twsi: use twsi_error() to handle wrong bus status when starting

(cherry picked from commit 46e0c03795443675f95db6da2195825d24a9fb7c)

twsi: fix handling of consecuitve write messages in transaction

Make sure to reset 'message_done' flag when jumping from a message to the
next one within the same interrupt handler call. This happe

twsi: fix handling of consecuitve write messages in transaction

Make sure to reset 'message_done' flag when jumping from a message to the
next one within the same interrupt handler call. This happens only when
a write with no-stop flag message is followed by a write with no-start
flag message.
Without this fix the second message would be prematurely "completed"
without waiting for an ACK (or NACK) for its first byte and without
sending subsequent bytes (if any).

Fixes: ff1e8581 twsi: support more message combinations in transfers

(cherry picked from commit e5268c3d435e0a0f0fef64e6213504dd189272f6)

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twsi: support more message combinations in transfers

Most prominently, add support for a transfer where a write with no-stop
flag is followed by a write with no-start flag. Logically, it's a
single

twsi: support more message combinations in transfers

Most prominently, add support for a transfer where a write with no-stop
flag is followed by a write with no-start flag. Logically, it's a
single larger write, but consumers may want to split it like that
because one part can be a register ID and the other part can be data to
be written to (or starting at) that register.

Such a transfer can be created by i2c tool and iic(4) driver, e.g., for
an EEPROM write at specific offset:
i2c -m tr -a 0x50 -d w -w 16 -o 0 -c 8 -v < /dev/random

This should be fixed by new code that handles the end of data transfer
for both reads and writes. It handles two existing conditions and one
new. Namely:
- the last message has been completed -- end of transfer;
- a message has been completed and the next one requires the start
condition;
- a message has been completed and the next one should be sent without
the start condition.

In the last case we simply switch to the next message and start sending
its data. Reads without the start condition are not supported yet,
though. That's because we NACK the last byte of the previous message,
so the device stops sending data. To fix this we will need to add a
look-ahead at the next message when handling the penultimate byte of the
current one.

This change also fixed a bug where msg_idx was not incremented after a
read message. Apparently, typically a read message is a last message in
a transfer, so the bug did not cause much trouble.

PR: 258994

(cherry picked from commit ff1e8581806f70e54fecddf8a6a23488dc7b968a)

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twsi: make data receiving code safer

Assert that we are not receiving data beyond the requested length.
Assert that we have not NACK-ed incoming data prematurely.
Abort the current transfer if the i

twsi: make data receiving code safer

Assert that we are not receiving data beyond the requested length.
Assert that we have not NACK-ed incoming data prematurely.
Abort the current transfer if the incoming data is NACK-ed or not
NACK-ed unexpectedly.

Add debug logging of received data to complement logging of sent data.

(cherry picked from commit 00c07d9559c6197957b00811a0b29876a5c8b573)

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twsi: remove redundant write of control register

The write at the end of twsi_intr() already handles all cases, no need
to have another write for TWSI_STATUS_START / TWSI_STATUS_RPTD_START.

(cherry

twsi: remove redundant write of control register

The write at the end of twsi_intr() already handles all cases, no need
to have another write for TWSI_STATUS_START / TWSI_STATUS_RPTD_START.

(cherry picked from commit aeacf172fd29b16b3661ff057c9abb238baba813)

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twsi: move handling of TWSI_CONTROL_ACK into the state machine

Previously the code set TWSI_CONTROL_ACK in twsi_transfer() based on
whether the first message had a length of one. That was done rega

twsi: move handling of TWSI_CONTROL_ACK into the state machine

Previously the code set TWSI_CONTROL_ACK in twsi_transfer() based on
whether the first message had a length of one. That was done regardless
of whether the message was a read or write and what kind of messages
followed it.
Now the bit is set or cleared while handling TWSI_STATUS_ADDR_R_ACK
state transition based on the current (read) message.

The old code did not correctly work in a scenario where a single byte
was read from an EEPROM device with two byte addressing.
For example:
i2c -m tr -a 0x50 -d r -w 16 -o 0 -c 1 -v
The reason is that the first message (a write) has two bytes, so
TWSI_CONTROL_ACK was set and never cleared.
Since the controller did not send NACK the EEPROM sent more data resulting
in a buffer overrun.

While working on TWSI_STATUS_ADDR_R_ACK I also added support for
the zero-length read access and then I did the same for zero-length write
access.
While rare, those types of I2C transactions are completely valid and are
used by some devices.

PR: 258994

(cherry picked from commit 04622a7f21157827fe75276a4520a52d3a571a86)

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twsi: unify error handling, explicitly handle more conditions

twsi_error() is a new function that stops the current transfer and sets
up softc when an error condition is detected.
TWSI_STATUS_DATA_W

twsi: unify error handling, explicitly handle more conditions

twsi_error() is a new function that stops the current transfer and sets
up softc when an error condition is detected.
TWSI_STATUS_DATA_WR_NACK, TWSI_STATUS_BUS_ERROR and
TWSI_STATUS_ARBITRATION_LOST are now handled explicitly rather than
via the catch-all unknown status.

Also, twsi_intr() now calls wakeup() in a single place when the
transfer is finished.

(cherry picked from commit a4fe8922085dfc1e5e6a6bac73ccc738e373165f)

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twsi: improve a handful of debug messages

- use 0x prefix for hex values
- print indexes and counts as decimals
- break too long lines

(cherry picked from commit 578707ed4efda4ec1c91ab1a8f1bace6b1e

twsi: improve a handful of debug messages

- use 0x prefix for hex values
- print indexes and counts as decimals
- break too long lines

(cherry picked from commit 578707ed4efda4ec1c91ab1a8f1bace6b1eb714a)

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twsi: do not attempt transfer if bus is not idle

(cherry picked from commit cb167e1ae95473d836393a07456d8dbcfbb7f758)

twsi: remove redundant enabling of the controller

(cherry picked from commit bc02583c4dd65275da89838a723bd3514cb316cf)

twsi: protect interaction between twsi_transfer and twsi_intr

All accesses to softc are now done under a mutex to prevent data races
between the open context and the interrupt handler.
Additionally,

twsi: protect interaction between twsi_transfer and twsi_intr

All accesses to softc are now done under a mutex to prevent data races
between the open context and the interrupt handler.
Additionally, the wait time in twsi_transfer is bounded now.
Previously we could get stuck there forever if an interrupt got lost.

(cherry picked from commit 69cfa60ddd4df814b507699f9bb7253ece054f40)

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