/*
 * Copyright (c) 2016 MediaTek Inc.
 * Author: PC Chen <pc.chen@mediatek.com>
 *         Tiffany Lin <tiffany.lin@mediatek.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <media/v4l2-event.h>
#include <media/v4l2-mem2mem.h>
#include <media/videobuf2-dma-contig.h>

#include "mtk_vcodec_drv.h"
#include "mtk_vcodec_dec.h"
#include "mtk_vcodec_dec_pm.h"
#include "mtk_vcodec_intr.h"
#include "mtk_vcodec_util.h"
#include "mtk_vpu.h"

#define VDEC_HW_ACTIVE	0x10
#define VDEC_IRQ_CFG	0x11
#define VDEC_IRQ_CLR	0x10
#define VDEC_IRQ_CFG_REG	0xa4

module_param(mtk_v4l2_dbg_level, int, 0644);
module_param(mtk_vcodec_dbg, bool, 0644);

/* Wake up context wait_queue */
static void wake_up_ctx(struct mtk_vcodec_ctx *ctx)
{
	ctx->int_cond = 1;
	wake_up_interruptible(&ctx->queue);
}

static irqreturn_t mtk_vcodec_dec_irq_handler(int irq, void *priv)
{
	struct mtk_vcodec_dev *dev = priv;
	struct mtk_vcodec_ctx *ctx;
	u32 cg_status = 0;
	unsigned int dec_done_status = 0;
	void __iomem *vdec_misc_addr = dev->reg_base[VDEC_MISC] +
					VDEC_IRQ_CFG_REG;

	ctx = mtk_vcodec_get_curr_ctx(dev);

	/* check if HW active or not */
	cg_status = readl(dev->reg_base[0]);
	if ((cg_status & VDEC_HW_ACTIVE) != 0) {
		mtk_v4l2_err("DEC ISR, VDEC active is not 0x0 (0x%08x)",
			     cg_status);
		return IRQ_HANDLED;
	}

	dec_done_status = readl(vdec_misc_addr);
	ctx->irq_status = dec_done_status;
	if ((dec_done_status & MTK_VDEC_IRQ_STATUS_DEC_SUCCESS) !=
		MTK_VDEC_IRQ_STATUS_DEC_SUCCESS)
		return IRQ_HANDLED;

	/* clear interrupt */
	writel((readl(vdec_misc_addr) | VDEC_IRQ_CFG),
		dev->reg_base[VDEC_MISC] + VDEC_IRQ_CFG_REG);
	writel((readl(vdec_misc_addr) & ~VDEC_IRQ_CLR),
		dev->reg_base[VDEC_MISC] + VDEC_IRQ_CFG_REG);

	wake_up_ctx(ctx);

	mtk_v4l2_debug(3,
			"mtk_vcodec_dec_irq_handler :wake up ctx %d, dec_done_status=%x",
			ctx->id, dec_done_status);

	return IRQ_HANDLED;
}

static void mtk_vcodec_dec_reset_handler(void *priv)
{
	struct mtk_vcodec_dev *dev = priv;
	struct mtk_vcodec_ctx *ctx;

	mtk_v4l2_err("Watchdog timeout!!");

	mutex_lock(&dev->dev_mutex);
	list_for_each_entry(ctx, &dev->ctx_list, list) {
		ctx->state = MTK_STATE_ABORT;
		mtk_v4l2_debug(0, "[%d] Change to state MTK_STATE_ERROR",
				ctx->id);
	}
	mutex_unlock(&dev->dev_mutex);
}

static int fops_vcodec_open(struct file *file)
{
	struct mtk_vcodec_dev *dev = video_drvdata(file);
	struct mtk_vcodec_ctx *ctx = NULL;
	int ret = 0;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	mutex_lock(&dev->dev_mutex);
	ctx->id = dev->id_counter++;
	v4l2_fh_init(&ctx->fh, video_devdata(file));
	file->private_data = &ctx->fh;
	v4l2_fh_add(&ctx->fh);
	INIT_LIST_HEAD(&ctx->list);
	ctx->dev = dev;
	init_waitqueue_head(&ctx->queue);
	mutex_init(&ctx->lock);

	ctx->type = MTK_INST_DECODER;
	ret = mtk_vcodec_dec_ctrls_setup(ctx);
	if (ret) {
		mtk_v4l2_err("Failed to setup mt vcodec controls");
		goto err_ctrls_setup;
	}
	ctx->m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev_dec, ctx,
		&mtk_vcodec_dec_queue_init);
	if (IS_ERR((__force void *)ctx->m2m_ctx)) {
		ret = PTR_ERR((__force void *)ctx->m2m_ctx);
		mtk_v4l2_err("Failed to v4l2_m2m_ctx_init() (%d)",
			ret);
		goto err_m2m_ctx_init;
	}
	mtk_vcodec_dec_set_default_params(ctx);

	if (v4l2_fh_is_singular(&ctx->fh)) {
		mtk_vcodec_dec_pw_on(&dev->pm);
		/*
		 * vpu_load_firmware checks if it was loaded already and
		 * does nothing in that case
		 */
		ret = vpu_load_firmware(dev->vpu_plat_dev);
		if (ret < 0) {
			/*
			 * Return 0 if downloading firmware successfully,
			 * otherwise it is failed
			 */
			mtk_v4l2_err("vpu_load_firmware failed!");
			goto err_load_fw;
		}

		dev->dec_capability =
			vpu_get_vdec_hw_capa(dev->vpu_plat_dev);
		mtk_v4l2_debug(0, "decoder capability %x", dev->dec_capability);
	}

	list_add(&ctx->list, &dev->ctx_list);

	mutex_unlock(&dev->dev_mutex);
	mtk_v4l2_debug(0, "%s decoder [%d]", dev_name(&dev->plat_dev->dev),
			ctx->id);
	return ret;

	/* Deinit when failure occurred */
err_load_fw:
	v4l2_m2m_ctx_release(ctx->m2m_ctx);
err_m2m_ctx_init:
	v4l2_ctrl_handler_free(&ctx->ctrl_hdl);
err_ctrls_setup:
	v4l2_fh_del(&ctx->fh);
	v4l2_fh_exit(&ctx->fh);
	kfree(ctx);
	mutex_unlock(&dev->dev_mutex);

	return ret;
}

static int fops_vcodec_release(struct file *file)
{
	struct mtk_vcodec_dev *dev = video_drvdata(file);
	struct mtk_vcodec_ctx *ctx = fh_to_ctx(file->private_data);

	mtk_v4l2_debug(0, "[%d] decoder", ctx->id);
	mutex_lock(&dev->dev_mutex);

	/*
	 * Call v4l2_m2m_ctx_release before mtk_vcodec_dec_release. First, it
	 * makes sure the worker thread is not running after vdec_if_deinit.
	 * Second, the decoder will be flushed and all the buffers will be
	 * returned in stop_streaming.
	 */
	v4l2_m2m_ctx_release(ctx->m2m_ctx);
	mtk_vcodec_dec_release(ctx);

	if (v4l2_fh_is_singular(&ctx->fh))
		mtk_vcodec_dec_pw_off(&dev->pm);
	v4l2_fh_del(&ctx->fh);
	v4l2_fh_exit(&ctx->fh);
	v4l2_ctrl_handler_free(&ctx->ctrl_hdl);

	list_del_init(&ctx->list);
	kfree(ctx);
	mutex_unlock(&dev->dev_mutex);
	return 0;
}

static const struct v4l2_file_operations mtk_vcodec_fops = {
	.owner		= THIS_MODULE,
	.open		= fops_vcodec_open,
	.release	= fops_vcodec_release,
	.poll		= v4l2_m2m_fop_poll,
	.unlocked_ioctl	= video_ioctl2,
	.mmap		= v4l2_m2m_fop_mmap,
};

static int mtk_vcodec_probe(struct platform_device *pdev)
{
	struct mtk_vcodec_dev *dev;
	struct video_device *vfd_dec;
	struct resource *res;
	int i, ret;

	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;

	INIT_LIST_HEAD(&dev->ctx_list);
	dev->plat_dev = pdev;

	dev->vpu_plat_dev = vpu_get_plat_device(dev->plat_dev);
	if (dev->vpu_plat_dev == NULL) {
		mtk_v4l2_err("[VPU] vpu device in not ready");
		return -EPROBE_DEFER;
	}

	vpu_wdt_reg_handler(dev->vpu_plat_dev, mtk_vcodec_dec_reset_handler,
			dev, VPU_RST_DEC);

	ret = mtk_vcodec_init_dec_pm(dev);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to get mt vcodec clock source");
		return ret;
	}

	for (i = 0; i < NUM_MAX_VDEC_REG_BASE; i++) {
		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
		if (res == NULL) {
			dev_err(&pdev->dev, "get memory resource failed.");
			ret = -ENXIO;
			goto err_res;
		}
		dev->reg_base[i] = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR((__force void *)dev->reg_base[i])) {
			ret = PTR_ERR((__force void *)dev->reg_base[i]);
			goto err_res;
		}
		mtk_v4l2_debug(2, "reg[%d] base=%p", i, dev->reg_base[i]);
	}

	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "failed to get irq resource");
		ret = -ENOENT;
		goto err_res;
	}

	dev->dec_irq = platform_get_irq(pdev, 0);
	ret = devm_request_irq(&pdev->dev, dev->dec_irq,
			mtk_vcodec_dec_irq_handler, 0, pdev->name, dev);
	if (ret) {
		dev_err(&pdev->dev, "Failed to install dev->dec_irq %d (%d)",
			dev->dec_irq,
			ret);
		goto err_res;
	}

	disable_irq(dev->dec_irq);
	mutex_init(&dev->dec_mutex);
	mutex_init(&dev->dev_mutex);
	spin_lock_init(&dev->irqlock);

	snprintf(dev->v4l2_dev.name, sizeof(dev->v4l2_dev.name), "%s",
		"[/MTK_V4L2_VDEC]");

	ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
	if (ret) {
		mtk_v4l2_err("v4l2_device_register err=%d", ret);
		goto err_res;
	}

	init_waitqueue_head(&dev->queue);

	vfd_dec = video_device_alloc();
	if (!vfd_dec) {
		mtk_v4l2_err("Failed to allocate video device");
		ret = -ENOMEM;
		goto err_dec_alloc;
	}
	vfd_dec->fops		= &mtk_vcodec_fops;
	vfd_dec->ioctl_ops	= &mtk_vdec_ioctl_ops;
	vfd_dec->release	= video_device_release;
	vfd_dec->lock		= &dev->dev_mutex;
	vfd_dec->v4l2_dev	= &dev->v4l2_dev;
	vfd_dec->vfl_dir	= VFL_DIR_M2M;
	vfd_dec->device_caps	= V4L2_CAP_VIDEO_M2M_MPLANE |
			V4L2_CAP_STREAMING;

	snprintf(vfd_dec->name, sizeof(vfd_dec->name), "%s",
		MTK_VCODEC_DEC_NAME);
	video_set_drvdata(vfd_dec, dev);
	dev->vfd_dec = vfd_dec;
	platform_set_drvdata(pdev, dev);

	dev->m2m_dev_dec = v4l2_m2m_init(&mtk_vdec_m2m_ops);
	if (IS_ERR((__force void *)dev->m2m_dev_dec)) {
		mtk_v4l2_err("Failed to init mem2mem dec device");
		ret = PTR_ERR((__force void *)dev->m2m_dev_dec);
		goto err_dec_mem_init;
	}

	dev->decode_workqueue =
		alloc_ordered_workqueue(MTK_VCODEC_DEC_NAME,
			WQ_MEM_RECLAIM | WQ_FREEZABLE);
	if (!dev->decode_workqueue) {
		mtk_v4l2_err("Failed to create decode workqueue");
		ret = -EINVAL;
		goto err_event_workq;
	}

	ret = video_register_device(vfd_dec, VFL_TYPE_GRABBER, 0);
	if (ret) {
		mtk_v4l2_err("Failed to register video device");
		goto err_dec_reg;
	}

	mtk_v4l2_debug(0, "decoder registered as /dev/video%d",
		vfd_dec->num);

	return 0;

err_dec_reg:
	destroy_workqueue(dev->decode_workqueue);
err_event_workq:
	v4l2_m2m_release(dev->m2m_dev_dec);
err_dec_mem_init:
	video_unregister_device(vfd_dec);
err_dec_alloc:
	v4l2_device_unregister(&dev->v4l2_dev);
err_res:
	mtk_vcodec_release_dec_pm(dev);
	return ret;
}

static const struct of_device_id mtk_vcodec_match[] = {
	{.compatible = "mediatek,mt8173-vcodec-dec",},
	{},
};

MODULE_DEVICE_TABLE(of, mtk_vcodec_match);

static int mtk_vcodec_dec_remove(struct platform_device *pdev)
{
	struct mtk_vcodec_dev *dev = platform_get_drvdata(pdev);

	flush_workqueue(dev->decode_workqueue);
	destroy_workqueue(dev->decode_workqueue);
	if (dev->m2m_dev_dec)
		v4l2_m2m_release(dev->m2m_dev_dec);

	if (dev->vfd_dec)
		video_unregister_device(dev->vfd_dec);

	v4l2_device_unregister(&dev->v4l2_dev);
	mtk_vcodec_release_dec_pm(dev);
	return 0;
}

static struct platform_driver mtk_vcodec_dec_driver = {
	.probe	= mtk_vcodec_probe,
	.remove	= mtk_vcodec_dec_remove,
	.driver	= {
		.name	= MTK_VCODEC_DEC_NAME,
		.of_match_table = mtk_vcodec_match,
	},
};

module_platform_driver(mtk_vcodec_dec_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Mediatek video codec V4L2 decoder driver");
