i2ctransfer: new applet

i2ctransfer sends and receives user defined i2c messages

v2: apply Xabier's comments: add -a option, don't decrement argc,
    use bb_show_usage() and xzalloc()
v3: fix possible out of bound access to msgs[nmsgs]

Reviewed-by: Xabier Oneca -- xOneca <xoneca@gmail.com>
Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Nikolaus Voss 2019-02-10 19:56:41 +01:00 committed by Denys Vlasenko
parent c89764c063
commit dac8f5ea38

View File

@ -36,17 +36,26 @@
//config: help //config: help
//config: Detect I2C chips. //config: Detect I2C chips.
//config: //config:
//config:config I2CTRANSFER
//config: bool "i2ctransfer (4.0 kb)"
//config: default y
//config: select PLATFORM_LINUX
//config: help
//config: Send user-defined I2C messages in one transfer.
//config:
//applet:IF_I2CGET(APPLET(i2cget, BB_DIR_USR_SBIN, BB_SUID_DROP)) //applet:IF_I2CGET(APPLET(i2cget, BB_DIR_USR_SBIN, BB_SUID_DROP))
//applet:IF_I2CSET(APPLET(i2cset, BB_DIR_USR_SBIN, BB_SUID_DROP)) //applet:IF_I2CSET(APPLET(i2cset, BB_DIR_USR_SBIN, BB_SUID_DROP))
//applet:IF_I2CDUMP(APPLET(i2cdump, BB_DIR_USR_SBIN, BB_SUID_DROP)) //applet:IF_I2CDUMP(APPLET(i2cdump, BB_DIR_USR_SBIN, BB_SUID_DROP))
//applet:IF_I2CDETECT(APPLET(i2cdetect, BB_DIR_USR_SBIN, BB_SUID_DROP)) //applet:IF_I2CDETECT(APPLET(i2cdetect, BB_DIR_USR_SBIN, BB_SUID_DROP))
//applet:IF_I2CTRANSFER(APPLET(i2ctransfer, BB_DIR_USR_SBIN, BB_SUID_DROP))
/* not NOEXEC: if hw operation stalls, use less memory in "hung" process */ /* not NOEXEC: if hw operation stalls, use less memory in "hung" process */
//kbuild:lib-$(CONFIG_I2CGET) += i2c_tools.o //kbuild:lib-$(CONFIG_I2CGET) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CSET) += i2c_tools.o //kbuild:lib-$(CONFIG_I2CSET) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CDUMP) += i2c_tools.o //kbuild:lib-$(CONFIG_I2CDUMP) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CDETECT) += i2c_tools.o //kbuild:lib-$(CONFIG_I2CDETECT) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CTRANSFER) += i2c_tools.o
/* /*
* Unsupported stuff: * Unsupported stuff:
@ -80,12 +89,19 @@
#define I2C_FUNCS 0x0705 #define I2C_FUNCS 0x0705
#define I2C_PEC 0x0708 #define I2C_PEC 0x0708
#define I2C_SMBUS 0x0720 #define I2C_SMBUS 0x0720
#define I2C_RDWR 0x0707
#define I2C_RDWR_IOCTL_MAX_MSGS 42
#define I2C_RDWR_IOCTL_MAX_MSGS_STR "42"
struct i2c_smbus_ioctl_data { struct i2c_smbus_ioctl_data {
__u8 read_write; __u8 read_write;
__u8 command; __u8 command;
__u32 size; __u32 size;
union i2c_smbus_data *data; union i2c_smbus_data *data;
}; };
struct i2c_rdwr_ioctl_data {
struct i2c_msg *msgs; /* pointers to i2c_msgs */
__u32 nmsgs; /* number of i2c_msgs */
};
/* end linux/i2c-dev.h */ /* end linux/i2c-dev.h */
/* /*
@ -262,7 +278,7 @@ static int i2c_bus_lookup(const char *bus_str)
return xstrtou_range(bus_str, 10, 0, 0xfffff); return xstrtou_range(bus_str, 10, 0, 0xfffff);
} }
#if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP #if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP || ENABLE_I2CTRANSFER
static int i2c_parse_bus_addr(const char *addr_str) static int i2c_parse_bus_addr(const char *addr_str)
{ {
/* Slave address must be in range 0x03 - 0x77. */ /* Slave address must be in range 0x03 - 0x77. */
@ -1373,3 +1389,163 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
return 0; return 0;
} }
#endif /* ENABLE_I2CDETECT */ #endif /* ENABLE_I2CDETECT */
#if ENABLE_I2CTRANSFER
static void check_i2c_func(int fd)
{
unsigned long funcs;
get_funcs_matrix(fd, &funcs);
if (!(funcs & I2C_FUNC_I2C))
bb_error_msg_and_die("adapter does not support I2C transfers");
}
//usage:#define i2ctransfer_trivial_usage
//usage: "[-fay] I2CBUS {rLENGTH[@ADDR] | wLENGTH[@ADDR] DATA...}..."
//usage:#define i2ctransfer_full_usage "\n\n"
//usage: "Read/write I2C data in one transfer"
//usage: "\n"
//usage: "\n -f Force access"
//usage: "\n -a Force scanning of non-regular addresses"
//usage: "\n -y Disable interactive mode"
int i2ctransfer_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int i2ctransfer_main(int argc UNUSED_PARAM, char **argv)
{
enum {
opt_f = (1 << 0),
opt_y = (1 << 1),
opt_a = (1 << 2),
};
int bus_num, bus_addr;
int fd;
unsigned opts, first, last;
int nmsgs, nmsgs_sent, i;
struct i2c_msg msgs[I2C_RDWR_IOCTL_MAX_MSGS];
struct i2c_rdwr_ioctl_data rdwr;
memset(msgs, 0, sizeof(msgs));
opts = getopt32(argv, "^"
"fya"
"\0" "-2" /* minimum 2 args */
);
first = 0x03;
last = 0x77;
if (opts & opt_a) {
first = 0x00;
last = 0x7f;
}
argv += optind;
bus_num = i2c_bus_lookup(argv[0]);
fd = i2c_dev_open(bus_num);
check_i2c_func(fd);
bus_addr = -1;
nmsgs = 0;
while (*++argv) {
char *arg_ptr;
unsigned len;
uint16_t flags;
char *end;
if (nmsgs >= I2C_RDWR_IOCTL_MAX_MSGS)
bb_error_msg_and_die("too many messages, max: "I2C_RDWR_IOCTL_MAX_MSGS_STR);
flags = 0;
arg_ptr = *argv;
switch (*arg_ptr++) {
case 'r': flags |= I2C_M_RD; break;
case 'w': break;
default:
bb_show_usage();
}
end = strchr(arg_ptr, '@');
if (end) *end = '\0';
len = xstrtou_range(arg_ptr, 0, 0, 0xffff);
if (end) {
bus_addr = xstrtou_range(end + 1, 0, first, last);
//TODO: will this work correctly if -f is specified?
if (!(opts & opt_f))
i2c_set_slave_addr(fd, bus_addr, (opts & opt_f));
} else {
/* Reuse last address if possible */
if (bus_addr < 0)
bb_error_msg_and_die("no address given in '%s'", *argv);
}
msgs[nmsgs].addr = bus_addr;
msgs[nmsgs].flags = flags;
msgs[nmsgs].len = len;
if (len)
msgs[nmsgs].buf = xzalloc(len);
if (!(flags & I2C_M_RD)) {
/* Consume DATA arg(s) */
unsigned buf_idx = 0;
while (buf_idx < len) {
uint8_t data8;
unsigned long data;
arg_ptr = *++argv;
if (!arg_ptr)
bb_show_usage();
data = strtoul(arg_ptr, &end, 0);
if (data > 0xff || arg_ptr == end)
bb_error_msg_and_die("invalid data byte '%s'", *argv);
data8 = data;
while (buf_idx < len) {
msgs[nmsgs].buf[buf_idx++] = data8;
if (!*end)
break;
switch (*end) {
/* Pseudo randomness (8 bit AXR with a=13 and b=27) */
case 'p':
data8 = (data8 ^ 27) + 13;
data8 = (data8 << 1) | (data8 >> 7);
break;
case '+': data8++; break;
case '-': data8--; break;
case '=': break;
default:
bb_error_msg_and_die("invalid data byte suffix: '%s'",
*argv);
}
}
}
}
nmsgs++;
}
if (!(opts & opt_y))
confirm_action(bus_addr, 0, 0, 0);
rdwr.msgs = msgs;
rdwr.nmsgs = nmsgs;
nmsgs_sent = ioctl_or_perror_and_die(fd, I2C_RDWR, &rdwr, "I2C_RDWR");
if (nmsgs_sent < nmsgs)
bb_error_msg("warning: only %u/%u messages sent", nmsgs_sent, nmsgs);
for (i = 0; i < nmsgs_sent; i++) {
if (msgs[i].len != 0 && (msgs[i].flags & I2C_M_RD)) {
int j;
for (j = 0; j < msgs[i].len - 1; j++)
printf("0x%02x ", msgs[i].buf[j]);
/* Print final byte with newline */
printf("0x%02x\n", msgs[i].buf[j]);
}
}
# if ENABLE_FEATURE_CLEAN_UP
close(fd);
for (i = 0; i < nmsgs; i++)
free(msgs[i].buf);
# endif
return 0;
}
#endif /* ENABLE_I2CTRANSFER */