diff options
author | Daniel Baluta <daniel.baluta@nxp.com> | 2020-11-11 13:11:18 +0200 |
---|---|---|
committer | Shawn Guo <shawnguo@kernel.org> | 2020-11-16 16:33:48 +0800 |
commit | 23d89aa0c2192f2d4582198b381d8805492c7925 (patch) | |
tree | a4f331d9c2613db9ca7ab53cc253d727902535e1 /drivers/firmware | |
parent | 046326989a1845db321d3b3db637e1336383b047 (diff) | |
download | linux-23d89aa0c2192f2d4582198b381d8805492c7925.tar.gz linux-23d89aa0c2192f2d4582198b381d8805492c7925.tar.bz2 linux-23d89aa0c2192f2d4582198b381d8805492c7925.zip |
firmware: imx-dsp: Export functions to request/free channels
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 <daniel.baluta@nxp.com>
Reviewed-by: Paul Olaru <paul.olaru@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r-- | drivers/firmware/imx/imx-dsp.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/firmware/imx/imx-dsp.c b/drivers/firmware/imx/imx-dsp.c index b6e95d6d34c0..a6c06d7476c3 100644 --- a/drivers/firmware/imx/imx-dsp.c +++ b/drivers/firmware/imx/imx-dsp.c @@ -60,6 +60,31 @@ static void imx_dsp_handle_rx(struct mbox_client *c, void *msg) } } +struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *dsp_ipc, int idx) +{ + struct imx_dsp_chan *dsp_chan; + + if (idx >= DSP_MU_CHAN_NUM) + return ERR_PTR(-EINVAL); + + dsp_chan = &dsp_ipc->chans[idx]; + dsp_chan->ch = mbox_request_channel_byname(&dsp_chan->cl, dsp_chan->name); + return dsp_chan->ch; +} +EXPORT_SYMBOL(imx_dsp_request_channel); + +void imx_dsp_free_channel(struct imx_dsp_ipc *dsp_ipc, int idx) +{ + struct imx_dsp_chan *dsp_chan; + + if (idx >= DSP_MU_CHAN_NUM) + return; + + dsp_chan = &dsp_ipc->chans[idx]; + mbox_free_channel(dsp_chan->ch); +} +EXPORT_SYMBOL(imx_dsp_free_channel); + static int imx_dsp_setup_channels(struct imx_dsp_ipc *dsp_ipc) { struct device *dev = dsp_ipc->dev; |