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          * Device Tree compatible string
  41          * See: Documentation/devicetree/usage-model.txt Chapter 2.2 for details
  42          */
  43         const char              *of_compatible;
  44
  45         /*
  46          * These resources can be specified relative to the parent device.
  47          * For accessing hardware you should use resources from the platform dev
  48          */
  49         int                     num_resources;
  50         const struct resource   *resources;
  51
  52         /* don't check for resource conflicts */
  53         bool                    ignore_resource_conflicts;
  54
  55         /*
  56          * Disable runtime PM callbacks for this subdevice - see
  57          * pm_runtime_no_callbacks().
  58          */
  59         bool                    pm_runtime_no_callbacks;
  60 };
  61
  62 /*
  63  * Convenience functions for clients using shared cells.  Refcounting
  64  * happens automatically, with the cell's enable/disable callbacks
  65  * being called only when a device is first being enabled or no other
  66  * clients are making use of it.
  67  */
  68 extern int mfd_cell_enable(struct platform_device *pdev);
  69 extern int mfd_cell_disable(struct platform_device *pdev);
  70
  71 /*
  72  * "Clone" multiple platform devices for a single cell. This is to be used
  73  * for devices that have multiple users of a cell.  For example, if an mfd
  74  * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver,
  75  * and a platform driver, the following bit of code would be use after first
  76  * calling mfd_add_devices():
  77  *
  78  * const char *fclones[] = { "foo-gpio", "foo-mtd" };
  79  * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones));
  80  *
  81  * Each driver (MTD, GPIO, and platform driver) would then register
  82  * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively.
  83  * The cell's .enable/.disable hooks should be used to deal with hardware
  84  * resource contention.
  85  */
  86 extern int mfd_clone_cell(const char *cell, const char **clones,
  87                 size_t n_clones);
  88
  89 /*
  90  * Given a platform device that's been created by mfd_add_devices(), fetch
  91  * the mfd_cell that created it.
  92  */
  93 static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev)
  94 {
  95         return pdev->mfd_cell;
  96 }
  97
  98 extern int mfd_add_devices(struct device *parent, int id,
  99                            struct mfd_cell *cells, int n_devs,
 100                            struct resource *mem_base,
 101                            int irq_base);
 102
 103 extern void mfd_remove_devices(struct device *parent);
 104
 105 #endif