acpi_dma.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * ACPI helpers for DMA request / controller
  4 *
  5 * Based on of_dma.h
  6 *
  7 * Copyright (C) 2013, Intel Corporation
  8 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
  9 */
 10
 11#ifndef __LINUX_ACPI_DMA_H
 12#define __LINUX_ACPI_DMA_H
 13
 14#include <linux/err.h>
 15#include <linux/dmaengine.h>
 16#include <linux/types.h>
 17
 18struct device;
 19
 20/**
 21 * struct acpi_dma_spec - slave device DMA resources
 22 * @chan_id:	channel unique id
 23 * @slave_id:	request line unique id
 24 * @dev:	struct device of the DMA controller to be used in the filter
 25 *		function
 26 */
 27struct acpi_dma_spec {
 28	int		chan_id;
 29	int		slave_id;
 30	struct device	*dev;
 31};
 32
 33/**
 34 * struct acpi_dma - representation of the registered DMAC
 35 * @dma_controllers:	linked list node
 36 * @dev:		struct device of this controller
 37 * @acpi_dma_xlate:	callback function to find a suitable channel
 38 * @data:		private data used by a callback function
 39 * @base_request_line:	first supported request line (CSRT)
 40 * @end_request_line:	last supported request line (CSRT)
 41 */
 42struct acpi_dma {
 43	struct list_head	dma_controllers;
 44	struct device		*dev;
 45	struct dma_chan		*(*acpi_dma_xlate)
 46				(struct acpi_dma_spec *, struct acpi_dma *);
 47	void			*data;
 48	unsigned short		base_request_line;
 49	unsigned short		end_request_line;
 50};
 51
 52/* Used with acpi_dma_simple_xlate() */
 53struct acpi_dma_filter_info {
 54	dma_cap_mask_t	dma_cap;
 55	dma_filter_fn	filter_fn;
 56};
 57
 58#ifdef CONFIG_DMA_ACPI
 59
 60int acpi_dma_controller_register(struct device *dev,
 61		struct dma_chan *(*acpi_dma_xlate)
 62		(struct acpi_dma_spec *, struct acpi_dma *),
 63		void *data);
 64int acpi_dma_controller_free(struct device *dev);
 65int devm_acpi_dma_controller_register(struct device *dev,
 66		struct dma_chan *(*acpi_dma_xlate)
 67		(struct acpi_dma_spec *, struct acpi_dma *),
 68		void *data);
 69
 70struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
 71						      size_t index);
 72struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
 73						     const char *name);
 74
 75struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
 76				       struct acpi_dma *adma);
 77#else
 78
 79static inline int acpi_dma_controller_register(struct device *dev,
 80		struct dma_chan *(*acpi_dma_xlate)
 81		(struct acpi_dma_spec *, struct acpi_dma *),
 82		void *data)
 83{
 84	return -ENODEV;
 85}
 86static inline int acpi_dma_controller_free(struct device *dev)
 87{
 88	return -ENODEV;
 89}
 90static inline int devm_acpi_dma_controller_register(struct device *dev,
 91		struct dma_chan *(*acpi_dma_xlate)
 92		(struct acpi_dma_spec *, struct acpi_dma *),
 93		void *data)
 94{
 95	return -ENODEV;
 96}
 97
 98static inline struct dma_chan *acpi_dma_request_slave_chan_by_index(
 99		struct device *dev, size_t index)
100{
101	return ERR_PTR(-ENODEV);
102}
103static inline struct dma_chan *acpi_dma_request_slave_chan_by_name(
104		struct device *dev, const char *name)
105{
106	return ERR_PTR(-ENODEV);
107}
108
109#define acpi_dma_simple_xlate	NULL
110
111#endif
112
113#define acpi_dma_request_slave_channel	acpi_dma_request_slave_chan_by_index
114
115#endif /* __LINUX_ACPI_DMA_H */