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