drivers/mfd/mfd-core.c

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