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         /* mfd_data can be used to pass data to client drivers */
  37         void                    *mfd_data;
  38
  39         /*
  40          * These resources can be specified relative to the parent device.
  41          * For accessing hardware you should use resources from the platform dev
  42          */
  43         int                     num_resources;
  44         const struct resource   *resources;
  45
  46         /* don't check for resource conflicts */
  47         bool                    ignore_resource_conflicts;
  48
  49         /*
  50          * Disable runtime PM callbacks for this subdevice - see
  51          * pm_runtime_no_callbacks().
  52          */
  53         bool                    pm_runtime_no_callbacks;
  54 };
  55
  56 /*
  57  * Convenience functions for clients using shared cells.  Refcounting
  58  * happens automatically, with the cell's enable/disable callbacks
  59  * being called only when a device is first being enabled or no other
  60  * clients are making use of it.
  61  */
  62 extern int mfd_cell_enable(struct platform_device *pdev);
  63 extern int mfd_cell_disable(struct platform_device *pdev);
  64
  65 /*
  66  * "Clone" multiple platform devices for a single cell. This is to be used
  67  * for devices that have multiple users of a cell.  For example, if an mfd
  68  * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver,
  69  * and a platform driver, the following bit of code would be use after first
  70  * calling mfd_add_devices():
  71  *
  72  * const char *fclones[] = { "foo-gpio", "foo-mtd" };
  73  * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones));
  74  *
  75  * Each driver (MTD, GPIO, and platform driver) would then register
  76  * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively.
  77  * The cell's .enable/.disable hooks should be used to deal with hardware
  78  * resource contention.
  79  */
  80 extern int mfd_clone_cell(const char *cell, const char **clones,
  81                 size_t n_clones);
  82
  83 /*
  84  * Given a platform device that's been created by mfd_add_devices(), fetch
  85  * the mfd_cell that created it.
  86  */
  87 static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev)
  88 {
  89         return pdev->mfd_cell;
  90 }
  91
  92 /*
  93  * Given a platform device that's been created by mfd_add_devices(), fetch
  94  * the .mfd_data entry from the mfd_cell that created it.
  95  * Otherwise just return the platform_data pointer.
  96  * This maintains compatibility with platform drivers whose devices aren't
  97  * created by the mfd layer, and expect platform_data to contain what would've
  98  * otherwise been in mfd_data.
  99  */
 100 static inline void *mfd_get_data(struct platform_device *pdev)
 101 {
 102         const struct mfd_cell *cell = mfd_get_cell(pdev);
 103
 104         if (cell)
 105                 return cell->mfd_data;
 106         else
 107                 return pdev->dev.platform_data;
 108 }
 109
 110 extern int mfd_add_devices(struct device *parent, int id,
 111                            struct mfd_cell *cells, int n_devs,
 112                            struct resource *mem_base,
 113                            int irq_base);
 114
 115 extern void mfd_remove_devices(struct device *parent);
 116
 117 #endif