/*
 * 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 = 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 (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\n", 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'\n",
                                        clones[i]);
        }

        put_device(dev);

        return 0;
}
EXPORT_SYMBOL(mfd_clone_cell);

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