diff options
author | Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> | 2020-04-27 10:58:27 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-28 15:42:32 +0300 |
commit | 0c6b20a1d720ad1d43a2aca0ffa1af07c201b55d (patch) | |
tree | bbfd706bfaa81900aa4dff3150b9be396e8218b9 /drivers/bus/mhi | |
parent | 48a4cc950348c507580df79632ad53d8a08b6c0e (diff) | |
download | linux-0c6b20a1d720ad1d43a2aca0ffa1af07c201b55d.tar.xz |
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 <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200427075829.9304-2-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/bus/mhi')
-rw-r--r-- | drivers/bus/mhi/core/main.c | 3 | ||||
-rw-r--r-- | drivers/bus/mhi/core/pm.c | 143 |
2 files changed, 145 insertions, 1 deletions
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index eb4256b81406..3e9aa3b2da77 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -267,7 +267,7 @@ int mhi_destroy_device(struct device *dev, void *data) return 0; } -static void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason) +void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason) { struct mhi_driver *mhi_drv; @@ -279,6 +279,7 @@ static void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason) if (mhi_drv->status_cb) mhi_drv->status_cb(mhi_dev, cb_reason); } +EXPORT_SYMBOL_GPL(mhi_notify); /* Bind MHI channels to MHI devices */ void mhi_create_devices(struct mhi_controller *mhi_cntrl) 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; |