kernel_samsung_a34x-permissive/include/linux/mfd/cros_ec_lpc_mec.h
2024-04-28 15:51:13 +02:00

91 lines
2.8 KiB
C

/*
* cros_ec_lpc_mec - LPC variant I/O for Microchip EC
*
* Copyright (C) 2016 Google, Inc
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* This driver uses the Chrome OS EC byte-level message-based protocol for
* communicating the keyboard state (which keys are pressed) from a keyboard EC
* to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing,
* but everything else (including deghosting) is done here. The main
* motivation for this is to keep the EC firmware as simple as possible, since
* it cannot be easily upgraded and EC flash/IRAM space is relatively
* expensive.
*/
#ifndef __LINUX_MFD_CROS_EC_MEC_H
#define __LINUX_MFD_CROS_EC_MEC_H
#include <linux/mfd/cros_ec_commands.h>
enum cros_ec_lpc_mec_emi_access_mode {
/* 8-bit access */
ACCESS_TYPE_BYTE = 0x0,
/* 16-bit access */
ACCESS_TYPE_WORD = 0x1,
/* 32-bit access */
ACCESS_TYPE_LONG = 0x2,
/*
* 32-bit access, read or write of MEC_EMI_EC_DATA_B3 causes the
* EC data register to be incremented.
*/
ACCESS_TYPE_LONG_AUTO_INCREMENT = 0x3,
};
enum cros_ec_lpc_mec_io_type {
MEC_IO_READ,
MEC_IO_WRITE,
};
/* Access IO ranges 0x800 thru 0x9ff using EMI interface instead of LPC */
#define MEC_EMI_RANGE_START EC_HOST_CMD_REGION0
#define MEC_EMI_RANGE_END (EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE)
/* EMI registers are relative to base */
#define MEC_EMI_BASE 0x800
#define MEC_EMI_HOST_TO_EC (MEC_EMI_BASE + 0)
#define MEC_EMI_EC_TO_HOST (MEC_EMI_BASE + 1)
#define MEC_EMI_EC_ADDRESS_B0 (MEC_EMI_BASE + 2)
#define MEC_EMI_EC_ADDRESS_B1 (MEC_EMI_BASE + 3)
#define MEC_EMI_EC_DATA_B0 (MEC_EMI_BASE + 4)
#define MEC_EMI_EC_DATA_B1 (MEC_EMI_BASE + 5)
#define MEC_EMI_EC_DATA_B2 (MEC_EMI_BASE + 6)
#define MEC_EMI_EC_DATA_B3 (MEC_EMI_BASE + 7)
/*
* cros_ec_lpc_mec_init
*
* Initialize MEC I/O.
*/
void cros_ec_lpc_mec_init(void);
/*
* cros_ec_lpc_mec_destroy
*
* Cleanup MEC I/O.
*/
void cros_ec_lpc_mec_destroy(void);
/**
* cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port
*
* @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request
* @offset: Base read / write address
* @length: Number of bytes to read / write
* @buf: Destination / source buffer
*
* @return 8-bit checksum of all bytes read / written
*/
u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
unsigned int offset, unsigned int length, u8 *buf);
#endif /* __LINUX_MFD_CROS_EC_MEC_H */