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>
102 lines
2 KiB
C
102 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// LPC interface for ChromeOS Embedded Controller
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//
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// Copyright (C) 2016 Google, Inc
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#include <linux/io.h>
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#include <linux/mfd/cros_ec.h>
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#include <linux/mfd/cros_ec_commands.h>
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#include "cros_ec_lpc_mec.h"
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static u8 lpc_read_bytes(unsigned int offset, unsigned int length, u8 *dest)
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{
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int i;
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int sum = 0;
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for (i = 0; i < length; ++i) {
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dest[i] = inb(offset + i);
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sum += dest[i];
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}
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/* Return checksum of all bytes read */
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return sum;
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}
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static u8 lpc_write_bytes(unsigned int offset, unsigned int length, u8 *msg)
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{
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int i;
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int sum = 0;
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for (i = 0; i < length; ++i) {
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outb(msg[i], offset + i);
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sum += msg[i];
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}
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/* Return checksum of all bytes written */
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return sum;
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}
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#ifdef CONFIG_CROS_EC_LPC_MEC
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u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length, u8 *dest)
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{
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int in_range = cros_ec_lpc_mec_in_range(offset, length);
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if (in_range < 0)
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return 0;
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return in_range ?
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cros_ec_lpc_io_bytes_mec(MEC_IO_READ,
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offset - EC_HOST_CMD_REGION0,
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length, dest) :
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lpc_read_bytes(offset, length, dest);
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}
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u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length, u8 *msg)
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{
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int in_range = cros_ec_lpc_mec_in_range(offset, length);
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if (in_range < 0)
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return 0;
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return in_range ?
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cros_ec_lpc_io_bytes_mec(MEC_IO_WRITE,
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offset - EC_HOST_CMD_REGION0,
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length, msg) :
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lpc_write_bytes(offset, length, msg);
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}
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void cros_ec_lpc_reg_init(void)
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{
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cros_ec_lpc_mec_init(EC_HOST_CMD_REGION0,
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EC_LPC_ADDR_MEMMAP + EC_MEMMAP_SIZE);
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}
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void cros_ec_lpc_reg_destroy(void)
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{
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cros_ec_lpc_mec_destroy();
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}
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#else /* CONFIG_CROS_EC_LPC_MEC */
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u8 cros_ec_lpc_read_bytes(unsigned int offset, unsigned int length, u8 *dest)
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{
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return lpc_read_bytes(offset, length, dest);
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}
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u8 cros_ec_lpc_write_bytes(unsigned int offset, unsigned int length, u8 *msg)
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{
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return lpc_write_bytes(offset, length, msg);
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}
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void cros_ec_lpc_reg_init(void)
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{
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}
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void cros_ec_lpc_reg_destroy(void)
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{
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}
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#endif /* CONFIG_CROS_EC_LPC_MEC */
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