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 <andriy.shevchenko@linux.intel.com> 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/err.h> 20 #include <linux/dmaengine.h> 21 22 /** 23 * struct acpi_dma_spec - slave device DMA resources 24 * @chan_id: channel unique id 25 * @slave_id: request line unique id 26 * @dev: struct device of the DMA controller to be used in the filter 27 * function 28 */ 29 struct acpi_dma_spec { 30 int chan_id; 31 int slave_id; 32 struct device *dev; 33 }; 34 35 /** 36 * struct acpi_dma - representation of the registered DMAC 37 * @dma_controllers: linked list node 38 * @dev: struct device of this controller 39 * @acpi_dma_xlate: callback function to find a suitable channel 40 * @data: private data used by a callback function 41 * @base_request_line: first supported request line (CSRT) 42 * @end_request_line: last supported request line (CSRT) 43 */ 44 struct acpi_dma { 45 struct list_head dma_controllers; 46 struct device *dev; 47 struct dma_chan *(*acpi_dma_xlate) 48 (struct acpi_dma_spec *, struct acpi_dma *); 49 void *data; 50 unsigned short base_request_line; 51 unsigned short end_request_line; 52 }; 53 54 /* Used with acpi_dma_simple_xlate() */ 55 struct acpi_dma_filter_info { 56 dma_cap_mask_t dma_cap; 57 dma_filter_fn filter_fn; 58 }; 59 60 #ifdef CONFIG_DMA_ACPI 61 62 int acpi_dma_controller_register(struct device *dev, 63 struct dma_chan *(*acpi_dma_xlate) 64 (struct acpi_dma_spec *, struct acpi_dma *), 65 void *data); 66 int acpi_dma_controller_free(struct device *dev); 67 int devm_acpi_dma_controller_register(struct device *dev, 68 struct dma_chan *(*acpi_dma_xlate) 69 (struct acpi_dma_spec *, struct acpi_dma *), 70 void *data); 71 void devm_acpi_dma_controller_free(struct device *dev); 72 73 struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, 74 size_t index); 75 struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, 76 const char *name); 77 78 struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, 79 struct acpi_dma *adma); 80 #else 81 82 static inline int acpi_dma_controller_register(struct device *dev, 83 struct dma_chan *(*acpi_dma_xlate) 84 (struct acpi_dma_spec *, struct acpi_dma *), 85 void *data) 86 { 87 return -ENODEV; 88 } 89 static inline int acpi_dma_controller_free(struct device *dev) 90 { 91 return -ENODEV; 92 } 93 static inline int devm_acpi_dma_controller_register(struct device *dev, 94 struct dma_chan *(*acpi_dma_xlate) 95 (struct acpi_dma_spec *, struct acpi_dma *), 96 void *data) 97 { 98 return -ENODEV; 99 } 100 static inline void devm_acpi_dma_controller_free(struct device *dev) 101 { 102 } 103 104 static inline struct dma_chan *acpi_dma_request_slave_chan_by_index( 105 struct device *dev, size_t index) 106 { 107 return ERR_PTR(-ENODEV); 108 } 109 static inline struct dma_chan *acpi_dma_request_slave_chan_by_name( 110 struct device *dev, const char *name) 111 { 112 return ERR_PTR(-ENODEV); 113 } 114 115 #define acpi_dma_simple_xlate NULL 116 117 #endif 118 119 #define acpi_dma_request_slave_channel acpi_dma_request_slave_chan_by_index 120 121 #endif /* __LINUX_ACPI_DMA_H */ 122