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 enum 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 
25 enum 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  */
46 void 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  */
57 int 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  */
69 u8 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 */
73