// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2017 Lucas Stach, Pengutronix
 */

#include <drm/drm_fourcc.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/genalloc.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <video/imx-ipu-v3.h>

#include "ipu-prv.h"

#define IPU_PRE_MAX_WIDTH	2048
#define IPU_PRE_NUM_SCANLINES	8

#define IPU_PRE_CTRL					0x000
#define IPU_PRE_CTRL_SET				0x004
#define  IPU_PRE_CTRL_ENABLE				(1 << 0)
#define  IPU_PRE_CTRL_BLOCK_EN				(1 << 1)
#define  IPU_PRE_CTRL_BLOCK_16				(1 << 2)
#define  IPU_PRE_CTRL_SDW_UPDATE			(1 << 4)
#define  IPU_PRE_CTRL_VFLIP				(1 << 5)
#define  IPU_PRE_CTRL_SO				(1 << 6)
#define  IPU_PRE_CTRL_INTERLACED_FIELD			(1 << 7)
#define  IPU_PRE_CTRL_HANDSHAKE_EN			(1 << 8)
#define  IPU_PRE_CTRL_HANDSHAKE_LINE_NUM(v)		((v & 0x3) << 9)
#define  IPU_PRE_CTRL_HANDSHAKE_ABORT_SKIP_EN		(1 << 11)
#define  IPU_PRE_CTRL_EN_REPEAT				(1 << 28)
#define  IPU_PRE_CTRL_TPR_REST_SEL			(1 << 29)
#define  IPU_PRE_CTRL_CLKGATE				(1 << 30)
#define  IPU_PRE_CTRL_SFTRST				(1 << 31)

#define IPU_PRE_CUR_BUF					0x030

#define IPU_PRE_NEXT_BUF				0x040

#define IPU_PRE_TPR_CTRL				0x070
#define  IPU_PRE_TPR_CTRL_TILE_FORMAT(v)		((v & 0xff) << 0)
#define  IPU_PRE_TPR_CTRL_TILE_FORMAT_MASK		0xff
#define  IPU_PRE_TPR_CTRL_TILE_FORMAT_16_BIT		(1 << 0)
#define  IPU_PRE_TPR_CTRL_TILE_FORMAT_SPLIT_BUF		(1 << 4)
#define  IPU_PRE_TPR_CTRL_TILE_FORMAT_SINGLE_BUF	(1 << 5)
#define  IPU_PRE_TPR_CTRL_TILE_FORMAT_SUPER_TILED	(1 << 6)

#define IPU_PRE_PREFETCH_ENG_CTRL			0x080
#define  IPU_PRE_PREF_ENG_CTRL_PREFETCH_EN		(1 << 0)
#define  IPU_PRE_PREF_ENG_CTRL_RD_NUM_BYTES(v)		((v & 0x7) << 1)
#define  IPU_PRE_PREF_ENG_CTRL_INPUT_ACTIVE_BPP(v)	((v & 0x3) << 4)
#define  IPU_PRE_PREF_ENG_CTRL_INPUT_PIXEL_FORMAT(v)	((v & 0x7) << 8)
#define  IPU_PRE_PREF_ENG_CTRL_SHIFT_BYPASS		(1 << 11)
#define  IPU_PRE_PREF_ENG_CTRL_FIELD_INVERSE		(1 << 12)
#define  IPU_PRE_PREF_ENG_CTRL_PARTIAL_UV_SWAP		(1 << 14)
#define  IPU_PRE_PREF_ENG_CTRL_TPR_COOR_OFFSET_EN	(1 << 15)

#define IPU_PRE_PREFETCH_ENG_INPUT_SIZE			0x0a0
#define  IPU_PRE_PREFETCH_ENG_INPUT_SIZE_WIDTH(v)	((v & 0xffff) << 0)
#define  IPU_PRE_PREFETCH_ENG_INPUT_SIZE_HEIGHT(v)	((v & 0xffff) << 16)

#define IPU_PRE_PREFETCH_ENG_PITCH			0x0d0
#define  IPU_PRE_PREFETCH_ENG_PITCH_Y(v)		((v & 0xffff) << 0)
#define  IPU_PRE_PREFETCH_ENG_PITCH_UV(v)		((v & 0xffff) << 16)

#define IPU_PRE_STORE_ENG_CTRL				0x110
#define  IPU_PRE_STORE_ENG_CTRL_STORE_EN		(1 << 0)
#define  IPU_PRE_STORE_ENG_CTRL_WR_NUM_BYTES(v)		((v & 0x7) << 1)
#define  IPU_PRE_STORE_ENG_CTRL_OUTPUT_ACTIVE_BPP(v)	((v & 0x3) << 4)

#define IPU_PRE_STORE_ENG_STATUS			0x120
#define  IPU_PRE_STORE_ENG_STATUS_STORE_BLOCK_X_MASK	0xffff
#define  IPU_PRE_STORE_ENG_STATUS_STORE_BLOCK_X_SHIFT	0
#define  IPU_PRE_STORE_ENG_STATUS_STORE_BLOCK_Y_MASK	0x3fff
#define  IPU_PRE_STORE_ENG_STATUS_STORE_BLOCK_Y_SHIFT	16
#define  IPU_PRE_STORE_ENG_STATUS_STORE_FIFO_FULL	(1 << 30)
#define  IPU_PRE_STORE_ENG_STATUS_STORE_FIELD		(1 << 31)

#define IPU_PRE_STORE_ENG_SIZE				0x130
#define  IPU_PRE_STORE_ENG_SIZE_INPUT_WIDTH(v)		((v & 0xffff) << 0)
#define  IPU_PRE_STORE_ENG_SIZE_INPUT_HEIGHT(v)		((v & 0xffff) << 16)

#define IPU_PRE_STORE_ENG_PITCH				0x140
#define  IPU_PRE_STORE_ENG_PITCH_OUT_PITCH(v)		((v & 0xffff) << 0)

#define IPU_PRE_STORE_ENG_ADDR				0x150

struct ipu_pre {
	struct list_head	list;
	struct device		*dev;

	void __iomem		*regs;
	struct clk		*clk_axi;
	struct gen_pool		*iram;

	dma_addr_t		buffer_paddr;
	void			*buffer_virt;

	struct {
		bool		in_use;
		uint64_t	modifier;
		unsigned int	height;
		unsigned int	safe_window_end;
		unsigned int	bufaddr;
		u32		ctrl;
		u8		cpp;
	} cur;
};

static DEFINE_MUTEX(ipu_pre_list_mutex);
static LIST_HEAD(ipu_pre_list);
static int available_pres;

int ipu_pre_get_available_count(void)
{
	return available_pres;
}

struct ipu_pre *
ipu_pre_lookup_by_phandle(struct device *dev, const char *name, int index)
{
	struct device_node *pre_node __free(device_node) =
		of_parse_phandle(dev->of_node, name, index);
	struct ipu_pre *pre;

	mutex_lock(&ipu_pre_list_mutex);
	list_for_each_entry(pre, &ipu_pre_list, list) {
		if (pre_node == pre->dev->of_node) {
			mutex_unlock(&ipu_pre_list_mutex);
			device_link_add(dev, pre->dev,
					DL_FLAG_AUTOREMOVE_CONSUMER);
			return pre;
		}
	}
	mutex_unlock(&ipu_pre_list_mutex);

	return NULL;
}

int ipu_pre_get(struct ipu_pre *pre)
{
	u32 val;

	if (pre->cur.in_use)
		return -EBUSY;

	/* first get the engine out of reset and remove clock gating */
	writel(0, pre->regs + IPU_PRE_CTRL);

	/* init defaults that should be applied to all streams */
	val = IPU_PRE_CTRL_HANDSHAKE_ABORT_SKIP_EN |
	      IPU_PRE_CTRL_HANDSHAKE_EN |
	      IPU_PRE_CTRL_TPR_REST_SEL |
	      IPU_PRE_CTRL_SDW_UPDATE;
	writel(val, pre->regs + IPU_PRE_CTRL);

	pre->cur.in_use = true;
	return 0;
}

void ipu_pre_put(struct ipu_pre *pre)
{
	writel(IPU_PRE_CTRL_SFTRST, pre->regs + IPU_PRE_CTRL);

	pre->cur.in_use = false;
}

static inline void
ipu_pre_update_safe_window(struct ipu_pre *pre)
{
	if (pre->cur.modifier == DRM_FORMAT_MOD_LINEAR)
		pre->cur.safe_window_end = pre->cur.height - 2;
	else
		pre->cur.safe_window_end = DIV_ROUND_UP(pre->cur.height, 4) - 1;
}

static void
ipu_pre_configure_modifier(struct ipu_pre *pre, uint64_t modifier)
{
	u32 val;

	val = readl(pre->regs + IPU_PRE_TPR_CTRL);
	val &= ~IPU_PRE_TPR_CTRL_TILE_FORMAT_MASK;
	if (modifier != DRM_FORMAT_MOD_LINEAR) {
		/* only support single buffer formats for now */
		val |= IPU_PRE_TPR_CTRL_TILE_FORMAT_SINGLE_BUF;
		if (modifier == DRM_FORMAT_MOD_VIVANTE_SUPER_TILED)
			val |= IPU_PRE_TPR_CTRL_TILE_FORMAT_SUPER_TILED;
		if (pre->cur.cpp == 2)
			val |= IPU_PRE_TPR_CTRL_TILE_FORMAT_16_BIT;
	}
	writel(val, pre->regs + IPU_PRE_TPR_CTRL);

	if (modifier == DRM_FORMAT_MOD_LINEAR)
		pre->cur.ctrl &= ~IPU_PRE_CTRL_BLOCK_EN;
	else
		pre->cur.ctrl |= IPU_PRE_CTRL_BLOCK_EN;

	pre->cur.modifier = modifier;
}

void ipu_pre_configure(struct ipu_pre *pre, unsigned int width,
		       unsigned int height, unsigned int stride, u32 format,
		       uint64_t modifier, unsigned int bufaddr)
{
	const struct drm_format_info *info = drm_format_info(format);
	u32 active_bpp = info->cpp[0] >> 1;
	u32 val;

	pre->cur.bufaddr = bufaddr;
	pre->cur.height = height;
	pre->cur.cpp = info->cpp[0];
	pre->cur.ctrl = readl(pre->regs + IPU_PRE_CTRL);

	/* calculate safe window for ctrl register updates */
	ipu_pre_update_safe_window(pre);

	writel(bufaddr, pre->regs + IPU_PRE_CUR_BUF);
	writel(bufaddr, pre->regs + IPU_PRE_NEXT_BUF);

	val = IPU_PRE_PREF_ENG_CTRL_INPUT_PIXEL_FORMAT(0) |
	      IPU_PRE_PREF_ENG_CTRL_INPUT_ACTIVE_BPP(active_bpp) |
	      IPU_PRE_PREF_ENG_CTRL_RD_NUM_BYTES(4) |
	      IPU_PRE_PREF_ENG_CTRL_SHIFT_BYPASS |
	      IPU_PRE_PREF_ENG_CTRL_PREFETCH_EN;
	writel(val, pre->regs + IPU_PRE_PREFETCH_ENG_CTRL);

	val = IPU_PRE_PREFETCH_ENG_INPUT_SIZE_WIDTH(width) |
	      IPU_PRE_PREFETCH_ENG_INPUT_SIZE_HEIGHT(height);
	writel(val, pre->regs + IPU_PRE_PREFETCH_ENG_INPUT_SIZE);

	val = IPU_PRE_PREFETCH_ENG_PITCH_Y(stride);
	writel(val, pre->regs + IPU_PRE_PREFETCH_ENG_PITCH);

	val = IPU_PRE_STORE_ENG_CTRL_OUTPUT_ACTIVE_BPP(active_bpp) |
	      IPU_PRE_STORE_ENG_CTRL_WR_NUM_BYTES(4) |
	      IPU_PRE_STORE_ENG_CTRL_STORE_EN;
	writel(val, pre->regs + IPU_PRE_STORE_ENG_CTRL);

	val = IPU_PRE_STORE_ENG_SIZE_INPUT_WIDTH(width) |
	      IPU_PRE_STORE_ENG_SIZE_INPUT_HEIGHT(height);
	writel(val, pre->regs + IPU_PRE_STORE_ENG_SIZE);

	val = IPU_PRE_STORE_ENG_PITCH_OUT_PITCH(stride);
	writel(val, pre->regs + IPU_PRE_STORE_ENG_PITCH);

	writel(pre->buffer_paddr, pre->regs + IPU_PRE_STORE_ENG_ADDR);

	ipu_pre_configure_modifier(pre, modifier);

	pre->cur.ctrl |= IPU_PRE_CTRL_EN_REPEAT | IPU_PRE_CTRL_ENABLE;
	writel(pre->cur.ctrl | IPU_PRE_CTRL_SDW_UPDATE,
	       pre->regs + IPU_PRE_CTRL);
}

void ipu_pre_update(struct ipu_pre *pre, uint64_t modifier, unsigned int bufaddr)
{
	if (bufaddr == pre->cur.bufaddr &&
	    modifier == pre->cur.modifier)
		return;

	writel(bufaddr, pre->regs + IPU_PRE_NEXT_BUF);
	pre->cur.bufaddr = bufaddr;

	if (modifier != pre->cur.modifier)
		ipu_pre_configure_modifier(pre, modifier);

	for (int i = 0;; i++) {
		unsigned short current_yblock;
		u32 val;

		if (i > 500) {
			dev_warn(pre->dev, "timeout waiting for PRE safe window\n");
			return;
		}

		val = readl(pre->regs + IPU_PRE_STORE_ENG_STATUS);
		current_yblock =
			(val >> IPU_PRE_STORE_ENG_STATUS_STORE_BLOCK_Y_SHIFT) &
			IPU_PRE_STORE_ENG_STATUS_STORE_BLOCK_Y_MASK;

		if (current_yblock != 0 &&
		    current_yblock < pre->cur.safe_window_end)
			break;

		udelay(10);
		cpu_relax();
	}

	writel(pre->cur.ctrl | IPU_PRE_CTRL_SDW_UPDATE,
	       pre->regs + IPU_PRE_CTRL);

	/* calculate safe window for the next update with the new modifier */
	ipu_pre_update_safe_window(pre);
}

bool ipu_pre_update_pending(struct ipu_pre *pre)
{
	return !!(readl_relaxed(pre->regs + IPU_PRE_CTRL) &
		  IPU_PRE_CTRL_SDW_UPDATE);
}

u32 ipu_pre_get_baddr(struct ipu_pre *pre)
{
	return (u32)pre->buffer_paddr;
}

static int ipu_pre_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct ipu_pre *pre;

	pre = devm_kzalloc(dev, sizeof(*pre), GFP_KERNEL);
	if (!pre)
		return -ENOMEM;

	pre->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(pre->regs))
		return PTR_ERR(pre->regs);

	pre->clk_axi = devm_clk_get(dev, "axi");
	if (IS_ERR(pre->clk_axi))
		return PTR_ERR(pre->clk_axi);

	pre->iram = of_gen_pool_get(dev->of_node, "fsl,iram", 0);
	if (!pre->iram)
		return -EPROBE_DEFER;

	/*
	 * Allocate IRAM buffer with maximum size. This could be made dynamic,
	 * but as there is no other user of this IRAM region and we can fit all
	 * max sized buffers into it, there is no need yet.
	 */
	pre->buffer_virt = gen_pool_dma_alloc(pre->iram, IPU_PRE_MAX_WIDTH *
					      IPU_PRE_NUM_SCANLINES * 4,
					      &pre->buffer_paddr);
	if (!pre->buffer_virt)
		return -ENOMEM;

	clk_prepare_enable(pre->clk_axi);

	pre->dev = dev;
	platform_set_drvdata(pdev, pre);
	mutex_lock(&ipu_pre_list_mutex);
	list_add(&pre->list, &ipu_pre_list);
	available_pres++;
	mutex_unlock(&ipu_pre_list_mutex);

	return 0;
}

static void ipu_pre_remove(struct platform_device *pdev)
{
	struct ipu_pre *pre = platform_get_drvdata(pdev);

	mutex_lock(&ipu_pre_list_mutex);
	list_del(&pre->list);
	available_pres--;
	mutex_unlock(&ipu_pre_list_mutex);

	clk_disable_unprepare(pre->clk_axi);

	if (pre->buffer_virt)
		gen_pool_free(pre->iram, (unsigned long)pre->buffer_virt,
			      IPU_PRE_MAX_WIDTH * IPU_PRE_NUM_SCANLINES * 4);
}

static const struct of_device_id ipu_pre_dt_ids[] = {
	{ .compatible = "fsl,imx6qp-pre", },
	{ /* sentinel */ },
};

struct platform_driver ipu_pre_drv = {
	.probe		= ipu_pre_probe,
	.remove_new	= ipu_pre_remove,
	.driver		= {
		.name	= "imx-ipu-pre",
		.of_match_table = ipu_pre_dt_ids,
	},
};