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/*
 * vimc-sensor.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/freezer.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/v4l2-mediabus.h>
#include <linux/vmalloc.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-tpg.h>

#include "vimc-common.h"

#define VIMC_SEN_DRV_NAME "vimc-sensor"

struct vimc_sen_device {
	struct vimc_ent_device ved;
	struct v4l2_subdev sd;
	struct device *dev;
	struct tpg_data tpg;
	struct task_struct *kthread_sen;
	u8 *frame;
	/* The active format */
	struct v4l2_mbus_framefmt mbus_format;
};

static const struct v4l2_mbus_framefmt fmt_default = {
	.width = 640,
	.height = 480,
	.code = MEDIA_BUS_FMT_RGB888_1X24,
	.field = V4L2_FIELD_NONE,
	.colorspace = V4L2_COLORSPACE_DEFAULT,
};

static int vimc_sen_init_cfg(struct v4l2_subdev *sd,
			     struct v4l2_subdev_pad_config *cfg)
{
	unsigned int i;

	for (i = 0; i < sd->entity.num_pads; i++) {
		struct v4l2_mbus_framefmt *mf;

		mf = v4l2_subdev_get_try_format(sd, cfg, i);
		*mf = fmt_default;
	}

	return 0;
}

static int vimc_sen_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);

	if (!vpix)
		return -EINVAL;

	code->code = vpix->code;

	return 0;
}

static int vimc_sen_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 */
	vpix = vimc_pix_map_by_code(fse->code);
	if (!vpix)
		return -EINVAL;

	fse->min_width = VIMC_FRAME_MIN_WIDTH;
	fse->max_width = VIMC_FRAME_MAX_WIDTH;
	fse->min_height = VIMC_FRAME_MIN_HEIGHT;
	fse->max_height = VIMC_FRAME_MAX_HEIGHT;

	return 0;
}

static int vimc_sen_get_fmt(struct v4l2_subdev *sd,
			    struct v4l2_subdev_pad_config *cfg,
			    struct v4l2_subdev_format *fmt)
{
	struct vimc_sen_device *vsen =
				container_of(sd, struct vimc_sen_device, sd);

	fmt->format = fmt->which == V4L2_SUBDEV_FORMAT_TRY ?
		      *v4l2_subdev_get_try_format(sd, cfg, fmt->pad) :
		      vsen->mbus_format;

	return 0;
}

static void vimc_sen_tpg_s_format(struct vimc_sen_device *vsen)
{
	const struct vimc_pix_map *vpix =
				vimc_pix_map_by_code(vsen->mbus_format.code);

	tpg_reset_source(&vsen->tpg, vsen->mbus_format.width,
			 vsen->mbus_format.height, vsen->mbus_format.field);
	tpg_s_bytesperline(&vsen->tpg, 0, vsen->mbus_format.width * vpix->bpp);
	tpg_s_buf_height(&vsen->tpg, vsen->mbus_format.height);
	tpg_s_fourcc(&vsen->tpg, vpix->pixelformat);
	/* TODO: add support for V4L2_FIELD_ALTERNATE */
	tpg_s_field(&vsen->tpg, vsen->mbus_format.field, false);
	tpg_s_colorspace(&vsen->tpg, vsen->mbus_format.colorspace);
	tpg_s_ycbcr_enc(&vsen->tpg, vsen->mbus_format.ycbcr_enc);
	tpg_s_quantization(&vsen->tpg, vsen->mbus_format.quantization);
	tpg_s_xfer_func(&vsen->tpg, vsen->mbus_format.xfer_func);
}

static void vimc_sen_adjust_fmt(struct v4l2_mbus_framefmt *fmt)
{
	const struct vimc_pix_map *vpix;

	/* Only accept code in the pix map table */
	vpix = vimc_pix_map_by_code(fmt->code);
	if (!vpix)
		fmt->code = 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;

	/* TODO: add support for V4L2_FIELD_ALTERNATE */
	if (fmt->field == V4L2_FIELD_ANY || fmt->field == V4L2_FIELD_ALTERNATE)
		fmt->field = fmt_default.field;

	vimc_colorimetry_clamp(fmt);
}

static int vimc_sen_set_fmt(struct v4l2_subdev *sd,
			    struct v4l2_subdev_pad_config *cfg,
			    struct v4l2_subdev_format *fmt)
{
	struct vimc_sen_device *vsen = v4l2_get_subdevdata(sd);
	struct v4l2_mbus_framefmt *mf;

	if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
		/* Do not change the format while stream is on */
		if (vsen->frame)
			return -EBUSY;

		mf = &vsen->mbus_format;
	} else {
		mf = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
	}

	/* Set the new format */
	vimc_sen_adjust_fmt(&fmt->format);

	dev_dbg(vsen->dev, "%s: format update: "
		"old:%dx%d (0x%x, %d, %d, %d, %d) "
		"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vsen->sd.name,
		/* old */
		mf->width, mf->height, mf->code,
		mf->colorspace,	mf->quantization,
		mf->xfer_func, mf->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);

	*mf = fmt->format;

	return 0;
}

static const struct v4l2_subdev_pad_ops vimc_sen_pad_ops = {
	.init_cfg		= vimc_sen_init_cfg,
	.enum_mbus_code		= vimc_sen_enum_mbus_code,
	.enum_frame_size	= vimc_sen_enum_frame_size,
	.get_fmt		= vimc_sen_get_fmt,
	.set_fmt		= vimc_sen_set_fmt,
};

static int vimc_sen_tpg_thread(void *data)
{
	struct vimc_sen_device *vsen = data;
	unsigned int i;

	set_freezable();
	set_current_state(TASK_UNINTERRUPTIBLE);

	for (;;) {
		try_to_freeze();
		if (kthread_should_stop())
			break;

		tpg_fill_plane_buffer(&vsen->tpg, 0, 0, vsen->frame);

		/* Send the frame to all source pads */
		for (i = 0; i < vsen->sd.entity.num_pads; i++)
			vimc_propagate_frame(&vsen->sd.entity.pads[i],
					     vsen->frame);

		/* 60 frames per second */
		schedule_timeout(HZ/60);
	}

	return 0;
}

static int vimc_sen_s_stream(struct v4l2_subdev *sd, int enable)
{
	struct vimc_sen_device *vsen =
				container_of(sd, struct vimc_sen_device, sd);
	int ret;

	if (enable) {
		const struct vimc_pix_map *vpix;
		unsigned int frame_size;

		if (vsen->kthread_sen)
			/* tpg is already executing */
			return 0;

		/* Calculate the frame size */
		vpix = vimc_pix_map_by_code(vsen->mbus_format.code);
		frame_size = vsen->mbus_format.width * vpix->bpp *
			     vsen->mbus_format.height;

		/*
		 * Allocate the frame buffer. Use vmalloc to be able to
		 * allocate a large amount of memory
		 */
		vsen->frame = vmalloc(frame_size);
		if (!vsen->frame)
			return -ENOMEM;

		/* configure the test pattern generator */
		vimc_sen_tpg_s_format(vsen);

		/* Initialize the image generator thread */
		vsen->kthread_sen = kthread_run(vimc_sen_tpg_thread, vsen,
					"%s-sen", vsen->sd.v4l2_dev->name);
		if (IS_ERR(vsen->kthread_sen)) {
			dev_err(vsen->dev, "%s: kernel_thread() failed\n",
				vsen->sd.name);
			vfree(vsen->frame);
			vsen->frame = NULL;
			return PTR_ERR(vsen->kthread_sen);
		}
	} else {
		if (!vsen->kthread_sen)
			return 0;

		/* Stop image generator */
		ret = kthread_stop(vsen->kthread_sen);
		if (ret)
			return ret;

		vsen->kthread_sen = NULL;
		vfree(vsen->frame);
		vsen->frame = NULL;
		return 0;
	}

	return 0;
}

static const struct v4l2_subdev_video_ops vimc_sen_video_ops = {
	.s_stream = vimc_sen_s_stream,
};

static const struct v4l2_subdev_ops vimc_sen_ops = {
	.pad = &vimc_sen_pad_ops,
	.video = &vimc_sen_video_ops,
};

static void vimc_sen_comp_unbind(struct device *comp, struct device *master,
				 void *master_data)
{
	struct vimc_ent_device *ved = dev_get_drvdata(comp);
	struct vimc_sen_device *vsen =
				container_of(ved, struct vimc_sen_device, ved);

	vimc_ent_sd_unregister(ved, &vsen->sd);
	tpg_free(&vsen->tpg);
	kfree(vsen);
}

static int vimc_sen_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_sen_device *vsen;
	int ret;

	/* Allocate the vsen struct */
	vsen = kzalloc(sizeof(*vsen), GFP_KERNEL);
	if (!vsen)
		return -ENOMEM;

	/* Initialize ved and sd */
	ret = vimc_ent_sd_register(&vsen->ved, &vsen->sd, v4l2_dev,
				   pdata->entity_name,
				   MEDIA_ENT_F_ATV_DECODER, 1,
				   (const unsigned long[1]) {MEDIA_PAD_FL_SOURCE},
				   &vimc_sen_ops);
	if (ret)
		goto err_free_vsen;

	dev_set_drvdata(comp, &vsen->ved);
	vsen->dev = comp;

	/* Initialize the frame format */
	vsen->mbus_format = fmt_default;

	/* Initialize the test pattern generator */
	tpg_init(&vsen->tpg, vsen->mbus_format.width,
		 vsen->mbus_format.height);
	ret = tpg_alloc(&vsen->tpg, VIMC_FRAME_MAX_WIDTH);
	if (ret)
		goto err_unregister_ent_sd;

	return 0;

err_unregister_ent_sd:
	vimc_ent_sd_unregister(&vsen->ved,  &vsen->sd);
err_free_vsen:
	kfree(vsen);

	return ret;
}

static const struct component_ops vimc_sen_comp_ops = {
	.bind = vimc_sen_comp_bind,
	.unbind = vimc_sen_comp_unbind,
};

static int vimc_sen_probe(struct platform_device *pdev)
{
	return component_add(&pdev->dev, &vimc_sen_comp_ops);
}

static int vimc_sen_remove(struct platform_device *pdev)
{
	component_del(&pdev->dev, &vimc_sen_comp_ops);

	return 0;
}

static const struct platform_device_id vimc_sen_driver_ids[] = {
	{
		.name           = VIMC_SEN_DRV_NAME,
	},
	{ }
};

static struct platform_driver vimc_sen_pdrv = {
	.probe		= vimc_sen_probe,
	.remove		= vimc_sen_remove,
	.id_table	= vimc_sen_driver_ids,
	.driver		= {
		.name	= VIMC_SEN_DRV_NAME,
	},
};

module_platform_driver(vimc_sen_pdrv);

MODULE_DEVICE_TABLE(platform, vimc_sen_driver_ids);

MODULE_DESCRIPTION("Virtual Media Controller Driver (VIMC) Sensor");
MODULE_AUTHOR("Helen Mae Koike Fornazier <helen.fornazier@gmail.com>");
MODULE_LICENSE("GPL");