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 int mfd_cell_enable(struct platform_device *pdev)
  25 {
  26         const struct mfd_cell *cell = mfd_get_cell(pdev);
  27         int err = 0;
  28
  29         /* only call enable hook if the cell wasn't previously enabled */
  30         if (atomic_inc_return(cell->usage_count) == 1)
  31                 err = cell->enable(pdev);
  32
  33         /* if the enable hook failed, decrement counter to allow retries */
  34         if (err)
  35                 atomic_dec(cell->usage_count);
  36
  37         return err;
  38 }
  39 EXPORT_SYMBOL(mfd_cell_enable);
  40
  41 int mfd_cell_disable(struct platform_device *pdev)
  42 {
  43         const struct mfd_cell *cell = mfd_get_cell(pdev);
  44         int err = 0;
  45
  46         /* only disable if no other clients are using it */
  47         if (atomic_dec_return(cell->usage_count) == 0)
  48                 err = cell->disable(pdev);
  49
  50         /* if the disable hook failed, increment to allow retries */
  51         if (err)
  52                 atomic_inc(cell->usage_count);
  53
  54         /* sanity check; did someone call disable too many times? */
  55         WARN_ON(atomic_read(cell->usage_count) < 0);
  56
  57         return err;
  58 }
  59 EXPORT_SYMBOL(mfd_cell_disable);
  60
  61 static int mfd_platform_add_cell(struct platform_device *pdev,
  62                                  const struct mfd_cell *cell)
  63 {
  64         if (!cell)
  65                 return 0;
  66
  67         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
  68         if (!pdev->mfd_cell)
  69                 return -ENOMEM;
  70
  71         return 0;
  72 }
  73
  74 static int mfd_add_device(struct device *parent, int id,
  75                           const struct mfd_cell *cell,
  76                           struct resource *mem_base,
  77                           int irq_base)
  78 {
  79         struct resource *res;
  80         struct platform_device *pdev;
  81         struct device_node *np = NULL;
  82         struct irq_domain *domain = NULL;
  83         int ret = -ENOMEM;
  84         int r;
  85
  86         pdev = platform_device_alloc(cell->name, id + cell->id);
  87         if (!pdev)
  88                 goto fail_alloc;
  89
  90         res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
  91         if (!res)
  92                 goto fail_device;
  93
  94         pdev->dev.parent = parent;
  95
  96         if (parent->of_node && cell->of_compatible) {
  97                 for_each_child_of_node(parent->of_node, np) {
  98                         if (of_device_is_compatible(np, cell->of_compatible)) {
  99                                 pdev->dev.of_node = np;
 100                                 domain = irq_find_host(parent->of_node);
 101                                 break;
 102                         }
 103                 }
 104         }
 105
 106         if (cell->pdata_size) {
 107                 ret = platform_device_add_data(pdev,
 108                                         cell->platform_data, cell->pdata_size);
 109                 if (ret)
 110                         goto fail_res;
 111         }
 112
 113         ret = mfd_platform_add_cell(pdev, cell);
 114         if (ret)
 115                 goto fail_res;
 116
 117         for (r = 0; r < cell->num_resources; r++) {
 118                 res[r].name = cell->resources[r].name;
 119                 res[r].flags = cell->resources[r].flags;
 120
 121                 /* Find out base to use */
 122                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 123                         res[r].parent = mem_base;
 124                         res[r].start = mem_base->start +
 125                                 cell->resources[r].start;
 126                         res[r].end = mem_base->start +
 127                                 cell->resources[r].end;
 128                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 129                         if (domain) {
 130                                 /* Unable to create mappings for IRQ ranges. */
 131                                 WARN_ON(cell->resources[r].start !=
 132                                         cell->resources[r].end);
 133                                 res[r].start = res[r].end = irq_create_mapping(
 134                                         domain, cell->resources[r].start);
 135                         } else {
 136                                 res[r].start = irq_base +
 137                                         cell->resources[r].start;
 138                                 res[r].end   = irq_base +
 139                                         cell->resources[r].end;
 140                         }
 141                 } else {
 142                         res[r].parent = cell->resources[r].parent;
 143                         res[r].start = cell->resources[r].start;
 144                         res[r].end   = cell->resources[r].end;
 145                 }
 146
 147                 if (!cell->ignore_resource_conflicts) {
 148                         ret = acpi_check_resource_conflict(&res[r]);
 149                         if (ret)
 150                                 goto fail_res;
 151                 }
 152         }
 153
 154         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 155         if (ret)
 156                 goto fail_res;
 157
 158         ret = platform_device_add(pdev);
 159         if (ret)
 160                 goto fail_res;
 161
 162         if (cell->pm_runtime_no_callbacks)
 163                 pm_runtime_no_callbacks(&pdev->dev);
 164
 165         kfree(res);
 166
 167         return 0;
 168
 169 fail_res:
 170         kfree(res);
 171 fail_device:
 172         platform_device_put(pdev);
 173 fail_alloc:
 174         return ret;
 175 }
 176
 177 int mfd_add_devices(struct device *parent, int id,
 178                     struct mfd_cell *cells, int n_devs,
 179                     struct resource *mem_base,
 180                     int irq_base)
 181 {
 182         int i;
 183         int ret = 0;
 184         atomic_t *cnts;
 185
 186         /* initialize reference counting for all cells */
 187         cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 188         if (!cnts)
 189                 return -ENOMEM;
 190
 191         for (i = 0; i < n_devs; i++) {
 192                 atomic_set(&cnts[i], 0);
 193                 cells[i].usage_count = &cnts[i];
 194                 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
 195                 if (ret)
 196                         break;
 197         }
 198
 199         if (ret)
 200                 mfd_remove_devices(parent);
 201
 202         return ret;
 203 }
 204 EXPORT_SYMBOL(mfd_add_devices);
 205
 206 static int mfd_remove_devices_fn(struct device *dev, void *c)
 207 {
 208         struct platform_device *pdev = to_platform_device(dev);
 209         const struct mfd_cell *cell = mfd_get_cell(pdev);
 210         atomic_t **usage_count = c;
 211
 212         /* find the base address of usage_count pointers (for freeing) */
 213         if (!*usage_count || (cell->usage_count < *usage_count))
 214                 *usage_count = cell->usage_count;
 215
 216         platform_device_unregister(pdev);
 217         return 0;
 218 }
 219
 220 void mfd_remove_devices(struct device *parent)
 221 {
 222         atomic_t *cnts = NULL;
 223
 224         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 225         kfree(cnts);
 226 }
 227 EXPORT_SYMBOL(mfd_remove_devices);
 228
 229 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 230 {
 231         struct mfd_cell cell_entry;
 232         struct device *dev;
 233         struct platform_device *pdev;
 234         int i;
 235
 236         /* fetch the parent cell's device (should already be registered!) */
 237         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 238         if (!dev) {
 239                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 240                 return -ENODEV;
 241         }
 242         pdev = to_platform_device(dev);
 243         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 244
 245         WARN_ON(!cell_entry.enable);
 246
 247         for (i = 0; i < n_clones; i++) {
 248                 cell_entry.name = clones[i];
 249                 /* don't give up if a single call fails; just report error */
 250                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
 251                         dev_err(dev, "failed to create platform device '%s'\n",
 252                                         clones[i]);
 253         }
 254
 255         return 0;
 256 }
 257 EXPORT_SYMBOL(mfd_clone_cell);
 258
 259 MODULE_LICENSE("GPL");
 260 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");