linux/comedi/comedi_isadma.h

0001 /* SPDX-License-Identifier: GPL-2.0+ */
0002 /*
0003  * COMEDI ISA DMA support functions
0004  * Copyright (c) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
0005  */
0006
0007 #ifndef _COMEDI_ISADMA_H
0008 #define _COMEDI_ISADMA_H
0009
0010 #include <linux/types.h>
0011
0012 struct comedi_device;
0013 struct device;
0014
0015 /*
0016  * These are used to avoid issues when <asm/dma.h> and the DMA_MODE_
0017  * defines are not available.
0018  */
0019 #define COMEDI_ISADMA_READ  0
0020 #define COMEDI_ISADMA_WRITE 1
0021
0022 /**
0023  * struct comedi_isadma_desc - cookie for ISA DMA
0024  * @virt_addr:  virtual address of buffer
0025  * @hw_addr:    hardware (bus) address of buffer
0026  * @chan:   DMA channel
0027  * @maxsize:    allocated size of buffer (in bytes)
0028  * @size:   transfer size (in bytes)
0029  * @mode:   DMA_MODE_READ or DMA_MODE_WRITE
0030  */
0031 struct comedi_isadma_desc {
0032     void *virt_addr;
0033     dma_addr_t hw_addr;
0034     unsigned int chan;
0035     unsigned int maxsize;
0036     unsigned int size;
0037     char mode;
0038 };
0039
0040 /**
0041  * struct comedi_isadma - ISA DMA data
0042  * @dev:    device to allocate non-coherent memory for
0043  * @desc:   cookie for each DMA buffer
0044  * @n_desc: the number of cookies
0045  * @cur_dma:    the current cookie in use
0046  * @chan:   the first DMA channel requested
0047  * @chan2:  the second DMA channel requested
0048  */
0049 struct comedi_isadma {
0050     struct device *dev;
0051     struct comedi_isadma_desc *desc;
0052     int n_desc;
0053     int cur_dma;
0054     unsigned int chan;
0055     unsigned int chan2;
0056 };
0057
0058 #if IS_ENABLED(CONFIG_ISA_DMA_API)
0059
0060 void comedi_isadma_program(struct comedi_isadma_desc *desc);
0061 unsigned int comedi_isadma_disable(unsigned int dma_chan);
0062 unsigned int comedi_isadma_disable_on_sample(unsigned int dma_chan,
0063                          unsigned int size);
0064 unsigned int comedi_isadma_poll(struct comedi_isadma *dma);
0065 void comedi_isadma_set_mode(struct comedi_isadma_desc *desc, char dma_dir);
0066
0067 struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *dev,
0068                       int n_desc, unsigned int dma_chan1,
0069                       unsigned int dma_chan2,
0070                       unsigned int maxsize, char dma_dir);
0071 void comedi_isadma_free(struct comedi_isadma *dma);
0072
0073 #else   /* !IS_ENABLED(CONFIG_ISA_DMA_API) */
0074
0075 static inline void comedi_isadma_program(struct comedi_isadma_desc *desc)
0076 {
0077 }
0078
0079 static inline unsigned int comedi_isadma_disable(unsigned int dma_chan)
0080 {
0081     return 0;
0082 }
0083
0084 static inline unsigned int
0085 comedi_isadma_disable_on_sample(unsigned int dma_chan, unsigned int size)
0086 {
0087     return 0;
0088 }
0089
0090 static inline unsigned int comedi_isadma_poll(struct comedi_isadma *dma)
0091 {
0092     return 0;
0093 }
0094
0095 static inline void comedi_isadma_set_mode(struct comedi_isadma_desc *desc,
0096                       char dma_dir)
0097 {
0098 }
0099
0100 static inline struct comedi_isadma *
0101 comedi_isadma_alloc(struct comedi_device *dev, int n_desc,
0102             unsigned int dma_chan1, unsigned int dma_chan2,
0103             unsigned int maxsize, char dma_dir)
0104 {
0105     return NULL;
0106 }
0107
0108 static inline void comedi_isadma_free(struct comedi_isadma *dma)
0109 {
0110 }
0111
0112 #endif  /* !IS_ENABLED(CONFIG_ISA_DMA_API) */
0113
0114 #endif  /* #ifndef _COMEDI_ISADMA_H */