// SPDX-License-Identifier: GPL-2.0
/*
 * Cedrus VPU driver
 *
 * Copyright (C) 2016 Florent Revest <florent.revest@free-electrons.com>
 * Copyright (C) 2018 Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 * Copyright (C) 2018 Bootlin
 *
 * Based on the vim2m driver, that is:
 *
 * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
 * Pawel Osciak, <pawel@osciak.com>
 * Marek Szyprowski, <m.szyprowski@samsung.com>
 */

#include <linux/platform_device.h>
#include <linux/of_reserved_mem.h>
#include <linux/of_device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/soc/sunxi/sunxi_sram.h>

#include <media/videobuf2-core.h>
#include <media/v4l2-mem2mem.h>

#include "cedrus.h"
#include "cedrus_hw.h"
#include "cedrus_regs.h"

int cedrus_engine_enable(struct cedrus_dev *dev, enum cedrus_codec codec)
{
	u32 reg = 0;

	/*
	 * FIXME: This is only valid on 32-bits DDR's, we should test
	 * it on the A13/A33.
	 */
	reg |= VE_MODE_REC_WR_MODE_2MB;
	reg |= VE_MODE_DDR_MODE_BW_128;

	switch (codec) {
	case CEDRUS_CODEC_MPEG2:
		reg |= VE_MODE_DEC_MPEG;
		break;

	default:
		return -EINVAL;
	}

	cedrus_write(dev, VE_MODE, reg);

	return 0;
}

void cedrus_engine_disable(struct cedrus_dev *dev)
{
	cedrus_write(dev, VE_MODE, VE_MODE_DISABLED);
}

void cedrus_dst_format_set(struct cedrus_dev *dev,
			   struct v4l2_pix_format *fmt)
{
	unsigned int width = fmt->width;
	unsigned int height = fmt->height;
	u32 chroma_size;
	u32 reg;

	switch (fmt->pixelformat) {
	case V4L2_PIX_FMT_NV12:
		chroma_size = ALIGN(width, 16) * ALIGN(height, 16) / 2;

		reg = VE_PRIMARY_OUT_FMT_NV12;
		cedrus_write(dev, VE_PRIMARY_OUT_FMT, reg);

		reg = VE_CHROMA_BUF_LEN_SDRT(chroma_size / 2);
		cedrus_write(dev, VE_CHROMA_BUF_LEN, reg);

		reg = chroma_size / 2;
		cedrus_write(dev, VE_PRIMARY_CHROMA_BUF_LEN, reg);

		reg = VE_PRIMARY_FB_LINE_STRIDE_LUMA(ALIGN(width, 16)) |
		      VE_PRIMARY_FB_LINE_STRIDE_CHROMA(ALIGN(width, 16) / 2);
		cedrus_write(dev, VE_PRIMARY_FB_LINE_STRIDE, reg);

		break;
	case V4L2_PIX_FMT_SUNXI_TILED_NV12:
	default:
		reg = VE_PRIMARY_OUT_FMT_TILED_32_NV12;
		cedrus_write(dev, VE_PRIMARY_OUT_FMT, reg);

		reg = VE_SECONDARY_OUT_FMT_TILED_32_NV12;
		cedrus_write(dev, VE_CHROMA_BUF_LEN, reg);

		break;
	}
}

static irqreturn_t cedrus_bh(int irq, void *data)
{
	struct cedrus_dev *dev = data;
	struct cedrus_ctx *ctx;

	ctx = v4l2_m2m_get_curr_priv(dev->m2m_dev);
	if (!ctx) {
		v4l2_err(&dev->v4l2_dev,
			 "Instance released before the end of transaction\n");
		return IRQ_HANDLED;
	}

	v4l2_m2m_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx);

	return IRQ_HANDLED;
}

static irqreturn_t cedrus_irq(int irq, void *data)
{
	struct cedrus_dev *dev = data;
	struct cedrus_ctx *ctx;
	struct vb2_v4l2_buffer *src_buf, *dst_buf;
	enum vb2_buffer_state state;
	enum cedrus_irq_status status;
	unsigned long flags;

	spin_lock_irqsave(&dev->irq_lock, flags);

	ctx = v4l2_m2m_get_curr_priv(dev->m2m_dev);
	if (!ctx) {
		v4l2_err(&dev->v4l2_dev,
			 "Instance released before the end of transaction\n");
		spin_unlock_irqrestore(&dev->irq_lock, flags);

		return IRQ_NONE;
	}

	status = dev->dec_ops[ctx->current_codec]->irq_status(ctx);
	if (status == CEDRUS_IRQ_NONE) {
		spin_unlock_irqrestore(&dev->irq_lock, flags);
		return IRQ_NONE;
	}

	dev->dec_ops[ctx->current_codec]->irq_disable(ctx);
	dev->dec_ops[ctx->current_codec]->irq_clear(ctx);

	src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);

	if (!src_buf || !dst_buf) {
		v4l2_err(&dev->v4l2_dev,
			 "Missing source and/or destination buffers\n");
		spin_unlock_irqrestore(&dev->irq_lock, flags);

		return IRQ_HANDLED;
	}

	if (status == CEDRUS_IRQ_ERROR)
		state = VB2_BUF_STATE_ERROR;
	else
		state = VB2_BUF_STATE_DONE;

	v4l2_m2m_buf_done(src_buf, state);
	v4l2_m2m_buf_done(dst_buf, state);

	spin_unlock_irqrestore(&dev->irq_lock, flags);

	return IRQ_WAKE_THREAD;
}

int cedrus_hw_probe(struct cedrus_dev *dev)
{
	const struct cedrus_variant *variant;
	struct resource *res;
	int irq_dec;
	int ret;

	variant = of_device_get_match_data(dev->dev);
	if (!variant)
		return -EINVAL;

	dev->capabilities = variant->capabilities;

	irq_dec = platform_get_irq(dev->pdev, 0);
	if (irq_dec <= 0) {
		v4l2_err(&dev->v4l2_dev, "Failed to get IRQ\n");

		return irq_dec;
	}
	ret = devm_request_threaded_irq(dev->dev, irq_dec, cedrus_irq,
					cedrus_bh, 0, dev_name(dev->dev),
					dev);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to request IRQ\n");

		return ret;
	}

	/*
	 * The VPU is only able to handle bus addresses so we have to subtract
	 * the RAM offset to the physcal addresses.
	 *
	 * This information will eventually be obtained from device-tree.
	 */

#ifdef PHYS_PFN_OFFSET
	dev->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
#endif

	ret = of_reserved_mem_device_init(dev->dev);
	if (ret && ret != -ENODEV) {
		v4l2_err(&dev->v4l2_dev, "Failed to reserve memory\n");

		return ret;
	}

	ret = sunxi_sram_claim(dev->dev);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to claim SRAM\n");

		goto err_mem;
	}

	dev->ahb_clk = devm_clk_get(dev->dev, "ahb");
	if (IS_ERR(dev->ahb_clk)) {
		v4l2_err(&dev->v4l2_dev, "Failed to get AHB clock\n");

		ret = PTR_ERR(dev->ahb_clk);
		goto err_sram;
	}

	dev->mod_clk = devm_clk_get(dev->dev, "mod");
	if (IS_ERR(dev->mod_clk)) {
		v4l2_err(&dev->v4l2_dev, "Failed to get MOD clock\n");

		ret = PTR_ERR(dev->mod_clk);
		goto err_sram;
	}

	dev->ram_clk = devm_clk_get(dev->dev, "ram");
	if (IS_ERR(dev->ram_clk)) {
		v4l2_err(&dev->v4l2_dev, "Failed to get RAM clock\n");

		ret = PTR_ERR(dev->ram_clk);
		goto err_sram;
	}

	dev->rstc = devm_reset_control_get(dev->dev, NULL);
	if (IS_ERR(dev->rstc)) {
		v4l2_err(&dev->v4l2_dev, "Failed to get reset control\n");

		ret = PTR_ERR(dev->rstc);
		goto err_sram;
	}

	res = platform_get_resource(dev->pdev, IORESOURCE_MEM, 0);
	dev->base = devm_ioremap_resource(dev->dev, res);
	if (!dev->base) {
		v4l2_err(&dev->v4l2_dev, "Failed to map registers\n");

		ret = -ENOMEM;
		goto err_sram;
	}

	ret = clk_set_rate(dev->mod_clk, CEDRUS_CLOCK_RATE_DEFAULT);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to set clock rate\n");

		goto err_sram;
	}

	ret = clk_prepare_enable(dev->ahb_clk);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to enable AHB clock\n");

		goto err_sram;
	}

	ret = clk_prepare_enable(dev->mod_clk);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to enable MOD clock\n");

		goto err_ahb_clk;
	}

	ret = clk_prepare_enable(dev->ram_clk);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to enable RAM clock\n");

		goto err_mod_clk;
	}

	ret = reset_control_reset(dev->rstc);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to apply reset\n");

		goto err_ram_clk;
	}

	return 0;

err_ram_clk:
	clk_disable_unprepare(dev->ram_clk);
err_mod_clk:
	clk_disable_unprepare(dev->mod_clk);
err_ahb_clk:
	clk_disable_unprepare(dev->ahb_clk);
err_sram:
	sunxi_sram_release(dev->dev);
err_mem:
	of_reserved_mem_device_release(dev->dev);

	return ret;
}

void cedrus_hw_remove(struct cedrus_dev *dev)
{
	reset_control_assert(dev->rstc);

	clk_disable_unprepare(dev->ram_clk);
	clk_disable_unprepare(dev->mod_clk);
	clk_disable_unprepare(dev->ahb_clk);

	sunxi_sram_release(dev->dev);

	of_reserved_mem_device_release(dev->dev);
}