/*
   *  linux/arch/arm/common/amba.c
   *
   *  Copyright (C) 2003 Deep Blue Solutions Ltd, 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 as
   * published by the Free Software Foundation.
   */
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/device.h>

  #include <linux/string.h>
  #include <linux/slab.h>

  #include <linux/io.h>

  #include <linux/pm.h>
  #include <linux/pm_runtime.h>

  #include <linux/amba/bus.h>

  #include <asm/irq.h>

  #include <asm/sizes.h>

  #define to_amba_driver(d)	container_of(d, struct amba_driver, drv)

  static const struct amba_id *
  amba_lookup(const struct amba_id *table, struct amba_device *dev)

  {
  	int ret = 0;
  
  	while (table->mask) {
  		ret = (dev->periphid & table->mask) == table->id;
  		if (ret)
  			break;
  		table++;
  	}
  
  	return ret ? table : NULL;
  }
  
  static int amba_match(struct device *dev, struct device_driver *drv)
  {
  	struct amba_device *pcdev = to_amba_device(dev);
  	struct amba_driver *pcdrv = to_amba_driver(drv);
  
  	return amba_lookup(pcdrv->id_table, pcdev) != NULL;
  }
  
  #ifdef CONFIG_HOTPLUG

  static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)

  {
  	struct amba_device *pcdev = to_amba_device(dev);

  	int retval = 0;

  	retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);

  	if (retval)
  		return retval;
  
  	retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);

  	return retval;

  }
  #else

  #define amba_uevent NULL

  #endif

  #define amba_attr_func(name,fmt,arg...)					\
  static ssize_t name##_show(struct device *_dev,				\
  			   struct device_attribute *attr, char *buf)	\
  {									\
  	struct amba_device *dev = to_amba_device(_dev);			\
  	return sprintf(buf, fmt, arg);					\
  }
  
  #define amba_attr(name,fmt,arg...)	\
  amba_attr_func(name,fmt,arg)		\
  static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
  
  amba_attr_func(id, "%08x
  ", dev->periphid);
  amba_attr(irq0, "%u
  ", dev->irq[0]);
  amba_attr(irq1, "%u
  ", dev->irq[1]);
  amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx
  ",
  	 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
  	 dev->res.flags);
  
  static struct device_attribute amba_dev_attrs[] = {
  	__ATTR_RO(id),
  	__ATTR_RO(resource),
  	__ATTR_NULL,
  };

  #ifdef CONFIG_PM_SLEEP
  
  static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
  {
  	struct amba_driver *adrv = to_amba_driver(dev->driver);
  	struct amba_device *adev = to_amba_device(dev);
  	int ret = 0;
  
  	if (dev->driver && adrv->suspend)
  		ret = adrv->suspend(adev, mesg);
  
  	return ret;
  }
  
  static int amba_legacy_resume(struct device *dev)
  {
  	struct amba_driver *adrv = to_amba_driver(dev->driver);
  	struct amba_device *adev = to_amba_device(dev);
  	int ret = 0;
  
  	if (dev->driver && adrv->resume)
  		ret = adrv->resume(adev);
  
  	return ret;
  }

  #endif /* CONFIG_PM_SLEEP */

  
  #ifdef CONFIG_SUSPEND
  
  static int amba_pm_suspend(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->suspend)
  			ret = drv->pm->suspend(dev);
  	} else {
  		ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
  	}
  
  	return ret;
  }

  static int amba_pm_resume(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->resume)
  			ret = drv->pm->resume(dev);
  	} else {
  		ret = amba_legacy_resume(dev);
  	}
  
  	return ret;
  }

  #else /* !CONFIG_SUSPEND */
  
  #define amba_pm_suspend		NULL
  #define amba_pm_resume		NULL

  
  #endif /* !CONFIG_SUSPEND */

  #ifdef CONFIG_HIBERNATE_CALLBACKS

  
  static int amba_pm_freeze(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->freeze)
  			ret = drv->pm->freeze(dev);
  	} else {
  		ret = amba_legacy_suspend(dev, PMSG_FREEZE);
  	}
  
  	return ret;
  }

  static int amba_pm_thaw(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->thaw)
  			ret = drv->pm->thaw(dev);
  	} else {
  		ret = amba_legacy_resume(dev);
  	}
  
  	return ret;
  }

  static int amba_pm_poweroff(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->poweroff)
  			ret = drv->pm->poweroff(dev);
  	} else {
  		ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
  	}
  
  	return ret;
  }

  static int amba_pm_restore(struct device *dev)
  {
  	struct device_driver *drv = dev->driver;
  	int ret = 0;
  
  	if (!drv)
  		return 0;
  
  	if (drv->pm) {
  		if (drv->pm->restore)
  			ret = drv->pm->restore(dev);
  	} else {
  		ret = amba_legacy_resume(dev);
  	}
  
  	return ret;
  }

  #else /* !CONFIG_HIBERNATE_CALLBACKS */

  
  #define amba_pm_freeze		NULL
  #define amba_pm_thaw		NULL
  #define amba_pm_poweroff		NULL
  #define amba_pm_restore		NULL

  #endif /* !CONFIG_HIBERNATE_CALLBACKS */

  #ifdef CONFIG_PM_RUNTIME
  /*
   * Hooks to provide runtime PM of the pclk (bus clock).  It is safe to
   * enable/disable the bus clock at runtime PM suspend/resume as this
   * does not result in loss of context.  However, disabling vcore power
   * would do, so we leave that to the driver.
   */
  static int amba_pm_runtime_suspend(struct device *dev)
  {
  	struct amba_device *pcdev = to_amba_device(dev);
  	int ret = pm_generic_runtime_suspend(dev);
  
  	if (ret == 0 && dev->driver)
  		clk_disable(pcdev->pclk);
  
  	return ret;
  }
  
  static int amba_pm_runtime_resume(struct device *dev)
  {
  	struct amba_device *pcdev = to_amba_device(dev);
  	int ret;
  
  	if (dev->driver) {
  		ret = clk_enable(pcdev->pclk);
  		/* Failure is probably fatal to the system, but... */
  		if (ret)
  			return ret;
  	}
  
  	return pm_generic_runtime_resume(dev);
  }
  #endif

  #ifdef CONFIG_PM
  
  static const struct dev_pm_ops amba_pm = {

  	.suspend	= amba_pm_suspend,
  	.resume		= amba_pm_resume,
  	.freeze		= amba_pm_freeze,
  	.thaw		= amba_pm_thaw,
  	.poweroff	= amba_pm_poweroff,
  	.restore	= amba_pm_restore,

  	SET_RUNTIME_PM_OPS(

  		amba_pm_runtime_suspend,
  		amba_pm_runtime_resume,

  		pm_generic_runtime_idle
  	)
  };
  
  #define AMBA_PM (&amba_pm)
  
  #else /* !CONFIG_PM */
  
  #define AMBA_PM	NULL
  
  #endif /* !CONFIG_PM */

  /*
   * Primecells are part of the Advanced Microcontroller Bus Architecture,
   * so we call the bus "amba".
   */

  struct bus_type amba_bustype = {

  	.name		= "amba",

  	.dev_attrs	= amba_dev_attrs,

  	.match		= amba_match,

  	.uevent		= amba_uevent,

  	.pm		= AMBA_PM,

  };
  
  static int __init amba_init(void)
  {
  	return bus_register(&amba_bustype);
  }
  
  postcore_initcall(amba_init);

  static int amba_get_enable_pclk(struct amba_device *pcdev)
  {
  	struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
  	int ret;
  
  	pcdev->pclk = pclk;
  
  	if (IS_ERR(pclk))
  		return PTR_ERR(pclk);

  	ret = clk_prepare(pclk);
  	if (ret) {
  		clk_put(pclk);
  		return ret;
  	}

  	ret = clk_enable(pclk);

  	if (ret) {
  		clk_unprepare(pclk);

  		clk_put(pclk);

  	}

  
  	return ret;
  }
  
  static void amba_put_disable_pclk(struct amba_device *pcdev)
  {
  	struct clk *pclk = pcdev->pclk;
  
  	clk_disable(pclk);

  	clk_unprepare(pclk);

  	clk_put(pclk);
  }

  static int amba_get_enable_vcore(struct amba_device *pcdev)
  {
  	struct regulator *vcore = regulator_get(&pcdev->dev, "vcore");
  	int ret;
  
  	pcdev->vcore = vcore;
  
  	if (IS_ERR(vcore)) {
  		/* It is OK not to supply a vcore regulator */
  		if (PTR_ERR(vcore) == -ENODEV)
  			return 0;
  		return PTR_ERR(vcore);
  	}
  
  	ret = regulator_enable(vcore);
  	if (ret) {
  		regulator_put(vcore);
  		pcdev->vcore = ERR_PTR(-ENODEV);
  	}
  
  	return ret;
  }
  
  static void amba_put_disable_vcore(struct amba_device *pcdev)
  {
  	struct regulator *vcore = pcdev->vcore;
  
  	if (!IS_ERR(vcore)) {
  		regulator_disable(vcore);
  		regulator_put(vcore);
  	}
  }

  /*
   * These are the device model conversion veneers; they convert the
   * device model structures to our more specific structures.
   */
  static int amba_probe(struct device *dev)
  {
  	struct amba_device *pcdev = to_amba_device(dev);
  	struct amba_driver *pcdrv = to_amba_driver(dev->driver);

  	const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);

  	int ret;

  	do {

  		ret = amba_get_enable_vcore(pcdev);
  		if (ret)
  			break;

  		ret = amba_get_enable_pclk(pcdev);
  		if (ret)
  			break;

  		pm_runtime_get_noresume(dev);
  		pm_runtime_set_active(dev);
  		pm_runtime_enable(dev);

  		ret = pcdrv->probe(pcdev, id);
  		if (ret == 0)
  			break;

  		pm_runtime_disable(dev);
  		pm_runtime_set_suspended(dev);
  		pm_runtime_put_noidle(dev);

  		amba_put_disable_pclk(pcdev);

  		amba_put_disable_vcore(pcdev);

  	} while (0);
  
  	return ret;

  }
  
  static int amba_remove(struct device *dev)
  {

  	struct amba_device *pcdev = to_amba_device(dev);

  	struct amba_driver *drv = to_amba_driver(dev->driver);

  	int ret;
  
  	pm_runtime_get_sync(dev);
  	ret = drv->remove(pcdev);
  	pm_runtime_put_noidle(dev);
  
  	/* Undo the runtime PM settings in amba_probe() */
  	pm_runtime_disable(dev);
  	pm_runtime_set_suspended(dev);
  	pm_runtime_put_noidle(dev);

  
  	amba_put_disable_pclk(pcdev);

  	amba_put_disable_vcore(pcdev);

  
  	return ret;

  }
  
  static void amba_shutdown(struct device *dev)
  {
  	struct amba_driver *drv = to_amba_driver(dev->driver);
  	drv->shutdown(to_amba_device(dev));
  }
  
  /**
   *	amba_driver_register - register an AMBA device driver
   *	@drv: amba device driver structure
   *
   *	Register an AMBA device driver with the Linux device model
   *	core.  If devices pre-exist, the drivers probe function will
   *	be called.
   */
  int amba_driver_register(struct amba_driver *drv)
  {
  	drv->drv.bus = &amba_bustype;
  
  #define SETFN(fn)	if (drv->fn) drv->drv.fn = amba_##fn
  	SETFN(probe);
  	SETFN(remove);
  	SETFN(shutdown);
  
  	return driver_register(&drv->drv);
  }
  
  /**
   *	amba_driver_unregister - remove an AMBA device driver
   *	@drv: AMBA device driver structure to remove
   *
   *	Unregister an AMBA device driver from the Linux device
   *	model.  The device model will call the drivers remove function
   *	for each device the device driver is currently handling.
   */
  void amba_driver_unregister(struct amba_driver *drv)
  {
  	driver_unregister(&drv->drv);
  }
  
  
  static void amba_device_release(struct device *dev)
  {
  	struct amba_device *d = to_amba_device(dev);
  
  	if (d->res.parent)
  		release_resource(&d->res);
  	kfree(d);
  }

  /**
   *	amba_device_register - register an AMBA device
   *	@dev: AMBA device to register
   *	@parent: parent memory resource
   *
   *	Setup the AMBA device, reading the cell ID if present.
   *	Claim the resource, and register the AMBA device with
   *	the Linux device manager.
   */
  int amba_device_register(struct amba_device *dev, struct resource *parent)
  {

  	u32 size;

  	void __iomem *tmp;
  	int i, ret;

  	device_initialize(&dev->dev);
  
  	/*
  	 * Copy from device_add
  	 */
  	if (dev->dev.init_name) {
  		dev_set_name(&dev->dev, "%s", dev->dev.init_name);
  		dev->dev.init_name = NULL;
  	}

  	dev->dev.release = amba_device_release;
  	dev->dev.bus = &amba_bustype;
  	dev->dev.dma_mask = &dev->dma_mask;

  	dev->res.name = dev_name(&dev->dev);

  
  	if (!dev->dev.coherent_dma_mask && dev->dma_mask)
  		dev_warn(&dev->dev, "coherent dma mask is unset
  ");
  
  	ret = request_resource(parent, &dev->res);

  	if (ret)
  		goto err_out;

  	/* Hard-coded primecell ID instead of plug-n-play */
  	if (dev->periphid != 0)
  		goto skip_probe;

  	/*
  	 * Dynamically calculate the size of the resource
  	 * and use this for iomap
  	 */
  	size = resource_size(&dev->res);
  	tmp = ioremap(dev->res.start, size);

  	if (!tmp) {
  		ret = -ENOMEM;
  		goto err_release;

  	}

  	ret = amba_get_enable_pclk(dev);
  	if (ret == 0) {
  		u32 pid, cid;

  		/*
  		 * Read pid and cid based on size of resource
  		 * they are located at end of region
  		 */
  		for (pid = 0, i = 0; i < 4; i++)
  			pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) <<
  				(i * 8);
  		for (cid = 0, i = 0; i < 4; i++)
  			cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) <<
  				(i * 8);

  		amba_put_disable_pclk(dev);

  		if (cid == AMBA_CID)

  			dev->periphid = pid;
  
  		if (!dev->periphid)
  			ret = -ENODEV;

  	}

  	iounmap(tmp);
  
  	if (ret)
  		goto err_release;

   skip_probe:

  	ret = device_add(&dev->dev);

  	if (ret)
  		goto err_release;
  
  	if (dev->irq[0] != NO_IRQ)
  		ret = device_create_file(&dev->dev, &dev_attr_irq0);
  	if (ret == 0 && dev->irq[1] != NO_IRQ)
  		ret = device_create_file(&dev->dev, &dev_attr_irq1);
  	if (ret == 0)
  		return ret;
  
  	device_unregister(&dev->dev);
  
   err_release:
  	release_resource(&dev->res);
   err_out:

  	return ret;
  }
  
  /**
   *	amba_device_unregister - unregister an AMBA device
   *	@dev: AMBA device to remove
   *
   *	Remove the specified AMBA device from the Linux device
   *	manager.  All files associated with this object will be
   *	destroyed, and device drivers notified that the device has
   *	been removed.  The AMBA device's resources including
   *	the amba_device structure will be freed once all
   *	references to it have been dropped.
   */
  void amba_device_unregister(struct amba_device *dev)
  {
  	device_unregister(&dev->dev);
  }
  
  
  struct find_data {
  	struct amba_device *dev;
  	struct device *parent;
  	const char *busid;
  	unsigned int id;
  	unsigned int mask;
  };
  
  static int amba_find_match(struct device *dev, void *data)
  {
  	struct find_data *d = data;
  	struct amba_device *pcdev = to_amba_device(dev);
  	int r;
  
  	r = (pcdev->periphid & d->mask) == d->id;
  	if (d->parent)
  		r &= d->parent == dev->parent;
  	if (d->busid)

  		r &= strcmp(dev_name(dev), d->busid) == 0;

  
  	if (r) {
  		get_device(dev);
  		d->dev = pcdev;
  	}
  
  	return r;
  }
  
  /**
   *	amba_find_device - locate an AMBA device given a bus id
   *	@busid: bus id for device (or NULL)
   *	@parent: parent device (or NULL)
   *	@id: peripheral ID (or 0)
   *	@mask: peripheral ID mask (or 0)
   *
   *	Return the AMBA device corresponding to the supplied parameters.
   *	If no device matches, returns NULL.
   *
   *	NOTE: When a valid device is found, its refcount is
   *	incremented, and must be decremented before the returned
   *	reference.
   */
  struct amba_device *
  amba_find_device(const char *busid, struct device *parent, unsigned int id,
  		 unsigned int mask)
  {
  	struct find_data data;
  
  	data.dev = NULL;
  	data.parent = parent;
  	data.busid = busid;
  	data.id = id;
  	data.mask = mask;
  
  	bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
  
  	return data.dev;
  }
  
  /**
   *	amba_request_regions - request all mem regions associated with device
   *	@dev: amba_device structure for device
   *	@name: name, or NULL to use driver name
   */
  int amba_request_regions(struct amba_device *dev, const char *name)
  {
  	int ret = 0;

  	u32 size;

  
  	if (!name)
  		name = dev->dev.driver->name;

  	size = resource_size(&dev->res);
  
  	if (!request_mem_region(dev->res.start, size, name))

  		ret = -EBUSY;
  
  	return ret;
  }
  
  /**

   *	amba_release_regions - release mem regions associated with device

   *	@dev: amba_device structure for device
   *
   *	Release regions claimed by a successful call to amba_request_regions.
   */
  void amba_release_regions(struct amba_device *dev)
  {

  	u32 size;
  
  	size = resource_size(&dev->res);
  	release_mem_region(dev->res.start, size);

  }
  
  EXPORT_SYMBOL(amba_driver_register);
  EXPORT_SYMBOL(amba_driver_unregister);
  EXPORT_SYMBOL(amba_device_register);
  EXPORT_SYMBOL(amba_device_unregister);
  EXPORT_SYMBOL(amba_find_device);
  EXPORT_SYMBOL(amba_request_regions);
  EXPORT_SYMBOL(amba_release_regions);