include/linux/acpi_dma.h

   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  */
  29 struct 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  */
  44 struct 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() */
  55 struct 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
  62 int 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);
  66 int acpi_dma_controller_free(struct device *dev);
  67 int 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);
  71 void devm_acpi_dma_controller_free(struct device *dev);
  72
  73 struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
  74                                                       size_t index);
  75 struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
  76                                                      const char *name);
  77
  78 struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
  79                                        struct acpi_dma *adma);
  80 #else
  81
  82 static 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 }
  89 static inline int acpi_dma_controller_free(struct device *dev)
  90 {
  91         return -ENODEV;
  92 }
  93 static 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 }
 100 static inline void devm_acpi_dma_controller_free(struct device *dev)
 101 {
 102 }
 103
 104 static 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 }
 109 static 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 */