// 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);
static DEFINE_MUTEX(mfd_of_node_mutex);

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

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

#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);
                }
        }

        device_set_node(&pdev->dev, acpi_fwnode_handle(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)
{
        struct mfd_of_node_entry *of_entry;
        u64 of_node_addr;

        /* Skip if OF node has previously been allocated to a device */
        scoped_guard(mutex, &mfd_of_node_mutex) {
                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 */
        if (of_property_read_reg(np, 0, &of_node_addr, NULL))
                /* OF node does not contatin a 'reg' property to match to */
                return -EAGAIN;

        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 = of_node_get(np);
        scoped_guard(mutex, &mfd_of_node_mutex)
                list_add_tail(&of_entry->list, &mfd_of_node_list);

        device_set_node(&pdev->dev, of_fwnode_handle(np));
        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 mfd_of_node_entry *of_entry, *tmp;
        bool disabled = false;
        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_scoped(parent->of_node, np) {
                        if (of_device_is_compatible(np, cell->of_compatible)) {
                                /* Skip 'disabled' devices */
                                if (!of_device_is_available(np)) {
                                        disabled = true;
                                        continue;
                                }

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

                                goto match;
                        }
                }

                if (disabled) {
                        /* Ignore 'disabled' devices error free */
                        ret = 0;
                        goto fail_alias;
                }

match:
                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:
        scoped_guard(mutex, &mfd_of_node_mutex) {
                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);

        scoped_guard(mutex, &mfd_of_node_mutex) {
                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_DESCRIPTION("Core MFD support");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");