[RFC PATCH 0/2] Introduce Tx doorbell with ACK

From: daniel . baluta
Date: Mon Jun 10 2019 - 10:18:56 EST


From: Daniel Baluta <daniel.baluta@xxxxxxx>

We need this in order to implement the communication protocol
between Linux kernel SOF IPC layer and DSP firmware found on i.MX8 boards.

First patch is just a bugfix and can be merged as it is.

The second patch is just a RFC to open the discussion on how to use the i.MX
mailbox API in order to communicate with the DSP. I want to know if this
scenario can be supported by the mailbox abstraction of MU or should I
go back and directly access MU registers.

We need to have two MU channels:
- channel #0, Host sends notification (via GIR) to DSP and gets a reply (via GIP)
- channel #1, DSP sends message to Host (via GIR) and gets a reply (via GIP).

The details of the protocol can be found in patch 2.

Daniel Baluta (2):
mailbox: imx: Clear GIEn bit at shutdown
imx: mailbox: Introduce TX doorbell with ACK

drivers/mailbox/imx-mailbox.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

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2.17.1