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