1 /*
2 * COMEDI ISA DMA support functions
3 * Copyright (c) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16 #ifndef _COMEDI_ISADMA_H
17 #define _COMEDI_ISADMA_H
18
19 #include <linux/types.h>
20
21 struct comedi_device;
22
23 /*
24 * These are used to avoid issues when <asm/dma.h> and the DMA_MODE_
25 * defines are not available.
26 */
27 #define COMEDI_ISADMA_READ 0
28 #define COMEDI_ISADMA_WRITE 1
29
30 /**
31 * struct comedi_isadma_desc - cookie for ISA DMA
32 * @virt_addr: virtual address of buffer
33 * @hw_addr: hardware (bus) address of buffer
34 * @chan: DMA channel
35 * @maxsize: allocated size of buffer (in bytes)
36 * @size: transfer size (in bytes)
37 * @mode: DMA_MODE_READ or DMA_MODE_WRITE
38 */
39 struct comedi_isadma_desc {
40 void *virt_addr;
41 dma_addr_t hw_addr;
42 unsigned int chan;
43 unsigned int maxsize;
44 unsigned int size;
45 char mode;
46 };
47
48 /**
49 * struct comedi_isadma - ISA DMA data
50 * @desc: cookie for each DMA buffer
51 * @n_desc: the number of cookies
52 * @cur_dma: the current cookie in use
53 * @chan: the first DMA channel requested
54 * @chan2: the second DMA channel requested
55 */
56 struct comedi_isadma {
57 struct comedi_isadma_desc *desc;
58 int n_desc;
59 int cur_dma;
60 unsigned int chan;
61 unsigned int chan2;
62 };
63
64 #if IS_ENABLED(CONFIG_ISA_DMA_API)
65
66 void comedi_isadma_program(struct comedi_isadma_desc *);
67 unsigned int comedi_isadma_disable(unsigned int dma_chan);
68 unsigned int comedi_isadma_disable_on_sample(unsigned int dma_chan,
69 unsigned int size);
70 unsigned int comedi_isadma_poll(struct comedi_isadma *);
71 void comedi_isadma_set_mode(struct comedi_isadma_desc *, char dma_dir);
72
73 struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *,
74 int n_desc, unsigned int dma_chan1,
75 unsigned int dma_chan2,
76 unsigned int maxsize, char dma_dir);
77 void comedi_isadma_free(struct comedi_isadma *);
78
79 #else /* !IS_ENABLED(CONFIG_ISA_DMA_API) */
80
comedi_isadma_program(struct comedi_isadma_desc * desc)81 static inline void comedi_isadma_program(struct comedi_isadma_desc *desc)
82 {
83 }
84
comedi_isadma_disable(unsigned int dma_chan)85 static inline unsigned int comedi_isadma_disable(unsigned int dma_chan)
86 {
87 return 0;
88 }
89
90 static inline unsigned int
comedi_isadma_disable_on_sample(unsigned int dma_chan,unsigned int size)91 comedi_isadma_disable_on_sample(unsigned int dma_chan, unsigned int size)
92 {
93 return 0;
94 }
95
comedi_isadma_poll(struct comedi_isadma * dma)96 static inline unsigned int comedi_isadma_poll(struct comedi_isadma *dma)
97 {
98 return 0;
99 }
100
comedi_isadma_set_mode(struct comedi_isadma_desc * desc,char dma_dir)101 static inline void comedi_isadma_set_mode(struct comedi_isadma_desc *desc,
102 char dma_dir)
103 {
104 }
105
106 static inline struct comedi_isadma *
comedi_isadma_alloc(struct comedi_device * dev,int n_desc,unsigned int dma_chan1,unsigned int dma_chan2,unsigned int maxsize,char dma_dir)107 comedi_isadma_alloc(struct comedi_device *dev, int n_desc,
108 unsigned int dma_chan1, unsigned int dma_chan2,
109 unsigned int maxsize, char dma_dir)
110 {
111 return NULL;
112 }
113
comedi_isadma_free(struct comedi_isadma * dma)114 static inline void comedi_isadma_free(struct comedi_isadma *dma)
115 {
116 }
117
118 #endif /* !IS_ENABLED(CONFIG_ISA_DMA_API) */
119
120 #endif /* #ifndef _COMEDI_ISADMA_H */
121