/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 and
   * only version 2 as published by the Free Software Foundation.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   * 02110-1301, USA.
   */
  
  #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/io.h>
  #include <linux/clk.h>
  #include <linux/iommu.h>
  #include <linux/interrupt.h>
  #include <linux/err.h>
  #include <linux/slab.h>
  
  #include <mach/iommu_hw-8xxx.h>
  #include <mach/iommu.h>

  #include <mach/clk.h>

  
  struct iommu_ctx_iter_data {
  	/* input */
  	const char *name;
  
  	/* output */
  	struct device *dev;
  };
  
  static struct platform_device *msm_iommu_root_dev;
  
  static int each_iommu_ctx(struct device *dev, void *data)
  {
  	struct iommu_ctx_iter_data *res = data;
  	struct msm_iommu_ctx_dev *c = dev->platform_data;
  
  	if (!res || !c || !c->name || !res->name)
  		return -EINVAL;
  
  	if (!strcmp(res->name, c->name)) {
  		res->dev = dev;
  		return 1;
  	}
  	return 0;
  }
  
  static int each_iommu(struct device *dev, void *data)
  {
  	return device_for_each_child(dev, data, each_iommu_ctx);
  }
  
  struct device *msm_iommu_get_ctx(const char *ctx_name)
  {
  	struct iommu_ctx_iter_data r;
  	int found;
  
  	if (!msm_iommu_root_dev) {
  		pr_err("No root IOMMU device.
  ");
  		goto fail;
  	}
  
  	r.name = ctx_name;
  	found = device_for_each_child(&msm_iommu_root_dev->dev, &r, each_iommu);
  
  	if (!found) {
  		pr_err("Could not find context <%s>
  ", ctx_name);
  		goto fail;
  	}
  
  	return r.dev;
  fail:
  	return NULL;
  }
  EXPORT_SYMBOL(msm_iommu_get_ctx);

  static void msm_iommu_reset(void __iomem *base, int ncb)

  {

  	int ctx;

  
  	SET_RPUE(base, 0);
  	SET_RPUEIE(base, 0);
  	SET_ESRRESTORE(base, 0);
  	SET_TBE(base, 0);
  	SET_CR(base, 0);
  	SET_SPDMBE(base, 0);
  	SET_TESTBUSCR(base, 0);
  	SET_TLBRSW(base, 0);
  	SET_GLOBAL_TLBIALL(base, 0);
  	SET_RPU_ACR(base, 0);
  	SET_TLBLKCRWE(base, 1);

  
  	for (ctx = 0; ctx < ncb; ctx++) {
  		SET_BPRCOSH(base, ctx, 0);
  		SET_BPRCISH(base, ctx, 0);
  		SET_BPRCNSH(base, ctx, 0);
  		SET_BPSHCFG(base, ctx, 0);
  		SET_BPMTCFG(base, ctx, 0);
  		SET_ACTLR(base, ctx, 0);
  		SET_SCTLR(base, ctx, 0);
  		SET_FSRRESTORE(base, ctx, 0);
  		SET_TTBR0(base, ctx, 0);
  		SET_TTBR1(base, ctx, 0);
  		SET_TTBCR(base, ctx, 0);
  		SET_BFBCR(base, ctx, 0);
  		SET_PAR(base, ctx, 0);
  		SET_FAR(base, ctx, 0);
  		SET_CTX_TLBIALL(base, ctx, 0);
  		SET_TLBFLPTER(base, ctx, 0);
  		SET_TLBSLPTER(base, ctx, 0);
  		SET_TLBLKCR(base, ctx, 0);
  		SET_PRRR(base, ctx, 0);
  		SET_NMRR(base, ctx, 0);
  		SET_CONTEXTIDR(base, ctx, 0);
  	}
  }
  
  static int msm_iommu_probe(struct platform_device *pdev)
  {

  	struct resource *r, *r2;

  	struct clk *iommu_clk;

  	struct clk *iommu_pclk;

  	struct msm_iommu_drvdata *drvdata;
  	struct msm_iommu_dev *iommu_dev = pdev->dev.platform_data;
  	void __iomem *regs_base;
  	resource_size_t	len;

  	int ret, irq, par;

  	if (pdev->id == -1) {
  		msm_iommu_root_dev = pdev;
  		return 0;
  	}

  	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);

  	if (!drvdata) {
  		ret = -ENOMEM;
  		goto fail;
  	}
  
  	if (!iommu_dev) {
  		ret = -ENODEV;
  		goto fail;
  	}

  	iommu_pclk = clk_get(NULL, "smmu_pclk");
  	if (IS_ERR(iommu_pclk)) {
  		ret = -ENODEV;
  		goto fail;
  	}
  
  	ret = clk_enable(iommu_pclk);
  	if (ret)
  		goto fail_enable;
  
  	iommu_clk = clk_get(&pdev->dev, "iommu_clk");
  
  	if (!IS_ERR(iommu_clk))	{
  		if (clk_get_rate(iommu_clk) == 0)
  			clk_set_min_rate(iommu_clk, 1);
  
  		ret = clk_enable(iommu_clk);
  		if (ret) {

  			clk_put(iommu_clk);

  			goto fail_pclk;

  		}

  	} else
  		iommu_clk = NULL;

  	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "physbase");

  	if (!r) {
  		ret = -ENODEV;
  		goto fail_clk;
  	}

  	len = resource_size(r);

  	r2 = request_mem_region(r->start, len, r->name);
  	if (!r2) {
  		pr_err("Could not request memory region: start=%p, len=%d
  ",
  							(void *) r->start, len);
  		ret = -EBUSY;
  		goto fail_clk;
  	}

  	regs_base = ioremap(r2->start, len);

  	if (!regs_base) {
  		pr_err("Could not ioremap: start=%p, len=%d
  ",
  			 (void *) r2->start, len);
  		ret = -EBUSY;
  		goto fail_mem;
  	}
  
  	irq = platform_get_irq_byname(pdev, "secure_irq");
  	if (irq < 0) {
  		ret = -ENODEV;
  		goto fail_io;
  	}

  	msm_iommu_reset(regs_base, iommu_dev->ncb);

  	SET_M(regs_base, 0, 1);
  	SET_PAR(regs_base, 0, 0);
  	SET_V2PCFG(regs_base, 0, 1);
  	SET_V2PPR(regs_base, 0, 0);
  	par = GET_PAR(regs_base, 0);
  	SET_V2PCFG(regs_base, 0, 0);
  	SET_M(regs_base, 0, 0);
  
  	if (!par) {
  		pr_err("%s: Invalid PAR value detected
  ", iommu_dev->name);

  		ret = -ENODEV;
  		goto fail_io;
  	}

  	ret = request_irq(irq, msm_iommu_fault_handler, 0,
  			"msm_iommu_secure_irpt_handler", drvdata);
  	if (ret) {
  		pr_err("Request IRQ %d failed with ret=%d
  ", irq, ret);
  		goto fail_io;
  	}

  	drvdata->pclk = iommu_pclk;
  	drvdata->clk = iommu_clk;
  	drvdata->base = regs_base;
  	drvdata->irq = irq;

  	drvdata->ncb = iommu_dev->ncb;

  	pr_info("device %s mapped at %p, irq %d with %d ctx banks
  ",

  		iommu_dev->name, regs_base, irq, iommu_dev->ncb);

  	platform_set_drvdata(pdev, drvdata);

  	if (iommu_clk)
  		clk_disable(iommu_clk);
  
  	clk_disable(iommu_pclk);

  	return 0;

  fail_io:
  	iounmap(regs_base);
  fail_mem:
  	release_mem_region(r->start, len);

  fail_clk:
  	if (iommu_clk) {
  		clk_disable(iommu_clk);
  		clk_put(iommu_clk);
  	}
  fail_pclk:
  	clk_disable(iommu_pclk);
  fail_enable:
  	clk_put(iommu_pclk);

  fail:
  	kfree(drvdata);
  	return ret;
  }
  
  static int msm_iommu_remove(struct platform_device *pdev)
  {
  	struct msm_iommu_drvdata *drv = NULL;
  
  	drv = platform_get_drvdata(pdev);
  	if (drv) {

  		if (drv->clk)
  			clk_put(drv->clk);
  		clk_put(drv->pclk);
  		memset(drv, 0, sizeof(*drv));

  		kfree(drv);
  		platform_set_drvdata(pdev, NULL);
  	}
  	return 0;
  }
  
  static int msm_iommu_ctx_probe(struct platform_device *pdev)
  {
  	struct msm_iommu_ctx_dev *c = pdev->dev.platform_data;
  	struct msm_iommu_drvdata *drvdata;
  	struct msm_iommu_ctx_drvdata *ctx_drvdata = NULL;

  	int i, ret;

  	if (!c || !pdev->dev.parent) {
  		ret = -EINVAL;
  		goto fail;
  	}
  
  	drvdata = dev_get_drvdata(pdev->dev.parent);
  
  	if (!drvdata) {
  		ret = -ENODEV;
  		goto fail;
  	}
  
  	ctx_drvdata = kzalloc(sizeof(*ctx_drvdata), GFP_KERNEL);
  	if (!ctx_drvdata) {
  		ret = -ENOMEM;
  		goto fail;
  	}
  	ctx_drvdata->num = c->num;
  	ctx_drvdata->pdev = pdev;
  
  	INIT_LIST_HEAD(&ctx_drvdata->attached_elm);
  	platform_set_drvdata(pdev, ctx_drvdata);

  	ret = clk_enable(drvdata->pclk);
  	if (ret)
  		goto fail;
  
  	if (drvdata->clk) {
  		ret = clk_enable(drvdata->clk);
  		if (ret) {
  			clk_disable(drvdata->pclk);
  			goto fail;
  		}
  	}

  	/* Program the M2V tables for this context */
  	for (i = 0; i < MAX_NUM_MIDS; i++) {
  		int mid = c->mids[i];
  		if (mid == -1)
  			break;
  
  		SET_M2VCBR_N(drvdata->base, mid, 0);
  		SET_CBACR_N(drvdata->base, c->num, 0);

  		/* Set VMID = 0 */
  		SET_VMID(drvdata->base, mid, 0);

  
  		/* Set the context number for that MID to this context */
  		SET_CBNDX(drvdata->base, mid, c->num);

  		/* Set MID associated with this context bank to 0*/
  		SET_CBVMID(drvdata->base, c->num, 0);
  
  		/* Set the ASID for TLB tagging for this context */
  		SET_CONTEXTIDR_ASID(drvdata->base, c->num, c->num);

  
  		/* Set security bit override to be Non-secure */
  		SET_NSCFG(drvdata->base, mid, 3);
  	}

  	if (drvdata->clk)
  		clk_disable(drvdata->clk);
  	clk_disable(drvdata->pclk);

  	dev_info(&pdev->dev, "context %s using bank %d
  ", c->name, c->num);

  	return 0;
  fail:
  	kfree(ctx_drvdata);
  	return ret;
  }
  
  static int msm_iommu_ctx_remove(struct platform_device *pdev)
  {
  	struct msm_iommu_ctx_drvdata *drv = NULL;
  	drv = platform_get_drvdata(pdev);
  	if (drv) {
  		memset(drv, 0, sizeof(struct msm_iommu_ctx_drvdata));
  		kfree(drv);
  		platform_set_drvdata(pdev, NULL);
  	}
  	return 0;
  }
  
  static struct platform_driver msm_iommu_driver = {
  	.driver = {
  		.name	= "msm_iommu",
  	},
  	.probe		= msm_iommu_probe,
  	.remove		= msm_iommu_remove,
  };
  
  static struct platform_driver msm_iommu_ctx_driver = {
  	.driver = {
  		.name	= "msm_iommu_ctx",
  	},
  	.probe		= msm_iommu_ctx_probe,
  	.remove		= msm_iommu_ctx_remove,
  };

  static int __init msm_iommu_driver_init(void)

  {
  	int ret;
  	ret = platform_driver_register(&msm_iommu_driver);
  	if (ret != 0) {
  		pr_err("Failed to register IOMMU driver
  ");
  		goto error;
  	}
  
  	ret = platform_driver_register(&msm_iommu_ctx_driver);
  	if (ret != 0) {
  		pr_err("Failed to register IOMMU context driver
  ");
  		goto error;
  	}
  
  error:
  	return ret;
  }

  static void __exit msm_iommu_driver_exit(void)

  {
  	platform_driver_unregister(&msm_iommu_ctx_driver);
  	platform_driver_unregister(&msm_iommu_driver);
  }
  
  subsys_initcall(msm_iommu_driver_init);
  module_exit(msm_iommu_driver_exit);
  
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Stepan Moskovchenko <stepanm@codeaurora.org>");