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/list.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/dmaengine.h>
18
19 /**
20 * struct acpi_dma_spec - slave device DMA resources
21 * @chan_id: channel unique id
22 * @slave_id: request line unique id
23 * @dev: struct device of the DMA controller to be used in the filter
24 * function
25 */
26 struct acpi_dma_spec {
27 int chan_id;
28 int slave_id;
29 struct device *dev;
30 };
31
32 /**
33 * struct acpi_dma - representation of the registered DMAC
34 * @dma_controllers: linked list node
35 * @dev: struct device of this controller
36 * @acpi_dma_xlate: callback function to find a suitable channel
37 * @data: private data used by a callback function
38 * @base_request_line: first supported request line (CSRT)
39 * @end_request_line: last supported request line (CSRT)
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 unsigned short base_request_line;
48 unsigned short end_request_line;
49 };
50
51 /* Used with acpi_dma_simple_xlate() */
52 struct acpi_dma_filter_info {
53 dma_cap_mask_t dma_cap;
54 dma_filter_fn filter_fn;
55 };
56
57 #ifdef CONFIG_DMA_ACPI
58
59 int acpi_dma_controller_register(struct device *dev,
60 struct dma_chan *(*acpi_dma_xlate)
61 (struct acpi_dma_spec *, struct acpi_dma *),
62 void *data);
63 int acpi_dma_controller_free(struct device *dev);
64 int devm_acpi_dma_controller_register(struct device *dev,
65 struct dma_chan *(*acpi_dma_xlate)
66 (struct acpi_dma_spec *, struct acpi_dma *),
67 void *data);
68 void devm_acpi_dma_controller_free(struct device *dev);
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 static inline void devm_acpi_dma_controller_free(struct device *dev)
98 {
99 }
100
101 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
102 struct device *dev, size_t index)
103 {
104 return ERR_PTR(-ENODEV);
105 }
106 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
107 struct device *dev, const char *name)
108 {
109 return ERR_PTR(-ENODEV);
110 }
111
112 #define acpi_dma_simple_xlate NULL
113
114 #endif
115
116 #define acpi_dma_request_slave_channel acpi_dma_request_slave_chan_by_index
117
118 #endif /* __LINUX_ACPI_DMA_H */
119
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