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authorGravatar Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>2019-02-10 19:56:41 +0100
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2019-02-10 19:59:07 +0100
commitdac8f5ea38b0f293bc9d3b10693ebb94648a992d (patch)
tree9e1cdca42877e3e86766aaba1ab58598903df131
parentc89764c0633670ef28166c70d03bc593f4a1179f (diff)
downloadbusybox-dac8f5ea38b0f293bc9d3b10693ebb94648a992d.tar.gz
busybox-dac8f5ea38b0f293bc9d3b10693ebb94648a992d.tar.bz2
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>
-rw-r--r--miscutils/i2c_tools.c178
1 files changed, 177 insertions, 1 deletions
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 */