drivers/mfd/mfd-core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * drivers/mfd/mfd-core.c
  *
  * core MFD support
  * Copyright (c) 2006 Ian Molton
  * Copyright (c) 2007,2008 Dmitry Baryshkov
  */

 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/acpi.h>
 #include <linux/list.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/of_address.h>
 #include <linux/regulator/consumer.h>

 static LIST_HEAD(mfd_of_node_list);

 struct mfd_of_node_entry {
 	struct list_head list;
 	struct device *dev;
 	struct device_node *np;
 };

 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);

 	if (!cell->enable) {
 		dev_dbg(&pdev->dev, "No .enable() call-back registered\n");
 		return 0;
 	}

 	return cell->enable(pdev);
 }
 EXPORT_SYMBOL(mfd_cell_enable);

 int mfd_cell_disable(struct platform_device *pdev)
 {
 	const struct mfd_cell *cell = mfd_get_cell(pdev);

 	if (!cell->disable) {
 		dev_dbg(&pdev->dev, "No .disable() call-back registered\n");
 		return 0;
 	}

 	return cell->disable(pdev);
 }
 EXPORT_SYMBOL(mfd_cell_disable);

 #if IS_ENABLED(CONFIG_ACPI)
 struct match_ids_walk_data {
 	struct acpi_device_id *ids;
 	struct acpi_device *adev;
 };

 static int match_device_ids(struct acpi_device *adev, void *data)
 {
 	struct match_ids_walk_data *wd = data;

 	if (!acpi_match_device_ids(adev, wd->ids)) {
 		wd->adev = adev;
 		return 1;
 	}

 	return 0;
 }

 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 *adev = NULL;
 	struct acpi_device *parent;

 	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 at least Intel Galileo Gen 2 is using it to distinguish
 	 * the children devices.
 	 */
 	if (match) {
 		if (match->pnpid) {
 			struct acpi_device_id ids[2] = {};
 			struct match_ids_walk_data wd = {
 				.adev = NULL,
 				.ids = ids,
 			};

 			strscpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
 			acpi_dev_for_each_child(parent, match_device_ids, &wd);
 			adev = wd.adev;
 		} else {
 			adev = acpi_find_child_device(parent, match->adr, false);
 		}
 	}

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

 static int mfd_match_of_node_to_dev(struct platform_device *pdev,
 				    struct device_node *np,
 				    const struct mfd_cell *cell)
 {
 #if IS_ENABLED(CONFIG_OF)
 	struct mfd_of_node_entry *of_entry;
 	const __be32 *reg;
 	u64 of_node_addr;

 	/* Skip if OF node has previously been allocated to a device */
 	list_for_each_entry(of_entry, &mfd_of_node_list, list)
 		if (of_entry->np == np)
 			return -EAGAIN;

 	if (!cell->use_of_reg)
 		/* No of_reg defined - allocate first free compatible match */
 		goto allocate_of_node;

 	/* We only care about each node's first defined address */
 	reg = of_get_address(np, 0, NULL, NULL);
 	if (!reg)
 		/* OF node does not contatin a 'reg' property to match to */
 		return -EAGAIN;

 	of_node_addr = of_read_number(reg, of_n_addr_cells(np));

 	if (cell->of_reg != of_node_addr)
 		/* No match */
 		return -EAGAIN;

 allocate_of_node:
 	of_entry = kzalloc(sizeof(*of_entry), GFP_KERNEL);
 	if (!of_entry)
 		return -ENOMEM;

 	of_entry->dev = &pdev->dev;
 	of_entry->np = np;
 	list_add_tail(&of_entry->list, &mfd_of_node_list);

 	pdev->dev.of_node = np;
 	pdev->dev.fwnode = &np->fwnode;
 #endif
 	return 0;
 }

 static int mfd_add_device(struct device *parent, int id,
 			  const struct mfd_cell *cell,
 			  struct resource *mem_base,
 			  int irq_base, struct irq_domain *domain)
 {
 	struct resource *res;
 	struct platform_device *pdev;
 	struct device_node *np = NULL;
 	struct mfd_of_node_entry *of_entry, *tmp;
 	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;

 	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
 	if (!pdev->mfd_cell)
 		goto fail_device;

 	res = kcalloc(cell->num_resources, sizeof(*res), 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 (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
 		for_each_child_of_node(parent->of_node, np) {
 			if (of_device_is_compatible(np, cell->of_compatible)) {
 				/* Ignore 'disabled' devices error free */
 				if (!of_device_is_available(np)) {
 					of_node_put(np);
 					ret = 0;
 					goto fail_alias;
 				}

 				ret = mfd_match_of_node_to_dev(pdev, np, cell);
 				if (ret == -EAGAIN)
 					continue;
 				of_node_put(np);
 				if (ret)
 					goto fail_alias;

 				break;
 			}
 		}

 		if (!pdev->dev.of_node)
 			pr_warn("%s: Failed to locate of_node [id: %d]\n",
 				cell->name, platform_id);
 	}

 	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_of_entry;
 	}

 	if (cell->swnode) {
 		ret = device_add_software_node(&pdev->dev, cell->swnode);
 		if (ret)
 			goto fail_of_entry;
 	}

 	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_res_conflict;
 			}
 		}
 	}

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

 	ret = platform_device_add(pdev);
 	if (ret)
 		goto fail_res_conflict;

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

 	kfree(res);

 	return 0;

 fail_res_conflict:
 	if (cell->swnode)
 		device_remove_software_node(&pdev->dev);
 fail_of_entry:
 	list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
 		if (of_entry->dev == &pdev->dev) {
 			list_del(&of_entry->list);
 			kfree(of_entry);
 		}
 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;
 }

 /**
  * mfd_add_devices - register child devices
  *
  * @parent:	Pointer to parent device.
  * @id:		Can be PLATFORM_DEVID_AUTO to let the Platform API take care
  *		of device numbering, or will be added to a device's cell_id.
  * @cells:	Array of (struct mfd_cell)s describing child devices.
  * @n_devs:	Number of child devices to register.
  * @mem_base:	Parent register range resource for child devices.
  * @irq_base:	Base of the range of virtual interrupt numbers allocated for
  *		this MFD device. Unused if @domain is specified.
  * @domain:	Interrupt domain to create mappings for hardware interrupts.
  */
 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;

 	for (i = 0; i < n_devs; i++) {
 		ret = mfd_add_device(parent, id, cells + i, mem_base,
 				     irq_base, domain);
 		if (ret)
 			goto fail;
 	}

 	return 0;

 fail:
 	if (i)
 		mfd_remove_devices(parent);

 	return ret;
 }
 EXPORT_SYMBOL(mfd_add_devices);

 static int mfd_remove_devices_fn(struct device *dev, void *data)
 {
 	struct platform_device *pdev;
 	const struct mfd_cell *cell;
 	struct mfd_of_node_entry *of_entry, *tmp;
 	int *level = data;

 	if (dev->type != &mfd_dev_type)
 		return 0;

 	pdev = to_platform_device(dev);
 	cell = mfd_get_cell(pdev);

 	if (level && cell->level > *level)
 		return 0;

 	if (cell->swnode)
 		device_remove_software_node(&pdev->dev);

 	list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
 		if (of_entry->dev == &pdev->dev) {
 			list_del(&of_entry->list);
 			kfree(of_entry);
 		}

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

 	platform_device_unregister(pdev);
 	return 0;
 }

 void mfd_remove_devices_late(struct device *parent)
 {
 	int level = MFD_DEP_LEVEL_HIGH;

 	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);
 }
 EXPORT_SYMBOL(mfd_remove_devices_late);

 void mfd_remove_devices(struct device *parent)
 {
 	int level = MFD_DEP_LEVEL_NORMAL;

 	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);
 }
 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.
  *
  * @dev:	Pointer to parent device.
  * @id:		Can be PLATFORM_DEVID_AUTO to let the Platform API take care
  *		of device numbering, or will be added to a device's cell_id.
  * @cells:	Array of (struct mfd_cell)s describing child devices.
  * @n_devs:	Number of child devices to register.
  * @mem_base:	Parent register range resource for child devices.
  * @irq_base:	Base of the range of virtual interrupt numbers allocated for
  *		this MFD device. Unused if @domain is specified.
  * @domain:	Interrupt domain to create mappings for hardware interrupts.
  */
 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);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* drivers/mfd/mfd-core.c
	*
	* core MFD support
	* Copyright (c) 2006 Ian Molton
	* Copyright (c) 2007,2008 Dmitry Baryshkov
	*/

	#include <linux/kernel.h>
	#include <linux/platform_device.h>
	#include <linux/acpi.h>
	#include <linux/list.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/of_address.h>
	#include <linux/regulator/consumer.h>

	static LIST_HEAD(mfd_of_node_list);

	struct mfd_of_node_entry {
	struct list_head list;
	struct device *dev;
	struct device_node *np;
	};

	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);

	if (!cell->enable) {
	dev_dbg(&pdev->dev, "No .enable() call-back registered\n");
	return 0;
	}

	return cell->enable(pdev);
	}
	EXPORT_SYMBOL(mfd_cell_enable);

	int mfd_cell_disable(struct platform_device *pdev)
	{
	const struct mfd_cell *cell = mfd_get_cell(pdev);

	if (!cell->disable) {
	dev_dbg(&pdev->dev, "No .disable() call-back registered\n");
	return 0;
	}

	return cell->disable(pdev);
	}
	EXPORT_SYMBOL(mfd_cell_disable);

	#if IS_ENABLED(CONFIG_ACPI)
	struct match_ids_walk_data {
	struct acpi_device_id *ids;
	struct acpi_device *adev;
	};

	static int match_device_ids(struct acpi_device adev, void data)
	{
	struct match_ids_walk_data *wd = data;

	if (!acpi_match_device_ids(adev, wd->ids)) {
	wd->adev = adev;
	return 1;
	}

	return 0;
	}

	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 *adev = NULL;
	struct acpi_device *parent;

	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 at least Intel Galileo Gen 2 is using it to distinguish
	* the children devices.
	*/
	if (match) {
	if (match->pnpid) {
	struct acpi_device_id ids[2] = {};
	struct match_ids_walk_data wd = {
	.adev = NULL,
	.ids = ids,
	};

	strscpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
	acpi_dev_for_each_child(parent, match_device_ids, &wd);
	adev = wd.adev;
	} else {
	adev = acpi_find_child_device(parent, match->adr, false);
	}
	}

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

	static int mfd_match_of_node_to_dev(struct platform_device *pdev,
	struct device_node *np,
	const struct mfd_cell *cell)
	{
	#if IS_ENABLED(CONFIG_OF)
	struct mfd_of_node_entry *of_entry;
	const __be32 *reg;
	u64 of_node_addr;

	/* Skip if OF node has previously been allocated to a device */
	list_for_each_entry(of_entry, &mfd_of_node_list, list)
	if (of_entry->np == np)
	return -EAGAIN;

	if (!cell->use_of_reg)
	/* No of_reg defined - allocate first free compatible match */
	goto allocate_of_node;

	/* We only care about each node's first defined address */
	reg = of_get_address(np, 0, NULL, NULL);
	if (!reg)
	/* OF node does not contatin a 'reg' property to match to */
	return -EAGAIN;

	of_node_addr = of_read_number(reg, of_n_addr_cells(np));

	if (cell->of_reg != of_node_addr)
	/* No match */
	return -EAGAIN;

	allocate_of_node:
	of_entry = kzalloc(sizeof(*of_entry), GFP_KERNEL);
	if (!of_entry)
	return -ENOMEM;

	of_entry->dev = &pdev->dev;
	of_entry->np = np;
	list_add_tail(&of_entry->list, &mfd_of_node_list);

	pdev->dev.of_node = np;
	pdev->dev.fwnode = &np->fwnode;
	#endif
	return 0;
	}

	static int mfd_add_device(struct device *parent, int id,
	const struct mfd_cell *cell,
	struct resource *mem_base,
	int irq_base, struct irq_domain *domain)
	{
	struct resource *res;
	struct platform_device *pdev;
	struct device_node *np = NULL;
	struct mfd_of_node_entry of_entry, tmp;
	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;

	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
	if (!pdev->mfd_cell)
	goto fail_device;

	res = kcalloc(cell->num_resources, sizeof(*res), 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 (IS_ENABLED(CONFIG_OF) && parent->of_node && cell->of_compatible) {
	for_each_child_of_node(parent->of_node, np) {
	if (of_device_is_compatible(np, cell->of_compatible)) {
	/* Ignore 'disabled' devices error free */
	if (!of_device_is_available(np)) {
	of_node_put(np);
	ret = 0;
	goto fail_alias;
	}

	ret = mfd_match_of_node_to_dev(pdev, np, cell);
	if (ret == -EAGAIN)
	continue;
	of_node_put(np);
	if (ret)
	goto fail_alias;

	break;
	}
	}

	if (!pdev->dev.of_node)
	pr_warn("%s: Failed to locate of_node [id: %d]\n",
	cell->name, platform_id);
	}

	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_of_entry;
	}

	if (cell->swnode) {
	ret = device_add_software_node(&pdev->dev, cell->swnode);
	if (ret)
	goto fail_of_entry;
	}

	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_res_conflict;
	}
	}
	}

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

	ret = platform_device_add(pdev);
	if (ret)
	goto fail_res_conflict;

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

	kfree(res);

	return 0;

	fail_res_conflict:
	if (cell->swnode)
	device_remove_software_node(&pdev->dev);
	fail_of_entry:
	list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
	if (of_entry->dev == &pdev->dev) {
	list_del(&of_entry->list);
	kfree(of_entry);
	}
	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;
	}

	/**
	* mfd_add_devices - register child devices
	*
	* @parent: Pointer to parent device.
	* @id: Can be PLATFORM_DEVID_AUTO to let the Platform API take care
	* of device numbering, or will be added to a device's cell_id.
	* @cells: Array of (struct mfd_cell)s describing child devices.
	* @n_devs: Number of child devices to register.
	* @mem_base: Parent register range resource for child devices.
	* @irq_base: Base of the range of virtual interrupt numbers allocated for
	* this MFD device. Unused if @domain is specified.
	* @domain: Interrupt domain to create mappings for hardware interrupts.
	*/
	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;

	for (i = 0; i < n_devs; i++) {
	ret = mfd_add_device(parent, id, cells + i, mem_base,
	irq_base, domain);
	if (ret)
	goto fail;
	}

	return 0;

	fail:
	if (i)
	mfd_remove_devices(parent);

	return ret;
	}
	EXPORT_SYMBOL(mfd_add_devices);

	static int mfd_remove_devices_fn(struct device dev, void data)
	{
	struct platform_device *pdev;
	const struct mfd_cell *cell;
	struct mfd_of_node_entry of_entry, tmp;
	int *level = data;

	if (dev->type != &mfd_dev_type)
	return 0;

	pdev = to_platform_device(dev);
	cell = mfd_get_cell(pdev);

	if (level && cell->level > *level)
	return 0;

	if (cell->swnode)
	device_remove_software_node(&pdev->dev);

	list_for_each_entry_safe(of_entry, tmp, &mfd_of_node_list, list)
	if (of_entry->dev == &pdev->dev) {
	list_del(&of_entry->list);
	kfree(of_entry);
	}

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

	platform_device_unregister(pdev);
	return 0;
	}

	void mfd_remove_devices_late(struct device *parent)
	{
	int level = MFD_DEP_LEVEL_HIGH;

	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);
	}
	EXPORT_SYMBOL(mfd_remove_devices_late);

	void mfd_remove_devices(struct device *parent)
	{
	int level = MFD_DEP_LEVEL_NORMAL;

	device_for_each_child_reverse(parent, &level, mfd_remove_devices_fn);
	}
	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.
	*
	* @dev: Pointer to parent device.
	* @id: Can be PLATFORM_DEVID_AUTO to let the Platform API take care
	* of device numbering, or will be added to a device's cell_id.
	* @cells: Array of (struct mfd_cell)s describing child devices.
	* @n_devs: Number of child devices to register.
	* @mem_base: Parent register range resource for child devices.
	* @irq_base: Base of the range of virtual interrupt numbers allocated for
	* this MFD device. Unused if @domain is specified.
	* @domain: Interrupt domain to create mappings for hardware interrupts.
	*/
	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);

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