diff options
| -rw-r--r-- | drivers/bus/mhi/host/internal.h | 4 | ||||
| -rw-r--r-- | drivers/bus/mhi/host/pm.c | 42 | ||||
| -rw-r--r-- | include/linux/mhi.h | 18 |
3 files changed, 56 insertions, 8 deletions
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h index 5fe49311b8eb..aaad40a07f69 100644 --- a/drivers/bus/mhi/host/internal.h +++ b/drivers/bus/mhi/host/internal.h @@ -80,6 +80,7 @@ enum dev_st_transition { DEV_ST_TRANSITION_FP, DEV_ST_TRANSITION_SYS_ERR, DEV_ST_TRANSITION_DISABLE, + DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE, DEV_ST_TRANSITION_MAX, }; @@ -90,7 +91,8 @@ enum dev_st_transition { dev_st_trans(MISSION_MODE, "MISSION MODE") \ dev_st_trans(FP, "FLASH PROGRAMMER") \ dev_st_trans(SYS_ERR, "SYS ERROR") \ - dev_st_trans_end(DISABLE, "DISABLE") + dev_st_trans(DISABLE, "DISABLE") \ + dev_st_trans_end(DISABLE_DESTROY_DEVICE, "DISABLE (DESTROY DEVICE)") extern const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX]; #define TO_DEV_STATE_TRANS_STR(state) (((state) >= DEV_ST_TRANSITION_MAX) ? \ diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c index 8b40d3f01acc..11c0e751f223 100644 --- a/drivers/bus/mhi/host/pm.c +++ b/drivers/bus/mhi/host/pm.c @@ -468,7 +468,8 @@ error_mission_mode: } /* Handle shutdown transitions */ -static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) +static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, + bool destroy_device) { enum mhi_pm_state cur_state; struct mhi_event *mhi_event; @@ -530,8 +531,16 @@ skip_mhi_reset: dev_dbg(dev, "Waiting for all pending threads to complete\n"); wake_up_all(&mhi_cntrl->state_event); - dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); - device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); + /* + * Only destroy the 'struct device' for channels if indicated by the + * 'destroy_device' flag. Because, during system suspend or hibernation + * state, there is no need to destroy the 'struct device' as the endpoint + * device would still be physically attached to the machine. + */ + if (destroy_device) { + dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); + } mutex_lock(&mhi_cntrl->pm_mutex); @@ -821,7 +830,10 @@ void mhi_pm_st_worker(struct work_struct *work) mhi_pm_sys_error_transition(mhi_cntrl); break; case DEV_ST_TRANSITION_DISABLE: - mhi_pm_disable_transition(mhi_cntrl); + mhi_pm_disable_transition(mhi_cntrl, false); + break; + case DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE: + mhi_pm_disable_transition(mhi_cntrl, true); break; default: break; @@ -1175,7 +1187,8 @@ error_exit: } EXPORT_SYMBOL_GPL(mhi_async_power_up); -void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) +static void __mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful, + bool destroy_device) { enum mhi_pm_state cur_state, transition_state; struct device *dev = &mhi_cntrl->mhi_dev->dev; @@ -1211,15 +1224,32 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) write_unlock_irq(&mhi_cntrl->pm_lock); mutex_unlock(&mhi_cntrl->pm_mutex); - mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE); + if (destroy_device) + mhi_queue_state_transition(mhi_cntrl, + DEV_ST_TRANSITION_DISABLE_DESTROY_DEVICE); + else + mhi_queue_state_transition(mhi_cntrl, + DEV_ST_TRANSITION_DISABLE); /* Wait for shutdown to complete */ flush_work(&mhi_cntrl->st_worker); disable_irq(mhi_cntrl->irq[0]); } + +void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) +{ + __mhi_power_down(mhi_cntrl, graceful, true); +} EXPORT_SYMBOL_GPL(mhi_power_down); +void mhi_power_down_keep_dev(struct mhi_controller *mhi_cntrl, + bool graceful) +{ + __mhi_power_down(mhi_cntrl, graceful, false); +} +EXPORT_SYMBOL_GPL(mhi_power_down_keep_dev); + int mhi_sync_power_up(struct mhi_controller *mhi_cntrl) { int ret = mhi_async_power_up(mhi_cntrl); diff --git a/include/linux/mhi.h b/include/linux/mhi.h index 77b8c0a26674..cde01e133a1b 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -630,13 +630,29 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl); int mhi_sync_power_up(struct mhi_controller *mhi_cntrl); /** - * mhi_power_down - Start MHI power down sequence + * mhi_power_down - Power down the MHI device and also destroy the + * 'struct device' for the channels associated with it. + * See also mhi_power_down_keep_dev() which is a variant + * of this API that keeps the 'struct device' for channels + * (useful during suspend/hibernation). * @mhi_cntrl: MHI controller * @graceful: Link is still accessible, so do a graceful shutdown process */ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful); /** + * mhi_power_down_keep_dev - Power down the MHI device but keep the 'struct + * device' for the channels associated with it. + * This is a variant of 'mhi_power_down()' and + * useful in scenarios such as suspend/hibernation + * where destroying of the 'struct device' is not + * needed. + * @mhi_cntrl: MHI controller + * @graceful: Link is still accessible, so do a graceful shutdown process + */ +void mhi_power_down_keep_dev(struct mhi_controller *mhi_cntrl, bool graceful); + +/** * mhi_unprepare_after_power_down - Free any allocated memory after power down * @mhi_cntrl: MHI controller */ |