Hi all,
I’m trying to implement the following transfer with the i2c-mpc driver:
Read MR: Initiate pressure management
+---------------------+
|S|6|5|4|3|2|1|0|R|A|S|
+---------------------+
First S - start condition
6:0 - slave address
R - read bit ('1')
A - wait for slave ACK
Second S - stop condition.
My guess was that doing that would be enough:
struct i2c_msg msg = {
.addr = <addr>,
.flags = I2C_M_RD,
.len = 0,
.buf = NULL,
};
return i2c_transfer(data->client->adapter, &msg, 1);
However, when the length parameter is 0, the wait for the CSR_MBB bit
in lines 617-630 of mpc_xfer in drivers/i2c/busses/i2c-mpc.c times
out.
I’m checking the NXP P2020 spec, and it says that
Note that a master can generate a STOP even if the slave has transmitted an
acknowledge bit, at which point the slave must release the bus.
To me everything seems OK here, but still CSR_MBB never becomes zero.
Would you be able to give me any advice?
Best regards,
Andrij Abyzov
