kernel/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         struct acpi_device *parent_adev;
  86         struct acpi_device *adev;
  87
  88         parent_adev = ACPI_COMPANION(pdev->dev.parent);
  89         if (!parent_adev)
  90                 return;
  91
  92         /*
  93          * MFD child device gets its ACPI handle either from the ACPI
  94          * device directly under the parent that matches the acpi_pnpid or
  95          * it will use the parent handle if is no acpi_pnpid is given.
  96          */
  97         adev = parent_adev;
  98         if (cell->acpi_pnpid) {
  99                 struct acpi_device_id ids[2] = {};
 100                 struct acpi_device *child_adev;
 101
 102                 strlcpy(ids[0].id, cell->acpi_pnpid, sizeof(ids[0].id));
 103                 list_for_each_entry(child_adev, &parent_adev->children, node)
 104                         if (acpi_match_device_ids(child_adev, ids)) {
 105                                 adev = child_adev;
 106                                 break;
 107                         }
 108         }
 109
 110         ACPI_COMPANION_SET(&pdev->dev, adev);
 111 }
 112 #else
 113 static inline void mfd_acpi_add_device(const struct mfd_cell *cell,
 114                                        struct platform_device *pdev)
 115 {
 116 }
 117 #endif
 118
 119 static int mfd_add_device(struct device *parent, int id,
 120                           const struct mfd_cell *cell, atomic_t *usage_count,
 121                           struct resource *mem_base,
 122                           int irq_base, struct irq_domain *domain)
 123 {
 124         struct resource *res;
 125         struct platform_device *pdev;
 126         struct device_node *np = NULL;
 127         int ret = -ENOMEM;
 128         int platform_id;
 129         int r;
 130
 131         if (id == PLATFORM_DEVID_AUTO)
 132                 platform_id = id;
 133         else
 134                 platform_id = id + cell->id;
 135
 136         pdev = platform_device_alloc(cell->name, platform_id);
 137         if (!pdev)
 138                 goto fail_alloc;
 139
 140         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
 141         if (!res)
 142                 goto fail_device;
 143
 144         pdev->dev.parent = parent;
 145         pdev->dev.type = &mfd_dev_type;
 146         pdev->dev.dma_mask = parent->dma_mask;
 147         pdev->dev.dma_parms = parent->dma_parms;
 148         pdev->dev.coherent_dma_mask = parent->coherent_dma_mask;
 149
 150         ret = regulator_bulk_register_supply_alias(
 151                         &pdev->dev, cell->parent_supplies,
 152                         parent, cell->parent_supplies,
 153                         cell->num_parent_supplies);
 154         if (ret < 0)
 155                 goto fail_res;
 156
 157         if (parent->of_node && cell->of_compatible) {
 158                 for_each_child_of_node(parent->of_node, np) {
 159                         if (of_device_is_compatible(np, cell->of_compatible)) {
 160                                 pdev->dev.of_node = np;
 161                                 break;
 162                         }
 163                 }
 164         }
 165
 166         mfd_acpi_add_device(cell, pdev);
 167
 168         if (cell->pdata_size) {
 169                 ret = platform_device_add_data(pdev,
 170                                         cell->platform_data, cell->pdata_size);
 171                 if (ret)
 172                         goto fail_alias;
 173         }
 174
 175         ret = mfd_platform_add_cell(pdev, cell, usage_count);
 176         if (ret)
 177                 goto fail_alias;
 178
 179         for (r = 0; r < cell->num_resources; r++) {
 180                 res[r].name = cell->resources[r].name;
 181                 res[r].flags = cell->resources[r].flags;
 182
 183                 /* Find out base to use */
 184                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 185                         res[r].parent = mem_base;
 186                         res[r].start = mem_base->start +
 187                                 cell->resources[r].start;
 188                         res[r].end = mem_base->start +
 189                                 cell->resources[r].end;
 190                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 191                         if (domain) {
 192                                 /* Unable to create mappings for IRQ ranges. */
 193                                 WARN_ON(cell->resources[r].start !=
 194                                         cell->resources[r].end);
 195                                 res[r].start = res[r].end = irq_create_mapping(
 196                                         domain, cell->resources[r].start);
 197                         } else {
 198                                 res[r].start = irq_base +
 199                                         cell->resources[r].start;
 200                                 res[r].end   = irq_base +
 201                                         cell->resources[r].end;
 202                         }
 203                 } else {
 204                         res[r].parent = cell->resources[r].parent;
 205                         res[r].start = cell->resources[r].start;
 206                         res[r].end   = cell->resources[r].end;
 207                 }
 208
 209                 if (!cell->ignore_resource_conflicts) {
 210                         ret = acpi_check_resource_conflict(&res[r]);
 211                         if (ret)
 212                                 goto fail_alias;
 213                 }
 214         }
 215
 216         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 217         if (ret)
 218                 goto fail_alias;
 219
 220         ret = platform_device_add(pdev);
 221         if (ret)
 222                 goto fail_alias;
 223
 224         if (cell->pm_runtime_no_callbacks)
 225                 pm_runtime_no_callbacks(&pdev->dev);
 226
 227         kfree(res);
 228
 229         return 0;
 230
 231 fail_alias:
 232         regulator_bulk_unregister_supply_alias(&pdev->dev,
 233                                                cell->parent_supplies,
 234                                                cell->num_parent_supplies);
 235 fail_res:
 236         kfree(res);
 237 fail_device:
 238         platform_device_put(pdev);
 239 fail_alloc:
 240         return ret;
 241 }
 242
 243 int mfd_add_devices(struct device *parent, int id,
 244                     const struct mfd_cell *cells, int n_devs,
 245                     struct resource *mem_base,
 246                     int irq_base, struct irq_domain *domain)
 247 {
 248         int i;
 249         int ret;
 250         atomic_t *cnts;
 251
 252         /* initialize reference counting for all cells */
 253         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 254         if (!cnts)
 255                 return -ENOMEM;
 256
 257         for (i = 0; i < n_devs; i++) {
 258                 atomic_set(&cnts[i], 0);
 259                 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
 260                                      irq_base, domain);
 261                 if (ret)
 262                         goto fail;
 263         }
 264
 265         return 0;
 266
 267 fail:
 268         if (i)
 269                 mfd_remove_devices(parent);
 270         else
 271                 kfree(cnts);
 272         return ret;
 273 }
 274 EXPORT_SYMBOL(mfd_add_devices);
 275
 276 static int mfd_remove_devices_fn(struct device *dev, void *c)
 277 {
 278         struct platform_device *pdev;
 279         const struct mfd_cell *cell;
 280         atomic_t **usage_count = c;
 281
 282         if (dev->type != &mfd_dev_type)
 283                 return 0;
 284
 285         pdev = to_platform_device(dev);
 286         cell = mfd_get_cell(pdev);
 287
 288         regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies,
 289                                                cell->num_parent_supplies);
 290
 291         /* find the base address of usage_count pointers (for freeing) */
 292         if (!*usage_count || (cell->usage_count < *usage_count))
 293                 *usage_count = cell->usage_count;
 294
 295         platform_device_unregister(pdev);
 296         return 0;
 297 }
 298
 299 void mfd_remove_devices(struct device *parent)
 300 {
 301         atomic_t *cnts = NULL;
 302
 303         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 304         kfree(cnts);
 305 }
 306 EXPORT_SYMBOL(mfd_remove_devices);
 307
 308 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 309 {
 310         struct mfd_cell cell_entry;
 311         struct device *dev;
 312         struct platform_device *pdev;
 313         int i;
 314
 315         /* fetch the parent cell's device (should already be registered!) */
 316         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 317         if (!dev) {
 318                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 319                 return -ENODEV;
 320         }
 321         pdev = to_platform_device(dev);
 322         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 323
 324         WARN_ON(!cell_entry.enable);
 325
 326         for (i = 0; i < n_clones; i++) {
 327                 cell_entry.name = clones[i];
 328                 /* don't give up if a single call fails; just report error */
 329                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
 330                                    cell_entry.usage_count, NULL, 0, NULL))
 331                         dev_err(dev, "failed to create platform device '%s'\n",
 332                                         clones[i]);
 333         }
 334
 335         return 0;
 336 }
 337 EXPORT_SYMBOL(mfd_clone_cell);
 338
 339 MODULE_LICENSE("GPL");
 340 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");