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
acpi_dma_controller_register(struct device * dev,struct dma_chan * (* acpi_dma_xlate)(struct acpi_dma_spec *,struct acpi_dma *),void * data)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 }
acpi_dma_controller_free(struct device * dev)88 static inline int acpi_dma_controller_free(struct device *dev)
89 {
90 return -ENODEV;
91 }
devm_acpi_dma_controller_register(struct device * dev,struct dma_chan * (* acpi_dma_xlate)(struct acpi_dma_spec *,struct acpi_dma *),void * data)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 }
devm_acpi_dma_controller_free(struct device * dev)99 static inline void devm_acpi_dma_controller_free(struct device *dev)
100 {
101 }
102
acpi_dma_request_slave_chan_by_index(struct device * dev,size_t index)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 }
acpi_dma_request_slave_chan_by_name(struct device * dev,const char * name)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 */
121