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6b7cb2227d
In order to allow this code to be re-used, remove the dependency on the rest of the cros_ec code from the cros_ec_lpc_mec functions. Instead of using a hardcoded register base address of 0x800 have this be passed in to cros_ec_lpc_mec_init(). The existing cros_ec use case now passes in the 0x800 base address this way. There are some error checks that happen in cros_ec_lpc_mec_in_range() that probably shouldn't be there, as they are checking kernel-space callers and not user-space input. However, we'll just do the refactor in this patch, and in a future patch might remove this error checking and fix all the instances of code that calls this. There's a similar problem in cros_ec_lpc_read_bytes(), where we return a checksum, but on error just return 0. This should probably be changed so that it returns int, but we don't want to have to mess with all the calling code for this fix. Maybe we'll come back through later and fix this. Signed-off-by: Duncan Laurie <dlaurie@google.com> Signed-off-by: Nick Crews <ncrews@chromium.org> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
80 lines
2.2 KiB
C
80 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* LPC variant I/O for Microchip EC
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*
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* Copyright (C) 2016 Google, Inc
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*/
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#ifndef __CROS_EC_LPC_MEC_H
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#define __CROS_EC_LPC_MEC_H
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enum cros_ec_lpc_mec_emi_access_mode {
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/* 8-bit access */
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ACCESS_TYPE_BYTE = 0x0,
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/* 16-bit access */
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ACCESS_TYPE_WORD = 0x1,
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/* 32-bit access */
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ACCESS_TYPE_LONG = 0x2,
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/*
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* 32-bit access, read or write of MEC_EMI_EC_DATA_B3 causes the
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* EC data register to be incremented.
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*/
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ACCESS_TYPE_LONG_AUTO_INCREMENT = 0x3,
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};
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enum cros_ec_lpc_mec_io_type {
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MEC_IO_READ,
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MEC_IO_WRITE,
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};
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/* EMI registers are relative to base */
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#define MEC_EMI_HOST_TO_EC(MEC_EMI_BASE) ((MEC_EMI_BASE) + 0)
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#define MEC_EMI_EC_TO_HOST(MEC_EMI_BASE) ((MEC_EMI_BASE) + 1)
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#define MEC_EMI_EC_ADDRESS_B0(MEC_EMI_BASE) ((MEC_EMI_BASE) + 2)
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#define MEC_EMI_EC_ADDRESS_B1(MEC_EMI_BASE) ((MEC_EMI_BASE) + 3)
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#define MEC_EMI_EC_DATA_B0(MEC_EMI_BASE) ((MEC_EMI_BASE) + 4)
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#define MEC_EMI_EC_DATA_B1(MEC_EMI_BASE) ((MEC_EMI_BASE) + 5)
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#define MEC_EMI_EC_DATA_B2(MEC_EMI_BASE) ((MEC_EMI_BASE) + 6)
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#define MEC_EMI_EC_DATA_B3(MEC_EMI_BASE) ((MEC_EMI_BASE) + 7)
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/**
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* cros_ec_lpc_mec_init() - Initialize MEC I/O.
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*
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* @base: MEC EMI Base address
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* @end: MEC EMI End address
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*/
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void cros_ec_lpc_mec_init(unsigned int base, unsigned int end);
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/*
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* cros_ec_lpc_mec_destroy
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*
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* Cleanup MEC I/O.
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*/
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void cros_ec_lpc_mec_destroy(void);
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/**
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* cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range.
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*
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* @offset: Address offset
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* @length: Number of bytes to check
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*
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* Return: 1 if in range, 0 if not, and -EINVAL on failure
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* such as the mec range not being initialized
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*/
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int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length);
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/**
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* cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port
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*
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* @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request
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* @offset: Base read / write address
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* @length: Number of bytes to read / write
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* @buf: Destination / source buffer
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*
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* @return 8-bit checksum of all bytes read / written
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*/
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u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
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unsigned int offset, unsigned int length, u8 *buf);
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#endif /* __CROS_EC_LPC_MEC_H */
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