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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
18struct 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 */
27struct 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 */
42struct 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() */
53struct 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
60int 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);
64int acpi_dma_controller_free(struct device *dev);
65int 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
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}
97
98static 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}
103static 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 */