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 {
  69         if (!cell)
  70                 return 0;
  71
  72         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
  73         if (!pdev->mfd_cell)
  74                 return -ENOMEM;
  75
  76         return 0;
  77 }
  78
  79 static int mfd_add_device(struct device *parent, int id,
  80                           const struct mfd_cell *cell,
  81                           struct resource *mem_base,
  82                           int irq_base, struct irq_domain *domain)
  83 {
  84         struct resource *res;
  85         struct platform_device *pdev;
  86         struct device_node *np = NULL;
  87         int ret = -ENOMEM;
  88         int r;
  89
  90         pdev = platform_device_alloc(cell->name, id + cell->id);
  91         if (!pdev)
  92                 goto fail_alloc;
  93
  94         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
  95         if (!res)
  96                 goto fail_device;
  97
  98         pdev->dev.parent = parent;
  99         pdev->dev.type = &mfd_dev_type;
 100         pdev->dev.dma_mask = parent->dma_mask;
 101         pdev->dev.dma_parms = parent->dma_parms;
 102
 103         ret = devm_regulator_bulk_register_supply_alias(
 104                         &pdev->dev, cell->parent_supplies,
 105                         parent, cell->parent_supplies,
 106                         cell->num_parent_supplies);
 107         if (ret < 0)
 108                 goto fail_res;
 109
 110         if (parent->of_node && cell->of_compatible) {
 111                 for_each_child_of_node(parent->of_node, np) {
 112                         if (of_device_is_compatible(np, cell->of_compatible)) {
 113                                 pdev->dev.of_node = np;
 114                                 break;
 115                         }
 116                 }
 117         }
 118
 119         if (cell->pdata_size) {
 120                 ret = platform_device_add_data(pdev,
 121                                         cell->platform_data, cell->pdata_size);
 122                 if (ret)
 123                         goto fail_alias;
 124         }
 125
 126         ret = mfd_platform_add_cell(pdev, cell);
 127         if (ret)
 128                 goto fail_alias;
 129
 130         for (r = 0; r < cell->num_resources; r++) {
 131                 res[r].name = cell->resources[r].name;
 132                 res[r].flags = cell->resources[r].flags;
 133
 134                 /* Find out base to use */
 135                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 136                         res[r].parent = mem_base;
 137                         res[r].start = mem_base->start +
 138                                 cell->resources[r].start;
 139                         res[r].end = mem_base->start +
 140                                 cell->resources[r].end;
 141                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 142                         if (domain) {
 143                                 /* Unable to create mappings for IRQ ranges. */
 144                                 WARN_ON(cell->resources[r].start !=
 145                                         cell->resources[r].end);
 146                                 res[r].start = res[r].end = irq_create_mapping(
 147                                         domain, cell->resources[r].start);
 148                         } else {
 149                                 res[r].start = irq_base +
 150                                         cell->resources[r].start;
 151                                 res[r].end   = irq_base +
 152                                         cell->resources[r].end;
 153                         }
 154                 } else {
 155                         res[r].parent = cell->resources[r].parent;
 156                         res[r].start = cell->resources[r].start;
 157                         res[r].end   = cell->resources[r].end;
 158                 }
 159
 160                 if (!cell->ignore_resource_conflicts) {
 161                         ret = acpi_check_resource_conflict(&res[r]);
 162                         if (ret)
 163                                 goto fail_alias;
 164                 }
 165         }
 166
 167         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 168         if (ret)
 169                 goto fail_alias;
 170
 171         ret = platform_device_add(pdev);
 172         if (ret)
 173                 goto fail_alias;
 174
 175         if (cell->pm_runtime_no_callbacks)
 176                 pm_runtime_no_callbacks(&pdev->dev);
 177
 178         kfree(res);
 179
 180         return 0;
 181
 182 fail_alias:
 183         devm_regulator_bulk_unregister_supply_alias(&pdev->dev,
 184                                                     cell->parent_supplies,
 185                                                     cell->num_parent_supplies);
 186 fail_res:
 187         kfree(res);
 188 fail_device:
 189         platform_device_put(pdev);
 190 fail_alloc:
 191         return ret;
 192 }
 193
 194 int mfd_add_devices(struct device *parent, int id,
 195                     struct mfd_cell *cells, int n_devs,
 196                     struct resource *mem_base,
 197                     int irq_base, struct irq_domain *domain)
 198 {
 199         int i;
 200         int ret = 0;
 201         atomic_t *cnts;
 202
 203         /* initialize reference counting for all cells */
 204         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 205         if (!cnts)
 206                 return -ENOMEM;
 207
 208         for (i = 0; i < n_devs; i++) {
 209                 atomic_set(&cnts[i], 0);
 210                 cells[i].usage_count = &cnts[i];
 211                 ret = mfd_add_device(parent, id, cells + i, mem_base,
 212                                      irq_base, domain);
 213                 if (ret)
 214                         break;
 215         }
 216
 217         if (ret)
 218                 mfd_remove_devices(parent);
 219
 220         return ret;
 221 }
 222 EXPORT_SYMBOL(mfd_add_devices);
 223
 224 static int mfd_remove_devices_fn(struct device *dev, void *c)
 225 {
 226         struct platform_device *pdev;
 227         const struct mfd_cell *cell;
 228         atomic_t **usage_count = c;
 229
 230         if (dev->type != &mfd_dev_type)
 231                 return 0;
 232
 233         pdev = to_platform_device(dev);
 234         cell = mfd_get_cell(pdev);
 235
 236         /* find the base address of usage_count pointers (for freeing) */
 237         if (!*usage_count || (cell->usage_count < *usage_count))
 238                 *usage_count = cell->usage_count;
 239
 240         platform_device_unregister(pdev);
 241         return 0;
 242 }
 243
 244 void mfd_remove_devices(struct device *parent)
 245 {
 246         atomic_t *cnts = NULL;
 247
 248         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 249         kfree(cnts);
 250 }
 251 EXPORT_SYMBOL(mfd_remove_devices);
 252
 253 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 254 {
 255         struct mfd_cell cell_entry;
 256         struct device *dev;
 257         struct platform_device *pdev;
 258         int i;
 259
 260         /* fetch the parent cell's device (should already be registered!) */
 261         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 262         if (!dev) {
 263                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 264                 return -ENODEV;
 265         }
 266         pdev = to_platform_device(dev);
 267         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 268
 269         WARN_ON(!cell_entry.enable);
 270
 271         for (i = 0; i < n_clones; i++) {
 272                 cell_entry.name = clones[i];
 273                 /* don't give up if a single call fails; just report error */
 274                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0,
 275                                    NULL))
 276                         dev_err(dev, "failed to create platform device '%s'\n",
 277                                         clones[i]);
 278         }
 279
 280         return 0;
 281 }
 282 EXPORT_SYMBOL(mfd_clone_cell);
 283
 284 MODULE_LICENSE("GPL");
 285 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");