Hi Wolfram,
On Mon, Mar 6, 2017 at 3:29 PM, Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
>
> This tool allows to construct and concat multiple I2C messages into one
> single transfer. Its aim is to test I2C master controllers, and so there
> is no SMBus fallback.
Thanks for the tool!
> I've been missing such a tool a number of times now, so I finally got
> paround to writing it myself. As with all I2C tools, it can be dangerous,
around
Very dangerous, it inserts spurious "p" characters ;-)
> --- /dev/null
> +++ b/tools/i2ctransfer.8
> +.SH DESCRIPTION
> +.B i2ctransfer
> +is a program to create I2C messages and send them combined as one transfer.
> +For read messages, the contents of the received buffers are printed to stdout, one line per read message.
> +.br
> +Please note the difference between a
> +.I transfer
> +and a
> +.I message
> +here.
> +A transfer may consist of multiple messages and is started with a START condition and ends with a STOP condition as described in the I2C specification.
Funny, this is the other way around than on SPI (an SPI message consists
of multiple transfers).
> +.TP
> +.B {r|w}
> +specifies if the message is read or write
> +.TP
> +.B <length_of_message>
> +specifies the number of bytes read or written in this message.
> +It is parsed as an unsigned 16 bit integer, but note that the Linux might apply an additional upper limit (8192 as of v4.10).
s/the Linux/Linux/ (or the kernel, or i2c driver?)
> +.TP
> +.B [@address]
> +specifies the address of the chip to be accessed for this message, and is an integer.
> +If omitted, reuse the previous address.
> +Normally, addresses outside the range of 0x03-0x77 and addresses with a kernel driver attached to them will be blocked.
So 10-bit adressing needs -f?
> --- /dev/null
> +++ b/tools/i2ctransfer.c
> @@ -0,0 +1,347 @@
> +static void print_msgs(struct i2c_msg *msgs, __u32 nmsgs, unsigned flags)
unsigned int nmsgs?
> +{
> + FILE *output = flags & PRINT_STDERR ? stderr : stdout;
> + unsigned i;
> + __u16 j;
unsigned int, too?
> +
> + for (i = 0; i < nmsgs; i++) {
> + int read = msgs[i].flags & I2C_M_RD;
> + int print_buf = (read && (flags & PRINT_READ_BUF)) ||
> + (!read && (flags & PRINT_WRITE_BUF));
> +
> + if (flags & PRINT_HEADER)
> + fprintf(output, "msg %u: addr 0x%02x, %s, len %u",
> + i, msgs[i].addr, read ? "read" : "write", msgs[i].len);
> +
> + if (msgs[i].len && print_buf) {
> + if (flags & PRINT_HEADER)
> + fprintf(output, ", buf ");
> + for (j = 0; j < msgs[i].len - 1; j++)
> + fprintf(output, "0x%02x ", msgs[i].buf[j]);
> + /* Print final byte with newline */
> + fprintf(output, "0x%02x\n", msgs[i].buf[j]);
> + } else if (flags & PRINT_HEADER) {
> + fprintf(output, "\n");
> + }
> + }
> +}
> +
> +static int confirm(const char *filename, struct i2c_msg *msgs, __u32 nmsgs)
unsigned int nmsgs?
> +{
> + fprintf(stderr, "WARNING! This program can confuse your I2C bus, cause data loss and worse!\n");
> + fprintf(stderr, "I will send the following messages to device file %s:\n", filename);
> + print_msgs(msgs, nmsgs, PRINT_STDERR | PRINT_HEADER | PRINT_WRITE_BUF);
> +
> + fprintf(stderr, "Continue? [y/N] ");
> + fflush(stderr);
> + if (!user_ack(0)) {
> + fprintf(stderr, "Aborting on user request.\n");
> + return 0;
> + }
> +
> + return 1;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + char filename[20];
> + int i2cbus, address = -1, file, arg_idx = 1, nmsgs = 0, nmsgs_sent, i;
unsigned int i?
> + while (arg_idx < argc) {
> + char *arg_ptr = argv[arg_idx];
> + unsigned long len, raw_data;
> + __u16 flags;
unsigned int flags?
> + __u8 data, *buf;
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
