/*
 * Copyright (c) 2017 Lucas Stach, Pengutronix
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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 <drm/drm_fourcc.h>
#include <linux/clk.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_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;
	bool			in_use;
	unsigned int		safe_window_end;
	unsigned int		last_bufaddr;
};

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 = 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);
			of_node_put(pre_node);
			return pre;
		}
	}
	mutex_unlock(&ipu_pre_list_mutex);

	of_node_put(pre_node);

	return NULL;
}

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

	if (pre->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_BLOCK_16 | IPU_PRE_CTRL_SDW_UPDATE;
	writel(val, pre->regs + IPU_PRE_CTRL);

	pre->in_use = true;
	return 0;
}

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

	pre->in_use = false;
}

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

	/* calculate safe window for ctrl register updates */
	pre->safe_window_end = height - 2;

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

	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);

	val = readl(pre->regs + IPU_PRE_CTRL);
	val |= IPU_PRE_CTRL_EN_REPEAT | IPU_PRE_CTRL_ENABLE |
	       IPU_PRE_CTRL_SDW_UPDATE;
	writel(val, pre->regs + IPU_PRE_CTRL);
}

void ipu_pre_update(struct ipu_pre *pre, unsigned int bufaddr)
{
	unsigned long timeout = jiffies + msecs_to_jiffies(5);
	unsigned short current_yblock;
	u32 val;

	if (bufaddr == pre->last_bufaddr)
		return;

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

	do {
		if (time_after(jiffies, timeout)) {
			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;
	} while (current_yblock == 0 || current_yblock >= pre->safe_window_end);

	writel(IPU_PRE_CTRL_SDW_UPDATE, pre->regs + IPU_PRE_CTRL_SET);
}

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 resource *res;
	struct ipu_pre *pre;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	pre->regs = devm_ioremap_resource(&pdev->dev, res);
	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 int 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);
	return 0;
}

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		= ipu_pre_remove,
	.driver		= {
		.name	= "imx-ipu-pre",
		.of_match_table = ipu_pre_dt_ids,
	},
};