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 
acpi_dma_controller_register(struct device * dev,struct dma_chan * (* acpi_dma_xlate)(struct acpi_dma_spec *,struct acpi_dma *),void * data)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 }
acpi_dma_controller_free(struct device * dev)86 static inline int acpi_dma_controller_free(struct device *dev)
87 {
88 	return -ENODEV;
89 }
devm_acpi_dma_controller_register(struct device * dev,struct dma_chan * (* acpi_dma_xlate)(struct acpi_dma_spec *,struct acpi_dma *),void * data)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 }
devm_acpi_dma_controller_free(struct device * dev)97 static inline void devm_acpi_dma_controller_free(struct device *dev)
98 {
99 }
100 
acpi_dma_request_slave_chan_by_index(struct device * dev,size_t index)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 }
acpi_dma_request_slave_chan_by_name(struct device * dev,const char * name)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