core.h

Go to the documentation of this file.

/*
 * drivers/mfd/mfd-core.h
 *
 * core MFD support
 * Copyright (c) 2006 Ian Molton
 * Copyright (c) 2007 Dmitry Baryshkov
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#ifndef MFD_CORE_H
#define MFD_CORE_H

#include <linux/platform_device.h>

struct irq_domain;

/*
 * This struct describes the MFD part ("cell").
 * After registration the copy of this structure will become the platform data
 * of the resulting platform_device
 */
struct mfd_cell {
    const char      *name;
    int         id;

    /* refcounting for multiple drivers to use a single cell */
    atomic_t        *usage_count;
    int         (*enable)(struct platform_device *dev);
    int         (*disable)(struct platform_device *dev);

    int         (*suspend)(struct platform_device *dev);
    int         (*resume)(struct platform_device *dev);

    /* platform data passed to the sub devices drivers */
    void            *platform_data;
    size_t          pdata_size;
    /*
     * Device Tree compatible string
     * See: Documentation/devicetree/usage-model.txt Chapter 2.2 for details
     */
    const char      *of_compatible;

    /*
     * These resources can be specified relative to the parent device.
     * For accessing hardware you should use resources from the platform dev
     */
    int         num_resources;
    const struct resource   *resources;

    /* don't check for resource conflicts */
    bool            ignore_resource_conflicts;

    /*
     * Disable runtime PM callbacks for this subdevice - see
     * pm_runtime_no_callbacks().
     */
    bool            pm_runtime_no_callbacks;
};

/*
 * Convenience functions for clients using shared cells.  Refcounting
 * happens automatically, with the cell's enable/disable callbacks
 * being called only when a device is first being enabled or no other
 * clients are making use of it.
 */
extern int mfd_cell_enable(struct platform_device *pdev);
extern int mfd_cell_disable(struct platform_device *pdev);

/*
 * "Clone" multiple platform devices for a single cell. This is to be used
 * for devices that have multiple users of a cell.  For example, if an mfd
 * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver,
 * and a platform driver, the following bit of code would be use after first
 * calling mfd_add_devices():
 *
 * const char *fclones[] = { "foo-gpio", "foo-mtd" };
 * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones));
 *
 * Each driver (MTD, GPIO, and platform driver) would then register
 * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively.
 * The cell's .enable/.disable hooks should be used to deal with hardware
 * resource contention.
 */
extern int mfd_clone_cell(const char *cell, const char **clones,
        size_t n_clones);

/*
 * Given a platform device that's been created by mfd_add_devices(), fetch
 * the mfd_cell that created it.
 */
static inline const struct mfd_cell *mfd_get_cell(struct platform_device *pdev)
{
    return pdev->mfd_cell;
}

extern int mfd_add_devices(struct device *parent, int id,
               struct mfd_cell *cells, int n_devs,
               struct resource *mem_base,
               int irq_base, struct irq_domain *irq_domain);

extern void mfd_remove_devices(struct device *parent);

#endif