LXR linux/include/linux/acpi

   1/*
   2 * ACPI helpers for DMA request / controller
   3 *
   4 * Based on of_dma.h
   5 *
   6 * Copyright (C) 2013, Intel Corporation
   7 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 */
  13
  14#ifndef __LINUX_ACPI_DMA_H
  15#define __LINUX_ACPI_DMA_H
  16
  17#include <linux/list.h>
  18#include <linux/device.h>
  19#include <linux/err.h>
  20#include <linux/dmaengine.h>
  21
  22/**
  23 * struct acpi_dma_spec - slave device DMA resources
  24 * @chan_id:    channel unique id
  25 * @slave_id:   request line unique id
  26 * @dev:        struct device of the DMA controller to be used in the filter
  27 *              function
  28 */
  29struct acpi_dma_spec {
  30        int             chan_id;
  31        int             slave_id;
  32        struct device   *dev;
  33};
  34
  35/**
  36 * struct acpi_dma - representation of the registered DMAC
  37 * @dma_controllers:    linked list node
  38 * @dev:                struct device of this controller
  39 * @acpi_dma_xlate:     callback function to find a suitable channel
  40 * @data:               private data used by a callback function
  41 * @base_request_line:  first supported request line (CSRT)
  42 * @end_request_line:   last supported request line (CSRT)
  43 */
  44struct acpi_dma {
  45        struct list_head        dma_controllers;
  46        struct device           *dev;
  47        struct dma_chan         *(*acpi_dma_xlate)
  48                                (struct acpi_dma_spec *, struct acpi_dma *);
  49        void                    *data;
  50        unsigned short          base_request_line;
  51        unsigned short          end_request_line;
  52};
  53
  54/* Used with acpi_dma_simple_xlate() */
  55struct acpi_dma_filter_info {
  56        dma_cap_mask_t  dma_cap;
  57        dma_filter_fn   filter_fn;
  58};
  59
  60#ifdef CONFIG_DMA_ACPI
  61
  62int acpi_dma_controller_register(struct device *dev,
  63                struct dma_chan *(*acpi_dma_xlate)
  64                (struct acpi_dma_spec *, struct acpi_dma *),
  65                void *data);
  66int acpi_dma_controller_free(struct device *dev);
  67int devm_acpi_dma_controller_register(struct device *dev,
  68                struct dma_chan *(*acpi_dma_xlate)
  69                (struct acpi_dma_spec *, struct acpi_dma *),
  70                void *data);
  71void devm_acpi_dma_controller_free(struct device *dev);
  72
  73struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
  74                                                      size_t index);
  75struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
  76                                                     const char *name);
  77
  78struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
  79                                       struct acpi_dma *adma);
  80#else
  81
  82static inline int acpi_dma_controller_register(struct device *dev,
  83                struct dma_chan *(*acpi_dma_xlate)
  84                (struct acpi_dma_spec *, struct acpi_dma *),
  85                void *data)
  86{
  87        return -ENODEV;
  88}
  89static inline int acpi_dma_controller_free(struct device *dev)
  90{
  91        return -ENODEV;
  92}
  93static inline int devm_acpi_dma_controller_register(struct device *dev,
  94                struct dma_chan *(*acpi_dma_xlate)
  95                (struct acpi_dma_spec *, struct acpi_dma *),
  96                void *data)
  97{
  98        return -ENODEV;
  99}
 100static inline void devm_acpi_dma_controller_free(struct device *dev)
 101{
 102}
 103
 104static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
 105                struct device *dev, size_t index)
 106{
 107        return ERR_PTR(-ENODEV);
 108}
 109static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
 110                struct device *dev, const char *name)
 111{
 112        return ERR_PTR(-ENODEV);
 113}
 114
 115#define acpi_dma_simple_xlate   NULL
 116
 117#endif
 118
 119#define acpi_dma_request_slave_channel  acpi_dma_request_slave_chan_by_index
 120
 121#endif /* __LINUX_ACPI_DMA_H */
 122