When I implemented this, I didn't actually have any i2c devices to test
with, and "quick write" sounded scary, and the one person who was
testing was fine with the "read byte" method of detection, so that's
what I did. Now I have a couple of i2c devices connected to my Raspberry
Pi, one of them responds to both "read byte" and "quick write", but the
other only responds to "quick write".
This patch adds -q, and makes it the default (as it is with other i2cdetect
implementations).
I've also improved the --help text slightly, switched to the FLAG()
macro, got rid of the not-super-clear error message if you don't have
any i2c buses (the other implementations go with Unix-like silence if
there are no buses too), and improved the error message when you supply
the wrong number of arguments.
Probably more to come now I'm actually playing with this myself, but
that's enough for one patch.
---
toys/other/i2ctools.c | 45 +++++++++++++++++++++++++------------------
1 file changed, 26 insertions(+), 19 deletions(-)
From ba1f1299901d07c5e9a7e24a51dafa1b6f643ebc Mon Sep 17 00:00:00 2001
From: Elliott Hughes <e...@google.com>
Date: Sat, 4 Sep 2021 18:43:54 -0700
Subject: [PATCH] i2cdetect: add -q.
When I implemented this, I didn't actually have any i2c devices to test
with, and "quick write" sounded scary, and the one person who was
testing was fine with the "read byte" method of detection, so that's
what I did. Now I have a couple of i2c devices connected to my Raspberry
Pi, one of them responds to both "read byte" and "quick write", but the
other only responds to "quick write".
This patch adds -q, and makes it the default (as it is with other i2cdetect
implementations).
I've also improved the --help text slightly, switched to the FLAG()
macro, got rid of the not-super-clear error message if you don't have
any i2c buses (the other implementations go with Unix-like silence if
there are no buses too), and improved the error message when you supply
the wrong number of arguments.
Probably more to come now I'm actually playing with this myself, but
that's enough for one patch.
---
toys/other/i2ctools.c | 45 +++++++++++++++++++++++++------------------
1 file changed, 26 insertions(+), 19 deletions(-)
diff --git a/toys/other/i2ctools.c b/toys/other/i2ctools.c
index cd1b892c..1a0bc6a4 100644
--- a/toys/other/i2ctools.c
+++ b/toys/other/i2ctools.c
@@ -11,7 +11,7 @@
* TODO: i2cget non-byte modes? default to current read address?
* TODO: i2cset -r? -m MASK? c/s modes, p mode modifier?
-USE_I2CDETECT(NEWTOY(i2cdetect, ">3aFly", TOYFLAG_USR|TOYFLAG_BIN))
+USE_I2CDETECT(NEWTOY(i2cdetect, ">3aFlqry[!qr]", TOYFLAG_USR|TOYFLAG_BIN))
USE_I2CDUMP(NEWTOY(i2cdump, "<2>2fy", TOYFLAG_USR|TOYFLAG_BIN))
USE_I2CGET(NEWTOY(i2cget, "<3>3fy", TOYFLAG_USR|TOYFLAG_BIN))
USE_I2CSET(NEWTOY(i2cset, "<4fy", TOYFLAG_USR|TOYFLAG_BIN))
@@ -20,15 +20,16 @@ config I2CDETECT
bool "i2cdetect"
default y
help
- usage: i2cdetect [-ary] BUS [FIRST LAST]
+ usage: i2cdetect [-aqry] BUS [FIRST LAST]
usage: i2cdetect -F BUS
usage: i2cdetect -l
Detect i2c devices.
- -a All addresses (0x00-0x7f rather than 0x03-0x77)
+ -a All addresses (0x00-0x7f rather than 0x03-0x77 or FIRST-LAST)
-F Show functionality
- -l List all buses
+ -l List available buses
+ -q Probe with SMBus Quick Write (default)
-r Probe with SMBus Read Byte
-y Answer "yes" to confirmation prompts (for script use)
@@ -76,7 +77,7 @@ printf_format static void confirm(const char *fmt, ...)
{
va_list va;
- if (toys.optflags & FLAG_y) return;
+ if (FLAG(y)) return;
va_start(va, fmt);
vfprintf(stderr, fmt, va);
@@ -106,19 +107,24 @@ static unsigned long i2c_get_funcs(int bus)
static int i2c_read_byte(int fd, int addr, int *byte)
{
- struct i2c_smbus_ioctl_data ioctl_data;
union i2c_smbus_data data;
+ struct i2c_smbus_ioctl_data ioctl_data = { .read_write=I2C_SMBUS_READ,
+ .size=I2C_SMBUS_BYTE_DATA, .command=addr, .data=&data };
memset(&data, 0, sizeof(data));
- ioctl_data.read_write = I2C_SMBUS_READ;
- ioctl_data.size = I2C_SMBUS_BYTE_DATA;
- ioctl_data.command = addr;
- ioctl_data.data = &data;
if (ioctl(fd, I2C_SMBUS, &ioctl_data) == -1) return -1;
*byte = data.byte;
return 0;
}
+static int i2c_quick_write(int fd, int addr)
+{
+ struct i2c_smbus_ioctl_data ioctl_data = { .read_write=I2C_SMBUS_QUICK,
+ .size=0, .command=addr };
+
+ return ioctl(fd, I2C_SMBUS, &ioctl_data);
+}
+
static void i2cdetect_dash_F(int bus)
{
size_t i;
@@ -178,21 +184,21 @@ static int i2cdetect_dash_l(struct dirtree *node)
void i2cdetect_main(void)
{
- if (toys.optflags & FLAG_l) {
+ if (FLAG(l)) {
if (toys.optc) error_exit("-l doesn't take arguments");
- dirtree_read("/sys/class/i2c-dev", i2cdetect_dash_l);
- } else if (toys.optflags & FLAG_F) {
+ dirtree_flagread("/sys/class/i2c-dev", DIRTREE_SHUTUP, i2cdetect_dash_l);
+ } else if (FLAG(F)) {
if (toys.optc != 1) error_exit("-F BUS");
i2cdetect_dash_F(atolx_range(*toys.optargs, 0, INT_MAX));
} else {
int bus, first = 0x03, last = 0x77, fd, row, addr, byte;
- if (toys.optflags & FLAG_a) {
+ if (FLAG(a)) {
first = 0x00;
last = 0x7f;
}
- if (toys.optc != 1 && toys.optc != 3) error_exit("bad args");
+ if (toys.optc != 1 && toys.optc != 3) help_exit("Needs 1 or 3 arguments");
bus = atolx_range(*toys.optargs, 0, INT_MAX);
if (toys.optc == 3) {
first = atolx_range(toys.optargs[1], 0, 0x7f);
@@ -216,7 +222,8 @@ void i2cdetect_main(void)
}
perror_exit("ioctl(I2C_SLAVE)");
}
- if (i2c_read_byte(fd, addr, &byte) == -1) xprintf(" --");
+ if ((FLAG(r) ? i2c_read_byte(fd, addr, &byte)
+ : i2c_quick_write(fd, addr)) == -1) xprintf(" --");
else xprintf(" %02x", addr);
}
}
@@ -238,7 +245,7 @@ void i2cdump_main(void)
confirm("Dump chip 0x%02x on bus %d?", chip, bus);
- fd = i2c_open(bus, (toys.optflags&FLAG_f)?I2C_SLAVE_FORCE:I2C_SLAVE, chip);
+ fd = i2c_open(bus, FLAG(f)?I2C_SLAVE_FORCE:I2C_SLAVE, chip);
printf(" 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef\n");
for (row = 0; row <= 0xf0; row += 16) {
xprintf("%02x:", row & 0xf0);
@@ -265,7 +272,7 @@ void i2cget_main(void)
confirm("Read register 0x%02x from chip 0x%02x on bus %d?", addr, chip, bus);
- fd = i2c_open(bus, (toys.optflags&FLAG_f)?I2C_SLAVE_FORCE:I2C_SLAVE, chip);
+ fd = i2c_open(bus, FLAG(f)?I2C_SLAVE_FORCE:I2C_SLAVE, chip);
if (i2c_read_byte(fd, addr, &byte) == -1) perror_exit("i2c_read_byte");
printf("0x%02x\n", byte);
close(fd);
@@ -305,7 +312,7 @@ void i2cset_main(void)
confirm("Write register 0x%02x from chip 0x%02x on bus %d?", addr, chip, bus);
- fd = i2c_open(bus, (toys.optflags&FLAG_f)?I2C_SLAVE_FORCE:I2C_SLAVE, chip);
+ fd = i2c_open(bus, FLAG(f)?I2C_SLAVE_FORCE:I2C_SLAVE, chip);
ioctl_data.read_write = I2C_SMBUS_WRITE;
ioctl_data.command = addr;
ioctl_data.data = &data;
--
2.33.0.153.gba50c8fa24-goog
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