linux/drivers/mfd/mfd-core.c
<<
>>
Prefs
   1/*
   2 * drivers/mfd/mfd-core.c
   3 *
   4 * core MFD support
   5 * Copyright (c) 2006 Ian Molton
   6 * Copyright (c) 2007,2008 Dmitry Baryshkov
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 *
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/platform_device.h>
  16#include <linux/acpi.h>
  17#include <linux/property.h>
  18#include <linux/mfd/core.h>
  19#include <linux/pm_runtime.h>
  20#include <linux/slab.h>
  21#include <linux/module.h>
  22#include <linux/irqdomain.h>
  23#include <linux/of.h>
  24#include <linux/regulator/consumer.h>
  25
  26static struct device_type mfd_dev_type = {
  27        .name   = "mfd_device",
  28};
  29
  30int mfd_cell_enable(struct platform_device *pdev)
  31{
  32        const struct mfd_cell *cell = mfd_get_cell(pdev);
  33        int err = 0;
  34
  35        /* only call enable hook if the cell wasn't previously enabled */
  36        if (atomic_inc_return(cell->usage_count) == 1)
  37                err = cell->enable(pdev);
  38
  39        /* if the enable hook failed, decrement counter to allow retries */
  40        if (err)
  41                atomic_dec(cell->usage_count);
  42
  43        return err;
  44}
  45EXPORT_SYMBOL(mfd_cell_enable);
  46
  47int mfd_cell_disable(struct platform_device *pdev)
  48{
  49        const struct mfd_cell *cell = mfd_get_cell(pdev);
  50        int err = 0;
  51
  52        /* only disable if no other clients are using it */
  53        if (atomic_dec_return(cell->usage_count) == 0)
  54                err = cell->disable(pdev);
  55
  56        /* if the disable hook failed, increment to allow retries */
  57        if (err)
  58                atomic_inc(cell->usage_count);
  59
  60        /* sanity check; did someone call disable too many times? */
  61        WARN_ON(atomic_read(cell->usage_count) < 0);
  62
  63        return err;
  64}
  65EXPORT_SYMBOL(mfd_cell_disable);
  66
  67static int mfd_platform_add_cell(struct platform_device *pdev,
  68                                 const struct mfd_cell *cell,
  69                                 atomic_t *usage_count)
  70{
  71        if (!cell)
  72                return 0;
  73
  74        pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
  75        if (!pdev->mfd_cell)
  76                return -ENOMEM;
  77
  78        pdev->mfd_cell->usage_count = usage_count;
  79        return 0;
  80}
  81
  82#if IS_ENABLED(CONFIG_ACPI)
  83static void mfd_acpi_add_device(const struct mfd_cell *cell,
  84                                struct platform_device *pdev)
  85{
  86        const struct mfd_cell_acpi_match *match = cell->acpi_match;
  87        struct acpi_device *parent, *child;
  88        struct acpi_device *adev;
  89
  90        parent = ACPI_COMPANION(pdev->dev.parent);
  91        if (!parent)
  92                return;
  93
  94        /*
  95         * MFD child device gets its ACPI handle either from the ACPI device
  96         * directly under the parent that matches the either _HID or _CID, or
  97         * _ADR or it will use the parent handle if is no ID is given.
  98         *
  99         * Note that use of _ADR is a grey area in the ACPI specification,
 100         * though Intel Galileo Gen2 is using it to distinguish the children
 101         * devices.
 102         */
 103        adev = parent;
 104        if (match) {
 105                if (match->pnpid) {
 106                        struct acpi_device_id ids[2] = {};
 107
 108                        strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
 109                        list_for_each_entry(child, &parent->children, node) {
 110                                if (acpi_match_device_ids(child, ids)) {
 111                                        adev = child;
 112                                        break;
 113                                }
 114                        }
 115                } else {
 116                        unsigned long long adr;
 117                        acpi_status status;
 118
 119                        list_for_each_entry(child, &parent->children, node) {
 120                                status = acpi_evaluate_integer(child->handle,
 121                                                               "_ADR", NULL,
 122                                                               &adr);
 123                                if (ACPI_SUCCESS(status) && match->adr == adr) {
 124                                        adev = child;
 125                                        break;
 126                                }
 127                        }
 128                }
 129        }
 130
 131        ACPI_COMPANION_SET(&pdev->dev, adev);
 132}
 133#else
 134static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
 135                                       struct platform_device *pdev)
 136{
 137}
 138#endif
 139
 140static int mfd_add_device(struct device *parent, int id,
 141                          const struct mfd_cell *cell, atomic_t *usage_count,
 142                          struct resource *mem_base,
 143                          int irq_base, struct irq_domain *domain)
 144{
 145        struct resource *res;
 146        struct platform_device *pdev;
 147        struct device_node *np = NULL;
 148        int ret = -ENOMEM;
 149        int platform_id;
 150        int r;
 151
 152        if (id == PLATFORM_DEVID_AUTO)
 153                platform_id = id;
 154        else
 155                platform_id = id + cell->id;
 156
 157        pdev = platform_device_alloc(cell->name, platform_id);
 158        if (!pdev)
 159                goto fail_alloc;
 160
 161        res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
 162        if (!res)
 163                goto fail_device;
 164
 165        pdev->dev.parent = parent;
 166        pdev->dev.type = &mfd_dev_type;
 167        pdev->dev.dma_mask = parent->dma_mask;
 168        pdev->dev.dma_parms = parent->dma_parms;
 169        pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
 170
 171        ret = regulator_bulk_register_supply_alias(
 172                        &pdev->dev, cell->parent_supplies,
 173                        parent, cell->parent_supplies,
 174                        cell->num_parent_supplies);
 175        if (ret < 0)
 176                goto fail_res;
 177
 178        if (parent->of_node && cell->of_compatible) {
 179                for_each_child_of_node(parent->of_node, np) {
 180                        if (of_device_is_compatible(np, cell->of_compatible)) {
 181                                pdev->dev.of_node = np;
 182                                break;
 183                        }
 184                }
 185        }
 186
 187        mfd_acpi_add_device(cell, pdev);
 188
 189        if (cell->pdata_size) {
 190                ret = platform_device_add_data(pdev,
 191                                        cell->platform_data, cell->pdata_size);
 192                if (ret)
 193                        goto fail_alias;
 194        }
 195
 196        if (cell->pset) {
 197                ret = platform_device_add_properties(pdev, cell->pset);
 198                if (ret)
 199                        goto fail_alias;
 200        }
 201
 202        ret = mfd_platform_add_cell(pdev, cell, usage_count);
 203        if (ret)
 204                goto fail_alias;
 205
 206        for (r = 0; r < cell->num_resources; r++) {
 207                res[r].name = cell->resources[r].name;
 208                res[r].flags = cell->resources[r].flags;
 209
 210                /* Find out base to use */
 211                if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 212                        res[r].parent = mem_base;
 213                        res[r].start = mem_base->start +
 214                                cell->resources[r].start;
 215                        res[r].end = mem_base->start +
 216                                cell->resources[r].end;
 217                } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 218                        if (domain) {
 219                                /* Unable to create mappings for IRQ ranges. */
 220                                WARN_ON(cell->resources[r].start !=
 221                                        cell->resources[r].end);
 222                                res[r].start = res[r].end = irq_create_mapping(
 223                                        domain, cell->resources[r].start);
 224                        } else {
 225                                res[r].start = irq_base +
 226                                        cell->resources[r].start;
 227                                res[r].end   = irq_base +
 228                                        cell->resources[r].end;
 229                        }
 230                } else {
 231                        res[r].parent = cell->resources[r].parent;
 232                        res[r].start = cell->resources[r].start;
 233                        res[r].end   = cell->resources[r].end;
 234                }
 235
 236                if (!cell->ignore_resource_conflicts) {
 237                        if (has_acpi_companion(&pdev->dev)) {
 238                                ret = acpi_check_resource_conflict(&res[r]);
 239                                if (ret)
 240                                        goto fail_alias;
 241                        }
 242                }
 243        }
 244
 245        ret = platform_device_add_resources(pdev, res, cell->num_resources);
 246        if (ret)
 247                goto fail_alias;
 248
 249        ret = platform_device_add(pdev);
 250        if (ret)
 251                goto fail_alias;
 252
 253        if (cell->pm_runtime_no_callbacks)
 254                pm_runtime_no_callbacks(&pdev->dev);
 255
 256        kfree(res);
 257
 258        return 0;
 259
 260fail_alias:
 261        regulator_bulk_unregister_supply_alias(&pdev->dev,
 262                                               cell->parent_supplies,
 263                                               cell->num_parent_supplies);
 264fail_res:
 265        kfree(res);
 266fail_device:
 267        platform_device_put(pdev);
 268fail_alloc:
 269        return ret;
 270}
 271
 272int mfd_add_devices(struct device *parent, int id,
 273                    const struct mfd_cell *cells, int n_devs,
 274                    struct resource *mem_base,
 275                    int irq_base, struct irq_domain *domain)
 276{
 277        int i;
 278        int ret;
 279        atomic_t *cnts;
 280
 281        /* initialize reference counting for all cells */
 282        cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 283        if (!cnts)
 284                return -ENOMEM;
 285
 286        for (i = 0; i < n_devs; i++) {
 287                atomic_set(&cnts[i], 0);
 288                ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
 289                                     irq_base, domain);
 290                if (ret)
 291                        goto fail;
 292        }
 293
 294        return 0;
 295
 296fail:
 297        if (i)
 298                mfd_remove_devices(parent);
 299        else
 300                kfree(cnts);
 301        return ret;
 302}
 303EXPORT_SYMBOL(mfd_add_devices);
 304
 305static int mfd_remove_devices_fn(struct device *dev, void *c)
 306{
 307        struct platform_device *pdev;
 308        const struct mfd_cell *cell;
 309        atomic_t **usage_count = c;
 310
 311        if (dev->type != &mfd_dev_type)
 312                return 0;
 313
 314        pdev = to_platform_device(dev);
 315        cell = mfd_get_cell(pdev);
 316
 317        regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
 318                                               cell->num_parent_supplies);
 319
 320        /* find the base address of usage_count pointers (for freeing) */
 321        if (!*usage_count || (cell->usage_count < *usage_count))
 322                *usage_count = cell->usage_count;
 323
 324        platform_device_unregister(pdev);
 325        return 0;
 326}
 327
 328void mfd_remove_devices(struct device *parent)
 329{
 330        atomic_t *cnts = NULL;
 331
 332        device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn);
 333        kfree(cnts);
 334}
 335EXPORT_SYMBOL(mfd_remove_devices);
 336
 337int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 338{
 339        struct mfd_cell cell_entry;
 340        struct device *dev;
 341        struct platform_device *pdev;
 342        int i;
 343
 344        /* fetch the parent cell's device (should already be registered!) */
 345        dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 346        if (!dev) {
 347                printk(KERN_ERR "failed to find device for cell %s\n", cell);
 348                return -ENODEV;
 349        }
 350        pdev = to_platform_device(dev);
 351        memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 352
 353        WARN_ON(!cell_entry.enable);
 354
 355        for (i = 0; i < n_clones; i++) {
 356                cell_entry.name = clones[i];
 357                /* don't give up if a single call fails; just report error */
 358                if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
 359                                   cell_entry.usage_count, NULL, 0, NULL))
 360                        dev_err(dev, "failed to create platform device '%s'\n",
 361                                        clones[i]);
 362        }
 363
 364        return 0;
 365}
 366EXPORT_SYMBOL(mfd_clone_cell);
 367
 368MODULE_LICENSE("GPL");
 369MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
 370