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 struct irq_domain;
  20
  21 /*
  22  * This struct describes the MFD part ("cell").
  23  * After registration the copy of this structure will become the platform data
  24  * of the resulting platform_device
  25  */
  26 struct mfd_cell {
  27         const char              *name;
  28         int                     id;
  29
  30         /* refcounting for multiple drivers to use a single cell */
  31         atomic_t                *usage_count;
  32         int                     (*enable)(struct platform_device *dev);
  33         int                     (*disable)(struct platform_device *dev);
  34
  35         int                     (*suspend)(struct platform_device *dev);
  36         int                     (*resume)(struct platform_device *dev);
  37
  38         /* platform data passed to the sub devices drivers */
  39         void                    *platform_data;
  40         size_t                  pdata_size;
  41         /*
  42          * Device Tree compatible string
  43          * See: Documentation/devicetree/usage-model.txt Chapter 2.2 for details
  44          */
  45         const char              *of_compatible;
  46
  47         /*
  48          * These resources can be specified relative to the parent device.
  49          * For accessing hardware you should use resources from the platform dev
  50          */
  51         int                     num_resources;
  52         const struct resource   *resources;
  53
  54         /* don't check for resource conflicts */
  55         bool                    ignore_resource_conflicts;
  56
  57         /*
  58          * Disable runtime PM callbacks for this subdevice - see
  59          * pm_runtime_no_callbacks().
  60          */
  61         bool                    pm_runtime_no_callbacks;
  62 };
  63
  64 /*
  65  * Convenience functions for clients using shared cells.  Refcounting
  66  * happens automatically, with the cell's enable/disable callbacks
  67  * being called only when a device is first being enabled or no other
  68  * clients are making use of it.
  69  */
  70 extern int mfd_cell_enable(struct platform_device *pdev);
  71 extern int mfd_cell_disable(struct platform_device *pdev);
  72
  73 /*
  74  * "Clone" multiple platform devices for a single cell. This is to be used
  75  * for devices that have multiple users of a cell.  For example, if an mfd
  76  * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver,
  77  * and a platform driver, the following bit of code would be use after first
  78  * calling mfd_add_devices():
  79  *
  80  * const char *fclones[] = { "foo-gpio", "foo-mtd" };
  81  * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones));
  82  *
  83  * Each driver (MTD, GPIO, and platform driver) would then register
  84  * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively.
  85  * The cell's .enable/.disable hooks should be used to deal with hardware
  86  * resource contention.
  87  */
  88 extern int mfd_clone_cell(const char *cell, const char **clones,
  89                 size_t n_clones);
  90
  91 /*
  92  * Given a platform device that's been created by mfd_add_devices(), fetch
  93  * the mfd_cell that created it.
  94  */
  95 static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev)
  96 {
  97         return pdev->mfd_cell;
  98 }
  99
 100 extern int mfd_add_devices(struct device *parent, int id,
 101                            struct mfd_cell *cells, int n_devs,
 102                            struct resource *mem_base,
 103                            int irq_base, struct irq_domain *irq_domain);
 104
 105 extern void mfd_remove_devices(struct device *parent);
 106
 107 #endif