kernel/linux.git/include/linux/firmware/imx/dsp.h, branch v6.6.132

ASoC: SOF: imx: remove error checks on NULL ipc

2023-07-31T22:22:15+00:00

imx_dsp_get_data() can return NULL, but the value is not checked before being usd, leading to static analysis warnings. sound/soc/sof/imx/imx8.c:85:32: error: dereference of NULL ‘0’ [CWE-476] [-Werror=analyzer-null-dereference] 85 | spin_lock_irqsave(&priv->sdev->ipc_lock, flags); | ~~~~^~~~~~ It appears this is not really a possible problem, so remove those checks. Signed-off-by: Pierre-Louis Bossart Reviewed-by: Rander Wang Reviewed-by: Daniel Baluta Reviewed-by: Yaochun Hung Link: https://lore.kernel.org/r/20230731213748.440285-5-pierre-louis.bossart@linux.intel.com Signed-off-by: Mark Brown

firmware: imx-dsp: Export functions to request/free channels

2020-11-16T08:33:48+00:00

In order to save power, we only need to request a channel when the communication with the DSP active. For this we export the following functions: - imx_dsp_request_channel, gets a channel with a given index - imx_dsp_free_channel, frees a channel with a given index Notice that we still request channels at probe to support devices that do not have PM callbacks implemented. More explanations about why requesting a channel has an effect on power savings: - requesting an mailbox channel will call mailbox's startup function. - startup function calls pm_runtime_get_sync which increments device usage count and will keep the device active. Specifically, mailbox clock will be always ON when a mailbox channel is requested. Signed-off-by: Daniel Baluta Reviewed-by: Paul Olaru Signed-off-by: Shawn Guo

firmware: imx: Add DSP IPC protocol interface

2019-08-12T13:19:25+00:00

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 Reviewed-by: Oleksij Rempel Signed-off-by: Shawn Guo