drivers/gpu/imx/dcss/dcss-ctxld.c - linux-imx - Git at Google

 /*
  * Copyright (C) 2017 NXP
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
  * Free Software Foundation; either version 2 of the License, or (at your
  * option) any later version.
  *
  * 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/device.h>
 #include <linux/bitops.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/sizes.h>
 #include <linux/io.h>
 #include <linux/dma-mapping.h>
 #include <linux/delay.h>
 #include <asm/cacheflush.h>

 #include "video/imx-dcss.h"
 #include "dcss-prv.h"

 #define DCSS_CTXLD_DEVNAME		"dcss_ctxld"

 #define DCSS_CTXLD_CONTROL_STATUS	0x0
 #define   CTXLD_ENABLE			BIT(0)
 #define   ARB_SEL			BIT(1)
 #define   RD_ERR_EN			BIT(2)
 #define   DB_COMP_EN			BIT(3)
 #define   SB_HP_COMP_EN			BIT(4)
 #define   SB_LP_COMP_EN			BIT(5)
 #define   DB_PEND_SB_REC_EN		BIT(6)
 #define   SB_PEND_DISP_ACTIVE_EN	BIT(7)
 #define   AHB_ERR_EN			BIT(8)
 #define   RD_ERR			BIT(16)
 #define   DB_COMP			BIT(17)
 #define   SB_HP_COMP			BIT(18)
 #define   SB_LP_COMP			BIT(19)
 #define   DB_PEND_SB_REC		BIT(20)
 #define   SB_PEND_DISP_ACTIVE		BIT(21)
 #define   AHB_ERR			BIT(22)
 #define DCSS_CTXLD_DB_BASE_ADDR		0x10
 #define DCSS_CTXLD_DB_COUNT		0x14
 #define DCSS_CTXLD_SB_BASE_ADDR		0x18
 #define DCSS_CTXLD_SB_COUNT		0x1C
 #define   SB_HP_COUNT_POS		0
 #define   SB_HP_COUNT_MASK		0xffff
 #define   SB_LP_COUNT_POS		16
 #define   SB_LP_COUNT_MASK		0xffff0000
 #define DCSS_AHB_ERR_ADDR		0x20

 #define CTXLD_IRQ_NAME			"ctx_ld" /* irq steer irq name */
 #define CTXLD_IRQ_COMPLETION		(DB_COMP | SB_HP_COMP | SB_LP_COMP)
 #define CTXLD_IRQ_ERROR			(RD_ERR | DB_PEND_SB_REC | AHB_ERR)

 /* The following sizes are in entries, 8 bytes each */
 #define CTXLD_DB_CTX_ENTRIES		1024	/* max 65536 */
 #define CTXLD_SB_LP_CTX_ENTRIES		10240	/* max 65536 */
 #define CTXLD_SB_HP_CTX_ENTRIES		20000	/* max 65536 */
 #define CTXLD_SB_CTX_ENTRIES		(CTXLD_SB_LP_CTX_ENTRIES + \
 					 CTXLD_SB_HP_CTX_ENTRIES)

 static struct dcss_debug_reg ctxld_debug_reg[] = {
 	DCSS_DBG_REG(DCSS_CTXLD_CONTROL_STATUS),
 	DCSS_DBG_REG(DCSS_CTXLD_DB_BASE_ADDR),
 	DCSS_DBG_REG(DCSS_CTXLD_DB_COUNT),
 	DCSS_DBG_REG(DCSS_CTXLD_SB_BASE_ADDR),
 	DCSS_DBG_REG(DCSS_CTXLD_SB_COUNT),
 	DCSS_DBG_REG(DCSS_AHB_ERR_ADDR),
 };

 /* Sizes, in entries, of the DB, SB_HP and SB_LP context regions. */
 static u16 dcss_ctxld_ctx_size[3] = {
 	CTXLD_DB_CTX_ENTRIES,
 	CTXLD_SB_HP_CTX_ENTRIES,
 	CTXLD_SB_LP_CTX_ENTRIES
 };

 /* this represents an entry in the context loader map */
 struct dcss_ctxld_item {
 	u32 val;
 	u32 ofs;
 };

 #define CTX_ITEM_SIZE			sizeof(struct dcss_ctxld_item)

 struct dcss_ctxld_priv {
 	struct dcss_soc *dcss;
 	void __iomem *ctxld_reg;
 	int irq;
 	bool irq_en;

 	struct dcss_ctxld_item *db[2];
 	struct dcss_ctxld_item *sb_hp[2];
 	struct dcss_ctxld_item *sb_lp[2];

 	dma_addr_t db_paddr[2];
 	dma_addr_t sb_paddr[2];

 	u16 ctx_size[2][3]; /* holds the sizes of DB, SB_HP and SB_LP ctx */
 	u8 current_ctx;

 	bool in_use;
 	bool run_again;

 	spinlock_t lock; /* protects concurent access to private data */
 };

 #ifdef CONFIG_DEBUG_FS
 void dcss_ctxld_dump_regs(struct seq_file *s, void *data)
 {
 	struct dcss_soc *dcss = data;
 	int j;

 	seq_puts(s, ">> Dumping CTXLD:\n");
 	for (j = 0; j < ARRAY_SIZE(ctxld_debug_reg); j++) {
 		seq_printf(s, "%-35s(0x%04x) -> 0x%08x\n",
 			   ctxld_debug_reg[j].name,
 			   ctxld_debug_reg[j].ofs,
 			   dcss_readl(dcss->ctxld_priv->ctxld_reg +
 				      ctxld_debug_reg[j].ofs));
 	}
 }
 #endif

 static int __dcss_ctxld_enable(struct dcss_ctxld_priv *ctxld);

 static irqreturn_t dcss_ctxld_irq_handler(int irq, void *data)
 {
 	struct dcss_ctxld_priv *priv = data;
 	u32 irq_status;

 	irq_status = dcss_readl(priv->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);

 	if (irq_status & CTXLD_IRQ_COMPLETION &&
 	    !(irq_status & CTXLD_ENABLE) && priv->in_use) {
 		priv->in_use = false;

 		if (priv->run_again) {
 			priv->run_again = false;
 			__dcss_ctxld_enable(priv);
 			goto exit;
 		}

 		if (priv->dcss->dcss_disable_callback) {
 			struct dcss_dtg_priv *dtg = priv->dcss->dtg_priv;

 			priv->dcss->dcss_disable_callback(dtg);
 		}
 	} else if (irq_status & CTXLD_IRQ_ERROR) {
 		/*
 		 * Except for throwing an error message and clearing the status
 		 * register, there's not much we can do here.
 		 */
 		dev_err(priv->dcss->dev, "ctxld: error encountered: %08x\n",
 			irq_status);
 		dev_err(priv->dcss->dev, "ctxld: db=%d, sb_hp=%d, sb_lp=%d\n",
 			priv->ctx_size[priv->current_ctx ^ 1][CTX_DB],
 			priv->ctx_size[priv->current_ctx ^ 1][CTX_SB_HP],
 			priv->ctx_size[priv->current_ctx ^ 1][CTX_SB_LP]);
 	}

 exit:
 	dcss_clr(irq_status & (CTXLD_IRQ_ERROR | CTXLD_IRQ_COMPLETION),
 		priv->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);

 	return IRQ_HANDLED;
 }

 static int dcss_ctxld_irq_config(struct dcss_ctxld_priv *ctxld)
 {
 	struct dcss_soc *dcss = ctxld->dcss;
 	struct platform_device *pdev = to_platform_device(dcss->dev);
 	int ret;

 	ctxld->irq = platform_get_irq_byname(pdev, CTXLD_IRQ_NAME);
 	if (ctxld->irq < 0) {
 		dev_err(dcss->dev, "ctxld: can't get irq number\n");
 		return ctxld->irq;
 	}

 	ret = devm_request_irq(dcss->dev, ctxld->irq,
 			       dcss_ctxld_irq_handler,
 			       IRQF_ONESHOT | IRQF_TRIGGER_RISING,
 			       DCSS_CTXLD_DEVNAME, ctxld);
 	if (ret) {
 		dev_err(dcss->dev, "ctxld: irq request failed.\n");
 		return ret;
 	}

 	ctxld->irq_en = true;

 	return 0;
 }

 void dcss_ctxld_hw_cfg(struct dcss_soc *dcss)
 {
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;

 	dcss_writel(RD_ERR_EN | SB_HP_COMP_EN |
 		    DB_PEND_SB_REC_EN | AHB_ERR_EN | RD_ERR | AHB_ERR,
 		    ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
 }

 /**
  * dcss_ctxld_alloc_ctx - Allocate context memory.
  *
  * @ctxld: Pointer to ctxld.
  *
  * Returns:
  * Zeron on success, negative errno on failure.
  */
 static int dcss_ctxld_alloc_ctx(struct dcss_ctxld_priv *ctxld)
 {
 	struct dcss_soc *dcss = ctxld->dcss;
 	struct dcss_ctxld_item *ctx;
 	int i;
 	dma_addr_t dma_handle;

 	for (i = 0; i < 2; i++) {
 		ctx = dmam_alloc_coherent(dcss->dev,
 					  CTXLD_DB_CTX_ENTRIES * sizeof(*ctx),
 					  &dma_handle, GFP_KERNEL);
 		if (!ctx)
 			return -ENOMEM;

 		ctxld->db[i] = ctx;
 		ctxld->db_paddr[i] = dma_handle;

 		ctx = dmam_alloc_coherent(dcss->dev,
 					  CTXLD_SB_CTX_ENTRIES * sizeof(*ctx),
 					  &dma_handle, GFP_KERNEL);
 		if (!ctx)
 			return -ENOMEM;

 		ctxld->sb_hp[i] = ctx;
 		ctxld->sb_lp[i] = ctx + CTXLD_SB_HP_CTX_ENTRIES;

 		ctxld->sb_paddr[i] = dma_handle;
 	}

 	return 0;
 }

 int dcss_ctxld_init(struct dcss_soc *dcss, unsigned long ctxld_base)
 {
 	struct dcss_ctxld_priv *priv;
 	int ret;

 	priv = devm_kzalloc(dcss->dev, sizeof(struct dcss_ctxld_priv),
 			    GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

 	dcss->ctxld_priv = priv;
 	priv->dcss = dcss;

 	ret = dcss_ctxld_alloc_ctx(priv);
 	if (ret) {
 		dev_err(dcss->dev, "ctxld: cannot allocate context memory.\n");
 		return ret;
 	}

 	priv->ctxld_reg = devm_ioremap(dcss->dev, ctxld_base, SZ_4K);
 	if (!priv->ctxld_reg) {
 		dev_err(dcss->dev, "ctxld: unable to remap ctxld base\n");
 		return -ENOMEM;
 	}

 	ret = dcss_ctxld_irq_config(priv);
 	if (!ret)
 		return ret;

 	dcss_ctxld_hw_cfg(dcss);

 	return 0;
 }

 void dcss_ctxld_exit(struct dcss_soc *dcss)
 {
 }

 static int __dcss_ctxld_enable(struct dcss_ctxld_priv *ctxld)
 {
 	int curr_ctx = ctxld->current_ctx;
 	u32 db_base, sb_base, sb_count;
 	u32 sb_hp_cnt, sb_lp_cnt, db_cnt;

 	if (dcss_dtrc_is_running(ctxld->dcss, 1) ||
 	    dcss_dtrc_is_running(ctxld->dcss, 2)) {
 		dcss_dtrc_switch_banks(ctxld->dcss);
 		ctxld->run_again = true;
 	}

 	sb_hp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_HP];
 	sb_lp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_LP];
 	db_cnt = ctxld->ctx_size[curr_ctx][CTX_DB];

 	/* make sure SB_LP context area comes after SB_HP */
 	if (sb_lp_cnt &&
 	    ctxld->sb_lp[curr_ctx] != ctxld->sb_hp[curr_ctx] + sb_hp_cnt) {
 		struct dcss_ctxld_item *sb_lp_adjusted;

 		sb_lp_adjusted = ctxld->sb_hp[curr_ctx] + sb_hp_cnt;

 		memcpy(sb_lp_adjusted, ctxld->sb_lp[curr_ctx],
 		       sb_lp_cnt * CTX_ITEM_SIZE);
 	}

 	db_base = db_cnt ? ctxld->db_paddr[curr_ctx] : 0;

 	dcss_writel(db_base, ctxld->ctxld_reg + DCSS_CTXLD_DB_BASE_ADDR);
 	dcss_writel(db_cnt, ctxld->ctxld_reg + DCSS_CTXLD_DB_COUNT);

 	if (sb_hp_cnt)
 		sb_count = ((sb_hp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK) |
 			   ((sb_lp_cnt << SB_LP_COUNT_POS) & SB_LP_COUNT_MASK);
 	else
 		sb_count = (sb_lp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK;

 	sb_base = sb_count ? ctxld->sb_paddr[curr_ctx] : 0;

 	dcss_writel(sb_base, ctxld->ctxld_reg + DCSS_CTXLD_SB_BASE_ADDR);
 	dcss_writel(sb_count, ctxld->ctxld_reg + DCSS_CTXLD_SB_COUNT);

 	/* enable the context loader */
 	dcss_set(CTXLD_ENABLE, ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);

 	ctxld->in_use = true;

 	/*
 	 * Toggle the current context to the alternate one so that any updates
 	 * in the modules' settings take place there.
 	 */
 	ctxld->current_ctx ^= 1;

 	ctxld->ctx_size[ctxld->current_ctx][CTX_DB] = 0;
 	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_HP] = 0;
 	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_LP] = 0;

 	return 0;
 }

 /**
  * dcss_ctxld_enable - Enable context loader module.
  *
  * @dcss: pointer to dcss_soc.
  *
  * Returns:
  * Zero on success, negative errno on failure.
  */
 int dcss_ctxld_enable(struct dcss_soc *dcss)
 {
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
 	unsigned long flags;

 	spin_lock_irqsave(&ctxld->lock, flags);
 	if (ctxld->in_use) {
 		ctxld->run_again = true;
 		spin_unlock_irqrestore(&ctxld->lock, flags);
 		return 0;
 	}

 	__dcss_ctxld_enable(ctxld);

 	spin_unlock_irqrestore(&ctxld->lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL(dcss_ctxld_enable);

 void dcss_ctxld_write_irqsafe(struct dcss_soc *dcss, u32 ctx_id, u32 val,
 			      u32 reg_ofs)
 {
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
 	int curr_ctx = ctxld->current_ctx;
 	struct dcss_ctxld_item *ctx[] = {
 		[CTX_DB] = ctxld->db[curr_ctx],
 		[CTX_SB_HP] = ctxld->sb_hp[curr_ctx],
 		[CTX_SB_LP] = ctxld->sb_lp[curr_ctx]
 	};
 	int item_idx = ctxld->ctx_size[curr_ctx][ctx_id];

 	/* if we hit this, we've got to increase the maximum context size */
 	BUG_ON(dcss_ctxld_ctx_size[ctx_id] - 1 < item_idx);

 	ctx[ctx_id][item_idx].val = val;
 	ctx[ctx_id][item_idx].ofs = reg_ofs;
 	ctxld->ctx_size[curr_ctx][ctx_id] += 1;
 }

 void dcss_ctxld_write(struct dcss_soc *dcss, u32 ctx_id, u32 val, u32 reg_ofs)
 {
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
 	unsigned long flags;

 	spin_lock_irqsave(&ctxld->lock, flags);
 	dcss_ctxld_write_irqsafe(dcss, ctx_id, val, reg_ofs);
 	spin_unlock_irqrestore(&ctxld->lock, flags);
 }

 int dcss_ctxld_resume(struct dcss_soc *dcss)
 {
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;

 	dcss_ctxld_hw_cfg(dcss);

 	if (!ctxld->irq_en) {
 		enable_irq(dcss->ctxld_priv->irq);
 		ctxld->irq_en = true;
 	}

 	return 0;
 }

 int dcss_ctxld_suspend(struct dcss_soc *dcss)
 {
 	int ret = 0;
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
 	int wait_time_ms = 0;
 	unsigned long flags;

 	while (ctxld->in_use && wait_time_ms < 500) {
 		msleep(20);
 		wait_time_ms += 20;
 	}

 	if (wait_time_ms > 500)
 		return -ETIMEDOUT;

 	spin_lock_irqsave(&ctxld->lock, flags);

 	if (ctxld->irq_en) {
 		disable_irq_nosync(dcss->ctxld_priv->irq);
 		ctxld->irq_en = false;
 	}

 	/* reset context region and sizes */
 	ctxld->current_ctx = 0;
 	ctxld->ctx_size[0][CTX_DB] = 0;
 	ctxld->ctx_size[0][CTX_SB_HP] = 0;
 	ctxld->ctx_size[0][CTX_SB_LP] = 0;

 	spin_unlock_irqrestore(&ctxld->lock, flags);
 	return ret;
 }

 #ifdef CONFIG_DEBUG_FS
 void dcss_ctxld_dump(struct seq_file *s, void *data)
 {
 	struct dcss_soc *dcss = data;
 	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
 	int curr_ctx = ctxld->current_ctx;
 	int i;
 	struct dcss_ctxld_item *ctx_db, *ctx_sb_hp, *ctx_sb_lp;
 	u32 ctx_db_size, ctx_sb_hp_size, ctx_sb_lp_size;

 	ctx_db_size = ctxld->ctx_size[curr_ctx ^ 1][CTX_DB];
 	ctx_sb_hp_size = ctxld->ctx_size[curr_ctx ^ 1][CTX_SB_HP];
 	ctx_sb_lp_size = ctxld->ctx_size[curr_ctx ^ 1][CTX_SB_LP];

 	ctx_db = ctxld->db[curr_ctx ^ 1];
 	ctx_sb_hp = ctxld->sb_hp[curr_ctx ^ 1];
 	ctx_sb_lp = ctxld->sb_hp[curr_ctx ^ 1] + ctx_sb_hp_size;

 	seq_puts(s, ">> Dumping loaded context:\n");
 	seq_puts(s, "\t>>Dumping CTX_DB:\n");
 	for (i = 0; i < ctx_db_size; i++)
 		seq_printf(s, "\t0x%16llx -> 0x%08x : 0x%08x\n",
 			   (u64)&ctx_db[i], ctx_db[i].ofs, ctx_db[i].val);
 	seq_puts(s, "\t>>Dumping CTX_SB_HP:\n");
 	for (i = 0; i < ctx_sb_hp_size; i++)
 		seq_printf(s, "\t0x%16llx -> 0x%08x : 0x%08x\n",
 			   (u64)&ctx_sb_hp[i], ctx_sb_hp[i].ofs,
 			   ctx_sb_hp[i].val);
 	seq_puts(s, "\t>>Dumping CTX_SB_LP:\n");
 	for (i = 0; i < ctx_sb_lp_size; i++)
 		seq_printf(s, "\t0x%16llx -> 0x%08x : 0x%08x\n",
 			   (u64)&ctx_sb_lp[i], ctx_sb_lp[i].ofs,
 			   ctx_sb_lp[i].val);
 }
 #endif
	/*
	* Copyright (C) 2017 NXP
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*
	* 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/device.h>
	#include <linux/bitops.h>
	#include <linux/platform_device.h>
	#include <linux/interrupt.h>
	#include <linux/sizes.h>
	#include <linux/io.h>
	#include <linux/dma-mapping.h>
	#include <linux/delay.h>
	#include <asm/cacheflush.h>

	#include "video/imx-dcss.h"
	#include "dcss-prv.h"

	#define DCSS_CTXLD_DEVNAME "dcss_ctxld"

	#define DCSS_CTXLD_CONTROL_STATUS 0x0
	#define CTXLD_ENABLE BIT(0)
	#define ARB_SEL BIT(1)
	#define RD_ERR_EN BIT(2)
	#define DB_COMP_EN BIT(3)
	#define SB_HP_COMP_EN BIT(4)
	#define SB_LP_COMP_EN BIT(5)
	#define DB_PEND_SB_REC_EN BIT(6)
	#define SB_PEND_DISP_ACTIVE_EN BIT(7)
	#define AHB_ERR_EN BIT(8)
	#define RD_ERR BIT(16)
	#define DB_COMP BIT(17)
	#define SB_HP_COMP BIT(18)
	#define SB_LP_COMP BIT(19)
	#define DB_PEND_SB_REC BIT(20)
	#define SB_PEND_DISP_ACTIVE BIT(21)
	#define AHB_ERR BIT(22)
	#define DCSS_CTXLD_DB_BASE_ADDR 0x10
	#define DCSS_CTXLD_DB_COUNT 0x14
	#define DCSS_CTXLD_SB_BASE_ADDR 0x18
	#define DCSS_CTXLD_SB_COUNT 0x1C
	#define SB_HP_COUNT_POS 0
	#define SB_HP_COUNT_MASK 0xffff
	#define SB_LP_COUNT_POS 16
	#define SB_LP_COUNT_MASK 0xffff0000
	#define DCSS_AHB_ERR_ADDR 0x20

	#define CTXLD_IRQ_NAME "ctx_ld" /* irq steer irq name */
	#define CTXLD_IRQ_COMPLETION (DB_COMP \| SB_HP_COMP \| SB_LP_COMP)
	#define CTXLD_IRQ_ERROR (RD_ERR \| DB_PEND_SB_REC \| AHB_ERR)

	/* The following sizes are in entries, 8 bytes each */
	#define CTXLD_DB_CTX_ENTRIES 1024 /* max 65536 */
	#define CTXLD_SB_LP_CTX_ENTRIES 10240 /* max 65536 */
	#define CTXLD_SB_HP_CTX_ENTRIES 20000 /* max 65536 */
	#define CTXLD_SB_CTX_ENTRIES (CTXLD_SB_LP_CTX_ENTRIES + \
	CTXLD_SB_HP_CTX_ENTRIES)

	static struct dcss_debug_reg ctxld_debug_reg[] = {
	DCSS_DBG_REG(DCSS_CTXLD_CONTROL_STATUS),
	DCSS_DBG_REG(DCSS_CTXLD_DB_BASE_ADDR),
	DCSS_DBG_REG(DCSS_CTXLD_DB_COUNT),
	DCSS_DBG_REG(DCSS_CTXLD_SB_BASE_ADDR),
	DCSS_DBG_REG(DCSS_CTXLD_SB_COUNT),
	DCSS_DBG_REG(DCSS_AHB_ERR_ADDR),
	};

	/* Sizes, in entries, of the DB, SB_HP and SB_LP context regions. */
	static u16 dcss_ctxld_ctx_size[3] = {
	CTXLD_DB_CTX_ENTRIES,
	CTXLD_SB_HP_CTX_ENTRIES,
	CTXLD_SB_LP_CTX_ENTRIES
	};

	/* this represents an entry in the context loader map */
	struct dcss_ctxld_item {
	u32 val;
	u32 ofs;
	};

	#define CTX_ITEM_SIZE sizeof(struct dcss_ctxld_item)

	struct dcss_ctxld_priv {
	struct dcss_soc *dcss;
	void __iomem *ctxld_reg;
	int irq;
	bool irq_en;

	struct dcss_ctxld_item *db[2];
	struct dcss_ctxld_item *sb_hp[2];
	struct dcss_ctxld_item *sb_lp[2];

	dma_addr_t db_paddr[2];
	dma_addr_t sb_paddr[2];

	u16 ctx_size[2][3]; /* holds the sizes of DB, SB_HP and SB_LP ctx */
	u8 current_ctx;

	bool in_use;
	bool run_again;

	spinlock_t lock; /* protects concurent access to private data */
	};

	#ifdef CONFIG_DEBUG_FS
	void dcss_ctxld_dump_regs(struct seq_file s, void data)
	{
	struct dcss_soc *dcss = data;
	int j;

	seq_puts(s, ">> Dumping CTXLD:\n");
	for (j = 0; j < ARRAY_SIZE(ctxld_debug_reg); j++) {
	seq_printf(s, "%-35s(0x%04x) -> 0x%08x\n",
	ctxld_debug_reg[j].name,
	ctxld_debug_reg[j].ofs,
	dcss_readl(dcss->ctxld_priv->ctxld_reg +
	ctxld_debug_reg[j].ofs));
	}
	}
	#endif

	static int __dcss_ctxld_enable(struct dcss_ctxld_priv *ctxld);

	static irqreturn_t dcss_ctxld_irq_handler(int irq, void *data)
	{
	struct dcss_ctxld_priv *priv = data;
	u32 irq_status;

	irq_status = dcss_readl(priv->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);

	if (irq_status & CTXLD_IRQ_COMPLETION &&
	!(irq_status & CTXLD_ENABLE) && priv->in_use) {
	priv->in_use = false;

	if (priv->run_again) {
	priv->run_again = false;
	__dcss_ctxld_enable(priv);
	goto exit;
	}

	if (priv->dcss->dcss_disable_callback) {
	struct dcss_dtg_priv *dtg = priv->dcss->dtg_priv;

	priv->dcss->dcss_disable_callback(dtg);
	}
	} else if (irq_status & CTXLD_IRQ_ERROR) {
	/*
	* Except for throwing an error message and clearing the status
	* register, there's not much we can do here.
	*/
	dev_err(priv->dcss->dev, "ctxld: error encountered: %08x\n",
	irq_status);
	dev_err(priv->dcss->dev, "ctxld: db=%d, sb_hp=%d, sb_lp=%d\n",
	priv->ctx_size[priv->current_ctx ^ 1][CTX_DB],
	priv->ctx_size[priv->current_ctx ^ 1][CTX_SB_HP],
	priv->ctx_size[priv->current_ctx ^ 1][CTX_SB_LP]);
	}

	exit:
	dcss_clr(irq_status & (CTXLD_IRQ_ERROR \| CTXLD_IRQ_COMPLETION),
	priv->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);

	return IRQ_HANDLED;
	}

	static int dcss_ctxld_irq_config(struct dcss_ctxld_priv *ctxld)
	{
	struct dcss_soc *dcss = ctxld->dcss;
	struct platform_device *pdev = to_platform_device(dcss->dev);
	int ret;

	ctxld->irq = platform_get_irq_byname(pdev, CTXLD_IRQ_NAME);
	if (ctxld->irq < 0) {
	dev_err(dcss->dev, "ctxld: can't get irq number\n");
	return ctxld->irq;
	}

	ret = devm_request_irq(dcss->dev, ctxld->irq,
	dcss_ctxld_irq_handler,
	IRQF_ONESHOT \| IRQF_TRIGGER_RISING,
	DCSS_CTXLD_DEVNAME, ctxld);
	if (ret) {
	dev_err(dcss->dev, "ctxld: irq request failed.\n");
	return ret;
	}

	ctxld->irq_en = true;

	return 0;
	}

	void dcss_ctxld_hw_cfg(struct dcss_soc *dcss)
	{
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;

	dcss_writel(RD_ERR_EN \| SB_HP_COMP_EN \|
	DB_PEND_SB_REC_EN \| AHB_ERR_EN \| RD_ERR \| AHB_ERR,
	ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);
	}

	/**
	* dcss_ctxld_alloc_ctx - Allocate context memory.
	*
	* @ctxld: Pointer to ctxld.
	*
	* Returns:
	* Zeron on success, negative errno on failure.
	*/
	static int dcss_ctxld_alloc_ctx(struct dcss_ctxld_priv *ctxld)
	{
	struct dcss_soc *dcss = ctxld->dcss;
	struct dcss_ctxld_item *ctx;
	int i;
	dma_addr_t dma_handle;

	for (i = 0; i < 2; i++) {
	ctx = dmam_alloc_coherent(dcss->dev,
	CTXLD_DB_CTX_ENTRIES * sizeof(*ctx),
	&dma_handle, GFP_KERNEL);
	if (!ctx)
	return -ENOMEM;

	ctxld->db[i] = ctx;
	ctxld->db_paddr[i] = dma_handle;

	ctx = dmam_alloc_coherent(dcss->dev,
	CTXLD_SB_CTX_ENTRIES * sizeof(*ctx),
	&dma_handle, GFP_KERNEL);
	if (!ctx)
	return -ENOMEM;

	ctxld->sb_hp[i] = ctx;
	ctxld->sb_lp[i] = ctx + CTXLD_SB_HP_CTX_ENTRIES;

	ctxld->sb_paddr[i] = dma_handle;
	}

	return 0;
	}

	int dcss_ctxld_init(struct dcss_soc *dcss, unsigned long ctxld_base)
	{
	struct dcss_ctxld_priv *priv;
	int ret;

	priv = devm_kzalloc(dcss->dev, sizeof(struct dcss_ctxld_priv),
	GFP_KERNEL);
	if (!priv)
	return -ENOMEM;

	dcss->ctxld_priv = priv;
	priv->dcss = dcss;

	ret = dcss_ctxld_alloc_ctx(priv);
	if (ret) {
	dev_err(dcss->dev, "ctxld: cannot allocate context memory.\n");
	return ret;
	}

	priv->ctxld_reg = devm_ioremap(dcss->dev, ctxld_base, SZ_4K);
	if (!priv->ctxld_reg) {
	dev_err(dcss->dev, "ctxld: unable to remap ctxld base\n");
	return -ENOMEM;
	}

	ret = dcss_ctxld_irq_config(priv);
	if (!ret)
	return ret;

	dcss_ctxld_hw_cfg(dcss);

	return 0;
	}

	void dcss_ctxld_exit(struct dcss_soc *dcss)
	{
	}

	static int __dcss_ctxld_enable(struct dcss_ctxld_priv *ctxld)
	{
	int curr_ctx = ctxld->current_ctx;
	u32 db_base, sb_base, sb_count;
	u32 sb_hp_cnt, sb_lp_cnt, db_cnt;

	if (dcss_dtrc_is_running(ctxld->dcss, 1) \|\|
	dcss_dtrc_is_running(ctxld->dcss, 2)) {
	dcss_dtrc_switch_banks(ctxld->dcss);
	ctxld->run_again = true;
	}

	sb_hp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_HP];
	sb_lp_cnt = ctxld->ctx_size[curr_ctx][CTX_SB_LP];
	db_cnt = ctxld->ctx_size[curr_ctx][CTX_DB];

	/* make sure SB_LP context area comes after SB_HP */
	if (sb_lp_cnt &&
	ctxld->sb_lp[curr_ctx] != ctxld->sb_hp[curr_ctx] + sb_hp_cnt) {
	struct dcss_ctxld_item *sb_lp_adjusted;

	sb_lp_adjusted = ctxld->sb_hp[curr_ctx] + sb_hp_cnt;

	memcpy(sb_lp_adjusted, ctxld->sb_lp[curr_ctx],
	sb_lp_cnt * CTX_ITEM_SIZE);
	}

	db_base = db_cnt ? ctxld->db_paddr[curr_ctx] : 0;

	dcss_writel(db_base, ctxld->ctxld_reg + DCSS_CTXLD_DB_BASE_ADDR);
	dcss_writel(db_cnt, ctxld->ctxld_reg + DCSS_CTXLD_DB_COUNT);

	if (sb_hp_cnt)
	sb_count = ((sb_hp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK) \|
	((sb_lp_cnt << SB_LP_COUNT_POS) & SB_LP_COUNT_MASK);
	else
	sb_count = (sb_lp_cnt << SB_HP_COUNT_POS) & SB_HP_COUNT_MASK;

	sb_base = sb_count ? ctxld->sb_paddr[curr_ctx] : 0;

	dcss_writel(sb_base, ctxld->ctxld_reg + DCSS_CTXLD_SB_BASE_ADDR);
	dcss_writel(sb_count, ctxld->ctxld_reg + DCSS_CTXLD_SB_COUNT);

	/* enable the context loader */
	dcss_set(CTXLD_ENABLE, ctxld->ctxld_reg + DCSS_CTXLD_CONTROL_STATUS);

	ctxld->in_use = true;

	/*
	* Toggle the current context to the alternate one so that any updates
	* in the modules' settings take place there.
	*/
	ctxld->current_ctx ^= 1;

	ctxld->ctx_size[ctxld->current_ctx][CTX_DB] = 0;
	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_HP] = 0;
	ctxld->ctx_size[ctxld->current_ctx][CTX_SB_LP] = 0;

	return 0;
	}

	/**
	* dcss_ctxld_enable - Enable context loader module.
	*
	* @dcss: pointer to dcss_soc.
	*
	* Returns:
	* Zero on success, negative errno on failure.
	*/
	int dcss_ctxld_enable(struct dcss_soc *dcss)
	{
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
	unsigned long flags;

	spin_lock_irqsave(&ctxld->lock, flags);
	if (ctxld->in_use) {
	ctxld->run_again = true;
	spin_unlock_irqrestore(&ctxld->lock, flags);
	return 0;
	}

	__dcss_ctxld_enable(ctxld);

	spin_unlock_irqrestore(&ctxld->lock, flags);

	return 0;
	}
	EXPORT_SYMBOL(dcss_ctxld_enable);

	void dcss_ctxld_write_irqsafe(struct dcss_soc *dcss, u32 ctx_id, u32 val,
	u32 reg_ofs)
	{
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
	int curr_ctx = ctxld->current_ctx;
	struct dcss_ctxld_item *ctx[] = {
	[CTX_DB] = ctxld->db[curr_ctx],
	[CTX_SB_HP] = ctxld->sb_hp[curr_ctx],
	[CTX_SB_LP] = ctxld->sb_lp[curr_ctx]
	};
	int item_idx = ctxld->ctx_size[curr_ctx][ctx_id];

	/* if we hit this, we've got to increase the maximum context size */
	BUG_ON(dcss_ctxld_ctx_size[ctx_id] - 1 < item_idx);

	ctx[ctx_id][item_idx].val = val;
	ctx[ctx_id][item_idx].ofs = reg_ofs;
	ctxld->ctx_size[curr_ctx][ctx_id] += 1;
	}

	void dcss_ctxld_write(struct dcss_soc *dcss, u32 ctx_id, u32 val, u32 reg_ofs)
	{
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
	unsigned long flags;

	spin_lock_irqsave(&ctxld->lock, flags);
	dcss_ctxld_write_irqsafe(dcss, ctx_id, val, reg_ofs);
	spin_unlock_irqrestore(&ctxld->lock, flags);
	}

	int dcss_ctxld_resume(struct dcss_soc *dcss)
	{
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;

	dcss_ctxld_hw_cfg(dcss);

	if (!ctxld->irq_en) {
	enable_irq(dcss->ctxld_priv->irq);
	ctxld->irq_en = true;
	}

	return 0;
	}

	int dcss_ctxld_suspend(struct dcss_soc *dcss)
	{
	int ret = 0;
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
	int wait_time_ms = 0;
	unsigned long flags;

	while (ctxld->in_use && wait_time_ms < 500) {
	msleep(20);
	wait_time_ms += 20;
	}

	if (wait_time_ms > 500)
	return -ETIMEDOUT;

	spin_lock_irqsave(&ctxld->lock, flags);

	if (ctxld->irq_en) {
	disable_irq_nosync(dcss->ctxld_priv->irq);
	ctxld->irq_en = false;
	}

	/* reset context region and sizes */
	ctxld->current_ctx = 0;
	ctxld->ctx_size[0][CTX_DB] = 0;
	ctxld->ctx_size[0][CTX_SB_HP] = 0;
	ctxld->ctx_size[0][CTX_SB_LP] = 0;

	spin_unlock_irqrestore(&ctxld->lock, flags);
	return ret;
	}

	#ifdef CONFIG_DEBUG_FS
	void dcss_ctxld_dump(struct seq_file s, void data)
	{
	struct dcss_soc *dcss = data;
	struct dcss_ctxld_priv *ctxld = dcss->ctxld_priv;
	int curr_ctx = ctxld->current_ctx;
	int i;
	struct dcss_ctxld_item ctx_db, ctx_sb_hp, *ctx_sb_lp;
	u32 ctx_db_size, ctx_sb_hp_size, ctx_sb_lp_size;

	ctx_db_size = ctxld->ctx_size[curr_ctx ^ 1][CTX_DB];
	ctx_sb_hp_size = ctxld->ctx_size[curr_ctx ^ 1][CTX_SB_HP];
	ctx_sb_lp_size = ctxld->ctx_size[curr_ctx ^ 1][CTX_SB_LP];

	ctx_db = ctxld->db[curr_ctx ^ 1];
	ctx_sb_hp = ctxld->sb_hp[curr_ctx ^ 1];
	ctx_sb_lp = ctxld->sb_hp[curr_ctx ^ 1] + ctx_sb_hp_size;

	seq_puts(s, ">> Dumping loaded context:\n");
	seq_puts(s, "\t>>Dumping CTX_DB:\n");
	for (i = 0; i < ctx_db_size; i++)
	seq_printf(s, "\t0x%16llx -> 0x%08x : 0x%08x\n",
	(u64)&ctx_db[i], ctx_db[i].ofs, ctx_db[i].val);
	seq_puts(s, "\t>>Dumping CTX_SB_HP:\n");
	for (i = 0; i < ctx_sb_hp_size; i++)
	seq_printf(s, "\t0x%16llx -> 0x%08x : 0x%08x\n",
	(u64)&ctx_sb_hp[i], ctx_sb_hp[i].ofs,
	ctx_sb_hp[i].val);
	seq_puts(s, "\t>>Dumping CTX_SB_LP:\n");
	for (i = 0; i < ctx_sb_lp_size; i++)
	seq_printf(s, "\t0x%16llx -> 0x%08x : 0x%08x\n",
	(u64)&ctx_sb_lp[i], ctx_sb_lp[i].ofs,
	ctx_sb_lp[i].val);
	}
	#endif