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         /* 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 }
  45 EXPORT_SYMBOL(mfd_cell_enable);
  46
  47 int 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 }
  65 EXPORT_SYMBOL(mfd_cell_disable);
  66
  67 static 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)
  83 static 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
 134 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
 135                                        struct platform_device *pdev)
 136 {
 137 }
 138 #endif
 139
 140 static 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->properties) {
 197                 ret = platform_device_add_properties(pdev, cell->properties);
 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
 260 fail_alias:
 261         regulator_bulk_unregister_supply_alias(&pdev->dev,
 262                                                cell->parent_supplies,
 263                                                cell->num_parent_supplies);
 264 fail_res:
 265         kfree(res);
 266 fail_device:
 267         platform_device_put(pdev);
 268 fail_alloc:
 269         return ret;
 270 }
 271
 272 int 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
 296 fail:
 297         if (i)
 298                 mfd_remove_devices(parent);
 299         else
 300                 kfree(cnts);
 301         return ret;
 302 }
 303 EXPORT_SYMBOL(mfd_add_devices);
 304
 305 static 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
 328 void 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 }
 335 EXPORT_SYMBOL(mfd_remove_devices);
 336
 337 static void devm_mfd_dev_release(struct device *dev, void *res)
 338 {
 339         mfd_remove_devices(dev);
 340 }
 341
 342 /**
 343  * devm_mfd_add_devices - Resource managed version of mfd_add_devices()
 344  *
 345  * Returns 0 on success or an appropriate negative error number on failure.
 346  * All child-devices of the MFD will automatically be removed when it gets
 347  * unbinded.
 348  */
 349 int devm_mfd_add_devices(struct device *dev, int id,
 350                          const struct mfd_cell *cells, int n_devs,
 351                          struct resource *mem_base,
 352                          int irq_base, struct irq_domain *domain)
 353 {
 354         struct device **ptr;
 355         int ret;
 356
 357         ptr = devres_alloc(devm_mfd_dev_release, sizeof(*ptr), GFP_KERNEL);
 358         if (!ptr)
 359                 return -ENOMEM;
 360
 361         ret = mfd_add_devices(dev, id, cells, n_devs, mem_base,
 362                               irq_base, domain);
 363         if (ret < 0) {
 364                 devres_free(ptr);
 365                 return ret;
 366         }
 367
 368         *ptr = dev;
 369         devres_add(dev, ptr);
 370
 371         return ret;
 372 }
 373 EXPORT_SYMBOL(devm_mfd_add_devices);
 374
 375 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 376 {
 377         struct mfd_cell cell_entry;
 378         struct device *dev;
 379         struct platform_device *pdev;
 380         int i;
 381
 382         /* fetch the parent cell's device (should already be registered!) */
 383         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 384         if (!dev) {
 385                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 386                 return -ENODEV;
 387         }
 388         pdev = to_platform_device(dev);
 389         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 390
 391         WARN_ON(!cell_entry.enable);
 392
 393         for (i = 0; i < n_clones; i++) {
 394                 cell_entry.name = clones[i];
 395                 /* don't give up if a single call fails; just report error */
 396                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
 397                                    cell_entry.usage_count, NULL, 0, NULL))
 398                         dev_err(dev, "failed to create platform device '%s'\n",
 399                                         clones[i]);
 400         }
 401
 402         put_device(dev);
 403
 404         return 0;
 405 }
 406 EXPORT_SYMBOL(mfd_clone_cell);
 407
 408 MODULE_LICENSE("GPL");
 409 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");