mirror of
https://review.coreboot.org/flashrom.git
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0969e43b3f
Some callers may find it easier to provide the path to an I2C device
at which to communicate with the device, rather than specify the bus
number- doing so might involve trying to parse a path to extract the
number only for flashrom to do the reverse, which is error-prone and
unnecessary.
This change adds support for a `devpath` option, continuing to
allow `bus` and requiring only one of them be specified.
TEST=Verified --flash-size outputs correct values with both
devpath=/dev/i2c-7 and bus=7, as well as noting that one is
required if neither is specified and only one may be specified
if both are given.
Signed-off-by: Peter Marheine <pmarheine@chromium.org>
Change-Id: Id2adf8a307b9205ce5e5804a6c3e22f19d0c34c9
Reviewed-on: https://review.coreboot.org/c/flashrom/+/51967
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
107 lines
2.4 KiB
C
107 lines
2.4 KiB
C
/*
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* This file is part of the flashrom project.
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*
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* Copyright (C) 2020 The Chromium OS Authors
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <linux/i2c.h>
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#include <linux/i2c-dev.h>
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#include "flash.h"
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#include "i2c_helper.h"
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/* Null characters are placeholders for bus number digits */
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#define I2C_DEV_PREFIX "/dev/i2c-\0\0\0"
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#define I2C_MAX_BUS 255
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int i2c_close(int fd)
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{
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return fd == -1 ? 0 : close(fd);
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}
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int i2c_open_path(const char *path, uint16_t addr, int force)
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{
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int fd = open(path, O_RDWR);
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if (fd < 0) {
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msg_perr("Unable to open I2C device %s: %s.\n", path, strerror(errno));
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return fd;
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}
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int request = force ? I2C_SLAVE_FORCE : I2C_SLAVE;
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int ret = ioctl(fd, request, addr);
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if (ret < 0) {
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msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno));
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i2c_close(fd);
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return ret;
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}
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return fd;
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}
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int i2c_open(int bus, uint16_t addr, int force)
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{
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char dev[sizeof(I2C_DEV_PREFIX)] = {0};
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int ret = -1;
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if (bus < 0 || bus > I2C_MAX_BUS) {
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msg_perr("Invalid I2C bus %d.\n", bus);
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return ret;
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}
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ret = snprintf(dev, sizeof(dev), "%s%d", I2C_DEV_PREFIX, bus);
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if (ret < 0) {
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msg_perr("Unable to join bus number to device name: %s.\n", strerror(errno));
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return ret;
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}
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return i2c_open_path(dev, addr, force);
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}
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int i2c_read(int fd, uint16_t addr, i2c_buffer_t *buf)
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{
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if (buf->len == 0)
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return 0;
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int ret = ioctl(fd, I2C_SLAVE, addr);
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if (ret < 0) {
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msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno));
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return ret;
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}
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return read(fd, buf->buf, buf->len);
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}
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int i2c_write(int fd, uint16_t addr, const i2c_buffer_t *buf)
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{
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if (buf->len == 0)
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return 0;
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int ret = ioctl(fd, I2C_SLAVE, addr);
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if (ret < 0) {
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msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno));
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return ret;
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}
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return write(fd, buf->buf, buf->len);
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}
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