Commit Graph

2 Commits

Author SHA1 Message Date
Daniel Baluta 0e4e8cc30a firmware: imx: Remove call to devm_of_platform_populate
IMX DSP device is created by SOF layer. The current call to
devm_of_platform_populate is not needed and it doesn't produce
any effects.

Fixes: ffbf23d503 ("firmware: imx: Add DSP IPC protocol interface)
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-10-28 09:57:13 +08:00
Daniel Baluta ffbf23d503 firmware: imx: Add DSP IPC protocol interface
Some of i.MX8 processors (e.g i.MX8QM, i.MX8QXP) contain
the Tensilica HiFi4 DSP for advanced pre- and post-audio
processing.

The communication between Host CPU and DSP firmware is
taking place using a shared memory area for message passing
and a dedicated Messaging Unit for notifications.

DSP IPC protocol offers a doorbell interface using
imx-mailbox API.

We use 4 MU channels (2 x TXDB, 2 x RXDB) to implement a
request-reply protocol.

Connection 0 (txdb0, rxdb0):
        - Host writes messasge to shared memory [SHMEM]
	- Host sends a request [MU]
	- DSP handles request [SHMEM]
	- DSP sends reply [MU]

Connection 1 (txdb1, rxdb1):
	- DSP writes a message to shared memory [SHMEM]
	- DSP sends a request [MU]
	- Host handles request [SHMEM]
	- Host sends reply [MU]

The protocol interface will be used by a Host client to
communicate with the DSP. First client will be the i.MX8
part from Sound Open Firmware infrastructure.

The protocol offers the following interface:

On Tx:
   - imx_dsp_ring_doorbell, will be called to notify the DSP
   that it needs to handle a request.

On Rx:
   - clients need to provide two callbacks:
	.handle_reply
	.handle_request
  - the callbacks will be used by the protocol on
    notification arrival from DSP.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2019-08-12 15:19:25 +02:00