/*
   *  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 <linux/sizes.h>
  
  #include <asm/irq.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;
  }
  
  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;
  }
  
  #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_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.
   */
  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_unprepare(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_prepare_enable(pcdev->pclk);
  		/* Failure is probably fatal to the system, but... */
  		if (ret)
  			return ret;
  	}
  
  	return pm_generic_runtime_resume(dev);
  }
  #endif
  
  static const struct dev_pm_ops amba_pm = {
  	.suspend	= pm_generic_suspend,
  	.resume		= pm_generic_resume,
  	.freeze		= pm_generic_freeze,
  	.thaw		= pm_generic_thaw,
  	.poweroff	= pm_generic_poweroff,
  	.restore	= pm_generic_restore,
  	SET_RUNTIME_PM_OPS(
  		amba_pm_runtime_suspend,
  		amba_pm_runtime_resume,
  		NULL
  	)
  };
  
  /*
   * 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)
  {
  	int ret;
  
  	pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
  	if (IS_ERR(pcdev->pclk))
  		return PTR_ERR(pcdev->pclk);
  
  	ret = clk_prepare_enable(pcdev->pclk);
  	if (ret)
  		clk_put(pcdev->pclk);
  
  	return ret;
  }
  
  static void amba_put_disable_pclk(struct amba_device *pcdev)
  {
  	clk_disable_unprepare(pcdev->pclk);
  	clk_put(pcdev->pclk);
  }
  
  /*
   * 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_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);
  	} 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);
  
  	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_add - add a previously allocated AMBA device structure
   *	@dev: AMBA device allocated by amba_device_alloc
   *	@parent: resource parent for this devices resources
   *
   *	Claim the resource, and read the device cell ID if not already
   *	initialized.  Register the AMBA device with the Linux device
   *	manager.
   */
  int amba_device_add(struct amba_device *dev, struct resource *parent)
  {
  	u32 size;
  	void __iomem *tmp;
  	int i, ret;
  
  	WARN_ON(dev->irq[0] == (unsigned int)-1);
  	WARN_ON(dev->irq[1] == (unsigned int)-1);
  
  	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])
  		ret = device_create_file(&dev->dev, &dev_attr_irq0);
  	if (ret == 0 && dev->irq[1])
  		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;
  }
  EXPORT_SYMBOL_GPL(amba_device_add);
  
  static struct amba_device *
  amba_aphb_device_add(struct device *parent, const char *name,
  		     resource_size_t base, size_t size, int irq1, int irq2,
  		     void *pdata, unsigned int periphid, u64 dma_mask,
  		     struct resource *resbase)
  {
  	struct amba_device *dev;
  	int ret;
  
  	dev = amba_device_alloc(name, base, size);
  	if (!dev)
  		return ERR_PTR(-ENOMEM);
  
  	dev->dev.coherent_dma_mask = dma_mask;
  	dev->irq[0] = irq1;
  	dev->irq[1] = irq2;
  	dev->periphid = periphid;
  	dev->dev.platform_data = pdata;
  	dev->dev.parent = parent;
  
  	ret = amba_device_add(dev, resbase);
  	if (ret) {
  		amba_device_put(dev);
  		return ERR_PTR(ret);
  	}
  
  	return dev;
  }
  
  struct amba_device *
  amba_apb_device_add(struct device *parent, const char *name,
  		    resource_size_t base, size_t size, int irq1, int irq2,
  		    void *pdata, unsigned int periphid)
  {
  	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
  				    periphid, 0, &iomem_resource);
  }
  EXPORT_SYMBOL_GPL(amba_apb_device_add);
  
  struct amba_device *
  amba_ahb_device_add(struct device *parent, const char *name,
  		    resource_size_t base, size_t size, int irq1, int irq2,
  		    void *pdata, unsigned int periphid)
  {
  	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
  				    periphid, ~0ULL, &iomem_resource);
  }
  EXPORT_SYMBOL_GPL(amba_ahb_device_add);
  
  struct amba_device *
  amba_apb_device_add_res(struct device *parent, const char *name,
  			resource_size_t base, size_t size, int irq1,
  			int irq2, void *pdata, unsigned int periphid,
  			struct resource *resbase)
  {
  	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
  				    periphid, 0, resbase);
  }
  EXPORT_SYMBOL_GPL(amba_apb_device_add_res);
  
  struct amba_device *
  amba_ahb_device_add_res(struct device *parent, const char *name,
  			resource_size_t base, size_t size, int irq1,
  			int irq2, void *pdata, unsigned int periphid,
  			struct resource *resbase)
  {
  	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
  				    periphid, ~0ULL, resbase);
  }
  EXPORT_SYMBOL_GPL(amba_ahb_device_add_res);
  
  
  static void amba_device_initialize(struct amba_device *dev, const char *name)
  {
  	device_initialize(&dev->dev);
  	if (name)
  		dev_set_name(&dev->dev, "%s", name);
  	dev->dev.release = amba_device_release;
  	dev->dev.bus = &amba_bustype;
  	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
  	dev->res.name = dev_name(&dev->dev);
  }
  
  /**
   *	amba_device_alloc - allocate an AMBA device
   *	@name: sysfs name of the AMBA device
   *	@base: base of AMBA device
   *	@size: size of AMBA device
   *
   *	Allocate and initialize an AMBA device structure.  Returns %NULL
   *	on failure.
   */
  struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
  	size_t size)
  {
  	struct amba_device *dev;
  
  	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  	if (dev) {
  		amba_device_initialize(dev, name);
  		dev->res.start = base;
  		dev->res.end = base + size - 1;
  		dev->res.flags = IORESOURCE_MEM;
  	}
  
  	return dev;
  }
  EXPORT_SYMBOL_GPL(amba_device_alloc);
  
  /**
   *	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)
  {
  	amba_device_initialize(dev, dev->dev.init_name);
  	dev->dev.init_name = NULL;
  
  	return amba_device_add(dev, parent);
  }
  
  /**
   *	amba_device_put - put an AMBA device
   *	@dev: AMBA device to put
   */
  void amba_device_put(struct amba_device *dev)
  {
  	put_device(&dev->dev);
  }
  EXPORT_SYMBOL_GPL(amba_device_put);
  
  /**
   *	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);