This reverts commit 5378bdf6a6.
Commit 5378bdf6a6 ("mailbox/pcc: support mailbox management of the shared buffer")
attempted to introduce generic helpers for managing the PCC shared memory,
but it largely duplicates functionality already provided by the mailbox
core and leaves gaps:
1. TX preparation: The mailbox framework already supports this via
->tx_prepare callback for mailbox clients. The patch adds
pcc_write_to_buffer() and expects clients to toggle pchan->chan.manage_writes,
but no drivers set manage_writes, so pcc_write_to_buffer() has no users.
2. RX handling: Data reception is already delivered through
mbox_chan_received_data() and client ->rx_callback. The patch adds an
optional pchan->chan.rx_alloc, which again has no users and duplicates
the existing path.
3. Completion handling: While adding last_tx_done is directionally useful,
the implementation only covers Type 3/4 and fails to handle the absence
of a command_complete register, so it is incomplete for other types.
Given the duplication and incomplete coverage, revert this change. Any new
requirements should be addressed in focused follow-ups rather than bundling
multiple behavioral changes together.
Fixes: 5378bdf6a6 ("mailbox/pcc: support mailbox management of the shared buffer")
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
f82c3e62b6