LXR linux/include/linux/acpi

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * ACPI helpers for DMA request / controller
   4 *
   5 * Based on of_dma.h
   6 *
   7 * Copyright (C) 2013, Intel Corporation
   8 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
   9 */
  10
  11#ifndef __LINUX_ACPI_DMA_H
  12#define __LINUX_ACPI_DMA_H
  13
  14#include <linux/list.h>
  15#include <linux/device.h>
  16#include <linux/err.h>
  17#include <linux/dmaengine.h>
  18
  19/**
  20 * struct acpi_dma_spec - slave device DMA resources
  21 * @chan_id:    channel unique id
  22 * @slave_id:   request line unique id
  23 * @dev:        struct device of the DMA controller to be used in the filter
  24 *              function
  25 */
  26struct acpi_dma_spec {
  27        int             chan_id;
  28        int             slave_id;
  29        struct device   *dev;
  30};
  31
  32/**
  33 * struct acpi_dma - representation of the registered DMAC
  34 * @dma_controllers:    linked list node
  35 * @dev:                struct device of this controller
  36 * @acpi_dma_xlate:     callback function to find a suitable channel
  37 * @data:               private data used by a callback function
  38 * @base_request_line:  first supported request line (CSRT)
  39 * @end_request_line:   last supported request line (CSRT)
  40 */
  41struct acpi_dma {
  42        struct list_head        dma_controllers;
  43        struct device           *dev;
  44        struct dma_chan         *(*acpi_dma_xlate)
  45                                (struct acpi_dma_spec *, struct acpi_dma *);
  46        void                    *data;
  47        unsigned short          base_request_line;
  48        unsigned short          end_request_line;
  49};
  50
  51/* Used with acpi_dma_simple_xlate() */
  52struct acpi_dma_filter_info {
  53        dma_cap_mask_t  dma_cap;
  54        dma_filter_fn   filter_fn;
  55};
  56
  57#ifdef CONFIG_DMA_ACPI
  58
  59int acpi_dma_controller_register(struct device *dev,
  60                struct dma_chan *(*acpi_dma_xlate)
  61                (struct acpi_dma_spec *, struct acpi_dma *),
  62                void *data);
  63int acpi_dma_controller_free(struct device *dev);
  64int devm_acpi_dma_controller_register(struct device *dev,
  65                struct dma_chan *(*acpi_dma_xlate)
  66                (struct acpi_dma_spec *, struct acpi_dma *),
  67                void *data);
  68void devm_acpi_dma_controller_free(struct device *dev);
  69
  70struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
  71                                                      size_t index);
  72struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
  73                                                     const char *name);
  74
  75struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
  76                                       struct acpi_dma *adma);
  77#else
  78
  79static inline int acpi_dma_controller_register(struct device *dev,
  80                struct dma_chan *(*acpi_dma_xlate)
  81                (struct acpi_dma_spec *, struct acpi_dma *),
  82                void *data)
  83{
  84        return -ENODEV;
  85}
  86static inline int acpi_dma_controller_free(struct device *dev)
  87{
  88        return -ENODEV;
  89}
  90static inline int devm_acpi_dma_controller_register(struct device *dev,
  91                struct dma_chan *(*acpi_dma_xlate)
  92                (struct acpi_dma_spec *, struct acpi_dma *),
  93                void *data)
  94{
  95        return -ENODEV;
  96}
  97static inline void devm_acpi_dma_controller_free(struct device *dev)
  98{
  99}
 100
 101static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
 102                struct device *dev, size_t index)
 103{
 104        return ERR_PTR(-ENODEV);
 105}
 106static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
 107                struct device *dev, const char *name)
 108{
 109        return ERR_PTR(-ENODEV);
 110}
 111
 112#define acpi_dma_simple_xlate   NULL
 113
 114#endif
 115
 116#define acpi_dma_request_slave_channel  acpi_dma_request_slave_chan_by_index
 117
 118#endif /* __LINUX_ACPI_DMA_H */
 119