1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
2 | /* |
3 | * COMEDI ISA DMA support functions |
4 | * Copyright (c) 2014 H Hartley Sweeten <hsweeten@visionengravers.com> |
5 | */ |
6 | |
7 | #ifndef _COMEDI_ISADMA_H |
8 | #define _COMEDI_ISADMA_H |
9 | |
10 | #include <linux/types.h> |
11 | |
12 | struct comedi_device; |
13 | struct device; |
14 | |
15 | /* |
16 | * These are used to avoid issues when <asm/dma.h> and the DMA_MODE_ |
17 | * defines are not available. |
18 | */ |
19 | #define COMEDI_ISADMA_READ 0 |
20 | #define COMEDI_ISADMA_WRITE 1 |
21 | |
22 | /** |
23 | * struct comedi_isadma_desc - cookie for ISA DMA |
24 | * @virt_addr: virtual address of buffer |
25 | * @hw_addr: hardware (bus) address of buffer |
26 | * @chan: DMA channel |
27 | * @maxsize: allocated size of buffer (in bytes) |
28 | * @size: transfer size (in bytes) |
29 | * @mode: DMA_MODE_READ or DMA_MODE_WRITE |
30 | */ |
31 | struct comedi_isadma_desc { |
32 | void *virt_addr; |
33 | dma_addr_t hw_addr; |
34 | unsigned int chan; |
35 | unsigned int maxsize; |
36 | unsigned int size; |
37 | char mode; |
38 | }; |
39 | |
40 | /** |
41 | * struct comedi_isadma - ISA DMA data |
42 | * @dev: device to allocate non-coherent memory for |
43 | * @desc: cookie for each DMA buffer |
44 | * @n_desc: the number of cookies |
45 | * @cur_dma: the current cookie in use |
46 | * @chan: the first DMA channel requested |
47 | * @chan2: the second DMA channel requested |
48 | */ |
49 | struct comedi_isadma { |
50 | struct device *dev; |
51 | struct comedi_isadma_desc *desc; |
52 | int n_desc; |
53 | int cur_dma; |
54 | unsigned int chan; |
55 | unsigned int chan2; |
56 | }; |
57 | |
58 | #if IS_ENABLED(CONFIG_ISA_DMA_API) |
59 | |
60 | void comedi_isadma_program(struct comedi_isadma_desc *desc); |
61 | unsigned int comedi_isadma_disable(unsigned int dma_chan); |
62 | unsigned int comedi_isadma_disable_on_sample(unsigned int dma_chan, |
63 | unsigned int size); |
64 | unsigned int comedi_isadma_poll(struct comedi_isadma *dma); |
65 | void comedi_isadma_set_mode(struct comedi_isadma_desc *desc, char dma_dir); |
66 | |
67 | struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *dev, |
68 | int n_desc, unsigned int dma_chan1, |
69 | unsigned int dma_chan2, |
70 | unsigned int maxsize, char dma_dir); |
71 | void comedi_isadma_free(struct comedi_isadma *dma); |
72 | |
73 | #else /* !IS_ENABLED(CONFIG_ISA_DMA_API) */ |
74 | |
75 | static inline void comedi_isadma_program(struct comedi_isadma_desc *desc) |
76 | { |
77 | } |
78 | |
79 | static inline unsigned int comedi_isadma_disable(unsigned int dma_chan) |
80 | { |
81 | return 0; |
82 | } |
83 | |
84 | static inline unsigned int |
85 | comedi_isadma_disable_on_sample(unsigned int dma_chan, unsigned int size) |
86 | { |
87 | return 0; |
88 | } |
89 | |
90 | static inline unsigned int comedi_isadma_poll(struct comedi_isadma *dma) |
91 | { |
92 | return 0; |
93 | } |
94 | |
95 | static inline void comedi_isadma_set_mode(struct comedi_isadma_desc *desc, |
96 | char dma_dir) |
97 | { |
98 | } |
99 | |
100 | static inline struct comedi_isadma * |
101 | comedi_isadma_alloc(struct comedi_device *dev, int n_desc, |
102 | unsigned int dma_chan1, unsigned int dma_chan2, |
103 | unsigned int maxsize, char dma_dir) |
104 | { |
105 | return NULL; |
106 | } |
107 | |
108 | static inline void comedi_isadma_free(struct comedi_isadma *dma) |
109 | { |
110 | } |
111 | |
112 | #endif /* !IS_ENABLED(CONFIG_ISA_DMA_API) */ |
113 | |
114 | #endif /* #ifndef _COMEDI_ISADMA_H */ |
115 | |