From dac8f5ea38b0f293bc9d3b10693ebb94648a992d Mon Sep 17 00:00:00 2001 From: Nikolaus Voss Date: Sun, 10 Feb 2019 19:56:41 +0100 Subject: [PATCH] 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 Signed-off-by: Nikolaus Voss Signed-off-by: Denys Vlasenko --- miscutils/i2c_tools.c | 178 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 177 insertions(+), 1 deletion(-) diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c index 610fed5d6..455ff028d 100644 --- a/miscutils/i2c_tools.c +++ b/miscutils/i2c_tools.c @@ -36,17 +36,26 @@ //config: help //config: Detect I2C chips. //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_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)) +//applet:IF_I2CTRANSFER(APPLET(i2ctransfer, BB_DIR_USR_SBIN, BB_SUID_DROP)) /* not NOEXEC: if hw operation stalls, use less memory in "hung" process */ //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 +//kbuild:lib-$(CONFIG_I2CTRANSFER) += i2c_tools.o /* * Unsupported stuff: @@ -80,12 +89,19 @@ #define I2C_FUNCS 0x0705 #define I2C_PEC 0x0708 #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 { __u8 read_write; __u8 command; __u32 size; 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 */ /* @@ -262,7 +278,7 @@ static int i2c_bus_lookup(const char *bus_str) 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) { /* Slave address must be in range 0x03 - 0x77. */ @@ -1373,3 +1389,163 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv) return 0; } #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 */ -- 2.25.1