The branch main has been updated by phk:
URL:
https://cgit.FreeBSD.org/src/commit/?id=5ab41ff8e92da548acf06b50384df538737aa8ee
commit 5ab41ff8e92da548acf06b50384df538737aa8ee
Author: Poul-Henning Kamp <p...@freebsd.org>
AuthorDate: 2021-05-12 21:34:58 +0000
Commit: Poul-Henning Kamp <p...@freebsd.org>
CommitDate: 2021-05-12 21:39:19 +0000
More refactoring:
Extract the '-a' mode into a separate function, and simplify the
hexdumping logic.
Dont call usage() without telling why.
---
usr.sbin/i2c/i2c.8 | 36 +++--------
usr.sbin/i2c/i2c.c | 181 +++++++++++++++++++++++++----------------------------
2 files changed, 97 insertions(+), 120 deletions(-)
diff --git a/usr.sbin/i2c/i2c.8 b/usr.sbin/i2c/i2c.8
index 1c5174e63f32..352b13157968 100644
--- a/usr.sbin/i2c/i2c.8
+++ b/usr.sbin/i2c/i2c.8
@@ -64,12 +64,12 @@ The options are as follows:
7-bit address on the I2C device to operate on (hex).
.It Fl b
binary mode - when performing a read operation, the data read from the device
-is output in binary format on stdout; when doing a write, the binary data to
-be written to the device is read from stdin.
+is output in binary format on stdout.
.It Fl c Ar count
-number of bytes to transfer (dec).
+number of bytes to transfer (decimal).
.It Fl d Ar r|w
transfer direction: r - read, w - write.
+Data to be written is read from stdin as binary bytes.
.It Fl f Ar device
I2C bus to use (default is /dev/iic0).
.It Fl m Ar tr|ss|rs|no
@@ -113,7 +113,7 @@ scan the bus for devices.
.It Fl v
be verbose.
.It Fl w Ar 0|8|16|16LE|16BE
-device addressing width (in bits).
+device offset width (in bits).
This is used to determine how to pass
.Ar offset
specified with
@@ -122,28 +122,6 @@ to the slave.
Zero means that the offset is ignored and not passed to the slave at all.
The endianess defaults to little-endian.
.El
-.Sh WARNINGS
-Great care must be taken when manipulating slave I2C devices with the
-.Nm
-utility.
-Often times important configuration data for the system is kept in non-volatile
-but write enabled memories located on the I2C bus, for example Ethernet
hardware
-addresses, RAM module parameters (SPD), processor reset configuration word etc.
-.Pp
-It is very easy to render the whole system unusable when such configuration
-data is deleted or altered, so use the
-.Dq -d w
-(write) command only if you know exactly what you are doing.
-.Pp
-Also avoid ungraceful interrupting of an ongoing transaction on the I2C bus,
-as it can lead to potentially dangerous effects.
-Consider the following scenario: when the host CPU is reset (for whatever
reason)
-in the middle of a started I2C transaction, the I2C slave device could be left
-in write mode waiting for data or offset to arrive.
-When the CPU reinitializes itself and talks to this I2C slave device again,
-the commands and other control info it sends are treated by the slave device
-as data or offset it was waiting for, and there's great potential for
-corruption if such a write is performed.
.Sh EXAMPLES
.Bl -bullet
.It
@@ -177,9 +155,15 @@ Reset the controller:
.Pp
i2c -f /dev/iic1 -r
.El
+.Sh WARNING
+Many systems store critical low-level information in I2C memories, and
+may contain other I2C devices, such as temperature or voltage sensors.
+Reading these can disturb the firmware's operation and writing to them
+can "brick" the hardware.
.Sh SEE ALSO
.Xr iic 4 ,
.Xr iicbus 4
+.Xr smbus 4
.Sh HISTORY
The
.Nm
diff --git a/usr.sbin/i2c/i2c.c b/usr.sbin/i2c/i2c.c
index 64233366a0a8..c862666fc9a7 100644
--- a/usr.sbin/i2c/i2c.c
+++ b/usr.sbin/i2c/i2c.c
@@ -73,9 +73,11 @@ struct skip_range {
};
__dead2 static void
-usage(void)
+usage(const char *msg)
{
+ if (msg != NULL)
+ fprintf(stderr, "%s\n", msg);
fprintf(stderr, "usage: %s -a addr [-f device] [-d [r|w]] [-o offset] "
"[-w [0|8|16]] [-c count] [-m [tr|ss|rs|no]] [-b] [-v]\n",
getprogname());
@@ -561,19 +563,71 @@ i2c_rdwr_transfer(int fd, struct options i2c_opt, char
*i2c_buf)
return (0);
}
+static int
+access_bus(int fd, struct options i2c_opt)
+{
+ char *i2c_buf;
+ int error, chunk_size = 16, i, ch;
+
+ i2c_buf = malloc(i2c_opt.count);
+ if (i2c_buf == NULL)
+ err(1, "data malloc");
+
+ /*
+ * For a write, read the data to be written to the chip from stdin.
+ */
+ if (i2c_opt.dir == 'w') {
+ if (i2c_opt.verbose && !i2c_opt.binary)
+ fprintf(stderr, "Enter %d bytes of data: ",
+ i2c_opt.count);
+ for (i = 0; i < i2c_opt.count; i++) {
+ ch = getchar();
+ if (ch == EOF) {
+ free(i2c_buf);
+ err(1, "not enough data, exiting\n");
+ }
+ i2c_buf[i] = ch;
+ }
+ }
+
+ if (i2c_opt.mode == I2C_MODE_TRANSFER)
+ error = i2c_rdwr_transfer(fd, i2c_opt, i2c_buf);
+ else if (i2c_opt.dir == 'w')
+ error = i2c_write(fd, i2c_opt, i2c_buf);
+ else
+ error = i2c_read(fd, i2c_opt, i2c_buf);
+
+ if (error == 0) {
+ if (i2c_opt.dir == 'r' && i2c_opt.binary) {
+ (void)fwrite(i2c_buf, 1, i2c_opt.count, stdout);
+ } else if (i2c_opt.verbose || i2c_opt.dir == 'r') {
+ if (i2c_opt.verbose)
+ fprintf(stderr, "\nData %s (hex):\n",
+ i2c_opt.dir == 'r' ? "read" : "written");
+
+ for (i = 0; i < i2c_opt.count; i++) {
+ fprintf (stderr, "%02hhx ", i2c_buf[i]);
+ if ((i % chunk_size) == chunk_size - 1)
+ fprintf(stderr, "\n");
+ }
+ if ((i % chunk_size) != 0)
+ fprintf(stderr, "\n");
+ }
+ }
+
+ free(i2c_buf);
+ return (error);
+}
+
int
main(int argc, char** argv)
{
struct options i2c_opt;
- char *skip_addr = NULL, *i2c_buf;
+ char *skip_addr = NULL;
const char *dev, *err_msg;
- int fd, error, chunk_size, i, j, ch;
+ int fd, error, ch;
errno = 0;
- error = 0;
-
- /* Line-break the output every chunk_size bytes */
- chunk_size = 16;
dev = I2C_DEV;
@@ -595,9 +649,8 @@ main(int argc, char** argv)
case 'a':
i2c_opt.addr = (strtoul(optarg, 0, 16) << 1);
if (i2c_opt.addr == 0 && errno == EINVAL)
- i2c_opt.addr_set = 0;
- else
- i2c_opt.addr_set = 1;
+ usage("Bad -a argument (hex)");
+ i2c_opt.addr_set = 1;
break;
case 'f':
dev = optarg;
@@ -608,13 +661,15 @@ main(int argc, char** argv)
case 'o':
i2c_opt.off = strtoul(optarg, 0, 16);
if (i2c_opt.off == 0 && errno == EINVAL)
- error = 1;
+ usage("Bad -o argument (hex)");
break;
case 'w':
i2c_opt.width = optarg;
break;
case 'c':
- i2c_opt.count = atoi(optarg);
+ i2c_opt.count = (strtoul(optarg, 0, 10));
+ if (i2c_opt.count == 0 && errno == EINVAL)
+ usage("Bad -c argument (decimal)");
break;
case 'm':
if (!strcmp(optarg, "no"))
@@ -626,7 +681,7 @@ main(int argc, char** argv)
else if (!strcmp(optarg, "tr"))
i2c_opt.mode = I2C_MODE_TRANSFER;
else
- usage();
+ usage("Bad -m argument ([no|ss|rs|tr])");
break;
case 'n':
i2c_opt.skip = 1;
@@ -645,16 +700,16 @@ main(int argc, char** argv)
i2c_opt.reset = 1;
break;
case 'h':
+ usage("Help:");
+ break;
default:
- usage();
+ usage("Bad argument");
}
}
argc -= optind;
argv += optind;
- if (argc > 0) {
- fprintf(stderr, "Too many arguments\n");
- usage();
- }
+ if (argc > 0)
+ usage("Too many arguments");
/* Set default mode if option -m is not specified */
if (i2c_opt.mode == I2C_MODE_NOTSET) {
@@ -664,24 +719,20 @@ main(int argc, char** argv)
i2c_opt.mode = I2C_MODE_NONE;
}
- if (i2c_opt.addr_set) {
- err_msg = encode_offset(i2c_opt.width, i2c_opt.off,
- i2c_opt.off_buf, &i2c_opt.off_len);
- if (err_msg != NULL) {
- fprintf(stderr, "%s", err_msg);
- exit(EX_USAGE);
- }
+ err_msg = encode_offset(i2c_opt.width, i2c_opt.off,
+ i2c_opt.off_buf, &i2c_opt.off_len);
+ if (err_msg != NULL) {
+ fprintf(stderr, "%s", err_msg);
+ exit(EX_USAGE);
}
/* Basic sanity check of command line arguments */
if (i2c_opt.scan) {
if (i2c_opt.addr_set)
- usage();
+ usage("-s and -a are incompatible");
} else if (i2c_opt.reset) {
if (i2c_opt.addr_set)
- usage();
- } else if (error) {
- usage();
+ usage("-r and -a are incompatible");
}
if (i2c_opt.verbose)
@@ -698,71 +749,13 @@ main(int argc, char** argv)
}
if (i2c_opt.scan)
- exit(scan_bus(dev, fd, i2c_opt.skip, skip_addr));
-
- if (i2c_opt.reset)
- exit(reset_bus(dev, fd));
-
- i2c_buf = malloc(i2c_opt.count);
- if (i2c_buf == NULL)
- err(1, "data malloc");
-
- /*
- * For a write, read the data to be written to the chip from stdin.
- */
- if (i2c_opt.dir == 'w') {
- if (i2c_opt.verbose && !i2c_opt.binary)
- fprintf(stderr, "Enter %d bytes of data: ",
- i2c_opt.count);
- for (i = 0; i < i2c_opt.count; i++) {
- ch = getchar();
- if (ch == EOF) {
- free(i2c_buf);
- err(1, "not enough data, exiting\n");
- }
- i2c_buf[i] = ch;
- }
- }
-
- if (i2c_opt.mode == I2C_MODE_TRANSFER)
- error = i2c_rdwr_transfer(fd, i2c_opt, i2c_buf);
- else if (i2c_opt.dir == 'w')
- error = i2c_write(fd, i2c_opt, i2c_buf);
+ error = scan_bus(dev, fd, i2c_opt.skip, skip_addr);
+ else if (i2c_opt.reset)
+ error = reset_bus(dev, fd);
else
- error = i2c_read(fd, i2c_opt, i2c_buf);
-
- if (error != 0) {
- free(i2c_buf);
- return (1);
- }
-
- error = close(fd);
- assert(error == 0);
+ error = access_bus(fd, i2c_opt);
- if (i2c_opt.verbose)
- fprintf(stderr, "\nData %s (hex):\n", i2c_opt.dir == 'r' ?
- "read" : "written");
-
- i = 0;
- j = 0;
- while (i < i2c_opt.count) {
- if (i2c_opt.verbose || (i2c_opt.dir == 'r' &&
- !i2c_opt.binary))
- fprintf (stderr, "%02hhx ", i2c_buf[i++]);
-
- if (i2c_opt.dir == 'r' && i2c_opt.binary) {
- fprintf(stdout, "%c", i2c_buf[j++]);
- if(!i2c_opt.verbose)
- i++;
- }
- if (!i2c_opt.verbose && (i2c_opt.dir == 'w'))
- break;
- if ((i % chunk_size) == 0)
- fprintf(stderr, "\n");
- }
- if ((i % chunk_size) != 0)
- fprintf(stderr, "\n");
-
- free(i2c_buf);
- return (0);
+ ch = close(fd);
+ assert(ch == 0);
+ return (error);
}
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