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