1 /* 2 * ACPI helpers for DMA request / controller 3 * 4 * Based on of_dma.h 5 * 6 * Copyright (C) 2013, Intel Corporation 7 * Author: Andy Shevchenko <[email protected]> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #ifndef __LINUX_ACPI_DMA_H 15 #define __LINUX_ACPI_DMA_H 16 17 #include <linux/list.h> 18 #include <linux/device.h> 19 #include <linux/dmaengine.h> 20 21 /** 22 * struct acpi_dma_spec - slave device DMA resources 23 * @chan_id: channel unique id 24 * @slave_id: request line unique id 25 * @dev: struct device of the DMA controller to be used in the filter 26 * function 27 */ 28 struct acpi_dma_spec { 29 int chan_id; 30 int slave_id; 31 struct device *dev; 32 }; 33 34 /** 35 * struct acpi_dma - representation of the registered DMAC 36 * @dma_controllers: linked list node 37 * @dev: struct device of this controller 38 * @acpi_dma_xlate: callback function to find a suitable channel 39 * @data: private data used by a callback function 40 * @base_request_line: first supported request line (CSRT) 41 * @end_request_line: last supported request line (CSRT) 42 */ 43 struct acpi_dma { 44 struct list_head dma_controllers; 45 struct device *dev; 46 struct dma_chan *(*acpi_dma_xlate) 47 (struct acpi_dma_spec *, struct acpi_dma *); 48 void *data; 49 unsigned short base_request_line; 50 unsigned short end_request_line; 51 }; 52 53 /* Used with acpi_dma_simple_xlate() */ 54 struct acpi_dma_filter_info { 55 dma_cap_mask_t dma_cap; 56 dma_filter_fn filter_fn; 57 }; 58 59 #ifdef CONFIG_DMA_ACPI 60 61 int acpi_dma_controller_register(struct device *dev, 62 struct dma_chan *(*acpi_dma_xlate) 63 (struct acpi_dma_spec *, struct acpi_dma *), 64 void *data); 65 int acpi_dma_controller_free(struct device *dev); 66 int devm_acpi_dma_controller_register(struct device *dev, 67 struct dma_chan *(*acpi_dma_xlate) 68 (struct acpi_dma_spec *, struct acpi_dma *), 69 void *data); 70 void devm_acpi_dma_controller_free(struct device *dev); 71 72 struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, 73 size_t index); 74 struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, 75 const char *name); 76 77 struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, 78 struct acpi_dma *adma); 79 #else 80 81 static inline int acpi_dma_controller_register(struct device *dev, 82 struct dma_chan *(*acpi_dma_xlate) 83 (struct acpi_dma_spec *, struct acpi_dma *), 84 void *data) 85 { 86 return -ENODEV; 87 } 88 static inline int acpi_dma_controller_free(struct device *dev) 89 { 90 return -ENODEV; 91 } 92 static inline int devm_acpi_dma_controller_register(struct device *dev, 93 struct dma_chan *(*acpi_dma_xlate) 94 (struct acpi_dma_spec *, struct acpi_dma *), 95 void *data) 96 { 97 return -ENODEV; 98 } 99 static inline void devm_acpi_dma_controller_free(struct device *dev) 100 { 101 } 102 103 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index( 104 struct device *dev, size_t index) 105 { 106 return NULL; 107 } 108 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name( 109 struct device *dev, const char *name) 110 { 111 return NULL; 112 } 113 114 #define acpi_dma_simple_xlate NULL 115 116 #endif 117 118 #define acpi_dma_request_slave_channel acpi_dma_request_slave_chan_by_index 119 120 #endif /* __LINUX_ACPI_DMA_H */ 121