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
  22 static struct device_type mfd_dev_type = {
  23         .name   = "mfd_device",
  24 };
  25
  26 int mfd_cell_enable(struct platform_device *pdev)
  27 {
  28         const struct mfd_cell *cell = mfd_get_cell(pdev);
  29         int err = 0;
  30
  31         /* only call enable hook if the cell wasn't previously enabled */
  32         if (atomic_inc_return(cell->usage_count) == 1)
  33                 err = cell->enable(pdev);
  34
  35         /* if the enable hook failed, decrement counter to allow retries */
  36         if (err)
  37                 atomic_dec(cell->usage_count);
  38
  39         return err;
  40 }
  41 EXPORT_SYMBOL(mfd_cell_enable);
  42
  43 int mfd_cell_disable(struct platform_device *pdev)
  44 {
  45         const struct mfd_cell *cell = mfd_get_cell(pdev);
  46         int err = 0;
  47
  48         /* only disable if no other clients are using it */
  49         if (atomic_dec_return(cell->usage_count) == 0)
  50                 err = cell->disable(pdev);
  51
  52         /* if the disable hook failed, increment to allow retries */
  53         if (err)
  54                 atomic_inc(cell->usage_count);
  55
  56         /* sanity check; did someone call disable too many times? */
  57         WARN_ON(atomic_read(cell->usage_count) < 0);
  58
  59         return err;
  60 }
  61 EXPORT_SYMBOL(mfd_cell_disable);
  62
  63 static int mfd_platform_add_cell(struct platform_device *pdev,
  64                                  const struct mfd_cell *cell)
  65 {
  66         if (!cell)
  67                 return 0;
  68
  69         pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
  70         if (!pdev->mfd_cell)
  71                 return -ENOMEM;
  72
  73         return 0;
  74 }
  75
  76 static int mfd_add_device(struct device *parent, int id,
  77                           const struct mfd_cell *cell,
  78                           struct resource *mem_base,
  79                           int irq_base)
  80 {
  81         struct resource *res;
  82         struct platform_device *pdev;
  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         pdev->dev.type = &mfd_dev_type;
  96
  97         if (cell->pdata_size) {
  98                 ret = platform_device_add_data(pdev,
  99                                         cell->platform_data, cell->pdata_size);
 100                 if (ret)
 101                         goto fail_res;
 102         }
 103
 104         ret = mfd_platform_add_cell(pdev, cell);
 105         if (ret)
 106                 goto fail_res;
 107
 108         for (r = 0; r < cell->num_resources; r++) {
 109                 res[r].name = cell->resources[r].name;
 110                 res[r].flags = cell->resources[r].flags;
 111
 112                 /* Find out base to use */
 113                 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 114                         res[r].parent = mem_base;
 115                         res[r].start = mem_base->start +
 116                                 cell->resources[r].start;
 117                         res[r].end = mem_base->start +
 118                                 cell->resources[r].end;
 119                 } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 120                         res[r].start = irq_base +
 121                                 cell->resources[r].start;
 122                         res[r].end   = irq_base +
 123                                 cell->resources[r].end;
 124                 } else {
 125                         res[r].parent = cell->resources[r].parent;
 126                         res[r].start = cell->resources[r].start;
 127                         res[r].end   = cell->resources[r].end;
 128                 }
 129
 130                 if (!cell->ignore_resource_conflicts) {
 131                         ret = acpi_check_resource_conflict(&res[r]);
 132                         if (ret)
 133                                 goto fail_res;
 134                 }
 135         }
 136
 137         ret = platform_device_add_resources(pdev, res, cell->num_resources);
 138         if (ret)
 139                 goto fail_res;
 140
 141         ret = platform_device_add(pdev);
 142         if (ret)
 143                 goto fail_res;
 144
 145         if (cell->pm_runtime_no_callbacks)
 146                 pm_runtime_no_callbacks(&pdev->dev);
 147
 148         kfree(res);
 149
 150         return 0;
 151
 152 fail_res:
 153         kfree(res);
 154 fail_device:
 155         platform_device_put(pdev);
 156 fail_alloc:
 157         return ret;
 158 }
 159
 160 int mfd_add_devices(struct device *parent, int id,
 161                     struct mfd_cell *cells, int n_devs,
 162                     struct resource *mem_base,
 163                     int irq_base)
 164 {
 165         int i;
 166         int ret = 0;
 167         atomic_t *cnts;
 168
 169         /* initialize reference counting for all cells */
 170         cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL);
 171         if (!cnts)
 172                 return -ENOMEM;
 173
 174         for (i = 0; i < n_devs; i++) {
 175                 atomic_set(&cnts[i], 0);
 176                 cells[i].usage_count = &cnts[i];
 177                 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
 178                 if (ret)
 179                         break;
 180         }
 181
 182         if (ret)
 183                 mfd_remove_devices(parent);
 184
 185         return ret;
 186 }
 187 EXPORT_SYMBOL(mfd_add_devices);
 188
 189 static int mfd_remove_devices_fn(struct device *dev, void *c)
 190 {
 191         struct platform_device *pdev;
 192         const struct mfd_cell *cell;
 193         atomic_t **usage_count = c;
 194
 195         if (dev->type != &mfd_dev_type)
 196                 return 0;
 197
 198         pdev = to_platform_device(dev);
 199         cell = mfd_get_cell(pdev);
 200
 201         /* find the base address of usage_count pointers (for freeing) */
 202         if (!*usage_count || (cell->usage_count < *usage_count))
 203                 *usage_count = cell->usage_count;
 204
 205         platform_device_unregister(pdev);
 206         return 0;
 207 }
 208
 209 void mfd_remove_devices(struct device *parent)
 210 {
 211         atomic_t *cnts = NULL;
 212
 213         device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 214         kfree(cnts);
 215 }
 216 EXPORT_SYMBOL(mfd_remove_devices);
 217
 218 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 219 {
 220         struct mfd_cell cell_entry;
 221         struct device *dev;
 222         struct platform_device *pdev;
 223         int i;
 224
 225         /* fetch the parent cell's device (should already be registered!) */
 226         dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 227         if (!dev) {
 228                 printk(KERN_ERR "failed to find device for cell %s\n", cell);
 229                 return -ENODEV;
 230         }
 231         pdev = to_platform_device(dev);
 232         memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 233
 234         WARN_ON(!cell_entry.enable);
 235
 236         for (i = 0; i < n_clones; i++) {
 237                 cell_entry.name = clones[i];
 238                 /* don't give up if a single call fails; just report error */
 239                 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
 240                         dev_err(dev, "failed to create platform device '%s'\n",
 241                                         clones[i]);
 242         }
 243
 244         return 0;
 245 }
 246 EXPORT_SYMBOL(mfd_clone_cell);
 247
 248 MODULE_LICENSE("GPL");
 249 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");