hush/miscutils/i2c_tools.c
Bartosz Golaszewski 7ca5c51cc8 i2c-tools: only try /dev/i2c/* if opening /dev/i2c-* fails with ENOENT
Trying to access /dev/i2c/* on every error after opening /dev/i2c-* can
mislead users who e.g. don't have root access. Instead of bailing-out
with "permission denied" we currently print "no such file or directory".

Fix it by trying open("/dev/i2c/%d") only if we got ENOENT.

Upstream i2cdetect tries to get any info it can from /sys and /proc even
when invoked by an unprivileged user, but we don't want to add unnecessary
bloat.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2015-05-11 17:26:27 +02:00

1404 lines
35 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Minimal i2c-tools implementation for busybox.
* Parts of code ported from i2c-tools:
* http://www.lm-sensors.org/wiki/I2CTools.
*
* Copyright (C) 2014 by Bartosz Golaszewski <bartekgola@gmail.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config I2CGET
//config: bool "i2cget"
//config: default y
//config: select PLATFORM_LINUX
//config: help
//config: Read from I2C/SMBus chip registers.
//config:
//config:config I2CSET
//config: bool "i2cset"
//config: default y
//config: select PLATFORM_LINUX
//config: help
//config: Set I2C registers.
//config:
//config:config I2CDUMP
//config: bool "i2cdump"
//config: default y
//config: select PLATFORM_LINUX
//config: help
//config: Examine I2C registers.
//config:
//config:config I2CDETECT
//config: bool "i2cdetect"
//config: default y
//config: select PLATFORM_LINUX
//config: help
//config: Detect I2C chips.
//config:
//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_I2CDUMP(APPLET(i2cdump, BB_DIR_USR_SBIN, BB_SUID_DROP))
//applet:IF_I2CDETECT(APPLET(i2cdetect, BB_DIR_USR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_I2CGET) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CSET) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CDUMP) += i2c_tools.o
//kbuild:lib-$(CONFIG_I2CDETECT) += i2c_tools.o
/*
* Unsupported stuff:
*
* - upstream i2c-tools can also look-up i2c busses by name, we only accept
* numbers,
* - bank and bankreg parameters for i2cdump are not supported because of
* their limited usefulness (see i2cdump manual entry for more info),
* - i2cdetect doesn't look for bus info in /proc as it does in upstream, but
* it shouldn't be a problem in modern kernels.
*/
#include "libbb.h"
/*
* /dev/i2c-X ioctl commands. The ioctl's parameter is always an unsigned long,
* except for:
* - I2C_FUNCS, takes pointer to an unsigned long
* - I2C_RDWR, takes pointer to struct i2c_rdwr_ioctl_data
* - I2C_SMBUS, takes pointer to struct i2c_smbus_ioctl_data
*/
/*
* NOTE: Slave address is 7 or 10 bits, but 10-bit addresses
* are not supported due to code brokenness.
*/
/* Use this slave address. */
#define I2C_SLAVE 0x0703
/* Use this slave address, even if it is already in use by a driver. */
#define I2C_SLAVE_FORCE 0x0706
/* 0 for 7 bit addrs, != 0 for 10 bit. */
#define I2C_TENBIT 0x0704
/* Get the adapter functionality mask. */
#define I2C_FUNCS 0x0705
/* Combined R/W transfer (one STOP only). */
#define I2C_RDWR 0x0707
/* != 0 to use PEC with SMBus. */
#define I2C_PEC 0x0708
/* SMBus transfer. */
#define I2C_SMBUS 0x0720
/* Structure used in the I2C_SMBUS ioctl call. */
struct i2c_smbus_ioctl_data {
uint8_t read_write;
uint8_t command;
uint32_t size;
union i2c_smbus_data *data;
};
/* Structure used in the I2C_RDWR ioctl call. */
struct i2c_rdwr_ioctl_data {
struct i2c_msg *msgs; /* Pointers to i2c_msgs. */
uint32_t nmsgs; /* Number of i2c_msgs. */
};
/* As specified in SMBus standard. */
#define I2C_SMBUS_BLOCK_MAX 32
/* Not specified but we use same structure. */
#define I2C_SMBUS_I2C_BLOCK_MAX 32
/* Data for SMBus Messages. */
union i2c_smbus_data {
uint8_t byte;
uint16_t word;
/* block[0] is used for length and one more for PEC */
uint8_t block[I2C_SMBUS_BLOCK_MAX + 2];
};
#define I2C_RDRW_IOCTL_MAX_MSGS 42
#define I2C_MAX_REGS 256
/* Smbus_access read or write markers. */
#define I2C_SMBUS_READ 1
#define I2C_SMBUS_WRITE 0
/* SMBus transaction types (size parameter in the below functions). */
#define I2C_SMBUS_QUICK 0
#define I2C_SMBUS_BYTE 1
#define I2C_SMBUS_BYTE_DATA 2
#define I2C_SMBUS_WORD_DATA 3
#define I2C_SMBUS_PROC_CALL 4
#define I2C_SMBUS_BLOCK_DATA 5
#define I2C_SMBUS_I2C_BLOCK_BROKEN 6
#define I2C_SMBUS_BLOCK_PROC_CALL 7
#define I2C_SMBUS_I2C_BLOCK_DATA 8
#define DETECT_MODE_AUTO 0
#define DETECT_MODE_QUICK 1
#define DETECT_MODE_READ 2
/* Defines to determine what functionality is present. */
#define I2C_FUNC_I2C 0x00000001
#define I2C_FUNC_10BIT_ADDR 0x00000002
#define I2C_FUNC_PROTOCOL_MANGLING 0x00000004
#define I2C_FUNC_SMBUS_PEC 0x00000008
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000
#define I2C_FUNC_SMBUS_QUICK 0x00010000
#define I2C_FUNC_SMBUS_READ_BYTE 0x00020000
#define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000
#define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000
#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000
#define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000
#define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000
#define I2C_FUNC_SMBUS_PROC_CALL 0x00800000
#define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000
#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
#define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000
#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000
#define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \
I2C_FUNC_SMBUS_WRITE_BYTE)
#define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
#define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \
I2C_FUNC_SMBUS_WRITE_WORD_DATA)
#define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
#define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
/*
* This is needed for ioctl_or_perror_and_die() since it only accepts pointers.
*/
static ALWAYS_INLINE void *itoptr(int i)
{
return (void*)(intptr_t)i;
}
static int32_t i2c_smbus_access(int fd, char read_write, uint8_t cmd,
int size, union i2c_smbus_data *data)
{
struct i2c_smbus_ioctl_data args;
args.read_write = read_write;
args.command = cmd;
args.size = size;
args.data = data;
return ioctl(fd, I2C_SMBUS, &args);
}
static int32_t i2c_smbus_read_byte(int fd)
{
union i2c_smbus_data data;
int err;
err = i2c_smbus_access(fd, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data);
if (err < 0)
return err;
return data.byte;
}
#if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP
static int32_t i2c_smbus_write_byte(int fd, uint8_t val)
{
return i2c_smbus_access(fd, I2C_SMBUS_WRITE,
val, I2C_SMBUS_BYTE, NULL);
}
static int32_t i2c_smbus_read_byte_data(int fd, uint8_t cmd)
{
union i2c_smbus_data data;
int err;
err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
I2C_SMBUS_BYTE_DATA, &data);
if (err < 0)
return err;
return data.byte;
}
static int32_t i2c_smbus_read_word_data(int fd, uint8_t cmd)
{
union i2c_smbus_data data;
int err;
err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
I2C_SMBUS_WORD_DATA, &data);
if (err < 0)
return err;
return data.word;
}
#endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
#if ENABLE_I2CSET
static int32_t i2c_smbus_write_byte_data(int file,
uint8_t cmd, uint8_t value)
{
union i2c_smbus_data data;
data.byte = value;
return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
I2C_SMBUS_BYTE_DATA, &data);
}
static int32_t i2c_smbus_write_word_data(int file, uint8_t cmd, uint16_t value)
{
union i2c_smbus_data data;
data.word = value;
return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
I2C_SMBUS_WORD_DATA, &data);
}
static int32_t i2c_smbus_write_block_data(int file, uint8_t cmd,
uint8_t length, const uint8_t *values)
{
union i2c_smbus_data data;
if (length > I2C_SMBUS_BLOCK_MAX)
length = I2C_SMBUS_BLOCK_MAX;
memcpy(data.block+1, values, length);
data.block[0] = length;
return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
I2C_SMBUS_BLOCK_DATA, &data);
}
static int32_t i2c_smbus_write_i2c_block_data(int file, uint8_t cmd,
uint8_t length, const uint8_t *values)
{
union i2c_smbus_data data;
if (length > I2C_SMBUS_BLOCK_MAX)
length = I2C_SMBUS_BLOCK_MAX;
memcpy(data.block+1, values, length);
data.block[0] = length;
return i2c_smbus_access(file, I2C_SMBUS_WRITE, cmd,
I2C_SMBUS_I2C_BLOCK_BROKEN, &data);
}
#endif /* ENABLE_I2CSET */
#if ENABLE_I2CDUMP
/*
* Returns the number of bytes read, vals must hold at
* least I2C_SMBUS_BLOCK_MAX bytes.
*/
static int32_t i2c_smbus_read_block_data(int fd, uint8_t cmd, uint8_t *vals)
{
union i2c_smbus_data data;
int i, err;
err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
I2C_SMBUS_BLOCK_DATA, &data);
if (err < 0)
return err;
for (i = 1; i <= data.block[0]; i++)
*vals++ = data.block[i];
return data.block[0];
}
static int32_t i2c_smbus_read_i2c_block_data(int fd, uint8_t cmd,
uint8_t len, uint8_t *vals)
{
union i2c_smbus_data data;
int i, err;
if (len > I2C_SMBUS_BLOCK_MAX)
len = I2C_SMBUS_BLOCK_MAX;
data.block[0] = len;
err = i2c_smbus_access(fd, I2C_SMBUS_READ, cmd,
len == 32 ? I2C_SMBUS_I2C_BLOCK_BROKEN :
I2C_SMBUS_I2C_BLOCK_DATA, &data);
if (err < 0)
return err;
for (i = 1; i <= data.block[0]; i++)
*vals++ = data.block[i];
return data.block[0];
}
#endif /* ENABLE_I2CDUMP */
#if ENABLE_I2CDETECT
static int32_t i2c_smbus_write_quick(int fd, uint8_t val)
{
return i2c_smbus_access(fd, val, 0, I2C_SMBUS_QUICK, NULL);
}
#endif /* ENABLE_I2CDETECT */
static int i2c_bus_lookup(const char *bus_str)
{
return xstrtou_range(bus_str, 10, 0, 0xfffff);
}
#if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP
static int i2c_parse_bus_addr(const char *addr_str)
{
/* Slave address must be in range 0x03 - 0x77. */
return xstrtou_range(addr_str, 16, 0x03, 0x77);
}
static void i2c_set_pec(int fd, int pec)
{
ioctl_or_perror_and_die(fd, I2C_PEC,
itoptr(pec ? 1 : 0),
"can't set PEC");
}
#endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
#if ENABLE_I2CGET || ENABLE_I2CSET
static int i2c_parse_data_addr(const char *data_addr)
{
/* Data address must be an 8 bit integer. */
return xstrtou_range(data_addr, 16, 0, 0xff);
}
#endif /* ENABLE_I2CGET || ENABLE_I2CSET */
/*
* Opens the device file associated with given i2c bus.
*
* Upstream i2c-tools also support opening devices by i2c bus name
* but we drop it here for size reduction.
*/
static int i2c_dev_open(int i2cbus)
{
char filename[sizeof("/dev/i2c-%d") + sizeof(int)*3];
int fd;
sprintf(filename, "/dev/i2c-%d", i2cbus);
fd = open(filename, O_RDWR);
if (fd < 0) {
if (errno == ENOENT) {
filename[8] = '/'; /* change to "/dev/i2c/%d" */
fd = xopen(filename, O_RDWR);
} else {
bb_perror_msg_and_die("can't open '%s'", filename);
}
}
return fd;
}
static void i2c_set_slave_addr(int fd, int addr, int force)
{
ioctl_or_perror_and_die(fd, force ? I2C_SLAVE_FORCE : I2C_SLAVE,
itoptr(addr),
"can't set address to 0x%02x", addr);
}
/* Size reducing helpers for xxx_check_funcs(). */
static void get_funcs_matrix(int fd, unsigned long *funcs)
{
ioctl_or_perror_and_die(fd, I2C_FUNCS, funcs,
"can't get adapter functionality matrix");
}
#if ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP
static void check_funcs_test_end(int funcs, int pec, const char *err)
{
if (pec && !(funcs & (I2C_FUNC_SMBUS_PEC | I2C_FUNC_I2C)))
bb_error_msg("warning: adapter does not support PEC");
if (err)
bb_error_msg_and_die(
"adapter has no %s capability", err);
}
#endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
/*
* The below functions emit an error message and exit if the adapter doesn't
* support desired functionalities.
*/
#if ENABLE_I2CGET || ENABLE_I2CDUMP
static void check_read_funcs(int fd, int mode, int data_addr, int pec)
{
unsigned long funcs;
const char *err = NULL;
get_funcs_matrix(fd, &funcs);
switch (mode) {
case I2C_SMBUS_BYTE:
if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE)) {
err = "SMBus receive byte";
break;
}
if (data_addr >= 0 && !(funcs & I2C_FUNC_SMBUS_WRITE_BYTE))
err = "SMBus send byte";
break;
case I2C_SMBUS_BYTE_DATA:
if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE_DATA))
err = "SMBus read byte";
break;
case I2C_SMBUS_WORD_DATA:
if (!(funcs & I2C_FUNC_SMBUS_READ_WORD_DATA))
err = "SMBus read word";
break;
#if ENABLE_I2CDUMP
case I2C_SMBUS_BLOCK_DATA:
if (!(funcs & I2C_FUNC_SMBUS_READ_BLOCK_DATA))
err = "SMBus block read";
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (!(funcs & I2C_FUNC_SMBUS_READ_I2C_BLOCK))
err = "I2C block read";
break;
#endif /* ENABLE_I2CDUMP */
default:
bb_error_msg_and_die("Programmer goofed!");
}
check_funcs_test_end(funcs, pec, err);
}
#endif /* ENABLE_I2CGET || ENABLE_I2CDUMP */
#if ENABLE_I2CSET
static void check_write_funcs(int fd, int mode, int pec)
{
unsigned long funcs;
const char *err = NULL;
get_funcs_matrix(fd, &funcs);
switch (mode) {
case I2C_SMBUS_BYTE:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE))
err = "SMBus send byte";
break;
case I2C_SMBUS_BYTE_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
err = "SMBus write byte";
break;
case I2C_SMBUS_WORD_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_WORD_DATA))
err = "SMBus write word";
break;
case I2C_SMBUS_BLOCK_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_BLOCK_DATA))
err = "SMBus block write";
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (!(funcs & I2C_FUNC_SMBUS_WRITE_I2C_BLOCK))
err = "I2C block write";
break;
}
check_funcs_test_end(funcs, pec, err);
}
#endif /* ENABLE_I2CSET */
static void confirm_or_abort(void)
{
fprintf(stderr, "Continue? [y/N] ");
fflush_all();
if (!bb_ask_confirmation())
bb_error_msg_and_die("aborting");
}
/*
* Return only if user confirms the action, abort otherwise.
*
* The messages displayed here are much less elaborate than their i2c-tools
* counterparts - this is done for size reduction.
*/
static void confirm_action(int bus_addr, int mode, int data_addr, int pec)
{
bb_error_msg("WARNING! This program can confuse your I2C bus");
/* Don't let the user break his/her EEPROMs */
if (bus_addr >= 0x50 && bus_addr <= 0x57 && pec) {
bb_error_msg_and_die("this is I2C not smbus - using PEC on I2C "
"devices may result in data loss, aborting");
}
if (mode == I2C_SMBUS_BYTE && data_addr >= 0 && pec)
bb_error_msg("WARNING! May interpret a write byte command "
"with PEC as a write byte data command");
if (pec)
bb_error_msg("PEC checking enabled");
confirm_or_abort();
}
#if ENABLE_I2CGET
//usage:#define i2cget_trivial_usage
//usage: "[-f] [-y] BUS CHIP-ADDRESS [DATA-ADDRESS [MODE]]"
//usage:#define i2cget_full_usage "\n\n"
//usage: "Read from I2C/SMBus chip registers\n"
//usage: "\n I2CBUS i2c bus number"
//usage: "\n ADDRESS 0x03 - 0x77"
//usage: "\nMODE is:"
//usage: "\n b read byte data (default)"
//usage: "\n w read word data"
//usage: "\n c write byte/read byte"
//usage: "\n Append p for SMBus PEC"
//usage: "\n"
//usage: "\n -f force access"
//usage: "\n -y disable interactive mode"
int i2cget_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int i2cget_main(int argc UNUSED_PARAM, char **argv)
{
const unsigned opt_f = (1 << 0), opt_y = (1 << 1);
const char *const optstr = "fy";
int bus_num, bus_addr, data_addr = -1, status;
int mode = I2C_SMBUS_BYTE, pec = 0, fd;
unsigned opts;
opt_complementary = "-2:?4"; /* from 2 to 4 args */
opts = getopt32(argv, optstr);
argv += optind;
bus_num = i2c_bus_lookup(argv[0]);
bus_addr = i2c_parse_bus_addr(argv[1]);
if (argv[2]) {
data_addr = i2c_parse_data_addr(argv[2]);
mode = I2C_SMBUS_BYTE_DATA;
if (argv[3]) {
switch (argv[3][0]) {
case 'b': /* Already set */ break;
case 'w': mode = I2C_SMBUS_WORD_DATA; break;
case 'c': mode = I2C_SMBUS_BYTE; break;
default:
bb_error_msg("invalid mode");
bb_show_usage();
}
pec = argv[3][1] == 'p';
}
}
fd = i2c_dev_open(bus_num);
check_read_funcs(fd, mode, data_addr, pec);
i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
if (!(opts & opt_y))
confirm_action(bus_addr, mode, data_addr, pec);
if (pec)
i2c_set_pec(fd, 1);
switch (mode) {
case I2C_SMBUS_BYTE:
if (data_addr >= 0) {
status = i2c_smbus_write_byte(fd, data_addr);
if (status < 0)
bb_error_msg("warning - write failed");
}
status = i2c_smbus_read_byte(fd);
break;
case I2C_SMBUS_WORD_DATA:
status = i2c_smbus_read_word_data(fd, data_addr);
break;
default: /* I2C_SMBUS_BYTE_DATA */
status = i2c_smbus_read_byte_data(fd, data_addr);
}
close(fd);
if (status < 0)
bb_perror_msg_and_die("read failed");
printf("0x%0*x\n", mode == I2C_SMBUS_WORD_DATA ? 4 : 2, status);
return 0;
}
#endif /* ENABLE_I2CGET */
#if ENABLE_I2CSET
//usage:#define i2cset_trivial_usage
//usage: "[-f] [-y] [-m MASK] BUS CHIP-ADDR DATA-ADDR [VALUE] ... [MODE]"
//usage:#define i2cset_full_usage "\n\n"
//usage: "Set I2C registers\n"
//usage: "\n I2CBUS i2c bus number"
//usage: "\n ADDRESS 0x03 - 0x77"
//usage: "\nMODE is:"
//usage: "\n c byte, no value"
//usage: "\n b byte data (default)"
//usage: "\n w word data"
//usage: "\n i I2C block data"
//usage: "\n s SMBus block data"
//usage: "\n Append p for SMBus PEC"
//usage: "\n"
//usage: "\n -f force access"
//usage: "\n -y disable interactive mode"
//usage: "\n -r read back and compare the result"
//usage: "\n -m MASK mask specifying which bits to write"
int i2cset_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int i2cset_main(int argc, char **argv)
{
const unsigned opt_f = (1 << 0), opt_y = (1 << 1),
opt_m = (1 << 2), opt_r = (1 << 3);
const char *const optstr = "fym:r";
int bus_num, bus_addr, data_addr, mode = I2C_SMBUS_BYTE, pec = 0;
int val, blen = 0, mask = 0, fd, status;
unsigned char block[I2C_SMBUS_BLOCK_MAX];
char *opt_m_arg = NULL;
unsigned opts;
opt_complementary = "-3"; /* from 3 to ? args */
opts = getopt32(argv, optstr, &opt_m_arg);
argv += optind;
argc -= optind;
bus_num = i2c_bus_lookup(argv[0]);
bus_addr = i2c_parse_bus_addr(argv[1]);
data_addr = i2c_parse_data_addr(argv[2]);
if (argv[3]) {
if (!argv[4] && argv[3][0] != 'c') {
mode = I2C_SMBUS_BYTE_DATA; /* Implicit b */
} else {
switch (argv[argc-1][0]) {
case 'c': /* Already set */ break;
case 'b': mode = I2C_SMBUS_BYTE_DATA; break;
case 'w': mode = I2C_SMBUS_WORD_DATA; break;
case 's': mode = I2C_SMBUS_BLOCK_DATA; break;
case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA; break;
default:
bb_error_msg("invalid mode");
bb_show_usage();
}
pec = argv[argc-1][1] == 'p';
if (mode == I2C_SMBUS_BLOCK_DATA ||
mode == I2C_SMBUS_I2C_BLOCK_DATA) {
if (pec && mode == I2C_SMBUS_I2C_BLOCK_DATA)
bb_error_msg_and_die(
"PEC not supported for I2C "
"block writes");
if (opts & opt_m)
bb_error_msg_and_die(
"mask not supported for block "
"writes");
}
}
}
/* Prepare the value(s) to be written according to current mode. */
switch (mode) {
case I2C_SMBUS_BYTE_DATA:
val = xstrtou_range(argv[3], 0, 0, 0xff);
break;
case I2C_SMBUS_WORD_DATA:
val = xstrtou_range(argv[3], 0, 0, 0xffff);
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_I2C_BLOCK_DATA:
for (blen = 3; blen < (argc - 1); blen++)
block[blen] = xstrtou_range(argv[blen], 0, 0, 0xff);
val = -1;
break;
default:
val = -1;
break;
}
if (opts & opt_m) {
mask = xstrtou_range(opt_m_arg, 0, 0,
(mode == I2C_SMBUS_BYTE ||
mode == I2C_SMBUS_BYTE_DATA) ? 0xff : 0xffff);
}
fd = i2c_dev_open(bus_num);
check_write_funcs(fd, mode, pec);
i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
if (!(opts & opt_y))
confirm_action(bus_addr, mode, data_addr, pec);
/*
* If we're using mask - read the current value here and adjust the
* value to be written.
*/
if (opts & opt_m) {
int tmpval;
switch (mode) {
case I2C_SMBUS_BYTE:
tmpval = i2c_smbus_read_byte(fd);
break;
case I2C_SMBUS_WORD_DATA:
tmpval = i2c_smbus_read_word_data(fd, data_addr);
break;
default:
tmpval = i2c_smbus_read_byte_data(fd, data_addr);
}
if (tmpval < 0)
bb_perror_msg_and_die("can't read old value");
val = (val & mask) | (tmpval & ~mask);
if (!(opts & opt_y)) {
bb_error_msg("old value 0x%0*x, write mask "
"0x%0*x, will write 0x%0*x to register "
"0x%02x",
mode == I2C_SMBUS_WORD_DATA ? 4 : 2, tmpval,
mode == I2C_SMBUS_WORD_DATA ? 4 : 2, mask,
mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val,
data_addr);
confirm_or_abort();
}
}
if (pec)
i2c_set_pec(fd, 1);
switch (mode) {
case I2C_SMBUS_BYTE:
status = i2c_smbus_write_byte(fd, data_addr);
break;
case I2C_SMBUS_WORD_DATA:
status = i2c_smbus_write_word_data(fd, data_addr, val);
break;
case I2C_SMBUS_BLOCK_DATA:
status = i2c_smbus_write_block_data(fd, data_addr,
blen, block);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
status = i2c_smbus_write_i2c_block_data(fd, data_addr,
blen, block);
break;
default: /* I2C_SMBUS_BYTE_DATA */
status = i2c_smbus_write_byte_data(fd, data_addr, val);
break;
}
if (status < 0)
bb_perror_msg_and_die("write failed");
if (pec)
i2c_set_pec(fd, 0); /* Clear PEC. */
/* No readback required - we're done. */
if (!(opts & opt_r))
return 0;
switch (mode) {
case I2C_SMBUS_BYTE:
status = i2c_smbus_read_byte(fd);
val = data_addr;
break;
case I2C_SMBUS_WORD_DATA:
status = i2c_smbus_read_word_data(fd, data_addr);
break;
default: /* I2C_SMBUS_BYTE_DATA */
status = i2c_smbus_read_byte_data(fd, data_addr);
}
if (status < 0) {
printf("Warning - readback failed\n");
} else
if (status != val) {
printf("Warning - data mismatch - wrote "
"0x%0*x, read back 0x%0*x\n",
mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val,
mode == I2C_SMBUS_WORD_DATA ? 4 : 2, status);
} else {
printf("Value 0x%0*x written, readback matched\n",
mode == I2C_SMBUS_WORD_DATA ? 4 : 2, val);
}
return 0;
}
#endif /* ENABLE_I2CSET */
#if ENABLE_I2CDUMP
//usage:#define i2cdump_trivial_usage
//usage: "[-f] [-r FIRST-LAST] [-y] BUS ADDR [MODE]"
//usage:#define i2cdump_full_usage "\n\n"
//usage: "Examine I2C registers\n"
//usage: "\n I2CBUS i2c bus number"
//usage: "\n ADDRESS 0x03 - 0x77"
//usage: "\nMODE is:"
//usage: "\n b byte (default)"
//usage: "\n w word"
//usage: "\n W word on even register addresses"
//usage: "\n i I2C block"
//usage: "\n s SMBus block"
//usage: "\n c consecutive byte"
//usage: "\n Append p for SMBus PEC"
//usage: "\n"
//usage: "\n -f force access"
//usage: "\n -y disable interactive mode"
//usage: "\n -r limit the number of registers being accessed"
int i2cdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int i2cdump_main(int argc UNUSED_PARAM, char **argv)
{
const unsigned opt_f = (1 << 0), opt_y = (1 << 1),
opt_r = (1 << 2);
const char *const optstr = "fyr:";
int bus_num, bus_addr, mode = I2C_SMBUS_BYTE_DATA, even = 0, pec = 0;
unsigned first = 0x00, last = 0xff;
int fd, i, j, res, blen = 0, tmp;
unsigned char cblock[I2C_SMBUS_BLOCK_MAX + I2C_MAX_REGS];
unsigned char block[I2C_SMBUS_BLOCK_MAX];
char *opt_r_str, *dash;
unsigned opts;
opt_complementary = "-2:?3"; /* from 2 to 3 args */
opts = getopt32(argv, optstr, &opt_r_str);
argv += optind;
bus_num = i2c_bus_lookup(argv[0]);
bus_addr = i2c_parse_bus_addr(argv[1]);
if (argv[2]) {
switch (argv[2][0]) {
case 'b': /* Already set */ break;
case 'c': mode = I2C_SMBUS_BYTE; break;
case 'w': mode = I2C_SMBUS_WORD_DATA; break;
case 'W':
mode = I2C_SMBUS_WORD_DATA;
even = 1;
break;
case 's': mode = I2C_SMBUS_BLOCK_DATA; break;
case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA; break;
default:
bb_error_msg_and_die("invalid mode");
}
if (argv[2][1] == 'p') {
if (argv[2][0] == 'W' || argv[2][0] == 'i') {
bb_error_msg_and_die(
"pec not supported for -W and -i");
} else {
pec = 1;
}
}
}
if (opts & opt_r) {
first = strtol(opt_r_str, &dash, 0);
if (dash == opt_r_str || *dash != '-' || first > 0xff)
bb_error_msg_and_die("invalid range");
last = xstrtou_range(++dash, 0, first, 0xff);
/* Range is not available for every mode */
switch (mode) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
break;
case I2C_SMBUS_WORD_DATA:
if (!even || (!(first % 2) && last % 2))
break;
/* Fall through */
default:
bb_error_msg_and_die(
"range not compatible with selected mode");
}
}
fd = i2c_dev_open(bus_num);
check_read_funcs(fd, mode, -1 /* data_addr */, pec);
i2c_set_slave_addr(fd, bus_addr, opts & opt_f);
if (pec)
i2c_set_pec(fd, 1);
if (!(opts & opt_y))
confirm_action(bus_addr, mode, -1 /* data_addr */, pec);
/* All but word data */
if (mode != I2C_SMBUS_WORD_DATA || even) {
/*
* FIXME This section has been ported from upstream i2cdump.
* It has been reworked a bit but is still pretty spaghetti
* and needs splitting into several functions.
*/
if (mode == I2C_SMBUS_BLOCK_DATA ||
mode == I2C_SMBUS_I2C_BLOCK_DATA) {
res = i2c_smbus_read_block_data(fd, 0, cblock);
blen = res;
} else {
for (res = 0; res < I2C_MAX_REGS; res += tmp) {
tmp = i2c_smbus_read_i2c_block_data(
fd, res, I2C_SMBUS_BLOCK_MAX,
cblock + res);
if (tmp < 0) {
bb_error_msg_and_die(
"block read failed");
}
}
if (res >= I2C_MAX_REGS)
res = I2C_MAX_REGS;
for (i = 0; i < res; i++)
block[i] = cblock[i];
if (mode != I2C_SMBUS_BLOCK_DATA)
for (i = res; i < I2C_MAX_REGS; i++)
cblock[i] = -1;
}
if (mode == I2C_SMBUS_BYTE) {
res = i2c_smbus_write_byte(fd, first);
if (res < 0)
bb_perror_msg_and_die(
"write start address failed");
}
printf(" 0 1 2 3 4 5 6 7 8 9 a b c d e f"
" 0123456789abcdef\n");
for (i = 0; i < I2C_MAX_REGS; i += 0x10) {
if (mode == I2C_SMBUS_BLOCK_DATA && i >= blen)
break;
if (i/16 < first/16)
continue;
if (i/16 > last/16)
break;
printf("%02x: ", i);
for (j = 0; j < 16; j++) {
fflush_all();
/* Skip unwanted registers */
if (i+j < first || i+j > last) {
printf(" ");
if (mode == I2C_SMBUS_WORD_DATA) {
printf(" ");
j++;
}
continue;
}
switch (mode) {
case I2C_SMBUS_BYTE_DATA:
res = i2c_smbus_read_byte_data(fd, i+j);
block[i+j] = res;
break;
case I2C_SMBUS_WORD_DATA:
res = i2c_smbus_read_word_data(fd, i+j);
if (res < 0) {
block[i+j] = res;
block[i+j+1] = res;
} else {
block[i+j] = res & 0xff;
block[i+j+1] = res >> 8;
}
break;
case I2C_SMBUS_BYTE:
res = i2c_smbus_read_byte(fd);
block[i+j] = res;
break;
default:
res = block[i+j];
}
if (mode == I2C_SMBUS_BLOCK_DATA &&
i+j >= blen) {
printf(" ");
} else if (res < 0) {
printf("XX ");
if (mode == I2C_SMBUS_WORD_DATA)
printf("XX ");
} else {
printf("%02x ", block[i+j]);
if (mode == I2C_SMBUS_WORD_DATA)
printf("%02x ", block[i+j+1]);
}
if (mode == I2C_SMBUS_WORD_DATA)
j++;
}
printf(" ");
for (j = 0; j < 16; j++) {
if (mode == I2C_SMBUS_BLOCK_DATA && i+j >= blen)
break;
/* Skip unwanted registers */
if (i+j < first || i+j > last) {
printf(" ");
continue;
}
res = block[i+j];
if (res < 0) {
//FIXME: impossible, block[] is uchar[]
printf("X");
} else if (res == 0x00 || res == 0xff) {
printf(".");
} else if (res < 32 || res >= 127) {
printf("?");
} else {
printf("%c", res);
}
}
printf("\n");
}
} else {
/* Word data. */
printf(" 0,8 1,9 2,a 3,b 4,c 5,d 6,e 7,f\n");
for (i = 0; i < 256; i += 8) {
if (i/8 < first/8)
continue;
if (i/8 > last/8)
break;
printf("%02x: ", i);
for (j = 0; j < 8; j++) {
/* Skip unwanted registers. */
if (i+j < first || i+j > last) {
printf(" ");
continue;
}
res = i2c_smbus_read_word_data(fd, i+j);
if (res < 0)
printf("XXXX ");
else
printf("%04x ", res & 0xffff);
}
printf("\n");
}
}
return 0;
}
#endif /* ENABLE_I2CDUMP */
#if ENABLE_I2CDETECT
enum adapter_type {
ADT_DUMMY = 0,
ADT_ISA,
ADT_I2C,
ADT_SMBUS,
};
struct adap_desc {
const char *funcs;
const char *algo;
};
static const struct adap_desc adap_descs[] = {
{ .funcs = "dummy",
.algo = "Dummy bus", },
{ .funcs = "isa",
.algo = "ISA bus", },
{ .funcs = "i2c",
.algo = "I2C adapter", },
{ .funcs = "smbus",
.algo = "SMBus adapter", },
};
struct i2c_func
{
long value;
const char* name;
};
static const struct i2c_func i2c_funcs_tab[] = {
{ .value = I2C_FUNC_I2C,
.name = "I2C" },
{ .value = I2C_FUNC_SMBUS_QUICK,
.name = "SMBus Quick Command" },
{ .value = I2C_FUNC_SMBUS_WRITE_BYTE,
.name = "SMBus Send Byte" },
{ .value = I2C_FUNC_SMBUS_READ_BYTE,
.name = "SMBus Receive Byte" },
{ .value = I2C_FUNC_SMBUS_WRITE_BYTE_DATA,
.name = "SMBus Write Byte" },
{ .value = I2C_FUNC_SMBUS_READ_BYTE_DATA,
.name = "SMBus Read Byte" },
{ .value = I2C_FUNC_SMBUS_WRITE_WORD_DATA,
.name = "SMBus Write Word" },
{ .value = I2C_FUNC_SMBUS_READ_WORD_DATA,
.name = "SMBus Read Word" },
{ .value = I2C_FUNC_SMBUS_PROC_CALL,
.name = "SMBus Process Call" },
{ .value = I2C_FUNC_SMBUS_WRITE_BLOCK_DATA,
.name = "SMBus Block Write" },
{ .value = I2C_FUNC_SMBUS_READ_BLOCK_DATA,
.name = "SMBus Block Read" },
{ .value = I2C_FUNC_SMBUS_BLOCK_PROC_CALL,
.name = "SMBus Block Process Call" },
{ .value = I2C_FUNC_SMBUS_PEC,
.name = "SMBus PEC" },
{ .value = I2C_FUNC_SMBUS_WRITE_I2C_BLOCK,
.name = "I2C Block Write" },
{ .value = I2C_FUNC_SMBUS_READ_I2C_BLOCK,
.name = "I2C Block Read" },
{ .value = 0, .name = NULL }
};
static enum adapter_type i2cdetect_get_funcs(int bus)
{
enum adapter_type ret;
unsigned long funcs;
int fd;
fd = i2c_dev_open(bus);
get_funcs_matrix(fd, &funcs);
if (funcs & I2C_FUNC_I2C)
ret = ADT_I2C;
else if (funcs & (I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
ret = ADT_SMBUS;
else
ret = ADT_DUMMY;
close(fd);
return ret;
}
static void NORETURN list_i2c_busses_and_exit(void)
{
const char *const i2cdev_path = "/sys/class/i2c-dev";
char path[NAME_MAX], name[128];
struct dirent *de, *subde;
enum adapter_type adt;
DIR *dir, *subdir;
int rv, bus;
char *pos;
FILE *fp;
/*
* XXX Upstream i2cdetect also looks for i2c bus info in /proc/bus/i2c,
* but we won't bother since it's only useful on older kernels (before
* 2.6.5). We expect sysfs to be present and mounted at /sys/.
*/
dir = xopendir(i2cdev_path);
while ((de = readdir(dir))) {
if (de->d_name[0] == '.')
continue;
/* Simple version for ISA chips. */
snprintf(path, NAME_MAX, "%s/%s/name",
i2cdev_path, de->d_name);
fp = fopen(path, "r");
if (fp == NULL) {
snprintf(path, NAME_MAX,
"%s/%s/device/name",
i2cdev_path, de->d_name);
fp = fopen(path, "r");
}
/* Non-ISA chips require the hard-way. */
if (fp == NULL) {
snprintf(path, NAME_MAX,
"%s/%s/device/name",
i2cdev_path, de->d_name);
subdir = opendir(path);
if (subdir == NULL)
continue;
while ((subde = readdir(subdir))) {
if (subde->d_name[0] == '.')
continue;
if (is_prefixed_with(subde->d_name, "i2c-")) {
snprintf(path, NAME_MAX,
"%s/%s/device/%s/name",
i2cdev_path, de->d_name,
subde->d_name);
fp = fopen(path, "r");
goto found;
}
}
}
found:
if (fp != NULL) {
/*
* Get the rest of the info and display a line
* for a single bus.
*/
memset(name, 0, sizeof(name));
pos = fgets(name, sizeof(name), fp);
fclose(fp);
if (pos == NULL)
continue;
pos = strchr(name, '\n');
if (pos != NULL)
*pos = '\0';
rv = sscanf(de->d_name, "i2c-%d", &bus);
if (rv != 1)
continue;
if (is_prefixed_with(name, "ISA"))
adt = ADT_ISA;
else
adt = i2cdetect_get_funcs(bus);
printf(
"i2c-%d\t%-10s\t%-32s\t%s\n",
bus, adap_descs[adt].funcs,
name, adap_descs[adt].algo);
}
}
exit(EXIT_SUCCESS);
}
static void NORETURN no_support(const char *cmd)
{
bb_error_msg_and_die("bus doesn't support %s", cmd);
}
static void will_skip(const char *cmd)
{
bb_error_msg(
"warning: can't use %s command, "
"will skip some addresses", cmd);
}
//usage:#define i2cdetect_trivial_usage
//usage: "[-F I2CBUS] [-l] [-y] [-a] [-q|-r] I2CBUS [FIRST LAST]"
//usage:#define i2cdetect_full_usage "\n\n"
//usage: "Detect I2C chips.\n"
//usage: "\n I2CBUS i2c bus number"
//usage: "\n FIRST and LAST limit the probing range"
//usage: "\n"
//usage: "\n -l output list of installed busses"
//usage: "\n -y disable interactive mode"
//usage: "\n -a force scanning of non-regular addresses"
//usage: "\n -q use smbus quick write commands for probing (default)"
//usage: "\n -r use smbus read byte commands for probing"
//usage: "\n -F display list of functionalities"
int i2cdetect_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
{
const unsigned opt_y = (1 << 0), opt_a = (1 << 1),
opt_q = (1 << 2), opt_r = (1 << 3),
opt_F = (1 << 4), opt_l = (1 << 5);
const char *const optstr = "yaqrFl";
int fd, bus_num, i, j, mode = DETECT_MODE_AUTO;
int status;
unsigned first = 0x00, last = 0x77;
unsigned long funcs;
unsigned opts;
opt_complementary = "q--r:r--q:" /* mutually exclusive */
"?3"; /* up to 3 args */
opts = getopt32(argv, optstr);
argv += optind;
if (opts & opt_l)
list_i2c_busses_and_exit();
if (!argv[0])
bb_show_usage();
bus_num = i2c_bus_lookup(argv[0]);
fd = i2c_dev_open(bus_num);
get_funcs_matrix(fd, &funcs);
if (opts & opt_F) {
/* Only list the functionalities. */
printf("Functionalities implemented by bus #%d\n", bus_num);
for (i = 0; i2c_funcs_tab[i].value; i++) {
printf("%-32s %s\n", i2c_funcs_tab[i].name,
funcs & i2c_funcs_tab[i].value ? "yes" : "no");
}
return EXIT_SUCCESS;
}
if (opts & opt_r)
mode = DETECT_MODE_READ;
else if (opts & opt_q)
mode = DETECT_MODE_QUICK;
if (opts & opt_a)
last = 0x7f;
/* Read address range. */
if (argv[1]) {
first = xstrtou_range(argv[1], 16, first, last);
if (argv[2])
last = xstrtou_range(argv[2], 16, first, last);
}
if (!(funcs & (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_READ_BYTE))) {
no_support("detection commands");
} else
if (mode == DETECT_MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_QUICK)) {
no_support("SMBus Quick Write command");
} else
if (mode == DETECT_MODE_READ && !(funcs & I2C_FUNC_SMBUS_READ_BYTE)) {
no_support("SMBus Receive Byte command");
} else {
if (!(funcs & I2C_FUNC_SMBUS_QUICK))
will_skip("SMBus Quick Write");
if (!(funcs & I2C_FUNC_SMBUS_READ_BYTE))
will_skip("SMBus Receive Byte");
}
if (!(opts & opt_y))
confirm_action(-1, -1, -1, 0);
printf(" 0 1 2 3 4 5 6 7 8 9 a b c d e f\n");
for (i = 0; i < 128; i += 16) {
printf("%02x: ", i);
for(j = 0; j < 16; j++) {
fflush_all();
if (mode == DETECT_MODE_AUTO) {
if ((i+j >= 0x30 && i+j <= 0x37) ||
(i+j >= 0x50 && i+j <= 0x5F))
mode = DETECT_MODE_READ;
else
mode = DETECT_MODE_QUICK;
}
/* Skip unwanted addresses. */
if (i+j < first
|| i+j > last
|| (mode == DETECT_MODE_READ && !(funcs & I2C_FUNC_SMBUS_READ_BYTE))
|| (mode == DETECT_MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_QUICK)))
{
printf(" ");
continue;
}
i2c_set_slave_addr(fd, i + j, 0);
switch (mode) {
case DETECT_MODE_READ:
/*
* This is known to lock SMBus on various
* write-only chips (mainly clock chips).
*/
status = i2c_smbus_read_byte(fd);
break;
default: /* DETECT_MODE_QUICK: */
/*
* This is known to corrupt the Atmel
* AT24RF08 EEPROM.
*/
status = i2c_smbus_write_quick(fd,
I2C_SMBUS_WRITE);
break;
}
if (status < 0)
printf("-- ");
else
printf("%02x ", i+j);
}
printf("\n");
}
return 0;
}
#endif /* ENABLE_I2CDETECT */