/* Copyright (c) 2011-2012, The Linux Foundation. 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.
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/device.h>
  #include <linux/io.h>
  #include <linux/err.h>
  #include <linux/slab.h>
  #include <linux/pm_runtime.h>
  #include <linux/coresight.h>
  #include <linux/amba/bus.h>
  #include <linux/clk.h>
  
  #include "coresight-priv.h"
  
  #define TPIU_SUPP_PORTSZ	0x000
  #define TPIU_CURR_PORTSZ	0x004
  #define TPIU_SUPP_TRIGMODES	0x100
  #define TPIU_TRIG_CNTRVAL	0x104
  #define TPIU_TRIG_MULT		0x108
  #define TPIU_SUPP_TESTPATM	0x200
  #define TPIU_CURR_TESTPATM	0x204
  #define TPIU_TEST_PATREPCNTR	0x208
  #define TPIU_FFSR		0x300
  #define TPIU_FFCR		0x304
  #define TPIU_FSYNC_CNTR		0x308
  #define TPIU_EXTCTL_INPORT	0x400
  #define TPIU_EXTCTL_OUTPORT	0x404
  #define TPIU_ITTRFLINACK	0xee4
  #define TPIU_ITTRFLIN		0xee8
  #define TPIU_ITATBDATA0		0xeec
  #define TPIU_ITATBCTR2		0xef0
  #define TPIU_ITATBCTR1		0xef4
  #define TPIU_ITATBCTR0		0xef8
  
  /** register definition **/
  /* FFCR - 0x304 */
  #define FFCR_FON_MAN		BIT(6)
  
  /**
   * @base:	memory mapped base address for this component.
   * @dev:	the device entity associated to this component.
   * @atclk:	optional clock for the core parts of the TPIU.
   * @csdev:	component vitals needed by the framework.
   */
  struct tpiu_drvdata {
  	void __iomem		*base;
  	struct device		*dev;
  	struct clk		*atclk;
  	struct coresight_device	*csdev;
  };
  
  static void tpiu_enable_hw(struct tpiu_drvdata *drvdata)
  {
  	CS_UNLOCK(drvdata->base);
  
  	/* TODO: fill this up */
  
  	CS_LOCK(drvdata->base);
  }
  
  static int tpiu_enable(struct coresight_device *csdev)
  {
  	struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  
  	pm_runtime_get_sync(csdev->dev.parent);
  	tpiu_enable_hw(drvdata);
  
  	dev_info(drvdata->dev, "TPIU enabled
  ");
  	return 0;
  }
  
  static void tpiu_disable_hw(struct tpiu_drvdata *drvdata)
  {
  	CS_UNLOCK(drvdata->base);
  
  	/* Clear formatter controle reg. */
  	writel_relaxed(0x0, drvdata->base + TPIU_FFCR);
  	/* Generate manual flush */
  	writel_relaxed(FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
  
  	CS_LOCK(drvdata->base);
  }
  
  static void tpiu_disable(struct coresight_device *csdev)
  {
  	struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  
  	tpiu_disable_hw(drvdata);
  	pm_runtime_put(csdev->dev.parent);
  
  	dev_info(drvdata->dev, "TPIU disabled
  ");
  }
  
  static const struct coresight_ops_sink tpiu_sink_ops = {
  	.enable		= tpiu_enable,
  	.disable	= tpiu_disable,
  };
  
  static const struct coresight_ops tpiu_cs_ops = {
  	.sink_ops	= &tpiu_sink_ops,
  };
  
  static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
  {
  	int ret;
  	void __iomem *base;
  	struct device *dev = &adev->dev;
  	struct coresight_platform_data *pdata = NULL;
  	struct tpiu_drvdata *drvdata;
  	struct resource *res = &adev->res;
  	struct coresight_desc *desc;
  	struct device_node *np = adev->dev.of_node;
  
  	if (np) {
  		pdata = of_get_coresight_platform_data(dev, np);
  		if (IS_ERR(pdata))
  			return PTR_ERR(pdata);
  		adev->dev.platform_data = pdata;
  	}
  
  	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
  	if (!drvdata)
  		return -ENOMEM;
  
  	drvdata->dev = &adev->dev;
  	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
  	if (!IS_ERR(drvdata->atclk)) {
  		ret = clk_prepare_enable(drvdata->atclk);
  		if (ret)
  			return ret;
  	}
  	dev_set_drvdata(dev, drvdata);
  
  	/* Validity for the resource is already checked by the AMBA core */
  	base = devm_ioremap_resource(dev, res);
  	if (IS_ERR(base))
  		return PTR_ERR(base);
  
  	drvdata->base = base;
  
  	/* Disable tpiu to support older devices */
  	tpiu_disable_hw(drvdata);
  
  	pm_runtime_put(&adev->dev);
  
  	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
  	if (!desc)
  		return -ENOMEM;
  
  	desc->type = CORESIGHT_DEV_TYPE_SINK;
  	desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_PORT;
  	desc->ops = &tpiu_cs_ops;
  	desc->pdata = pdata;
  	desc->dev = dev;
  	drvdata->csdev = coresight_register(desc);
  	if (IS_ERR(drvdata->csdev))
  		return PTR_ERR(drvdata->csdev);
  
  	dev_info(dev, "TPIU initialized
  ");
  	return 0;
  }
  
  static int tpiu_remove(struct amba_device *adev)
  {
  	struct tpiu_drvdata *drvdata = amba_get_drvdata(adev);
  
  	coresight_unregister(drvdata->csdev);
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int tpiu_runtime_suspend(struct device *dev)
  {
  	struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);
  
  	if (drvdata && !IS_ERR(drvdata->atclk))
  		clk_disable_unprepare(drvdata->atclk);
  
  	return 0;
  }
  
  static int tpiu_runtime_resume(struct device *dev)
  {
  	struct tpiu_drvdata *drvdata = dev_get_drvdata(dev);
  
  	if (drvdata && !IS_ERR(drvdata->atclk))
  		clk_prepare_enable(drvdata->atclk);
  
  	return 0;
  }
  #endif
  
  static const struct dev_pm_ops tpiu_dev_pm_ops = {
  	SET_RUNTIME_PM_OPS(tpiu_runtime_suspend, tpiu_runtime_resume, NULL)
  };
  
  static struct amba_id tpiu_ids[] = {
  	{
  		.id	= 0x0003b912,
  		.mask	= 0x0003ffff,
  	},
  	{
  		.id	= 0x0004b912,
  		.mask	= 0x0007ffff,
  	},
  	{ 0, 0},
  };
  
  static struct amba_driver tpiu_driver = {
  	.drv = {
  		.name	= "coresight-tpiu",
  		.owner	= THIS_MODULE,
  		.pm	= &tpiu_dev_pm_ops,
  	},
  	.probe		= tpiu_probe,
  	.remove		= tpiu_remove,
  	.id_table	= tpiu_ids,
  };
  
  module_amba_driver(tpiu_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("CoreSight Trace Port Interface Unit driver");