root/include/linux/acpi_dma.h

DEFINITIONS

1. acpi_dma_controller_register
2. acpi_dma_controller_free
3. devm_acpi_dma_controller_register
4. devm_acpi_dma_controller_free
5. acpi_dma_request_slave_chan_by_index
6. acpi_dma_request_slave_chan_by_name

/*
 * ACPI helpers for DMA request / controller
 *
 * Based on of_dma.h
 *
 * Copyright (C) 2013, Intel Corporation
 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 *
 * 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 __LINUX_ACPI_DMA_H
#define __LINUX_ACPI_DMA_H

#include <linux/list.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/dmaengine.h>

/**
 * struct acpi_dma_spec - slave device DMA resources
 * @chan_id:    channel unique id
 * @slave_id:   request line unique id
 * @dev:        struct device of the DMA controller to be used in the filter
 *              function
 */
struct acpi_dma_spec {
        int             chan_id;
        int             slave_id;
        struct device   *dev;
};

/**
 * struct acpi_dma - representation of the registered DMAC
 * @dma_controllers:    linked list node
 * @dev:                struct device of this controller
 * @acpi_dma_xlate:     callback function to find a suitable channel
 * @data:               private data used by a callback function
 * @base_request_line:  first supported request line (CSRT)
 * @end_request_line:   last supported request line (CSRT)
 */
struct acpi_dma {
        struct list_head        dma_controllers;
        struct device           *dev;
        struct dma_chan         *(*acpi_dma_xlate)
                                (struct acpi_dma_spec *, struct acpi_dma *);
        void                    *data;
        unsigned short          base_request_line;
        unsigned short          end_request_line;
};

/* Used with acpi_dma_simple_xlate() */
struct acpi_dma_filter_info {
        dma_cap_mask_t  dma_cap;
        dma_filter_fn   filter_fn;
};

#ifdef CONFIG_DMA_ACPI

int acpi_dma_controller_register(struct device *dev,
                struct dma_chan *(*acpi_dma_xlate)
                (struct acpi_dma_spec *, struct acpi_dma *),
                void *data);
int acpi_dma_controller_free(struct device *dev);
int devm_acpi_dma_controller_register(struct device *dev,
                struct dma_chan *(*acpi_dma_xlate)
                (struct acpi_dma_spec *, struct acpi_dma *),
                void *data);
void devm_acpi_dma_controller_free(struct device *dev);

struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
                                                      size_t index);
struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
                                                     const char *name);

struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
                                       struct acpi_dma *adma);
#else

static inline int acpi_dma_controller_register(struct device *dev,
                struct dma_chan *(*acpi_dma_xlate)
                (struct acpi_dma_spec *, struct acpi_dma *),
                void *data)
{
        return -ENODEV;
}
static inline int acpi_dma_controller_free(struct device *dev)
{
        return -ENODEV;
}
static inline int devm_acpi_dma_controller_register(struct device *dev,
                struct dma_chan *(*acpi_dma_xlate)
                (struct acpi_dma_spec *, struct acpi_dma *),
                void *data)
{
        return -ENODEV;
}
static inline void devm_acpi_dma_controller_free(struct device *dev)
{
}

static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
                struct device *dev, size_t index)
{
        return ERR_PTR(-ENODEV);
}
static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
                struct device *dev, const char *name)
{
        return ERR_PTR(-ENODEV);
}

#define acpi_dma_simple_xlate   NULL

#endif

#define acpi_dma_request_slave_channel  acpi_dma_request_slave_chan_by_index

#endif /* __LINUX_ACPI_DMA_H */