@@ -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;
@@ -55,6 +55,9 @@ static inline void *imx_dsp_get_data(struct imx_dsp_ipc *ipc)
int imx_dsp_ring_doorbell(struct imx_dsp_ipc *dsp, unsigned int chan_idx);
+struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *ipc, int idx);
+void imx_dsp_free_channel(struct imx_dsp_ipc *ipc, int idx);
+
#else
static inline int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc,
@@ -63,5 +66,12 @@ static inline int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc,
return -ENOTSUPP;
}
+struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *ipc, int idx)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
+void imx_dsp_free_channel(struct imx_dsp_ipc *ipc, int idx) { }
+
#endif
#endif /* _IMX_DSP_IPC_H */
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> --- drivers/firmware/imx/imx-dsp.c | 25 +++++++++++++++++++++++++ include/linux/firmware/imx/dsp.h | 10 ++++++++++ 2 files changed, 35 insertions(+)