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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * LPC variant I/O for Microchip EC
4 *
5 * Copyright (C) 2016 Google, Inc
6 */
7
8#ifndef __CROS_EC_LPC_MEC_H
9#define __CROS_EC_LPC_MEC_H
10
11enum cros_ec_lpc_mec_emi_access_mode {
12 /* 8-bit access */
13 ACCESS_TYPE_BYTE = 0x0,
14 /* 16-bit access */
15 ACCESS_TYPE_WORD = 0x1,
16 /* 32-bit access */
17 ACCESS_TYPE_LONG = 0x2,
18 /*
19 * 32-bit access, read or write of MEC_EMI_EC_DATA_B3 causes the
20 * EC data register to be incremented.
21 */
22 ACCESS_TYPE_LONG_AUTO_INCREMENT = 0x3,
23};
24
25enum cros_ec_lpc_mec_io_type {
26 MEC_IO_READ,
27 MEC_IO_WRITE,
28};
29
30/* EMI registers are relative to base */
31#define MEC_EMI_HOST_TO_EC(MEC_EMI_BASE) ((MEC_EMI_BASE) + 0)
32#define MEC_EMI_EC_TO_HOST(MEC_EMI_BASE) ((MEC_EMI_BASE) + 1)
33#define MEC_EMI_EC_ADDRESS_B0(MEC_EMI_BASE) ((MEC_EMI_BASE) + 2)
34#define MEC_EMI_EC_ADDRESS_B1(MEC_EMI_BASE) ((MEC_EMI_BASE) + 3)
35#define MEC_EMI_EC_DATA_B0(MEC_EMI_BASE) ((MEC_EMI_BASE) + 4)
36#define MEC_EMI_EC_DATA_B1(MEC_EMI_BASE) ((MEC_EMI_BASE) + 5)
37#define MEC_EMI_EC_DATA_B2(MEC_EMI_BASE) ((MEC_EMI_BASE) + 6)
38#define MEC_EMI_EC_DATA_B3(MEC_EMI_BASE) ((MEC_EMI_BASE) + 7)
39
40/**
41 * cros_ec_lpc_mec_init() - Initialize MEC I/O.
42 *
43 * @base: MEC EMI Base address
44 * @end: MEC EMI End address
45 */
46void cros_ec_lpc_mec_init(unsigned int base, unsigned int end);
47
48/**
49 * cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range.
50 *
51 * @offset: Address offset
52 * @length: Number of bytes to check
53 *
54 * Return: 1 if in range, 0 if not, and -EINVAL on failure
55 * such as the mec range not being initialized
56 */
57int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length);
58
59/**
60 * cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port
61 *
62 * @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request
63 * @offset: Base read / write address
64 * @length: Number of bytes to read / write
65 * @buf: Destination / source buffer
66 *
67 * @return 8-bit checksum of all bytes read / written
68 */
69u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
70 unsigned int offset, unsigned int length, u8 *buf);
71
72#endif /* __CROS_EC_LPC_MEC_H */