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/dmaengine.h>
  20
  21 /**
  22  * struct acpi_dma_spec - slave device DMA resources
  23  * @chan_id:    channel unique id
  24  * @slave_id:   request line unique id
  25  * @dev:        struct device of the DMA controller to be used in the filter
  26  *              function
  27  */
  28 struct acpi_dma_spec {
  29         int             chan_id;
  30         int             slave_id;
  31         struct device   *dev;
  32 };
  33
  34 /**
  35  * struct acpi_dma - representation of the registered DMAC
  36  * @dma_controllers:    linked list node
  37  * @dev:                struct device of this controller
  38  * @acpi_dma_xlate:     callback function to find a suitable channel
  39  * @data:               private data used by a callback function
  40  */
  41 struct 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 };
  48
  49 /* Used with acpi_dma_simple_xlate() */
  50 struct acpi_dma_filter_info {
  51         dma_cap_mask_t  dma_cap;
  52         dma_filter_fn   filter_fn;
  53 };
  54
  55 #ifdef CONFIG_DMA_ACPI
  56
  57 int acpi_dma_controller_register(struct device *dev,
  58                 struct dma_chan *(*acpi_dma_xlate)
  59                 (struct acpi_dma_spec *, struct acpi_dma *),
  60                 void *data);
  61 int acpi_dma_controller_free(struct device *dev);
  62 int devm_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 void devm_acpi_dma_controller_free(struct device *dev);
  67
  68 struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
  69                                                       size_t index);
  70 struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
  71                                                      const char *name);
  72
  73 struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
  74                                        struct acpi_dma *adma);
  75 #else
  76
  77 static inline int acpi_dma_controller_register(struct device *dev,
  78                 struct dma_chan *(*acpi_dma_xlate)
  79                 (struct acpi_dma_spec *, struct acpi_dma *),
  80                 void *data)
  81 {
  82         return -ENODEV;
  83 }
  84 static inline int acpi_dma_controller_free(struct device *dev)
  85 {
  86         return -ENODEV;
  87 }
  88 static inline int devm_acpi_dma_controller_register(struct device *dev,
  89                 struct dma_chan *(*acpi_dma_xlate)
  90                 (struct acpi_dma_spec *, struct acpi_dma *),
  91                 void *data)
  92 {
  93         return -ENODEV;
  94 }
  95 static inline void devm_acpi_dma_controller_free(struct device *dev)
  96 {
  97 }
  98
  99 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
 100                 struct device *dev, size_t index)
 101 {
 102         return NULL;
 103 }
 104 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
 105                 struct device *dev, const char *name)
 106 {
 107         return NULL;
 108 }
 109
 110 #define acpi_dma_simple_xlate   NULL
 111
 112 #endif
 113
 114 #define acpi_dma_request_slave_channel  acpi_dma_request_slave_chan_by_index
 115
 116 #endif /* __LINUX_ACPI_DMA_H */