/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (C) 2020 embedded brains GmbH.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* The command implemented here has a similar interface like the one from Linux
* i2c tools. Think of it as a heavily simplified version of them. Instead of
* the bus number they expect a bus path.
*
* Additionally the i2cget has a continuous read mode that isn't available on
* Linux but does something similar to i2cdump.
*/
#include <dev/i2c/i2c.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <rtems/shell.h>
static const char rtems_i2cget_shell_usage [] =
"i2cget <I2C_BUS> <CHIP-ADDRESS> <DATA-ADDRESS> [<NR-BYTES>]\n"
"\tGet one or more bytes from an EEPROM like i2c device.\n"
"\tNote that multiple bytes will be read in continuous mode.\n";
static int read_bytes(
int fd,
uint16_t i2c_address,
uint8_t data_address,
uint16_t nr_bytes
)
{
int rv;
uint8_t value[nr_bytes];
i2c_msg msgs[] = {{
.addr = i2c_address,
.flags = 0,
.buf = &data_address,
.len = 1,
}, {
.addr = i2c_address,
.flags = I2C_M_RD,
.buf = value,
.len = nr_bytes,
}};
struct i2c_rdwr_ioctl_data payload = {
.msgs = msgs,
.nmsgs = sizeof(msgs)/sizeof(msgs[0]),
};
uint16_t i;
rv = ioctl(fd, I2C_RDWR, &payload);
if (rv < 0) {
perror("ioctl failed");
} else {
for (i = 0; i < nr_bytes; ++i) {
printf("0x%02x ", value[i]);
}
printf("\n");
}
return rv;
}
static int rtems_i2cget_shell_main(int argc, char *argv[])
{
int fd;
int rv;
const char *bus;
uint16_t chip_address;
uint8_t data_address;
uint16_t nr_bytes;
if (argc < 4 || argc > 5) {
printf(rtems_i2cget_shell_usage);
return 1;
}
errno = 0;
chip_address = (uint16_t) strtoul(argv[2], NULL, 0);
if (errno != 0) {
perror("Couldn't read chip address");
return 1;
}
errno = 0;
data_address = (uint8_t) strtoul(argv[3], NULL, 0);
if (errno != 0) {
perror("Couldn't read data address");
return 1;
}
nr_bytes = 1;
if (argc == 5) {
errno = 0;
nr_bytes = (uint16_t) strtoul(argv[4], NULL, 0);
if (errno != 0) {
perror("Couldn't read number of bytes");
return 1;
}
}
bus = argv[1];
fd = open(bus, O_RDWR);
if (fd < 0) {
perror("Couldn't open bus");
return 1;
}
rv = read_bytes(fd, chip_address, data_address, nr_bytes);
close(fd);
return rv;
}
rtems_shell_cmd_t rtems_shell_I2CGET_Command = {
.name = "i2cget",
.usage = rtems_i2cget_shell_usage,
.topic = "misc",
.command = rtems_i2cget_shell_main,
};
