diff options
| -rw-r--r-- | drivers/bus/mhi/ep/Makefile | 2 | ||||
| -rw-r--r-- | drivers/bus/mhi/ep/internal.h | 11 | ||||
| -rw-r--r-- | drivers/bus/mhi/ep/main.c | 54 | ||||
| -rw-r--r-- | drivers/bus/mhi/ep/sm.c | 136 | ||||
| -rw-r--r-- | include/linux/mhi_ep.h | 12 |
5 files changed, 213 insertions, 2 deletions
diff --git a/drivers/bus/mhi/ep/Makefile b/drivers/bus/mhi/ep/Makefile index 7ba0e04801eb..aad85f180b70 100644 --- a/drivers/bus/mhi/ep/Makefile +++ b/drivers/bus/mhi/ep/Makefile @@ -1,2 +1,2 @@ obj-$(CONFIG_MHI_BUS_EP) += mhi_ep.o -mhi_ep-y := main.o mmio.o ring.o +mhi_ep-y := main.o mmio.o ring.o sm.o diff --git a/drivers/bus/mhi/ep/internal.h b/drivers/bus/mhi/ep/internal.h index e096d9cb2cb1..4f2e26841702 100644 --- a/drivers/bus/mhi/ep/internal.h +++ b/drivers/bus/mhi/ep/internal.h @@ -146,6 +146,11 @@ struct mhi_ep_event { struct mhi_ep_ring ring; }; +struct mhi_ep_state_transition { + struct list_head node; + enum mhi_state state; +}; + struct mhi_ep_chan { char *name; struct mhi_ep_device *mhi_dev; @@ -200,5 +205,11 @@ void mhi_ep_mmio_update_ner(struct mhi_ep_cntrl *mhi_cntrl); /* MHI EP core functions */ int mhi_ep_send_state_change_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state state); int mhi_ep_send_ee_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_ee_type exec_env); +bool mhi_ep_check_mhi_state(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state cur_mhi_state, + enum mhi_state mhi_state); +int mhi_ep_set_mhi_state(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state mhi_state); +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); #endif diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index eca1f58ba5fb..c912daf6dc65 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -105,6 +105,43 @@ static int mhi_ep_send_cmd_comp_event(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_e return mhi_ep_send_event(mhi_cntrl, 0, &event, 0); } +static void mhi_ep_state_worker(struct work_struct *work) +{ + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, state_work); + struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct mhi_ep_state_transition *itr, *tmp; + unsigned long flags; + LIST_HEAD(head); + int ret; + + spin_lock_irqsave(&mhi_cntrl->list_lock, flags); + list_splice_tail_init(&mhi_cntrl->st_transition_list, &head); + spin_unlock_irqrestore(&mhi_cntrl->list_lock, flags); + + list_for_each_entry_safe(itr, tmp, &head, node) { + list_del(&itr->node); + dev_dbg(dev, "Handling MHI state transition to %s\n", + mhi_state_str(itr->state)); + + switch (itr->state) { + case MHI_STATE_M0: + ret = mhi_ep_set_m0_state(mhi_cntrl); + if (ret) + dev_err(dev, "Failed to transition to M0 state\n"); + break; + case MHI_STATE_M3: + ret = mhi_ep_set_m3_state(mhi_cntrl); + if (ret) + dev_err(dev, "Failed to transition to M3 state\n"); + break; + default: + dev_err(dev, "Invalid MHI state transition: %d\n", itr->state); + break; + } + kfree(itr); + } +} + static void mhi_ep_release_device(struct device *dev) { struct mhi_ep_device *mhi_dev = to_mhi_ep_device(dev); @@ -314,6 +351,17 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, goto err_free_ch; } + INIT_WORK(&mhi_cntrl->state_work, mhi_ep_state_worker); + + mhi_cntrl->wq = alloc_workqueue("mhi_ep_wq", 0, 0); + if (!mhi_cntrl->wq) { + ret = -ENOMEM; + goto err_free_cmd; + } + + INIT_LIST_HEAD(&mhi_cntrl->st_transition_list); + spin_lock_init(&mhi_cntrl->state_lock); + spin_lock_init(&mhi_cntrl->list_lock); mutex_init(&mhi_cntrl->event_lock); /* Set MHI version and AMSS EE before enumeration */ @@ -323,7 +371,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, /* Set controller index */ ret = ida_alloc(&mhi_ep_cntrl_ida, GFP_KERNEL); if (ret < 0) - goto err_free_cmd; + goto err_destroy_wq; mhi_cntrl->index = ret; @@ -351,6 +399,8 @@ err_put_dev: put_device(&mhi_dev->dev); err_ida_free: ida_free(&mhi_ep_cntrl_ida, mhi_cntrl->index); +err_destroy_wq: + destroy_workqueue(mhi_cntrl->wq); err_free_cmd: kfree(mhi_cntrl->mhi_cmd); err_free_ch: @@ -364,6 +414,8 @@ void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl) { struct mhi_ep_device *mhi_dev = mhi_cntrl->mhi_dev; + destroy_workqueue(mhi_cntrl->wq); + kfree(mhi_cntrl->mhi_cmd); kfree(mhi_cntrl->mhi_chan); diff --git a/drivers/bus/mhi/ep/sm.c b/drivers/bus/mhi/ep/sm.c new file mode 100644 index 000000000000..ffc02f5d0a0d --- /dev/null +++ b/drivers/bus/mhi/ep/sm.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022 Linaro Ltd. + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> + */ + +#include <linux/errno.h> +#include <linux/mhi_ep.h> +#include "internal.h" + +bool __must_check mhi_ep_check_mhi_state(struct mhi_ep_cntrl *mhi_cntrl, + enum mhi_state cur_mhi_state, + enum mhi_state mhi_state) +{ + if (mhi_state == MHI_STATE_SYS_ERR) + return true; /* Allowed in any state */ + + if (mhi_state == MHI_STATE_READY) + return cur_mhi_state == MHI_STATE_RESET; + + if (mhi_state == MHI_STATE_M0) + return cur_mhi_state == MHI_STATE_M3 || cur_mhi_state == MHI_STATE_READY; + + if (mhi_state == MHI_STATE_M3) + return cur_mhi_state == MHI_STATE_M0; + + return false; +} + +int mhi_ep_set_mhi_state(struct mhi_ep_cntrl *mhi_cntrl, enum mhi_state mhi_state) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + + if (!mhi_ep_check_mhi_state(mhi_cntrl, mhi_cntrl->mhi_state, mhi_state)) { + dev_err(dev, "MHI state change to %s from %s is not allowed!\n", + mhi_state_str(mhi_state), + mhi_state_str(mhi_cntrl->mhi_state)); + return -EACCES; + } + + /* TODO: Add support for M1 and M2 states */ + if (mhi_state == MHI_STATE_M1 || mhi_state == MHI_STATE_M2) { + dev_err(dev, "MHI state (%s) not supported\n", mhi_state_str(mhi_state)); + return -EOPNOTSUPP; + } + + mhi_ep_mmio_masked_write(mhi_cntrl, EP_MHISTATUS, MHISTATUS_MHISTATE_MASK, mhi_state); + mhi_cntrl->mhi_state = mhi_state; + + if (mhi_state == MHI_STATE_READY) + mhi_ep_mmio_masked_write(mhi_cntrl, EP_MHISTATUS, MHISTATUS_READY_MASK, 1); + + if (mhi_state == MHI_STATE_SYS_ERR) + mhi_ep_mmio_masked_write(mhi_cntrl, EP_MHISTATUS, MHISTATUS_SYSERR_MASK, 1); + + return 0; +} + +int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_state old_state; + int ret; + + spin_lock_bh(&mhi_cntrl->state_lock); + old_state = mhi_cntrl->mhi_state; + + ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M0); + spin_unlock_bh(&mhi_cntrl->state_lock); + + if (ret) + return ret; + + /* Signal host that the device moved to M0 */ + ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M0); + if (ret) { + dev_err(dev, "Failed sending M0 state change event\n"); + return ret; + } + + if (old_state == MHI_STATE_READY) { + /* Send AMSS EE event to host */ + ret = mhi_ep_send_ee_event(mhi_cntrl, MHI_EE_AMSS); + if (ret) { + dev_err(dev, "Failed sending AMSS EE event\n"); + return ret; + } + } + + return 0; +} + +int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret; + + spin_lock_bh(&mhi_cntrl->state_lock); + ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M3); + spin_unlock_bh(&mhi_cntrl->state_lock); + + if (ret) + return ret; + + /* Signal host that the device moved to M3 */ + ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M3); + if (ret) { + dev_err(dev, "Failed sending M3 state change event\n"); + return ret; + } + + return 0; +} + +int mhi_ep_set_ready_state(struct mhi_ep_cntrl *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_state mhi_state; + int ret, is_ready; + + spin_lock_bh(&mhi_cntrl->state_lock); + /* Ensure that the MHISTATUS is set to RESET by host */ + mhi_state = mhi_ep_mmio_masked_read(mhi_cntrl, EP_MHISTATUS, MHISTATUS_MHISTATE_MASK); + is_ready = mhi_ep_mmio_masked_read(mhi_cntrl, EP_MHISTATUS, MHISTATUS_READY_MASK); + + if (mhi_state != MHI_STATE_RESET || is_ready) { + dev_err(dev, "READY state transition failed. MHI host not in RESET state\n"); + spin_unlock_bh(&mhi_cntrl->state_lock); + return -EIO; + } + + ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_READY); + spin_unlock_bh(&mhi_cntrl->state_lock); + + return ret; +} diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h index 46236ffb528a..2880d2aa88b8 100644 --- a/include/linux/mhi_ep.h +++ b/include/linux/mhi_ep.h @@ -67,6 +67,11 @@ struct mhi_ep_db_info { * @cmd_ctx_host_pa: Physical address of host command context data structure * @chdb: Array of channel doorbell interrupt info * @event_lock: Lock for protecting event rings + * @list_lock: Lock for protecting state transition and channel doorbell lists + * @state_lock: Lock for protecting state transitions + * @st_transition_list: List of state transitions + * @wq: Dedicated workqueue for handling rings and state changes + * @state_work: State transition worker * @raise_irq: CB function for raising IRQ to the host * @alloc_map: CB function for allocating memory in endpoint for storing host context and mapping it * @unmap_free: CB function to unmap and free the allocated memory in endpoint for storing host context @@ -100,6 +105,13 @@ struct mhi_ep_cntrl { struct mhi_ep_db_info chdb[4]; struct mutex event_lock; + spinlock_t list_lock; + spinlock_t state_lock; + + struct list_head st_transition_list; + + struct workqueue_struct *wq; + struct work_struct state_work; void (*raise_irq)(struct mhi_ep_cntrl *mhi_cntrl, u32 vector); int (*alloc_map)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t *phys_ptr, |