Commit e4b7b5f0 authored by Manivannan Sadhasivam's avatar Manivannan Sadhasivam Committed by Greg Kroah-Hartman
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bus: mhi: ep: Add support for suspending and resuming channels 



Add support for suspending and resuming the channels in MHI endpoint stack.
The channels will be moved to the suspended state during M3 state
transition and will be resumed during M0 transition.

Reviewed-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220405135754.6622-18-manivannan.sadhasivam@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2d945a39

drivers/bus/mhi/ep/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -212,5 +212,7 @@ int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl); 
int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl);

int mhi_ep_set_ready_state(struct mhi_ep_cntrl *mhi_cntrl);

void mhi_ep_handle_syserr(struct mhi_ep_cntrl *mhi_cntrl);

void mhi_ep_resume_channels(struct mhi_ep_cntrl *mhi_cntrl);

void mhi_ep_suspend_channels(struct mhi_ep_cntrl *mhi_cntrl);



#endif

drivers/bus/mhi/ep/main.c

+58 −0
Original line number Diff line number Diff line
@@ -1097,6 +1097,64 @@ void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl) 
}

EXPORT_SYMBOL_GPL(mhi_ep_power_down);



void mhi_ep_suspend_channels(struct mhi_ep_cntrl *mhi_cntrl)

{

	struct mhi_ep_chan *mhi_chan;

	u32 tmp;

	int i;



	for (i = 0; i < mhi_cntrl->max_chan; i++) {

		mhi_chan = &mhi_cntrl->mhi_chan[i];



		if (!mhi_chan->mhi_dev)

			continue;



		mutex_lock(&mhi_chan->lock);

		/* Skip if the channel is not currently running */

		tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[i].chcfg);

		if (FIELD_GET(CHAN_CTX_CHSTATE_MASK, tmp) != MHI_CH_STATE_RUNNING) {

			mutex_unlock(&mhi_chan->lock);

			continue;

		}



		dev_dbg(&mhi_chan->mhi_dev->dev, "Suspending channel\n");

		/* Set channel state to SUSPENDED */

		tmp &= ~CHAN_CTX_CHSTATE_MASK;

		tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_SUSPENDED);

		mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp);

		mutex_unlock(&mhi_chan->lock);

	}

}



void mhi_ep_resume_channels(struct mhi_ep_cntrl *mhi_cntrl)

{

	struct mhi_ep_chan *mhi_chan;

	u32 tmp;

	int i;



	for (i = 0; i < mhi_cntrl->max_chan; i++) {

		mhi_chan = &mhi_cntrl->mhi_chan[i];



		if (!mhi_chan->mhi_dev)

			continue;



		mutex_lock(&mhi_chan->lock);

		/* Skip if the channel is not currently suspended */

		tmp = le32_to_cpu(mhi_cntrl->ch_ctx_cache[i].chcfg);

		if (FIELD_GET(CHAN_CTX_CHSTATE_MASK, tmp) != MHI_CH_STATE_SUSPENDED) {

			mutex_unlock(&mhi_chan->lock);

			continue;

		}



		dev_dbg(&mhi_chan->mhi_dev->dev, "Resuming channel\n");

		/* Set channel state to RUNNING */

		tmp &= ~CHAN_CTX_CHSTATE_MASK;

		tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING);

		mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp);

		mutex_unlock(&mhi_chan->lock);

	}

}



static void mhi_ep_release_device(struct device *dev)

{

	struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev);

drivers/bus/mhi/ep/sm.c

+5 −0
Original line number Diff line number Diff line
@@ -62,8 +62,11 @@ int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl) 
	enum mhi_state old_state;

	int ret;



	/* If MHI is in M3, resume suspended channels */

	spin_lock_bh(&mhi_cntrl->state_lock);

	old_state = mhi_cntrl->mhi_state;

	if (old_state == MHI_STATE_M3)

		mhi_ep_resume_channels(mhi_cntrl);



	ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M0);

	spin_unlock_bh(&mhi_cntrl->state_lock);
@@ -106,6 +109,8 @@ int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl) 
		return ret;

	}



	mhi_ep_suspend_channels(mhi_cntrl);



	/* Signal host that the device moved to M3 */

	ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M3);

	if (ret) {