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  * @base_request_line:  first supported request line (CSRT)
  41  * @end_request_line:   last supported request line (CSRT)
  42  */
  43 struct acpi_dma {
  44         struct list_head        dma_controllers;
  45         struct device           *dev;
  46         struct dma_chan         *(*acpi_dma_xlate)
  47                                 (struct acpi_dma_spec *, struct acpi_dma *);
  48         void                    *data;
  49         unsigned short          base_request_line;
  50         unsigned short          end_request_line;
  51 };
  52
  53 /* Used with acpi_dma_simple_xlate() */
  54 struct acpi_dma_filter_info {
  55         dma_cap_mask_t  dma_cap;
  56         dma_filter_fn   filter_fn;
  57 };
  58
  59 #ifdef CONFIG_DMA_ACPI
  60
  61 int acpi_dma_controller_register(struct device *dev,
  62                 struct dma_chan *(*acpi_dma_xlate)
  63                 (struct acpi_dma_spec *, struct acpi_dma *),
  64                 void *data);
  65 int acpi_dma_controller_free(struct device *dev);
  66 int devm_acpi_dma_controller_register(struct device *dev,
  67                 struct dma_chan *(*acpi_dma_xlate)
  68                 (struct acpi_dma_spec *, struct acpi_dma *),
  69                 void *data);
  70 void devm_acpi_dma_controller_free(struct device *dev);
  71
  72 struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
  73                                                       size_t index);
  74 struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
  75                                                      const char *name);
  76
  77 struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
  78                                        struct acpi_dma *adma);
  79 #else
  80
  81 static inline int acpi_dma_controller_register(struct device *dev,
  82                 struct dma_chan *(*acpi_dma_xlate)
  83                 (struct acpi_dma_spec *, struct acpi_dma *),
  84                 void *data)
  85 {
  86         return -ENODEV;
  87 }
  88 static inline int acpi_dma_controller_free(struct device *dev)
  89 {
  90         return -ENODEV;
  91 }
  92 static inline int devm_acpi_dma_controller_register(struct device *dev,
  93                 struct dma_chan *(*acpi_dma_xlate)
  94                 (struct acpi_dma_spec *, struct acpi_dma *),
  95                 void *data)
  96 {
  97         return -ENODEV;
  98 }
  99 static inline void devm_acpi_dma_controller_free(struct device *dev)
 100 {
 101 }
 102
 103 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
 104                 struct device *dev, size_t index)
 105 {
 106         return NULL;
 107 }
 108 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
 109                 struct device *dev, const char *name)
 110 {
 111         return NULL;
 112 }
 113
 114 #define acpi_dma_simple_xlate   NULL
 115
 116 #endif
 117
 118 #define acpi_dma_request_slave_channel  acpi_dma_request_slave_chan_by_index
 119
 120 #endif /* __LINUX_ACPI_DMA_H */