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