drivers/gpu/ipu-v3/ipu-pre.c - linux-mtk - Git at Google

 /*
  * 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_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;
 	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_CONSUMER);
 			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_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,
 		       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;

 	/* calculate safe window for ctrl register updates */
 	if (modifier == DRM_FORMAT_MOD_LINEAR)
 		pre->safe_window_end = height - 2;
 	else
 		pre->safe_window_end = DIV_ROUND_UP(height, 4) - 1;

 	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_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 (info->cpp[0] == 2)
 			val |= IPU_PRE_TPR_CTRL_TILE_FORMAT_16_BIT;
 	}
 	writel(val, pre->regs + IPU_PRE_TPR_CTRL);

 	val = readl(pre->regs + IPU_PRE_CTRL);
 	val |= IPU_PRE_CTRL_EN_REPEAT | IPU_PRE_CTRL_ENABLE |
 	       IPU_PRE_CTRL_SDW_UPDATE;
 	if (modifier == DRM_FORMAT_MOD_LINEAR)
 		val &= ~IPU_PRE_CTRL_BLOCK_EN;
 	else
 		val |= IPU_PRE_CTRL_BLOCK_EN;
 	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,
 	},
 };
	/*
	* 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_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;
	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_CONSUMER);
	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_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,
	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;

	/* calculate safe window for ctrl register updates */
	if (modifier == DRM_FORMAT_MOD_LINEAR)
	pre->safe_window_end = height - 2;
	else
	pre->safe_window_end = DIV_ROUND_UP(height, 4) - 1;

	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_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 (info->cpp[0] == 2)
	val \|= IPU_PRE_TPR_CTRL_TILE_FORMAT_16_BIT;
	}
	writel(val, pre->regs + IPU_PRE_TPR_CTRL);

	val = readl(pre->regs + IPU_PRE_CTRL);
	val \|= IPU_PRE_CTRL_EN_REPEAT \| IPU_PRE_CTRL_ENABLE \|
	IPU_PRE_CTRL_SDW_UPDATE;
	if (modifier == DRM_FORMAT_MOD_LINEAR)
	val &= ~IPU_PRE_CTRL_BLOCK_EN;
	else
	val \|= IPU_PRE_CTRL_BLOCK_EN;
	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,
	},
	};