xref: /linux/include/linux/of_dma.h (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
1 /*
2  * OF helpers for DMA request / controller
3  *
4  * Based on of_gpio.h
5  *
6  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #ifndef __LINUX_OF_DMA_H
14 #define __LINUX_OF_DMA_H
15 
16 #include <linux/of.h>
17 #include <linux/dmaengine.h>
18 
19 struct device_node;
20 
21 struct of_dma {
22 	struct list_head	of_dma_controllers;
23 	struct device_node	*of_node;
24 	int			of_dma_nbcells;
25 	struct dma_chan		*(*of_dma_xlate)
26 				(struct of_phandle_args *, struct of_dma *);
27 	void			*of_dma_data;
28 	int			use_count;
29 };
30 
31 struct of_dma_filter_info {
32 	dma_cap_mask_t	dma_cap;
33 	dma_filter_fn	filter_fn;
34 };
35 
36 #ifdef CONFIG_OF
37 extern int of_dma_controller_register(struct device_node *np,
38 		struct dma_chan *(*of_dma_xlate)
39 		(struct of_phandle_args *, struct of_dma *),
40 		void *data);
41 extern int of_dma_controller_free(struct device_node *np);
42 extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
43 						     char *name);
44 extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
45 		struct of_dma *ofdma);
46 #else
47 static inline int of_dma_controller_register(struct device_node *np,
48 		struct dma_chan *(*of_dma_xlate)
49 		(struct of_phandle_args *, struct of_dma *),
50 		void *data)
51 {
52 	return -ENODEV;
53 }
54 
55 static inline int of_dma_controller_free(struct device_node *np)
56 {
57 	return -ENODEV;
58 }
59 
60 static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
61 						     char *name)
62 {
63 	return NULL;
64 }
65 
66 static inline struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
67 		struct of_dma *ofdma)
68 {
69 	return NULL;
70 }
71 
72 #endif
73 
74 #endif /* __LINUX_OF_DMA_H */
75