diff options
Diffstat (limited to 'include/linux/mfd/cros_ec_lpc_mec.h')
| -rw-r--r-- | include/linux/mfd/cros_ec_lpc_mec.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/include/linux/mfd/cros_ec_lpc_mec.h b/include/linux/mfd/cros_ec_lpc_mec.h new file mode 100644 index 000000000000..176496ddc66c --- /dev/null +++ b/include/linux/mfd/cros_ec_lpc_mec.h @@ -0,0 +1,90 @@ +/* + * 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 */ |