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
  24 static struct device_type mfd_dev_type = {
  25         .name   = "mfd_device",
  26 };
  27
  28 int mfd_cell_enable(struct platform_device *pdev)
  29 {
  30         const struct mfd_cell *cell = mfd_get_cell(pdev);
  31         int err = 0;
  32
  33         /* only call enable hook if the cell wasn't previously enabled */
  34         if (atomic_inc_return(cell->usage_count) == 1)
  35                 err = cell->enable(pdev);
  36
  37         /* if the enable hook failed, decrement counter to allow retries */
  38         if (err)
  39                 atomic_dec(cell->usage_count);
  40
  41         return err;
  42 }
  43 EXPORT_SYMBOL(mfd_cell_enable);
  44
  45 int mfd_cell_disable(struct platform_device *pdev)
  46 {
  47         const struct mfd_cell *cell = mfd_get_cell(pdev);
  48         int err = 0;
  49
  50         /* only disable if no other clients are using it */
  51         if (atomic_dec_return(cell->usage_count) == 0)
  52                 err = cell->disable(pdev);
  53
  54         /* if the disable hook failed, increment to allow retries */
  55         if (err)
  56                 atomic_inc(cell->usage_count);
  57
  58         /* sanity check; did someone call disable too many times? */
  59         WARN_ON(atomic_read(cell->usage_count) < 0);
  60
  61         return err;
  62 }
  63 EXPORT_SYMBOL(mfd_cell_disable);
  64
  65 static int mfd_platform_add_cell(struct platform_device *pdev,
  66                                  const struct mfd_cell *cell,
  67                                  atomic_t *usage_count)
  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         pdev->mfd_cell->usage_count = usage_count;
  77         return 0;
  78 }
  79
  80 static int mfd_add_device(struct device *parent, int id,
  81                           const struct mfd_cell *cell, atomic_t *usage_count,
  82                           struct resource *mem_base,
  83                           int irq_base, struct irq_domain *domain)
  84 {
  85         struct resource *res;
  86         struct platform_device *pdev;
  87         struct device_node *np = NULL;
  88         int ret = -ENOMEM;
  89         int r;
  90
  91         pdev = platform_device_alloc(cell->name, id + cell->id);
  92         if (!pdev)
  93                 goto fail_alloc;
  94
  95         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
  96         if (!res)
  97                 goto fail_device;
  98
  99         pdev->dev.parent = parent;
 100         pdev->dev.type = &mfd_dev_type;
 101         pdev->dev.dma_mask = parent->dma_mask;
 102         pdev->dev.dma_parms = parent->dma_parms;
 103
 104         if (parent->of_node && cell->of_compatible) {
 105                 for_each_child_of_node(parent->of_node, np) {
 106                         if (of_device_is_compatible(np, cell->of_compatible)) {
 107                                 pdev->dev.of_node = np;
 108                                 break;
 109                         }
 110                 }
 111         }
 112
 113         if (cell->pdata_size) {
 114                 ret = platform_device_add_data(pdev,
 115                                         cell->platform_data, cell->pdata_size);
 116                 if (ret)
 117                         goto fail_res;
 118         }
 119
 120         ret = mfd_platform_add_cell(pdev, cell, usage_count);
 121         if (ret)
 122                 goto fail_res;
 123
 124         for (r = 0; r < cell->num_resources; r++) {
 125                 res[r].name = cell->resources[r].name;
 126                 res[r].flags = cell->resources[r].flags;
 127
 128                 /* Find out base to use */
 129                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 130                         res[r].parent = mem_base;
 131                         res[r].start = mem_base->start +
 132                                 cell->resources[r].start;
 133                         res[r].end = mem_base->start +
 134                                 cell->resources[r].end;
 135                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 136                         if (domain) {
 137                                 /* Unable to create mappings for IRQ ranges. */
 138                                 WARN_ON(cell->resources[r].start !=
 139                                         cell->resources[r].end);
 140                                 res[r].start = res[r].end = irq_create_mapping(
 141                                         domain, cell->resources[r].start);
 142                         } else {
 143                                 res[r].start = irq_base +
 144                                         cell->resources[r].start;
 145                                 res[r].end   = irq_base +
 146                                         cell->resources[r].end;
 147                         }
 148                 } else {
 149                         res[r].parent = cell->resources[r].parent;
 150                         res[r].start = cell->resources[r].start;
 151                         res[r].end   = cell->resources[r].end;
 152                 }
 153
 154                 if (!cell->ignore_resource_conflicts) {
 155                         ret = acpi_check_resource_conflict(&res[r]);
 156                         if (ret)
 157                                 goto fail_res;
 158                 }
 159         }
 160
 161         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 162         if (ret)
 163                 goto fail_res;
 164
 165         ret = platform_device_add(pdev);
 166         if (ret)
 167                 goto fail_res;
 168
 169         if (cell->pm_runtime_no_callbacks)
 170                 pm_runtime_no_callbacks(&pdev->dev);
 171
 172         kfree(res);
 173
 174         return 0;
 175
 176 fail_res:
 177         kfree(res);
 178 fail_device:
 179         platform_device_put(pdev);
 180 fail_alloc:
 181         return ret;
 182 }
 183
 184 int mfd_add_devices(struct device *parent, int id,
 185                     const struct mfd_cell *cells, int n_devs,
 186                     struct resource *mem_base,
 187                     int irq_base, struct irq_domain *domain)
 188 {
 189         int i;
 190         int ret;
 191         atomic_t *cnts;
 192
 193         /* initialize reference counting for all cells */
 194         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 195         if (!cnts)
 196                 return -ENOMEM;
 197
 198         for (i = 0; i < n_devs; i++) {
 199                 atomic_set(&cnts[i], 0);
 200                 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base,
 201                                      irq_base, domain);
 202                 if (ret)
 203                         goto fail;
 204         }
 205
 206         return 0;
 207
 208 fail:
 209         if (i)
 210                 mfd_remove_devices(parent);
 211         else
 212                 kfree(cnts);
 213         return ret;
 214 }
 215 EXPORT_SYMBOL(mfd_add_devices);
 216
 217 static int mfd_remove_devices_fn(struct device *dev, void *c)
 218 {
 219         struct platform_device *pdev;
 220         const struct mfd_cell *cell;
 221         atomic_t **usage_count = c;
 222
 223         if (dev->type != &mfd_dev_type)
 224                 return 0;
 225
 226         pdev = to_platform_device(dev);
 227         cell = mfd_get_cell(pdev);
 228
 229         /* find the base address of usage_count pointers (for freeing) */
 230         if (!*usage_count || (cell->usage_count < *usage_count))
 231                 *usage_count = cell->usage_count;
 232
 233         platform_device_unregister(pdev);
 234         return 0;
 235 }
 236
 237 void mfd_remove_devices(struct device *parent)
 238 {
 239         atomic_t *cnts = NULL;
 240
 241         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 242         kfree(cnts);
 243 }
 244 EXPORT_SYMBOL(mfd_remove_devices);
 245
 246 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 247 {
 248         struct mfd_cell cell_entry;
 249         struct device *dev;
 250         struct platform_device *pdev;
 251         int i;
 252
 253         /* fetch the parent cell's device (should already be registered!) */
 254         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 255         if (!dev) {
 256                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 257                 return -ENODEV;
 258         }
 259         pdev = to_platform_device(dev);
 260         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 261
 262         WARN_ON(!cell_entry.enable);
 263
 264         for (i = 0; i < n_clones; i++) {
 265                 cell_entry.name = clones[i];
 266                 /* don't give up if a single call fails; just report error */
 267                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry,
 268                                    cell_entry.usage_count, NULL, 0, NULL))
 269                         dev_err(dev, "failed to create platform device '%s'\n",
 270                                         clones[i]);
 271         }
 272
 273         return 0;
 274 }
 275 EXPORT_SYMBOL(mfd_clone_cell);
 276
 277 MODULE_LICENSE("GPL");
 278 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");