xref: /openbmc/linux/include/linux/logic_iomem.h (revision e4624435)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2021 Intel Corporation
4  * Author: johannes@sipsolutions.net
5  */
6 #ifndef __LOGIC_IOMEM_H
7 #define __LOGIC_IOMEM_H
8 #include <linux/types.h>
9 #include <linux/ioport.h>
10 
11 /**
12  * struct logic_iomem_ops - emulated IO memory ops
13  * @read: read an 8, 16, 32 or 64 bit quantity from the given offset,
14  *	size is given in bytes (1, 2, 4 or 8)
15  *	(64-bit only necessary if CONFIG_64BIT is set)
16  * @write: write an 8, 16 32 or 64 bit quantity to the given offset,
17  *	size is given in bytes (1, 2, 4 or 8)
18  *	(64-bit only necessary if CONFIG_64BIT is set)
19  * @set: optional, for memset_io()
20  * @copy_from: optional, for memcpy_fromio()
21  * @copy_to: optional, for memcpy_toio()
22  * @unmap: optional, this region is getting unmapped
23  */
24 struct logic_iomem_ops {
25 	unsigned long (*read)(void *priv, unsigned int offset, int size);
26 	void (*write)(void *priv, unsigned int offset, int size,
27 		      unsigned long val);
28 
29 	void (*set)(void *priv, unsigned int offset, u8 value, int size);
30 	void (*copy_from)(void *priv, void *buffer, unsigned int offset,
31 			  int size);
32 	void (*copy_to)(void *priv, unsigned int offset, const void *buffer,
33 			int size);
34 
35 	void (*unmap)(void *priv);
36 };
37 
38 /**
39  * struct logic_iomem_region_ops - ops for an IO memory handler
40  * @map: map a range in the registered IO memory region, must
41  *	fill *ops with the ops and may fill *priv to be passed
42  *	to the ops. The offset is given as the offset into the
43  *	registered resource region.
44  *	The return value is negative for errors, or >= 0 for
45  *	success. On success, the return value is added to the
46  *	offset for later ops, to allow for partial mappings.
47  */
48 struct logic_iomem_region_ops {
49 	long (*map)(unsigned long offset, size_t size,
50 		    const struct logic_iomem_ops **ops,
51 		    void **priv);
52 };
53 
54 /**
55  * logic_iomem_add_region - register an IO memory region
56  * @resource: the resource description for this region
57  * @ops: the IO memory mapping ops for this resource
58  */
59 int logic_iomem_add_region(struct resource *resource,
60 			   const struct logic_iomem_region_ops *ops);
61 
62 #endif /* __LOGIC_IOMEM_H */
63