include/linux/mfd/core.h

   1 /*
   2  * drivers/mfd/mfd-core.h
   3  *
   4  * core MFD support
   5  * Copyright (c) 2006 Ian Molton
   6  * Copyright (c) 2007 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 #ifndef MFD_CORE_H
  15 #define MFD_CORE_H
  16
  17 #include <linux/platform_device.h>
  18
  19 /*
  20  * This struct describes the MFD part ("cell").
  21  * After registration the copy of this structure will become the platform data
  22  * of the resulting platform_device
  23  */
  24 struct mfd_cell {
  25         const char              *name;
  26         int                     id;
  27
  28         /* refcounting for multiple drivers to use a single cell */
  29         atomic_t                *usage_count;
  30         int                     (*enable)(struct platform_device *dev);
  31         int                     (*disable)(struct platform_device *dev);
  32
  33         int                     (*suspend)(struct platform_device *dev);
  34         int                     (*resume)(struct platform_device *dev);
  35
  36         /* platform data passed to the sub devices drivers */
  37         void                    *platform_data;
  38         size_t                  pdata_size;
  39
  40         /*
  41          * These resources can be specified relative to the parent device.
  42          * For accessing hardware you should use resources from the platform dev
  43          */
  44         int                     num_resources;
  45         const struct resource   *resources;
  46
  47         /* don't check for resource conflicts */
  48         bool                    ignore_resource_conflicts;
  49
  50         /*
  51          * Disable runtime PM callbacks for this subdevice - see
  52          * pm_runtime_no_callbacks().
  53          */
  54         bool                    pm_runtime_no_callbacks;
  55 };
  56
  57 /*
  58  * Convenience functions for clients using shared cells.  Refcounting
  59  * happens automatically, with the cell's enable/disable callbacks
  60  * being called only when a device is first being enabled or no other
  61  * clients are making use of it.
  62  */
  63 extern int mfd_cell_enable(struct platform_device *pdev);
  64 extern int mfd_cell_disable(struct platform_device *pdev);
  65
  66 /*
  67  * "Clone" multiple platform devices for a single cell. This is to be used
  68  * for devices that have multiple users of a cell.  For example, if an mfd
  69  * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver,
  70  * and a platform driver, the following bit of code would be use after first
  71  * calling mfd_add_devices():
  72  *
  73  * const char *fclones[] = { "foo-gpio", "foo-mtd" };
  74  * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones));
  75  *
  76  * Each driver (MTD, GPIO, and platform driver) would then register
  77  * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively.
  78  * The cell's .enable/.disable hooks should be used to deal with hardware
  79  * resource contention.
  80  */
  81 extern int mfd_clone_cell(const char *cell, const char **clones,
  82                 size_t n_clones);
  83
  84 /*
  85  * Given a platform device that's been created by mfd_add_devices(), fetch
  86  * the mfd_cell that created it.
  87  */
  88 static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev)
  89 {
  90         return pdev->mfd_cell;
  91 }
  92
  93 extern int mfd_add_devices(struct device *parent, int id,
  94                            struct mfd_cell *cells, int n_devs,
  95                            struct resource *mem_base,
  96                            int irq_base);
  97
  98 extern void mfd_remove_devices(struct device *parent);
  99
 100 #endif