mirror of
https://review.coreboot.org/flashrom.git
synced 2025-04-27 23:22:37 +02:00
i2c_helper: Add support for the Linux I2C subsystem
See https://www.kernel.org/doc/Documentation/i2c/ for details. This creates common interface for I2C access functions, and adds implementation for linux I2C functions. BUG=b:148746232 BRANCH=none TEST=build success Signed-off-by: Shiyu Sun <sshiyu@chromium.org> Change-Id: Ie0487824dfb71970bede17f617dbbb30ddf78c12 Reviewed-on: https://review.coreboot.org/c/flashrom/+/39686 Tested-by: Edward O'Callaghan <quasisec@chromium.org> Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
This commit is contained in:
parent
fe6b98b91c
commit
dc2c83bbc7
9
Makefile
9
Makefile
@ -418,6 +418,10 @@ override CONFIG_RAYER_SPI = no
|
||||
endif
|
||||
endif
|
||||
|
||||
ifeq ($(TARGET_OS), Linux)
|
||||
CONFIG_LINUX_I2C_HELPER = yes
|
||||
endif
|
||||
|
||||
###############################################################################
|
||||
# General architecture-specific settings.
|
||||
# Like above for the OS, below we verify user-supplied options depending on the target architecture.
|
||||
@ -1048,6 +1052,11 @@ LIBS += -lni845x
|
||||
PROGRAMMER_OBJS += ni845x_spi.o
|
||||
endif
|
||||
|
||||
ifeq ($(CONFIG_LINUX_I2C_HELPER), yes)
|
||||
LIB_OBJS += i2c_helper_linux.o
|
||||
FEATURE_CFLAGS += -D'CONFIG_I2C_SUPPORT=1'
|
||||
endif
|
||||
|
||||
ifneq ($(NEED_SERIAL), )
|
||||
LIB_OBJS += serial.o custom_baud.o
|
||||
endif
|
||||
|
112
i2c_helper.h
Normal file
112
i2c_helper.h
Normal file
@ -0,0 +1,112 @@
|
||||
/*
|
||||
* This file is part of the flashrom project.
|
||||
*
|
||||
* Copyright (C) 2020 The Chromium OS Authors
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* 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.
|
||||
*/
|
||||
|
||||
#ifndef I2C_HELPER_H
|
||||
#define I2C_HELPER_H
|
||||
|
||||
#include <inttypes.h>
|
||||
|
||||
/**
|
||||
* An convinent structure that contains the buffer size and the buffer
|
||||
* pointer. Used to wrap buffer details while doing the I2C data
|
||||
* transfer on both input and output. It is the client's responsibility
|
||||
* to use i2c_buffer_t_fill to initialize this struct instead of
|
||||
* trying to construct it directly.
|
||||
*/
|
||||
typedef struct {
|
||||
void *buf;
|
||||
uint16_t len;
|
||||
} i2c_buffer_t;
|
||||
|
||||
/**
|
||||
* i2c_buffer_t_fill - fills in the i2c_buffer_t
|
||||
*
|
||||
* @i2c_buf: pointer to the be constructed.
|
||||
* @buf: buffer contains data to be included in i2c_buffer_t.
|
||||
* @len: length of buffer to be included in i2c_buffer_t.
|
||||
*
|
||||
* This function takes in a pointer to an initialized i2c_buffer_t
|
||||
* object with related information, and fill in the i2c_buffer_t with
|
||||
* some validation applied. The function does allow initialization with
|
||||
* NULL buffer but will make sure len == 0 in such case.
|
||||
*
|
||||
* returns 0 on success, <0 to indicate failure
|
||||
*/
|
||||
static inline int i2c_buffer_t_fill(i2c_buffer_t *i2c_buf, void *buf, uint16_t len)
|
||||
{
|
||||
if (!i2c_buf || (!buf && len))
|
||||
return -1;
|
||||
|
||||
i2c_buf->buf = buf;
|
||||
i2c_buf->len = len;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* i2c_open - opens the target I2C device and set the I2C slave address
|
||||
*
|
||||
* @bus: I2C bus number of the target device.
|
||||
* @addr: I2C slave address.
|
||||
* @force: whether to force set the I2C slave address.
|
||||
*
|
||||
* This function returns a file descriptor for the target device. It is
|
||||
* the client's responsibility to pass the return value to i2c_close to
|
||||
* clean up.
|
||||
*
|
||||
* returns fd of target device on success, <0 to indicate failure
|
||||
*/
|
||||
int i2c_open(int bus, uint16_t addr, int force);
|
||||
|
||||
/**
|
||||
* i2c_close - closes the file descriptor returned by i2c_open
|
||||
*
|
||||
* @fd: file descriptor to be closed.
|
||||
*
|
||||
* It is the client's responsibility to set fd = -1 when it is
|
||||
* done with it.
|
||||
*
|
||||
* returns 0 on success, <0 to indicate failure
|
||||
*/
|
||||
int i2c_close(int fd);
|
||||
|
||||
/**
|
||||
* i2c_read - reads data from the I2C device
|
||||
*
|
||||
* @fd: file descriptor of the target device.
|
||||
* @addr: I2C slave address of the target device.
|
||||
* @buf_read: data struct includes reading buffer and size.
|
||||
*
|
||||
* This function does accept empty read and do nothing on such case.
|
||||
*
|
||||
* returns read length on success, <0 to indicate failure
|
||||
*/
|
||||
int i2c_read(int fd, uint16_t addr, i2c_buffer_t *buf_read);
|
||||
|
||||
/**
|
||||
* i2c_write - writes command/data into the I2C device
|
||||
*
|
||||
* @fd: file descriptor of the target device.
|
||||
* @addr: I2C slave address of the target device.
|
||||
* @buf_write: data struct includes writting buffer and size.
|
||||
*
|
||||
* This function does accept empty write and do nothing on such case.
|
||||
*
|
||||
* returns wrote length on success, <0 to indicate failure.
|
||||
*/
|
||||
int i2c_write(int fd, uint16_t addr, const i2c_buffer_t *buf_write);
|
||||
|
||||
#endif /* !I2C_HELPER_H */
|
113
i2c_helper_linux.c
Normal file
113
i2c_helper_linux.c
Normal file
@ -0,0 +1,113 @@
|
||||
/*
|
||||
* This file is part of the flashrom project.
|
||||
*
|
||||
* Copyright (C) 2020 The Chromium OS Authors
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* 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.
|
||||
*/
|
||||
|
||||
#include <errno.h>
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <sys/fcntl.h>
|
||||
#include <sys/ioctl.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <linux/i2c.h>
|
||||
#include <linux/i2c-dev.h>
|
||||
|
||||
#include "flash.h"
|
||||
#include "i2c_helper.h"
|
||||
|
||||
#define I2C_DEV_PREFIX "/dev/i2c-"
|
||||
#define I2C_MAX_BUS 255
|
||||
|
||||
int i2c_close(int fd)
|
||||
{
|
||||
return fd == -1 ? 0 : close(fd);
|
||||
}
|
||||
|
||||
int i2c_open(int bus, uint16_t addr, int force)
|
||||
{
|
||||
int ret = -1;
|
||||
int fd = -1;
|
||||
|
||||
/* Maximum i2c bus number is 255(3 char), +1 for null terminated string. */
|
||||
int path_len = strlen(I2C_DEV_PREFIX) + 4;
|
||||
int request = force ? I2C_SLAVE_FORCE : I2C_SLAVE;
|
||||
|
||||
if (bus < 0 || bus > I2C_MAX_BUS) {
|
||||
msg_perr("Invalid I2C bus %d.\n", bus);
|
||||
return ret;
|
||||
}
|
||||
|
||||
char *dev = calloc(1, path_len);
|
||||
if (!dev) {
|
||||
msg_perr("Unable to allocate space for device name of len %d: %s.\n",
|
||||
path_len, strerror(errno));
|
||||
goto linux_i2c_open_err;
|
||||
}
|
||||
|
||||
ret = snprintf(dev, path_len, "%s%d", I2C_DEV_PREFIX, bus);
|
||||
if (ret < 0) {
|
||||
msg_perr("Unable to join bus number to device name: %s.\n", strerror(errno));
|
||||
goto linux_i2c_open_err;
|
||||
}
|
||||
|
||||
fd = open(dev, O_RDWR);
|
||||
if (fd < 0) {
|
||||
msg_perr("Unable to open I2C device %s: %s.\n", dev, strerror(errno));
|
||||
ret = fd;
|
||||
goto linux_i2c_open_err;
|
||||
}
|
||||
|
||||
ret = ioctl(fd, request, addr);
|
||||
if (ret < 0) {
|
||||
msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno));
|
||||
i2c_close(fd);
|
||||
goto linux_i2c_open_err;
|
||||
}
|
||||
|
||||
linux_i2c_open_err:
|
||||
if (dev)
|
||||
free(dev);
|
||||
|
||||
return ret ? ret : fd;
|
||||
}
|
||||
|
||||
int i2c_read(int fd, uint16_t addr, i2c_buffer_t *buf)
|
||||
{
|
||||
if (buf->len == 0)
|
||||
return 0;
|
||||
|
||||
int ret = ioctl(fd, I2C_SLAVE, addr);
|
||||
if (ret < 0) {
|
||||
msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno));
|
||||
return ret;
|
||||
}
|
||||
|
||||
return read(fd, buf->buf, buf->len);
|
||||
}
|
||||
|
||||
int i2c_write(int fd, uint16_t addr, const i2c_buffer_t *buf)
|
||||
{
|
||||
if (buf->len == 0)
|
||||
return 0;
|
||||
|
||||
int ret = ioctl(fd, I2C_SLAVE, addr);
|
||||
if (ret < 0) {
|
||||
msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno));
|
||||
return ret;
|
||||
}
|
||||
|
||||
return write(fd, buf->buf, buf->len);
|
||||
}
|
@ -290,6 +290,11 @@ if config_bitbang_spi
|
||||
cargs += '-DCONFIG_BITBANG_SPI=1'
|
||||
endif
|
||||
|
||||
if host_machine.system() == 'linux'
|
||||
srcs += 'i2c_helper_linux.c'
|
||||
cargs += '-DCONFIG_I2C_SUPPORT=1'
|
||||
endif
|
||||
|
||||
# raw memory, MSR or PCI port I/O access
|
||||
if need_raw_access
|
||||
srcs += 'hwaccess.c'
|
||||
|
Loading…
x
Reference in New Issue
Block a user