/pisp_be_config.h

···
 /* preferred byte alignment for outputs */
 #define PISP_BACK_END_OUTPUT_MAX_ALIGN 64u
 
-/* minimum allowed tile width anywhere in the pipeline */
-#define PISP_BACK_END_MIN_TILE_WIDTH 16u
-/* minimum allowed tile width anywhere in the pipeline */
-#define PISP_BACK_END_MIN_TILE_HEIGHT 16u
+/* minimum allowed tile sizes anywhere in the pipeline */
+#define PISP_BACK_END_MIN_TILE_WIDTH	16u
+#define PISP_BACK_END_MIN_TILE_HEIGHT	16u
+#define PISP_BACK_END_MAX_TILE_WIDTH	65536u
+#define PISP_BACK_END_MAX_TILE_HEIGHT	65536u
 
 #define PISP_BACK_END_NUM_OUTPUTS 2
 #define PISP_BACK_END_HOG_OUTPUT 1