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 static int mfd_add_device(struct device *parent, int id,
  82                           const struct mfd_cell *cell, atomic_t *usage_count,
  83                           struct resource *mem_base,
  84                           int irq_base, struct irq_domain *domain)
  85 {
  86         struct resource *res;
  87         struct platform_device *pdev;
  88         struct device_node *np = NULL;
  89         int ret = -ENOMEM;
  90         int r;
  91
  92         pdev = platform_device_alloc(cell->name, id + cell->id);
  93         if (!pdev)
  94                 goto fail_alloc;
  95
  96         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
  97         if (!res)
  98                 goto fail_device;
  99
 100         pdev->dev.parent = parent;
 101         pdev->dev.type = &mfd_dev_type;
 102         pdev->dev.dma_mask = parent->dma_mask;
 103         pdev->dev.dma_parms = parent->dma_parms;
 104
 105         ret = devm_regulator_bulk_register_supply_alias(
 106                         &pdev->dev, cell->parent_supplies,
 107                         parent, cell->parent_supplies,
 108                         cell->num_parent_supplies);
 109         if (ret < 0)
 110                 goto fail_res;
 111
 112         if (parent->of_node && cell->of_compatible) {
 113                 for_each_child_of_node(parent->of_node, np) {
 114                         if (of_device_is_compatible(np, cell->of_compatible)) {
 115                                 pdev->dev.of_node = np;
 116                                 break;
 117                         }
 118                 }
 119         }
 120
 121         if (cell->pdata_size) {
 122                 ret = platform_device_add_data(pdev,
 123                                         cell->platform_data, cell->pdata_size);
 124                 if (ret)
 125                         goto fail_alias;
 126         }
 127
 128         ret = mfd_platform_add_cell(pdev, cell, usage_count);
 129         if (ret)
 130                 goto fail_alias;
 131
 132         for (r = 0; r < cell->num_resources; r++) {
 133                 res[r].name = cell->resources[r].name;
 134                 res[r].flags = cell->resources[r].flags;
 135
 136                 /* Find out base to use */
 137                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 138                         res[r].parent = mem_base;
 139                         res[r].start = mem_base->start +
 140                                 cell->resources[r].start;
 141                         res[r].end = mem_base->start +
 142                                 cell->resources[r].end;
 143                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 144                         if (domain) {
 145                                 /* Unable to create mappings for IRQ ranges. */
 146                                 WARN_ON(cell->resources[r].start !=
 147                                         cell->resources[r].end);
 148                                 res[r].start = res[r].end = irq_create_mapping(
 149                                         domain, cell->resources[r].start);
 150                         } else {
 151                                 res[r].start = irq_base +
 152                                         cell->resources[r].start;
 153                                 res[r].end   = irq_base +
 154                                         cell->resources[r].end;
 155                         }
 156                 } else {
 157                         res[r].parent = cell->resources[r].parent;
 158                         res[r].start = cell->resources[r].start;
 159                         res[r].end   = cell->resources[r].end;
 160                 }
 161
 162                 if (!cell->ignore_resource_conflicts) {
 163                         ret = acpi_check_resource_conflict(&res[r]);
 164                         if (ret)
 165                                 goto fail_alias;
 166                 }
 167         }
 168
 169         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 170         if (ret)
 171                 goto fail_alias;
 172
 173         ret = platform_device_add(pdev);
 174         if (ret)
 175                 goto fail_alias;
 176
 177         if (cell->pm_runtime_no_callbacks)
 178                 pm_runtime_no_callbacks(&pdev->dev);
 179
 180         kfree(res);
 181
 182         return 0;
 183
 184 fail_alias:
 185         devm_regulator_bulk_unregister_supply_alias(&pdev->dev,
 186                                                     cell->parent_supplies,
 187                                                     cell->num_parent_supplies);
 188 fail_res:
 189         kfree(res);
 190 fail_device:
 191         platform_device_put(pdev);
 192 fail_alloc:
 193         return ret;
 194 }
 195
 196 int mfd_add_devices(struct device *parent, int id,
 197                     const struct mfd_cell *cells, int n_devs,
 198                     struct resource *mem_base,
 199                     int irq_base, struct irq_domain *domain)
 200 {
 201         int i;
 202         int ret;
 203         atomic_t *cnts;
 204
 205         /* initialize reference counting for all cells */
 206         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 207         if (!cnts)
 208                 return -ENOMEM;
 209
 210         for (i = 0; i < n_devs; i++) {
 211                 atomic_set(&cnts[i], 0);
 212                 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
 213                                      irq_base, domain);
 214                 if (ret)
 215                         goto fail;
 216         }
 217
 218         return 0;
 219
 220 fail:
 221         if (i)
 222                 mfd_remove_devices(parent);
 223         else
 224                 kfree(cnts);
 225         return ret;
 226 }
 227 EXPORT_SYMBOL(mfd_add_devices);
 228
 229 static int mfd_remove_devices_fn(struct device *dev, void *c)
 230 {
 231         struct platform_device *pdev;
 232         const struct mfd_cell *cell;
 233         atomic_t **usage_count = c;
 234
 235         if (dev->type != &mfd_dev_type)
 236                 return 0;
 237
 238         pdev = to_platform_device(dev);
 239         cell = mfd_get_cell(pdev);
 240
 241         /* find the base address of usage_count pointers (for freeing) */
 242         if (!*usage_count || (cell->usage_count < *usage_count))
 243                 *usage_count = cell->usage_count;
 244
 245         platform_device_unregister(pdev);
 246         return 0;
 247 }
 248
 249 void mfd_remove_devices(struct device *parent)
 250 {
 251         atomic_t *cnts = NULL;
 252
 253         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 254         kfree(cnts);
 255 }
 256 EXPORT_SYMBOL(mfd_remove_devices);
 257
 258 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 259 {
 260         struct mfd_cell cell_entry;
 261         struct device *dev;
 262         struct platform_device *pdev;
 263         int i;
 264
 265         /* fetch the parent cell's device (should already be registered!) */
 266         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 267         if (!dev) {
 268                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 269                 return -ENODEV;
 270         }
 271         pdev = to_platform_device(dev);
 272         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 273
 274         WARN_ON(!cell_entry.enable);
 275
 276         for (i = 0; i < n_clones; i++) {
 277                 cell_entry.name = clones[i];
 278                 /* don't give up if a single call fails; just report error */
 279                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
 280                                    cell_entry.usage_count, NULL, 0, NULL))
 281                         dev_err(dev, "failed to create platform device '%s'\n",
 282                                         clones[i]);
 283         }
 284
 285         return 0;
 286 }
 287 EXPORT_SYMBOL(mfd_clone_cell);
 288
 289 MODULE_LICENSE("GPL");
 290 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");