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