/*
   * drivers/mfd/mfd-core.c
   *
   * core MFD support
   * Copyright (c) 2006 Ian Molton
   * Copyright (c) 2007,2008 Dmitry Baryshkov
   *
   * 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/kernel.h>
  #include <linux/platform_device.h>

  #include <linux/acpi.h>

  #include <linux/property.h>

  #include <linux/mfd/core.h>

  #include <linux/pm_runtime.h>

  #include <linux/slab.h>

  #include <linux/module.h>

  #include <linux/irqdomain.h>
  #include <linux/of.h>

  #include <linux/regulator/consumer.h>

  static struct device_type mfd_dev_type = {
  	.name	= "mfd_device",
  };

  int mfd_cell_enable(struct platform_device *pdev)

  {
  	const struct mfd_cell *cell = mfd_get_cell(pdev);
  	int err = 0;
  
  	/* only call enable hook if the cell wasn't previously enabled */
  	if (atomic_inc_return(cell->usage_count) == 1)
  		err = cell->enable(pdev);
  
  	/* if the enable hook failed, decrement counter to allow retries */
  	if (err)
  		atomic_dec(cell->usage_count);
  
  	return err;
  }

  EXPORT_SYMBOL(mfd_cell_enable);

  int mfd_cell_disable(struct platform_device *pdev)

  {
  	const struct mfd_cell *cell = mfd_get_cell(pdev);
  	int err = 0;
  
  	/* only disable if no other clients are using it */
  	if (atomic_dec_return(cell->usage_count) == 0)
  		err = cell->disable(pdev);
  
  	/* if the disable hook failed, increment to allow retries */
  	if (err)
  		atomic_inc(cell->usage_count);
  
  	/* sanity check; did someone call disable too many times? */
  	WARN_ON(atomic_read(cell->usage_count) < 0);
  
  	return err;
  }

  EXPORT_SYMBOL(mfd_cell_disable);

  static int mfd_platform_add_cell(struct platform_device *pdev,

  				 const struct mfd_cell *cell,
  				 atomic_t *usage_count)

  {
  	if (!cell)
  		return 0;
  
  	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
  	if (!pdev->mfd_cell)
  		return -ENOMEM;

  	pdev->mfd_cell->usage_count = usage_count;

  	return 0;
  }

  #if IS_ENABLED(CONFIG_ACPI)
  static void mfd_acpi_add_device(const struct mfd_cell *cell,
  				struct platform_device *pdev)
  {

  	const struct mfd_cell_acpi_match *match = cell->acpi_match;
  	struct acpi_device *parent, *child;

  	struct acpi_device *adev;

  	parent = ACPI_COMPANION(pdev->dev.parent);
  	if (!parent)

  		return;
  
  	/*

  	 * MFD child device gets its ACPI handle either from the ACPI device
  	 * directly under the parent that matches the either _HID or _CID, or
  	 * _ADR or it will use the parent handle if is no ID is given.
  	 *
  	 * Note that use of _ADR is a grey area in the ACPI specification,
  	 * though Intel Galileo Gen2 is using it to distinguish the children
  	 * devices.

  	 */

  	adev = parent;
  	if (match) {
  		if (match->pnpid) {
  			struct acpi_device_id ids[2] = {};
  
  			strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
  			list_for_each_entry(child, &parent->children, node) {

  				if (!acpi_match_device_ids(child, ids)) {

  					adev = child;
  					break;
  				}

  			}

  		} else {
  			unsigned long long adr;
  			acpi_status status;
  
  			list_for_each_entry(child, &parent->children, node) {
  				status = acpi_evaluate_integer(child->handle,
  							       "_ADR", NULL,
  							       &adr);
  				if (ACPI_SUCCESS(status) && match->adr == adr) {
  					adev = child;
  					break;
  				}
  			}
  		}

  	}
  
  	ACPI_COMPANION_SET(&pdev->dev, adev);
  }
  #else
  static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
  				       struct platform_device *pdev)
  {
  }
  #endif

  static int mfd_add_device(struct device *parent, int id,

  			  const struct mfd_cell *cell, atomic_t *usage_count,

  			  struct resource *mem_base,

  			  int irq_base, struct irq_domain *domain)

  {

  	struct resource *res;

  	struct platform_device *pdev;

  	struct device_node *np = NULL;

  	int ret = -ENOMEM;

  	int platform_id;

  	int r;

  	if (id == PLATFORM_DEVID_AUTO)

  		platform_id = id;
  	else
  		platform_id = id + cell->id;
  
  	pdev = platform_device_alloc(cell->name, platform_id);

  	if (!pdev)
  		goto fail_alloc;

  	res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
  	if (!res)
  		goto fail_device;

  	pdev->dev.parent = parent;

  	pdev->dev.type = &mfd_dev_type;

  	pdev->dev.dma_mask = parent->dma_mask;
  	pdev->dev.dma_parms = parent->dma_parms;

  	pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;

  	ret = regulator_bulk_register_supply_alias(

  			&pdev->dev, cell->parent_supplies,
  			parent, cell->parent_supplies,
  			cell->num_parent_supplies);
  	if (ret < 0)
  		goto fail_res;

  	if (parent->of_node && cell->of_compatible) {
  		for_each_child_of_node(parent->of_node, np) {
  			if (of_device_is_compatible(np, cell->of_compatible)) {
  				pdev->dev.of_node = np;

  				break;
  			}
  		}
  	}

  	mfd_acpi_add_device(cell, pdev);

  	if (cell->pdata_size) {
  		ret = platform_device_add_data(pdev,
  					cell->platform_data, cell->pdata_size);
  		if (ret)

  			goto fail_alias;

  	}

  	if (cell->properties) {
  		ret = platform_device_add_properties(pdev, cell->properties);

  		if (ret)
  			goto fail_alias;
  	}

  	ret = mfd_platform_add_cell(pdev, cell, usage_count);

  	if (ret)

  		goto fail_alias;

  	for (r = 0; r < cell->num_resources; r++) {
  		res[r].name = cell->resources[r].name;
  		res[r].flags = cell->resources[r].flags;
  
  		/* Find out base to use */

  		if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {

  			res[r].parent = mem_base;
  			res[r].start = mem_base->start +
  				cell->resources[r].start;
  			res[r].end = mem_base->start +
  				cell->resources[r].end;
  		} else if (cell->resources[r].flags & IORESOURCE_IRQ) {

  			if (domain) {
  				/* Unable to create mappings for IRQ ranges. */
  				WARN_ON(cell->resources[r].start !=
  					cell->resources[r].end);
  				res[r].start = res[r].end = irq_create_mapping(
  					domain, cell->resources[r].start);
  			} else {
  				res[r].start = irq_base +
  					cell->resources[r].start;
  				res[r].end   = irq_base +
  					cell->resources[r].end;
  			}

  		} else {
  			res[r].parent = cell->resources[r].parent;
  			res[r].start = cell->resources[r].start;
  			res[r].end   = cell->resources[r].end;
  		}

  		if (!cell->ignore_resource_conflicts) {

  			if (has_acpi_companion(&pdev->dev)) {
  				ret = acpi_check_resource_conflict(&res[r]);
  				if (ret)
  					goto fail_alias;
  			}

  		}

  	}

  	ret = platform_device_add_resources(pdev, res, cell->num_resources);
  	if (ret)

  		goto fail_alias;

  
  	ret = platform_device_add(pdev);
  	if (ret)

  		goto fail_alias;

  	if (cell->pm_runtime_no_callbacks)
  		pm_runtime_no_callbacks(&pdev->dev);

  	kfree(res);

  
  	return 0;

  fail_alias:

  	regulator_bulk_unregister_supply_alias(&pdev->dev,
  					       cell->parent_supplies,
  					       cell->num_parent_supplies);

  fail_res:
  	kfree(res);

  fail_device:
  	platform_device_put(pdev);
  fail_alloc:
  	return ret;
  }

  int mfd_add_devices(struct device *parent, int id,

  		    const struct mfd_cell *cells, int n_devs,

  		    struct resource *mem_base,

  		    int irq_base, struct irq_domain *domain)

  {
  	int i;

  	int ret;

  	atomic_t *cnts;
  
  	/* initialize reference counting for all cells */

  	cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);

  	if (!cnts)
  		return -ENOMEM;

  
  	for (i = 0; i < n_devs; i++) {

  		atomic_set(&cnts[i], 0);

  		ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,

  				     irq_base, domain);

  		if (ret)

  			goto fail;

  	}

  	return 0;

  fail:
  	if (i)
  		mfd_remove_devices(parent);
  	else
  		kfree(cnts);

  	return ret;
  }
  EXPORT_SYMBOL(mfd_add_devices);

  static int mfd_remove_devices_fn(struct device *dev, void *c)

  {

  	struct platform_device *pdev;
  	const struct mfd_cell *cell;

  	atomic_t **usage_count = c;

  	if (dev->type != &mfd_dev_type)
  		return 0;
  
  	pdev = to_platform_device(dev);
  	cell = mfd_get_cell(pdev);

  	regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
  					       cell->num_parent_supplies);

  	/* find the base address of usage_count pointers (for freeing) */
  	if (!*usage_count || (cell->usage_count < *usage_count))
  		*usage_count = cell->usage_count;
  
  	platform_device_unregister(pdev);

  	return 0;
  }

  void mfd_remove_devices(struct device *parent)

  {

  	atomic_t *cnts = NULL;

  	device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn);

  	kfree(cnts);

  }
  EXPORT_SYMBOL(mfd_remove_devices);

  static void devm_mfd_dev_release(struct device *dev, void *res)
  {
  	mfd_remove_devices(dev);
  }
  
  /**
   * devm_mfd_add_devices - Resource managed version of mfd_add_devices()
   *
   * Returns 0 on success or an appropriate negative error number on failure.
   * All child-devices of the MFD will automatically be removed when it gets
   * unbinded.
   */
  int devm_mfd_add_devices(struct device *dev, int id,
  			 const struct mfd_cell *cells, int n_devs,
  			 struct resource *mem_base,
  			 int irq_base, struct irq_domain *domain)
  {
  	struct device **ptr;
  	int ret;
  
  	ptr = devres_alloc(devm_mfd_dev_release, sizeof(*ptr), GFP_KERNEL);
  	if (!ptr)
  		return -ENOMEM;
  
  	ret = mfd_add_devices(dev, id, cells, n_devs, mem_base,
  			      irq_base, domain);
  	if (ret < 0) {
  		devres_free(ptr);
  		return ret;
  	}
  
  	*ptr = dev;
  	devres_add(dev, ptr);
  
  	return ret;
  }
  EXPORT_SYMBOL(devm_mfd_add_devices);

  int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)

  {
  	struct mfd_cell cell_entry;
  	struct device *dev;
  	struct platform_device *pdev;

  	int i;

  
  	/* fetch the parent cell's device (should already be registered!) */
  	dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
  	if (!dev) {
  		printk(KERN_ERR "failed to find device for cell %s
  ", cell);
  		return -ENODEV;
  	}
  	pdev = to_platform_device(dev);
  	memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
  
  	WARN_ON(!cell_entry.enable);

  	for (i = 0; i < n_clones; i++) {
  		cell_entry.name = clones[i];
  		/* don't give up if a single call fails; just report error */

  		if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
  				   cell_entry.usage_count, NULL, 0, NULL))

  			dev_err(dev, "failed to create platform device '%s'
  ",
  					clones[i]);
  	}

  	return 0;

  }

  EXPORT_SYMBOL(mfd_clone_cell);

  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");