include/linux/acpi_dma.h

   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/err.h>
  15 #include <linux/dmaengine.h>
  16 #include <linux/types.h>
  17
  18 struct device;
  19
  20 /**
  21  * struct acpi_dma_spec - slave device DMA resources
  22  * @chan_id:    channel unique id
  23  * @slave_id:   request line unique id
  24  * @dev:        struct device of the DMA controller to be used in the filter
  25  *              function
  26  */
  27 struct acpi_dma_spec {
  28         int             chan_id;
  29         int             slave_id;
  30         struct device   *dev;
  31 };
  32
  33 /**
  34  * struct acpi_dma - representation of the registered DMAC
  35  * @dma_controllers:    linked list node
  36  * @dev:                struct device of this controller
  37  * @acpi_dma_xlate:     callback function to find a suitable channel
  38  * @data:               private data used by a callback function
  39  * @base_request_line:  first supported request line (CSRT)
  40  * @end_request_line:   last supported request line (CSRT)
  41  */
  42 struct acpi_dma {
  43         struct list_head        dma_controllers;
  44         struct device           *dev;
  45         struct dma_chan         *(*acpi_dma_xlate)
  46                                 (struct acpi_dma_spec *, struct acpi_dma *);
  47         void                    *data;
  48         unsigned short          base_request_line;
  49         unsigned short          end_request_line;
  50 };
  51
  52 /* Used with acpi_dma_simple_xlate() */
  53 struct acpi_dma_filter_info {
  54         dma_cap_mask_t  dma_cap;
  55         dma_filter_fn   filter_fn;
  56 };
  57
  58 #ifdef CONFIG_DMA_ACPI
  59
  60 int acpi_dma_controller_register(struct device *dev,
  61                 struct dma_chan *(*acpi_dma_xlate)
  62                 (struct acpi_dma_spec *, struct acpi_dma *),
  63                 void *data);
  64 int acpi_dma_controller_free(struct device *dev);
  65 int devm_acpi_dma_controller_register(struct device *dev,
  66                 struct dma_chan *(*acpi_dma_xlate)
  67                 (struct acpi_dma_spec *, struct acpi_dma *),
  68                 void *data);
  69
  70 struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
  71                                                       size_t index);
  72 struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
  73                                                      const char *name);
  74
  75 struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
  76                                        struct acpi_dma *adma);
  77 #else
  78
  79 static 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 }
  86 static inline int acpi_dma_controller_free(struct device *dev)
  87 {
  88         return -ENODEV;
  89 }
  90 static 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 }
  97
  98 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
  99                 struct device *dev, size_t index)
 100 {
 101         return ERR_PTR(-ENODEV);
 102 }
 103 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
 104                 struct device *dev, const char *name)
 105 {
 106         return ERR_PTR(-ENODEV);
 107 }
 108
 109 #define acpi_dma_simple_xlate   NULL
 110
 111 #endif
 112
 113 #define acpi_dma_request_slave_channel  acpi_dma_request_slave_chan_by_index
 114
 115 #endif /* __LINUX_ACPI_DMA_H */