From 5fb83d97aa176035e1f55af1025128f5df59d878 Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Mon, 29 Nov 2021 16:25:24 +0530 Subject: [PATCH] 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: Alex Elder Signed-off-by: Manivannan Sadhasivam --- drivers/bus/mhi/ep/internal.h | 2 ++ drivers/bus/mhi/ep/main.c | 58 +++++++++++++++++++++++++++++++++++ drivers/bus/mhi/ep/sm.c | 5 +++ 3 files changed, 65 insertions(+) diff --git a/drivers/bus/mhi/ep/internal.h b/drivers/bus/mhi/ep/internal.h index d201d755560c1..a2125fa5fe2f9 100644 --- a/drivers/bus/mhi/ep/internal.h +++ b/drivers/bus/mhi/ep/internal.h @@ -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 diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index 660d1e9791d3c..bae5f40ec15e5 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -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); diff --git a/drivers/bus/mhi/ep/sm.c b/drivers/bus/mhi/ep/sm.c index e3865b85399d1..3655c19e23c7b 100644 --- a/drivers/bus/mhi/ep/sm.c +++ b/drivers/bus/mhi/ep/sm.c @@ -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) { -- 2.30.2