From 0c6b20a1d720ad1d43a2aca0ffa1af07c201b55d Mon Sep 17 00:00:00 2001 From: Manivannan Sadhasivam Date: Mon, 27 Apr 2020 13:28:27 +0530 Subject: bus: mhi: core: Add support for MHI suspend and resume Add support for MHI suspend and resume states. While at it, the mhi_notify() function needs to be exported as well. Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20200427075829.9304-2-manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/bus/mhi/core/pm.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) (limited to 'drivers/bus/mhi/core/pm.c') diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index 52690cb5c89c..3529419d076b 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -669,6 +669,149 @@ void mhi_pm_st_worker(struct work_struct *work) } } +int mhi_pm_suspend(struct mhi_controller *mhi_cntrl) +{ + struct mhi_chan *itr, *tmp; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_pm_state new_state; + int ret; + + if (mhi_cntrl->pm_state == MHI_PM_DISABLE) + return -EINVAL; + + if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) + return -EIO; + + /* Return busy if there are any pending resources */ + if (atomic_read(&mhi_cntrl->dev_wake)) + return -EBUSY; + + /* Take MHI out of M2 state */ + read_lock_bh(&mhi_cntrl->pm_lock); + mhi_cntrl->wake_get(mhi_cntrl, false); + read_unlock_bh(&mhi_cntrl->pm_lock); + + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_cntrl->dev_state == MHI_STATE_M0 || + mhi_cntrl->dev_state == MHI_STATE_M1 || + MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state), + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + + read_lock_bh(&mhi_cntrl->pm_lock); + mhi_cntrl->wake_put(mhi_cntrl, false); + read_unlock_bh(&mhi_cntrl->pm_lock); + + if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { + dev_err(dev, + "Could not enter M0/M1 state"); + return -EIO; + } + + write_lock_irq(&mhi_cntrl->pm_lock); + + if (atomic_read(&mhi_cntrl->dev_wake)) { + write_unlock_irq(&mhi_cntrl->pm_lock); + return -EBUSY; + } + + dev_info(dev, "Allowing M3 transition\n"); + new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_ENTER); + if (new_state != MHI_PM_M3_ENTER) { + write_unlock_irq(&mhi_cntrl->pm_lock); + dev_err(dev, + "Error setting to PM state: %s from: %s\n", + to_mhi_pm_state_str(MHI_PM_M3_ENTER), + to_mhi_pm_state_str(mhi_cntrl->pm_state)); + return -EIO; + } + + /* Set MHI to M3 and wait for completion */ + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M3); + write_unlock_irq(&mhi_cntrl->pm_lock); + dev_info(dev, "Wait for M3 completion\n"); + + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_cntrl->dev_state == MHI_STATE_M3 || + MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state), + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + + if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { + dev_err(dev, + "Did not enter M3 state, MHI state: %s, PM state: %s\n", + TO_MHI_STATE_STR(mhi_cntrl->dev_state), + to_mhi_pm_state_str(mhi_cntrl->pm_state)); + return -EIO; + } + + /* Notify clients about entering LPM */ + list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) { + mutex_lock(&itr->mutex); + if (itr->mhi_dev) + mhi_notify(itr->mhi_dev, MHI_CB_LPM_ENTER); + mutex_unlock(&itr->mutex); + } + + return 0; +} +EXPORT_SYMBOL_GPL(mhi_pm_suspend); + +int mhi_pm_resume(struct mhi_controller *mhi_cntrl) +{ + struct mhi_chan *itr, *tmp; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_pm_state cur_state; + int ret; + + dev_info(dev, "Entered with PM state: %s, MHI state: %s\n", + to_mhi_pm_state_str(mhi_cntrl->pm_state), + TO_MHI_STATE_STR(mhi_cntrl->dev_state)); + + if (mhi_cntrl->pm_state == MHI_PM_DISABLE) + return 0; + + if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) + return -EIO; + + /* Notify clients about exiting LPM */ + list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) { + mutex_lock(&itr->mutex); + if (itr->mhi_dev) + mhi_notify(itr->mhi_dev, MHI_CB_LPM_EXIT); + mutex_unlock(&itr->mutex); + } + + write_lock_irq(&mhi_cntrl->pm_lock); + cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_EXIT); + if (cur_state != MHI_PM_M3_EXIT) { + write_unlock_irq(&mhi_cntrl->pm_lock); + dev_info(dev, + "Error setting to PM state: %s from: %s\n", + to_mhi_pm_state_str(MHI_PM_M3_EXIT), + to_mhi_pm_state_str(mhi_cntrl->pm_state)); + return -EIO; + } + + /* Set MHI to M0 and wait for completion */ + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M0); + write_unlock_irq(&mhi_cntrl->pm_lock); + + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_cntrl->dev_state == MHI_STATE_M0 || + MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state), + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + + if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { + dev_err(dev, + "Did not enter M0 state, MHI state: %s, PM state: %s\n", + TO_MHI_STATE_STR(mhi_cntrl->dev_state), + to_mhi_pm_state_str(mhi_cntrl->pm_state)); + return -EIO; + } + + return 0; +} +EXPORT_SYMBOL_GPL(mhi_pm_resume); + int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl) { int ret; -- cgit v1.2.3