drivers/mfd/mfd-core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * drivers/mfd/mfd-core.c
   4  *
   5  * core MFD support
   6  * Copyright (c) 2006 Ian Molton
   7  * Copyright (c) 2007,2008 Dmitry Baryshkov
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/acpi.h>
  13 #include <linux/property.h>
  14 #include <linux/mfd/core.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/slab.h>
  17 #include <linux/module.h>
  18 #include <linux/irqdomain.h>
  19 #include <linux/of.h>
  20 #include <linux/regulator/consumer.h>
  21
  22 static struct device_type mfd_dev_type = {
  23         .name   = "mfd_device",
  24 };
  25
  26 int mfd_cell_enable(struct platform_device *pdev)
  27 {
  28         const struct mfd_cell *cell = mfd_get_cell(pdev);
  29         int err = 0;
  30
  31         /* only call enable hook if the cell wasn't previously enabled */
  32         if (atomic_inc_return(cell->usage_count) == 1)
  33                 err = cell->enable(pdev);
  34
  35         /* if the enable hook failed, decrement counter to allow retries */
  36         if (err)
  37                 atomic_dec(cell->usage_count);
  38
  39         return err;
  40 }
  41 EXPORT_SYMBOL(mfd_cell_enable);
  42
  43 int mfd_cell_disable(struct platform_device *pdev)
  44 {
  45         const struct mfd_cell *cell = mfd_get_cell(pdev);
  46         int err = 0;
  47
  48         /* only disable if no other clients are using it */
  49         if (atomic_dec_return(cell->usage_count) == 0)
  50                 err = cell->disable(pdev);
  51
  52         /* if the disable hook failed, increment to allow retries */
  53         if (err)
  54                 atomic_inc(cell->usage_count);
  55
  56         /* sanity check; did someone call disable too many times? */
  57         WARN_ON(atomic_read(cell->usage_count) < 0);
  58
  59         return err;
  60 }
  61 EXPORT_SYMBOL(mfd_cell_disable);
  62
  63 static int mfd_platform_add_cell(struct platform_device *pdev,
  64                                  const struct mfd_cell *cell,
  65                                  atomic_t *usage_count)
  66 {
  67         if (!cell)
  68                 return 0;
  69
  70         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
  71         if (!pdev->mfd_cell)
  72                 return -ENOMEM;
  73
  74         pdev->mfd_cell->usage_count = usage_count;
  75         return 0;
  76 }
  77
  78 #if IS_ENABLED(CONFIG_ACPI)
  79 static void mfd_acpi_add_device(const struct mfd_cell *cell,
  80                                 struct platform_device *pdev)
  81 {
  82         const struct mfd_cell_acpi_match *match = cell->acpi_match;
  83         struct acpi_device *parent, *child;
  84         struct acpi_device *adev;
  85
  86         parent = ACPI_COMPANION(pdev->dev.parent);
  87         if (!parent)
  88                 return;
  89
  90         /*
  91          * MFD child device gets its ACPI handle either from the ACPI device
  92          * directly under the parent that matches the either _HID or _CID, or
  93          * _ADR or it will use the parent handle if is no ID is given.
  94          *
  95          * Note that use of _ADR is a grey area in the ACPI specification,
  96          * though Intel Galileo Gen2 is using it to distinguish the children
  97          * devices.
  98          */
  99         adev = parent;
 100         if (match) {
 101                 if (match->pnpid) {
 102                         struct acpi_device_id ids[2] = {};
 103
 104                         strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
 105                         list_for_each_entry(child, &parent->children, node) {
 106                                 if (!acpi_match_device_ids(child, ids)) {
 107                                         adev = child;
 108                                         break;
 109                                 }
 110                         }
 111                 } else {
 112                         unsigned long long adr;
 113                         acpi_status status;
 114
 115                         list_for_each_entry(child, &parent->children, node) {
 116                                 status = acpi_evaluate_integer(child->handle,
 117                                                                "_ADR", NULL,
 118                                                                &adr);
 119                                 if (ACPI_SUCCESS(status) && match->adr == adr) {
 120                                         adev = child;
 121                                         break;
 122                                 }
 123                         }
 124                 }
 125         }
 126
 127         ACPI_COMPANION_SET(&pdev->dev, adev);
 128 }
 129 #else
 130 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
 131                                        struct platform_device *pdev)
 132 {
 133 }
 134 #endif
 135
 136 static int mfd_add_device(struct device *parent, int id,
 137                           const struct mfd_cell *cell, atomic_t *usage_count,
 138                           struct resource *mem_base,
 139                           int irq_base, struct irq_domain *domain)
 140 {
 141         struct resource *res;
 142         struct platform_device *pdev;
 143         struct device_node *np = NULL;
 144         int ret = -ENOMEM;
 145         int platform_id;
 146         int r;
 147
 148         if (id == PLATFORM_DEVID_AUTO)
 149                 platform_id = id;
 150         else
 151                 platform_id = id + cell->id;
 152
 153         pdev = platform_device_alloc(cell->name, platform_id);
 154         if (!pdev)
 155                 goto fail_alloc;
 156
 157         res = kcalloc(cell->num_resources, sizeof(*res), GFP_KERNEL);
 158         if (!res)
 159                 goto fail_device;
 160
 161         pdev->dev.parent = parent;
 162         pdev->dev.type = &mfd_dev_type;
 163         pdev->dev.dma_mask = parent->dma_mask;
 164         pdev->dev.dma_parms = parent->dma_parms;
 165         pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
 166
 167         ret = regulator_bulk_register_supply_alias(
 168                         &pdev->dev, cell->parent_supplies,
 169                         parent, cell->parent_supplies,
 170                         cell->num_parent_supplies);
 171         if (ret < 0)
 172                 goto fail_res;
 173
 174         if (parent->of_node && cell->of_compatible) {
 175                 for_each_child_of_node(parent->of_node, np) {
 176                         if (of_device_is_compatible(np, cell->of_compatible)) {
 177                                 pdev->dev.of_node = np;
 178                                 pdev->dev.fwnode = &np->fwnode;
 179                                 break;
 180                         }
 181                 }
 182         }
 183
 184         mfd_acpi_add_device(cell, pdev);
 185
 186         if (cell->pdata_size) {
 187                 ret = platform_device_add_data(pdev,
 188                                         cell->platform_data, cell->pdata_size);
 189                 if (ret)
 190                         goto fail_alias;
 191         }
 192
 193         if (cell->properties) {
 194                 ret = platform_device_add_properties(pdev, cell->properties);
 195                 if (ret)
 196                         goto fail_alias;
 197         }
 198
 199         ret = mfd_platform_add_cell(pdev, cell, usage_count);
 200         if (ret)
 201                 goto fail_alias;
 202
 203         for (r = 0; r < cell->num_resources; r++) {
 204                 res[r].name = cell->resources[r].name;
 205                 res[r].flags = cell->resources[r].flags;
 206
 207                 /* Find out base to use */
 208                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 209                         res[r].parent = mem_base;
 210                         res[r].start = mem_base->start +
 211                                 cell->resources[r].start;
 212                         res[r].end = mem_base->start +
 213                                 cell->resources[r].end;
 214                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 215                         if (domain) {
 216                                 /* Unable to create mappings for IRQ ranges. */
 217                                 WARN_ON(cell->resources[r].start !=
 218                                         cell->resources[r].end);
 219                                 res[r].start = res[r].end = irq_create_mapping(
 220                                         domain, cell->resources[r].start);
 221                         } else {
 222                                 res[r].start = irq_base +
 223                                         cell->resources[r].start;
 224                                 res[r].end   = irq_base +
 225                                         cell->resources[r].end;
 226                         }
 227                 } else {
 228                         res[r].parent = cell->resources[r].parent;
 229                         res[r].start = cell->resources[r].start;
 230                         res[r].end   = cell->resources[r].end;
 231                 }
 232
 233                 if (!cell->ignore_resource_conflicts) {
 234                         if (has_acpi_companion(&pdev->dev)) {
 235                                 ret = acpi_check_resource_conflict(&res[r]);
 236                                 if (ret)
 237                                         goto fail_alias;
 238                         }
 239                 }
 240         }
 241
 242         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 243         if (ret)
 244                 goto fail_alias;
 245
 246         ret = platform_device_add(pdev);
 247         if (ret)
 248                 goto fail_alias;
 249
 250         if (cell->pm_runtime_no_callbacks)
 251                 pm_runtime_no_callbacks(&pdev->dev);
 252
 253         kfree(res);
 254
 255         return 0;
 256
 257 fail_alias:
 258         regulator_bulk_unregister_supply_alias(&pdev->dev,
 259                                                cell->parent_supplies,
 260                                                cell->num_parent_supplies);
 261 fail_res:
 262         kfree(res);
 263 fail_device:
 264         platform_device_put(pdev);
 265 fail_alloc:
 266         return ret;
 267 }
 268
 269 /**
 270  * mfd_add_devices - register child devices
 271  *
 272  * @parent:     Pointer to parent device.
 273  * @id:         Can be PLATFORM_DEVID_AUTO to let the Platform API take care
 274  *              of device numbering, or will be added to a device's cell_id.
 275  * @cells:      Array of (struct mfd_cell)s describing child devices.
 276  * @n_devs:     Number of child devices to register.
 277  * @mem_base:   Parent register range resource for child devices.
 278  * @irq_base:   Base of the range of virtual interrupt numbers allocated for
 279  *              this MFD device. Unused if @domain is specified.
 280  * @domain:     Interrupt domain to create mappings for hardware interrupts.
 281  */
 282 int mfd_add_devices(struct device *parent, int id,
 283                     const struct mfd_cell *cells, int n_devs,
 284                     struct resource *mem_base,
 285                     int irq_base, struct irq_domain *domain)
 286 {
 287         int i;
 288         int ret;
 289         atomic_t *cnts;
 290
 291         /* initialize reference counting for all cells */
 292         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 293         if (!cnts)
 294                 return -ENOMEM;
 295
 296         for (i = 0; i < n_devs; i++) {
 297                 atomic_set(&cnts[i], 0);
 298                 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
 299                                      irq_base, domain);
 300                 if (ret)
 301                         goto fail;
 302         }
 303
 304         return 0;
 305
 306 fail:
 307         if (i)
 308                 mfd_remove_devices(parent);
 309         else
 310                 kfree(cnts);
 311         return ret;
 312 }
 313 EXPORT_SYMBOL(mfd_add_devices);
 314
 315 static int mfd_remove_devices_fn(struct device *dev, void *c)
 316 {
 317         struct platform_device *pdev;
 318         const struct mfd_cell *cell;
 319         atomic_t **usage_count = c;
 320
 321         if (dev->type != &mfd_dev_type)
 322                 return 0;
 323
 324         pdev = to_platform_device(dev);
 325         cell = mfd_get_cell(pdev);
 326
 327         regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
 328                                                cell->num_parent_supplies);
 329
 330         /* find the base address of usage_count pointers (for freeing) */
 331         if (!*usage_count || (cell->usage_count < *usage_count))
 332                 *usage_count = cell->usage_count;
 333
 334         platform_device_unregister(pdev);
 335         return 0;
 336 }
 337
 338 void mfd_remove_devices(struct device *parent)
 339 {
 340         atomic_t *cnts = NULL;
 341
 342         device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn);
 343         kfree(cnts);
 344 }
 345 EXPORT_SYMBOL(mfd_remove_devices);
 346
 347 static void devm_mfd_dev_release(struct device *dev, void *res)
 348 {
 349         mfd_remove_devices(dev);
 350 }
 351
 352 /**
 353  * devm_mfd_add_devices - Resource managed version of mfd_add_devices()
 354  *
 355  * Returns 0 on success or an appropriate negative error number on failure.
 356  * All child-devices of the MFD will automatically be removed when it gets
 357  * unbinded.
 358  */
 359 int devm_mfd_add_devices(struct device *dev, int id,
 360                          const struct mfd_cell *cells, int n_devs,
 361                          struct resource *mem_base,
 362                          int irq_base, struct irq_domain *domain)
 363 {
 364         struct device **ptr;
 365         int ret;
 366
 367         ptr = devres_alloc(devm_mfd_dev_release, sizeof(*ptr), GFP_KERNEL);
 368         if (!ptr)
 369                 return -ENOMEM;
 370
 371         ret = mfd_add_devices(dev, id, cells, n_devs, mem_base,
 372                               irq_base, domain);
 373         if (ret < 0) {
 374                 devres_free(ptr);
 375                 return ret;
 376         }
 377
 378         *ptr = dev;
 379         devres_add(dev, ptr);
 380
 381         return ret;
 382 }
 383 EXPORT_SYMBOL(devm_mfd_add_devices);
 384
 385 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 386 {
 387         struct mfd_cell cell_entry;
 388         struct device *dev;
 389         struct platform_device *pdev;
 390         int i;
 391
 392         /* fetch the parent cell's device (should already be registered!) */
 393         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 394         if (!dev) {
 395                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 396                 return -ENODEV;
 397         }
 398         pdev = to_platform_device(dev);
 399         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 400
 401         WARN_ON(!cell_entry.enable);
 402
 403         for (i = 0; i < n_clones; i++) {
 404                 cell_entry.name = clones[i];
 405                 /* don't give up if a single call fails; just report error */
 406                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
 407                                    cell_entry.usage_count, NULL, 0, NULL))
 408                         dev_err(dev, "failed to create platform device '%s'\n",
 409                                         clones[i]);
 410         }
 411
 412         put_device(dev);
 413
 414         return 0;
 415 }
 416 EXPORT_SYMBOL(mfd_clone_cell);
 417
 418 MODULE_LICENSE("GPL");
 419 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");