linux/drivers/mfd/mfd-core.c
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   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
  24static struct device_type mfd_dev_type = {
  25        .name   = "mfd_device",
  26};
  27
  28int 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}
  43EXPORT_SYMBOL(mfd_cell_enable);
  44
  45int 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}
  63EXPORT_SYMBOL(mfd_cell_disable);
  64
  65static 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
  78static 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
 172fail_res:
 173        kfree(res);
 174fail_device:
 175        platform_device_put(pdev);
 176fail_alloc:
 177        return ret;
 178}
 179
 180int 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}
 208EXPORT_SYMBOL(mfd_add_devices);
 209
 210static 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
 230void 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}
 237EXPORT_SYMBOL(mfd_remove_devices);
 238
 239int 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}
 268EXPORT_SYMBOL(mfd_clone_cell);
 269
 270MODULE_LICENSE("GPL");
 271MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
 272
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