include/linux/logic_iomem.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * Copyright (C) 2021 Intel Corporation
0004  * Author: johannes@sipsolutions.net
0005  */
0006 #ifndef __LOGIC_IOMEM_H
0007 #define __LOGIC_IOMEM_H
0008 #include <linux/types.h>
0009 #include <linux/ioport.h>
0010
0011 /**
0012  * struct logic_iomem_ops - emulated IO memory ops
0013  * @read: read an 8, 16, 32 or 64 bit quantity from the given offset,
0014  *  size is given in bytes (1, 2, 4 or 8)
0015  *  (64-bit only necessary if CONFIG_64BIT is set)
0016  * @write: write an 8, 16 32 or 64 bit quantity to the given offset,
0017  *  size is given in bytes (1, 2, 4 or 8)
0018  *  (64-bit only necessary if CONFIG_64BIT is set)
0019  * @set: optional, for memset_io()
0020  * @copy_from: optional, for memcpy_fromio()
0021  * @copy_to: optional, for memcpy_toio()
0022  * @unmap: optional, this region is getting unmapped
0023  */
0024 struct logic_iomem_ops {
0025     unsigned long (*read)(void *priv, unsigned int offset, int size);
0026     void (*write)(void *priv, unsigned int offset, int size,
0027               unsigned long val);
0028
0029     void (*set)(void *priv, unsigned int offset, u8 value, int size);
0030     void (*copy_from)(void *priv, void *buffer, unsigned int offset,
0031               int size);
0032     void (*copy_to)(void *priv, unsigned int offset, const void *buffer,
0033             int size);
0034
0035     void (*unmap)(void *priv);
0036 };
0037
0038 /**
0039  * struct logic_iomem_region_ops - ops for an IO memory handler
0040  * @map: map a range in the registered IO memory region, must
0041  *  fill *ops with the ops and may fill *priv to be passed
0042  *  to the ops. The offset is given as the offset into the
0043  *  registered resource region.
0044  *  The return value is negative for errors, or >= 0 for
0045  *  success. On success, the return value is added to the
0046  *  offset for later ops, to allow for partial mappings.
0047  */
0048 struct logic_iomem_region_ops {
0049     long (*map)(unsigned long offset, size_t size,
0050             const struct logic_iomem_ops **ops,
0051             void **priv);
0052 };
0053
0054 /**
0055  * logic_iomem_add_region - register an IO memory region
0056  * @resource: the resource description for this region
0057  * @ops: the IO memory mapping ops for this resource
0058  */
0059 int logic_iomem_add_region(struct resource *resource,
0060                const struct logic_iomem_region_ops *ops);
0061
0062 #endif /* __LOGIC_IOMEM_H */