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
11#include <linux/acpi.h>
12
13enum cros_ec_lpc_mec_emi_access_mode {
14	/* 8-bit access */
15	ACCESS_TYPE_BYTE = 0x0,
16	/* 16-bit access */
17	ACCESS_TYPE_WORD = 0x1,
18	/* 32-bit access */
19	ACCESS_TYPE_LONG = 0x2,
20	/*
21	 * 32-bit access, read or write of MEC_EMI_EC_DATA_B3 causes the
22	 * EC data register to be incremented.
23	 */
24	ACCESS_TYPE_LONG_AUTO_INCREMENT = 0x3,
25};
26
27enum cros_ec_lpc_mec_io_type {
28	MEC_IO_READ,
29	MEC_IO_WRITE,
30};
31
32/* EMI registers are relative to base */
33#define MEC_EMI_HOST_TO_EC(MEC_EMI_BASE)	((MEC_EMI_BASE) + 0)
34#define MEC_EMI_EC_TO_HOST(MEC_EMI_BASE)	((MEC_EMI_BASE) + 1)
35#define MEC_EMI_EC_ADDRESS_B0(MEC_EMI_BASE)	((MEC_EMI_BASE) + 2)
36#define MEC_EMI_EC_ADDRESS_B1(MEC_EMI_BASE)	((MEC_EMI_BASE) + 3)
37#define MEC_EMI_EC_DATA_B0(MEC_EMI_BASE)	((MEC_EMI_BASE) + 4)
38#define MEC_EMI_EC_DATA_B1(MEC_EMI_BASE)	((MEC_EMI_BASE) + 5)
39#define MEC_EMI_EC_DATA_B2(MEC_EMI_BASE)	((MEC_EMI_BASE) + 6)
40#define MEC_EMI_EC_DATA_B3(MEC_EMI_BASE)	((MEC_EMI_BASE) + 7)
41
42/**
43 * cros_ec_lpc_mec_init() - Initialize MEC I/O.
44 *
45 * @base: MEC EMI Base address
46 * @end: MEC EMI End address
47 */
48void cros_ec_lpc_mec_init(unsigned int base, unsigned int end);
49
50/**
51 * cros_ec_lpc_mec_acpi_mutex() - Find and set ACPI mutex for MEC
52 *
53 * @adev:     Parent ACPI device
54 * @pathname: Name of AML mutex
55 * @return:   Negative error code, or zero for success
56 */
57int cros_ec_lpc_mec_acpi_mutex(struct acpi_device *adev, const char *pathname);
58
59/**
60 * cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range.
61 *
62 * @offset: Address offset
63 * @length: Number of bytes to check
64 *
65 * Return: 1 if in range, 0 if not, and -EINVAL on failure
66 *         such as the mec range not being initialized
67 */
68int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length);
69
70/**
71 * cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port
72 *
73 * @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request
74 * @offset:  Base read / write address
75 * @length:  Number of bytes to read / write
76 * @buf:     Destination / source buffer
77 *
78 * @return:  A negative error code on error, or 8-bit checksum of all
79 *           bytes read / written
80 */
81int cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
82			     unsigned int offset, unsigned int length, u8 *buf);
83
84#endif /* __CROS_EC_LPC_MEC_H */