text: /*
   * vimc-scaler.c Virtual Media Controller Driver
   *
   * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   */
  
  #include <linux/component.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/vmalloc.h>
  #include <linux/v4l2-mediabus.h>
  #include <media/v4l2-subdev.h>
  
  #include "vimc-common.h"
  
  #define VIMC_SCA_DRV_NAME "vimc-scaler"
  
  static unsigned int sca_mult = 3;
  module_param(sca_mult, uint, 0000);
  MODULE_PARM_DESC(sca_mult, " the image size multiplier");
  
  #define IS_SINK(pad)	(!pad)
  #define IS_SRC(pad)	(pad)
  #define MAX_ZOOM	8
  
  struct vimc_sca_device {
  	struct vimc_ent_device ved;
  	struct v4l2_subdev sd;
  	struct device *dev;
  	/* NOTE: the source fmt is the same as the sink
  	 * with the width and hight multiplied by mult
  	 */
  	struct v4l2_mbus_framefmt sink_fmt;
  	/* Values calculated when the stream starts */
  	u8 *src_frame;
  	unsigned int src_line_size;
  	unsigned int bpp;
  };
  
  static const struct v4l2_mbus_framefmt sink_fmt_default = {
  	.width = 640,
  	.height = 480,
  	.code = MEDIA_BUS_FMT_RGB888_1X24,
  	.field = V4L2_FIELD_NONE,
  	.colorspace = V4L2_COLORSPACE_DEFAULT,
  };
  
  static int vimc_sca_init_cfg(struct v4l2_subdev *sd,
  			     struct v4l2_subdev_pad_config *cfg)
  {
  	struct v4l2_mbus_framefmt *mf;
  	unsigned int i;
  
  	mf = v4l2_subdev_get_try_format(sd, cfg, 0);
  	*mf = sink_fmt_default;
  
  	for (i = 1; i < sd->entity.num_pads; i++) {
  		mf = v4l2_subdev_get_try_format(sd, cfg, i);
  		*mf = sink_fmt_default;
  		mf->width = mf->width * sca_mult;
  		mf->height = mf->height * sca_mult;
  	}
  
  	return 0;
  }
  
  static int vimc_sca_enum_mbus_code(struct v4l2_subdev *sd,
  				   struct v4l2_subdev_pad_config *cfg,
  				   struct v4l2_subdev_mbus_code_enum *code)
  {
  	const struct vimc_pix_map *vpix = vimc_pix_map_by_index(code->index);
  
  	/* We don't support bayer format */
  	if (!vpix || vpix->bayer)
  		return -EINVAL;
  
  	code->code = vpix->code;
  
  	return 0;
  }
  
  static int vimc_sca_enum_frame_size(struct v4l2_subdev *sd,
  				    struct v4l2_subdev_pad_config *cfg,
  				    struct v4l2_subdev_frame_size_enum *fse)
  {
  	const struct vimc_pix_map *vpix;
  
  	if (fse->index)
  		return -EINVAL;
  
  	/* Only accept code in the pix map table in non bayer format */
  	vpix = vimc_pix_map_by_code(fse->code);
  	if (!vpix || vpix->bayer)
  		return -EINVAL;
  
  	fse->min_width = VIMC_FRAME_MIN_WIDTH;
  	fse->min_height = VIMC_FRAME_MIN_HEIGHT;
  
  	if (IS_SINK(fse->pad)) {
  		fse->max_width = VIMC_FRAME_MAX_WIDTH;
  		fse->max_height = VIMC_FRAME_MAX_HEIGHT;
  	} else {
  		fse->max_width = VIMC_FRAME_MAX_WIDTH * MAX_ZOOM;
  		fse->max_height = VIMC_FRAME_MAX_HEIGHT * MAX_ZOOM;
  	}
  
  	return 0;
  }
  
  static int vimc_sca_get_fmt(struct v4l2_subdev *sd,
  			    struct v4l2_subdev_pad_config *cfg,
  			    struct v4l2_subdev_format *format)
  {
  	struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
  
  	/* Get the current sink format */
  	format->format = (format->which == V4L2_SUBDEV_FORMAT_TRY) ?
  			 *v4l2_subdev_get_try_format(sd, cfg, 0) :
  			 vsca->sink_fmt;
  
  	/* Scale the frame size for the source pad */
  	if (IS_SRC(format->pad)) {
  		format->format.width = vsca->sink_fmt.width * sca_mult;
  		format->format.height = vsca->sink_fmt.height * sca_mult;
  	}
  
  	return 0;
  }
  
  static void vimc_sca_adjust_sink_fmt(struct v4l2_mbus_framefmt *fmt)
  {
  	const struct vimc_pix_map *vpix;
  
  	/* Only accept code in the pix map table in non bayer format */
  	vpix = vimc_pix_map_by_code(fmt->code);
  	if (!vpix || vpix->bayer)
  		fmt->code = sink_fmt_default.code;
  
  	fmt->width = clamp_t(u32, fmt->width, VIMC_FRAME_MIN_WIDTH,
  			     VIMC_FRAME_MAX_WIDTH) & ~1;
  	fmt->height = clamp_t(u32, fmt->height, VIMC_FRAME_MIN_HEIGHT,
  			      VIMC_FRAME_MAX_HEIGHT) & ~1;
  
  	if (fmt->field == V4L2_FIELD_ANY)
  		fmt->field = sink_fmt_default.field;
  
  	vimc_colorimetry_clamp(fmt);
  }
  
  static int vimc_sca_set_fmt(struct v4l2_subdev *sd,
  			    struct v4l2_subdev_pad_config *cfg,
  			    struct v4l2_subdev_format *fmt)
  {
  	struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
  	struct v4l2_mbus_framefmt *sink_fmt;
  
  	if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
  		/* Do not change the format while stream is on */
  		if (vsca->src_frame)
  			return -EBUSY;
  
  		sink_fmt = &vsca->sink_fmt;
  	} else {
  		sink_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
  	}
  
  	/*
  	 * Do not change the format of the source pad,
  	 * it is propagated from the sink
  	 */
  	if (IS_SRC(fmt->pad)) {
  		fmt->format = *sink_fmt;
  		fmt->format.width = sink_fmt->width * sca_mult;
  		fmt->format.height = sink_fmt->height * sca_mult;
  	} else {
  		/* Set the new format in the sink pad */
  		vimc_sca_adjust_sink_fmt(&fmt->format);
  
  		dev_dbg(vsca->dev, "%s: sink format update: "
  			"old:%dx%d (0x%x, %d, %d, %d, %d) "
  			"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vsca->sd.name,
  			/* old */
  			sink_fmt->width, sink_fmt->height, sink_fmt->code,
  			sink_fmt->colorspace, sink_fmt->quantization,
  			sink_fmt->xfer_func, sink_fmt->ycbcr_enc,
  			/* new */
  			fmt->format.width, fmt->format.height, fmt->format.code,
  			fmt->format.colorspace,	fmt->format.quantization,
  			fmt->format.xfer_func, fmt->format.ycbcr_enc);
  
  		*sink_fmt = fmt->format;
  	}
  
  	return 0;
  }
  
  static const struct v4l2_subdev_pad_ops vimc_sca_pad_ops = {
  	.init_cfg		= vimc_sca_init_cfg,
  	.enum_mbus_code		= vimc_sca_enum_mbus_code,
  	.enum_frame_size	= vimc_sca_enum_frame_size,
  	.get_fmt		= vimc_sca_get_fmt,
  	.set_fmt		= vimc_sca_set_fmt,
  };
  
  static int vimc_sca_s_stream(struct v4l2_subdev *sd, int enable)
  {
  	struct vimc_sca_device *vsca = v4l2_get_subdevdata(sd);
  
  	if (enable) {
  		const struct vimc_pix_map *vpix;
  		unsigned int frame_size;
  
  		if (vsca->src_frame)
  			return 0;
  
  		/* Save the bytes per pixel of the sink */
  		vpix = vimc_pix_map_by_code(vsca->sink_fmt.code);
  		vsca->bpp = vpix->bpp;
  
  		/* Calculate the width in bytes of the src frame */
  		vsca->src_line_size = vsca->sink_fmt.width *
  				      sca_mult * vsca->bpp;
  
  		/* Calculate the frame size of the source pad */
  		frame_size = vsca->src_line_size * vsca->sink_fmt.height *
  			     sca_mult;
  
  		/* Allocate the frame buffer. Use vmalloc to be able to
  		 * allocate a large amount of memory
  		 */
  		vsca->src_frame = vmalloc(frame_size);
  		if (!vsca->src_frame)
  			return -ENOMEM;
  
  	} else {
  		if (!vsca->src_frame)
  			return 0;
  
  		vfree(vsca->src_frame);
  		vsca->src_frame = NULL;
  	}
  
  	return 0;
  }
  
  static const struct v4l2_subdev_video_ops vimc_sca_video_ops = {
  	.s_stream = vimc_sca_s_stream,
  };
  
  static const struct v4l2_subdev_ops vimc_sca_ops = {
  	.pad = &vimc_sca_pad_ops,
  	.video = &vimc_sca_video_ops,
  };
  
  static void vimc_sca_fill_pix(u8 *const ptr,
  			      const u8 *const pixel,
  			      const unsigned int bpp)
  {
  	unsigned int i;
  
  	/* copy the pixel to the pointer */
  	for (i = 0; i < bpp; i++)
  		ptr[i] = pixel[i];
  }
  
  static void vimc_sca_scale_pix(const struct vimc_sca_device *const vsca,
  			       const unsigned int lin, const unsigned int col,
  			       const u8 *const sink_frame)
  {
  	unsigned int i, j, index;
  	const u8 *pixel;
  
  	/* Point to the pixel value in position (lin, col) in the sink frame */
  	index = VIMC_FRAME_INDEX(lin, col,
  				 vsca->sink_fmt.width,
  				 vsca->bpp);
  	pixel = &sink_frame[index];
  
  	dev_dbg(vsca->dev,
  		"sca: %s: --- scale_pix sink pos %dx%d, index %d ---\n",
  		vsca->sd.name, lin, col, index);
  
  	/* point to the place we are going to put the first pixel
  	 * in the scaled src frame
  	 */
  	index = VIMC_FRAME_INDEX(lin * sca_mult, col * sca_mult,
  				 vsca->sink_fmt.width * sca_mult, vsca->bpp);
  
  	dev_dbg(vsca->dev, "sca: %s: scale_pix src pos %dx%d, index %d\n",
  		vsca->sd.name, lin * sca_mult, col * sca_mult, index);
  
  	/* Repeat this pixel mult times */
  	for (i = 0; i < sca_mult; i++) {
  		/* Iterate through each beginning of a
  		 * pixel repetition in a line
  		 */
  		for (j = 0; j < sca_mult * vsca->bpp; j += vsca->bpp) {
  			dev_dbg(vsca->dev,
  				"sca: %s: sca: scale_pix src pos %d\n",
  				vsca->sd.name, index + j);
  
  			/* copy the pixel to the position index + j */
  			vimc_sca_fill_pix(&vsca->src_frame[index + j],
  					  pixel, vsca->bpp);
  		}
  
  		/* move the index to the next line */
  		index += vsca->src_line_size;
  	}
  }
  
  static void vimc_sca_fill_src_frame(const struct vimc_sca_device *const vsca,
  				    const u8 *const sink_frame)
  {
  	unsigned int i, j;
  
  	/* Scale each pixel from the original sink frame */
  	/* TODO: implement scale down, only scale up is supported for now */
  	for (i = 0; i < vsca->sink_fmt.height; i++)
  		for (j = 0; j < vsca->sink_fmt.width; j++)
  			vimc_sca_scale_pix(vsca, i, j, sink_frame);
  }
  
  static void *vimc_sca_process_frame(struct vimc_ent_device *ved,
  				    const void *sink_frame)
  {
  	struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
  						    ved);
  
  	/* If the stream in this node is not active, just return */
  	if (!vsca->src_frame)
  		return ERR_PTR(-EINVAL);
  
  	vimc_sca_fill_src_frame(vsca, sink_frame);
  
  	return vsca->src_frame;
  };
  
  static void vimc_sca_comp_unbind(struct device *comp, struct device *master,
  				 void *master_data)
  {
  	struct vimc_ent_device *ved = dev_get_drvdata(comp);
  	struct vimc_sca_device *vsca = container_of(ved, struct vimc_sca_device,
  						    ved);
  
  	vimc_ent_sd_unregister(ved, &vsca->sd);
  	kfree(vsca);
  }
  
  
  static int vimc_sca_comp_bind(struct device *comp, struct device *master,
  			      void *master_data)
  {
  	struct v4l2_device *v4l2_dev = master_data;
  	struct vimc_platform_data *pdata = comp->platform_data;
  	struct vimc_sca_device *vsca;
  	int ret;
  
  	/* Allocate the vsca struct */
  	vsca = kzalloc(sizeof(*vsca), GFP_KERNEL);
  	if (!vsca)
  		return -ENOMEM;
  
  	/* Initialize ved and sd */
  	ret = vimc_ent_sd_register(&vsca->ved, &vsca->sd, v4l2_dev,
  				   pdata->entity_name,
  				   MEDIA_ENT_F_ATV_DECODER, 2,
  				   (const unsigned long[2]) {MEDIA_PAD_FL_SINK,
  				   MEDIA_PAD_FL_SOURCE},
  				   &vimc_sca_ops);
  	if (ret) {
  		kfree(vsca);
  		return ret;
  	}
  
  	vsca->ved.process_frame = vimc_sca_process_frame;
  	dev_set_drvdata(comp, &vsca->ved);
  	vsca->dev = comp;
  
  	/* Initialize the frame format */
  	vsca->sink_fmt = sink_fmt_default;
  
  	return 0;
  }
  
  static const struct component_ops vimc_sca_comp_ops = {
  	.bind = vimc_sca_comp_bind,
  	.unbind = vimc_sca_comp_unbind,
  };
  
  static int vimc_sca_probe(struct platform_device *pdev)
  {
  	return component_add(&pdev->dev, &vimc_sca_comp_ops);
  }
  
  static int vimc_sca_remove(struct platform_device *pdev)
  {
  	component_del(&pdev->dev, &vimc_sca_comp_ops);
  
  	return 0;
  }
  
  static const struct platform_device_id vimc_sca_driver_ids[] = {
  	{
  		.name           = VIMC_SCA_DRV_NAME,
  	},
  	{ }
  };
  
  static struct platform_driver vimc_sca_pdrv = {
  	.probe		= vimc_sca_probe,
  	.remove		= vimc_sca_remove,
  	.id_table	= vimc_sca_driver_ids,
  	.driver		= {
  		.name	= VIMC_SCA_DRV_NAME,
  	},
  };
  
  module_platform_driver(vimc_sca_pdrv);
  
  MODULE_DEVICE_TABLE(platform, vimc_sca_driver_ids);
  
  MODULE_DESCRIPTION("Virtual Media Controller Driver (VIMC) Scaler");
  MODULE_AUTHOR("Helen Mae Koike Fornazier <helen.fornazier@gmail.com>");
  MODULE_LICENSE("GPL");
  