[media] V4L2: soc-camera: move generic functions into a separate file

The sh_mobile_ceu_camera driver implements a generic algorithm for setting
up an optimal client and host scaling and cropping configuration. This
patch makes those functions available for all drivers.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/soc_camera/Kconfig

@@ -8,6 +8,9 @@ config SOC_CAMERA
 	  over a bus like PCI or USB. For example some i2c camera connected
 	  directly to the data bus of an SoC.
 
+config SOC_CAMERA_SCALE_CROP
+	tristate
+
 config SOC_CAMERA_PLATFORM
 	tristate "platform camera support"
 	depends on SOC_CAMERA
@@ -51,6 +54,7 @@ config VIDEO_SH_MOBILE_CEU
 	tristate "SuperH Mobile CEU Interface driver"
 	depends on VIDEO_DEV && SOC_CAMERA && HAS_DMA && HAVE_CLK
 	select VIDEOBUF2_DMA_CONTIG
+	select SOC_CAMERA_SCALE_CROP
 	---help---
 	  This is a v4l2 driver for the SuperH Mobile CEU Interface
 

drivers/media/platform/soc_camera/Makefile

 obj-$(CONFIG_SOC_CAMERA)		+= soc_camera.o soc_mediabus.o
+obj-$(CONFIG_SOC_CAMERA_SCALE_CROP)	+= soc_scale_crop.o
+
+# a platform subdevice driver stub, allowing to support cameras by adding a
+# couple of callback functions to the board code
 obj-$(CONFIG_SOC_CAMERA_PLATFORM)	+= soc_camera_platform.o
 
 # soc-camera host drivers have to be linked after camera drivers

drivers/media/platform/soc_camera/soc_scale_crop.h

+/*
+ * soc-camera generic scaling-cropping manipulation functions
+ *
+ * Copyright (C) 2013 Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * 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 SOC_SCALE_CROP_H
+#define SOC_SCALE_CROP_H
+
+#include <linux/kernel.h>
+
+struct soc_camera_device;
+
+struct v4l2_crop;
+struct v4l2_mbus_framefmt;
+struct v4l2_pix_format;
+struct v4l2_rect;
+struct v4l2_subdev;
+
+static inline unsigned int soc_camera_shift_scale(unsigned int size,
+				unsigned int shift, unsigned int scale)
+{
+	return DIV_ROUND_CLOSEST(size << shift, scale);
+}
+
+#define soc_camera_calc_scale(in, shift, out) soc_camera_shift_scale(in, shift, out)
+
+int soc_camera_client_g_rect(struct v4l2_subdev *sd, struct v4l2_rect *rect);
+int soc_camera_client_s_crop(struct v4l2_subdev *sd,
+			struct v4l2_crop *crop, struct v4l2_crop *cam_crop,
+			struct v4l2_rect *target_rect, struct v4l2_rect *subrect);
+int soc_camera_client_scale(struct soc_camera_device *icd,
+			struct v4l2_rect *rect, struct v4l2_rect *subrect,
+			struct v4l2_mbus_framefmt *mf,
+			unsigned int *width, unsigned int *height,
+			bool host_can_scale, unsigned int shift);
+void soc_camera_calc_client_output(struct soc_camera_device *icd,
+		struct v4l2_rect *rect, struct v4l2_rect *subrect,
+		const struct v4l2_pix_format *pix, struct v4l2_mbus_framefmt *mf,
+		unsigned int shift);
+
+#endif