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
  24int 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}
  39EXPORT_SYMBOL(mfd_cell_enable);
  40
  41int 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}
  59EXPORT_SYMBOL(mfd_cell_disable);
  60
  61static 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
  74static int mfd_add_device(struct device *parent, int id,
  75                          const struct mfd_cell *cell,
  76                          struct resource *mem_base,
  77                          int irq_base, struct irq_domain *domain)
  78{
  79        struct resource *res;
  80        struct platform_device *pdev;
  81        struct device_node *np = NULL;
  82        int ret = -ENOMEM;
  83        int r;
  84
  85        pdev = platform_device_alloc(cell->name, id + cell->id);
  86        if (!pdev)
  87                goto fail_alloc;
  88
  89        res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
  90        if (!res)
  91                goto fail_device;
  92
  93        pdev->dev.parent = parent;
  94
  95        if (parent->of_node && cell->of_compatible) {
  96                for_each_child_of_node(parent->of_node, np) {
  97                        if (of_device_is_compatible(np, cell->of_compatible)) {
  98                                pdev->dev.of_node = np;
  99                                break;
 100                        }
 101                }
 102        }
 103
 104        if (cell->pdata_size) {
 105                ret = platform_device_add_data(pdev,
 106                                        cell->platform_data, cell->pdata_size);
 107                if (ret)
 108                        goto fail_res;
 109        }
 110
 111        ret = mfd_platform_add_cell(pdev, cell);
 112        if (ret)
 113                goto fail_res;
 114
 115        for (r = 0; r < cell->num_resources; r++) {
 116                res[r].name = cell->resources[r].name;
 117                res[r].flags = cell->resources[r].flags;
 118
 119                /* Find out base to use */
 120                if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
 121                        res[r].parent = mem_base;
 122                        res[r].start = mem_base->start +
 123                                cell->resources[r].start;
 124                        res[r].end = mem_base->start +
 125                                cell->resources[r].end;
 126                } else if (cell->resources[r].flags & IORESOURCE_IRQ) {
 127                        if (domain) {
 128                                /* Unable to create mappings for IRQ ranges. */
 129                                WARN_ON(cell->resources[r].start !=
 130                                        cell->resources[r].end);
 131                                res[r].start = res[r].end = irq_create_mapping(
 132                                        domain, cell->resources[r].start);
 133                        } else {
 134                                res[r].start = irq_base +
 135                                        cell->resources[r].start;
 136                                res[r].end   = irq_base +
 137                                        cell->resources[r].end;
 138                        }
 139                } else {
 140                        res[r].parent = cell->resources[r].parent;
 141                        res[r].start = cell->resources[r].start;
 142                        res[r].end   = cell->resources[r].end;
 143                }
 144
 145                if (!cell->ignore_resource_conflicts) {
 146                        ret = acpi_check_resource_conflict(&res[r]);
 147                        if (ret)
 148                                goto fail_res;
 149                }
 150        }
 151
 152        ret = platform_device_add_resources(pdev, res, cell->num_resources);
 153        if (ret)
 154                goto fail_res;
 155
 156        ret = platform_device_add(pdev);
 157        if (ret)
 158                goto fail_res;
 159
 160        if (cell->pm_runtime_no_callbacks)
 161                pm_runtime_no_callbacks(&pdev->dev);
 162
 163        kfree(res);
 164
 165        return 0;
 166
 167fail_res:
 168        kfree(res);
 169fail_device:
 170        platform_device_put(pdev);
 171fail_alloc:
 172        return ret;
 173}
 174
 175int mfd_add_devices(struct device *parent, int id,
 176                    struct mfd_cell *cells, int n_devs,
 177                    struct resource *mem_base,
 178                    int irq_base, struct irq_domain *domain)
 179{
 180        int i;
 181        int ret = 0;
 182        atomic_t *cnts;
 183
 184        /* initialize reference counting for all cells */
 185        cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL);
 186        if (!cnts)
 187                return -ENOMEM;
 188
 189        for (i = 0; i < n_devs; i++) {
 190                atomic_set(&cnts[i], 0);
 191                cells[i].usage_count = &cnts[i];
 192                ret = mfd_add_device(parent, id, cells + i, mem_base,
 193                                     irq_base, domain);
 194                if (ret)
 195                        break;
 196        }
 197
 198        if (ret)
 199                mfd_remove_devices(parent);
 200
 201        return ret;
 202}
 203EXPORT_SYMBOL(mfd_add_devices);
 204
 205static int mfd_remove_devices_fn(struct device *dev, void *c)
 206{
 207        struct platform_device *pdev = to_platform_device(dev);
 208        const struct mfd_cell *cell = mfd_get_cell(pdev);
 209        atomic_t **usage_count = c;
 210
 211        /* find the base address of usage_count pointers (for freeing) */
 212        if (!*usage_count || (cell->usage_count < *usage_count))
 213                *usage_count = cell->usage_count;
 214
 215        platform_device_unregister(pdev);
 216        return 0;
 217}
 218
 219void mfd_remove_devices(struct device *parent)
 220{
 221        atomic_t *cnts = NULL;
 222
 223        device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
 224        kfree(cnts);
 225}
 226EXPORT_SYMBOL(mfd_remove_devices);
 227
 228int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
 229{
 230        struct mfd_cell cell_entry;
 231        struct device *dev;
 232        struct platform_device *pdev;
 233        int i;
 234
 235        /* fetch the parent cell's device (should already be registered!) */
 236        dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
 237        if (!dev) {
 238                printk(KERN_ERR "failed to find device for cell %s\n", cell);
 239                return -ENODEV;
 240        }
 241        pdev = to_platform_device(dev);
 242        memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
 243
 244        WARN_ON(!cell_entry.enable);
 245
 246        for (i = 0; i < n_clones; i++) {
 247                cell_entry.name = clones[i];
 248                /* don't give up if a single call fails; just report error */
 249                if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0,
 250                                   NULL))
 251                        dev_err(dev, "failed to create platform device '%s'\n",
 252                                        clones[i]);
 253        }
 254
 255        return 0;
 256}
 257EXPORT_SYMBOL(mfd_clone_cell);
 258
 259MODULE_LICENSE("GPL");
 260MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");
 261
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