diff options
Diffstat (limited to 'drivers/bus/mhi/host/pm.c')
| -rw-r--r-- | drivers/bus/mhi/host/pm.c | 1162 |
1 files changed, 1162 insertions, 0 deletions
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c new file mode 100644 index 000000000..fe8ecd6ea --- /dev/null +++ b/drivers/bus/mhi/host/pm.c @@ -0,0 +1,1162 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved. + * + */ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/dma-direction.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/mhi.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/wait.h> +#include "internal.h" + +/* + * Not all MHI state transitions are synchronous. Transitions like Linkdown, + * SYS_ERR, and shutdown can happen anytime asynchronously. This function will + * transition to a new state only if we're allowed to. + * + * Priority increases as we go down. For instance, from any state in L0, the + * transition can be made to states in L1, L2 and L3. A notable exception to + * this rule is state DISABLE. From DISABLE state we can only transition to + * POR state. Also, while in L2 state, user cannot jump back to previous + * L1 or L0 states. + * + * Valid transitions: + * L0: DISABLE <--> POR + * POR <--> POR + * POR -> M0 -> M2 --> M0 + * POR -> FW_DL_ERR + * FW_DL_ERR <--> FW_DL_ERR + * M0 <--> M0 + * M0 -> FW_DL_ERR + * M0 -> M3_ENTER -> M3 -> M3_EXIT --> M0 + * L1: SYS_ERR_DETECT -> SYS_ERR_PROCESS --> POR + * L2: SHUTDOWN_PROCESS -> DISABLE + * L3: LD_ERR_FATAL_DETECT <--> LD_ERR_FATAL_DETECT + * LD_ERR_FATAL_DETECT -> SHUTDOWN_PROCESS + */ +static struct mhi_pm_transitions const dev_state_transitions[] = { + /* L0 States */ + { + MHI_PM_DISABLE, + MHI_PM_POR + }, + { + MHI_PM_POR, + MHI_PM_POR | MHI_PM_DISABLE | MHI_PM_M0 | + MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR + }, + { + MHI_PM_M0, + MHI_PM_M0 | MHI_PM_M2 | MHI_PM_M3_ENTER | + MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_FW_DL_ERR + }, + { + MHI_PM_M2, + MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT + }, + { + MHI_PM_M3_ENTER, + MHI_PM_M3 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT + }, + { + MHI_PM_M3, + MHI_PM_M3_EXIT | MHI_PM_SYS_ERR_DETECT | + MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT + }, + { + MHI_PM_M3_EXIT, + MHI_PM_M0 | MHI_PM_SYS_ERR_DETECT | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT + }, + { + MHI_PM_FW_DL_ERR, + MHI_PM_FW_DL_ERR | MHI_PM_SYS_ERR_DETECT | + MHI_PM_SHUTDOWN_PROCESS | MHI_PM_LD_ERR_FATAL_DETECT + }, + /* L1 States */ + { + MHI_PM_SYS_ERR_DETECT, + MHI_PM_SYS_ERR_PROCESS | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT + }, + { + MHI_PM_SYS_ERR_PROCESS, + MHI_PM_POR | MHI_PM_SHUTDOWN_PROCESS | + MHI_PM_LD_ERR_FATAL_DETECT + }, + /* L2 States */ + { + MHI_PM_SHUTDOWN_PROCESS, + MHI_PM_DISABLE | MHI_PM_LD_ERR_FATAL_DETECT + }, + /* L3 States */ + { + MHI_PM_LD_ERR_FATAL_DETECT, + MHI_PM_LD_ERR_FATAL_DETECT | MHI_PM_SHUTDOWN_PROCESS + }, +}; + +enum mhi_pm_state __must_check mhi_tryset_pm_state(struct mhi_controller *mhi_cntrl, + enum mhi_pm_state state) +{ + unsigned long cur_state = mhi_cntrl->pm_state; + int index = find_last_bit(&cur_state, 32); + + if (unlikely(index >= ARRAY_SIZE(dev_state_transitions))) + return cur_state; + + if (unlikely(dev_state_transitions[index].from_state != cur_state)) + return cur_state; + + if (unlikely(!(dev_state_transitions[index].to_states & state))) + return cur_state; + + mhi_cntrl->pm_state = state; + return mhi_cntrl->pm_state; +} + +void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl, enum mhi_state state) +{ + if (state == MHI_STATE_RESET) { + mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL, + MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 1); + } else { + mhi_write_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL, + MHICTRL_MHISTATE_MASK, + MHICTRL_MHISTATE_SHIFT, state); + } +} + +/* NOP for backward compatibility, host allowed to ring DB in M2 state */ +static void mhi_toggle_dev_wake_nop(struct mhi_controller *mhi_cntrl) +{ +} + +static void mhi_toggle_dev_wake(struct mhi_controller *mhi_cntrl) +{ + mhi_cntrl->wake_get(mhi_cntrl, false); + mhi_cntrl->wake_put(mhi_cntrl, true); +} + +/* Handle device ready state transition */ +int mhi_ready_state_transition(struct mhi_controller *mhi_cntrl) +{ + void __iomem *base = mhi_cntrl->regs; + struct mhi_event *mhi_event; + enum mhi_pm_state cur_state; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + u32 reset = 1, ready = 0; + int ret, i; + + /* Wait for RESET to be cleared and READY bit to be set by the device */ + wait_event_timeout(mhi_cntrl->state_event, + MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) || + mhi_read_reg_field(mhi_cntrl, base, MHICTRL, + MHICTRL_RESET_MASK, + MHICTRL_RESET_SHIFT, &reset) || + mhi_read_reg_field(mhi_cntrl, base, MHISTATUS, + MHISTATUS_READY_MASK, + MHISTATUS_READY_SHIFT, &ready) || + (!reset && ready), + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + + /* Check if device entered error state */ + if (MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) { + dev_err(dev, "Device link is not accessible\n"); + return -EIO; + } + + /* Timeout if device did not transition to ready state */ + if (reset || !ready) { + dev_err(dev, "Device Ready timeout\n"); + return -ETIMEDOUT; + } + + dev_dbg(dev, "Device in READY State\n"); + write_lock_irq(&mhi_cntrl->pm_lock); + cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_POR); + mhi_cntrl->dev_state = MHI_STATE_READY; + write_unlock_irq(&mhi_cntrl->pm_lock); + + if (cur_state != MHI_PM_POR) { + dev_err(dev, "Error moving to state %s from %s\n", + to_mhi_pm_state_str(MHI_PM_POR), + to_mhi_pm_state_str(cur_state)); + return -EIO; + } + + read_lock_bh(&mhi_cntrl->pm_lock); + if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) { + dev_err(dev, "Device registers not accessible\n"); + goto error_mmio; + } + + /* Configure MMIO registers */ + ret = mhi_init_mmio(mhi_cntrl); + if (ret) { + dev_err(dev, "Error configuring MMIO registers\n"); + goto error_mmio; + } + + /* Add elements to all SW event rings */ + mhi_event = mhi_cntrl->mhi_event; + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { + struct mhi_ring *ring = &mhi_event->ring; + + /* Skip if this is an offload or HW event */ + if (mhi_event->offload_ev || mhi_event->hw_ring) + continue; + + ring->wp = ring->base + ring->len - ring->el_size; + *ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size; + /* Update all cores */ + smp_wmb(); + + /* Ring the event ring db */ + spin_lock_irq(&mhi_event->lock); + mhi_ring_er_db(mhi_event); + spin_unlock_irq(&mhi_event->lock); + } + + /* Set MHI to M0 state */ + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M0); + read_unlock_bh(&mhi_cntrl->pm_lock); + + return 0; + +error_mmio: + read_unlock_bh(&mhi_cntrl->pm_lock); + + return -EIO; +} + +int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl) +{ + enum mhi_pm_state cur_state; + struct mhi_chan *mhi_chan; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int i; + + write_lock_irq(&mhi_cntrl->pm_lock); + mhi_cntrl->dev_state = MHI_STATE_M0; + cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M0); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (unlikely(cur_state != MHI_PM_M0)) { + dev_err(dev, "Unable to transition to M0 state\n"); + return -EIO; + } + mhi_cntrl->M0++; + + /* Wake up the device */ + read_lock_bh(&mhi_cntrl->pm_lock); + mhi_cntrl->wake_get(mhi_cntrl, true); + + /* Ring all event rings and CMD ring only if we're in mission mode */ + if (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) { + struct mhi_event *mhi_event = mhi_cntrl->mhi_event; + struct mhi_cmd *mhi_cmd = + &mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING]; + + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { + if (mhi_event->offload_ev) + continue; + + spin_lock_irq(&mhi_event->lock); + mhi_ring_er_db(mhi_event); + spin_unlock_irq(&mhi_event->lock); + } + + /* Only ring primary cmd ring if ring is not empty */ + spin_lock_irq(&mhi_cmd->lock); + if (mhi_cmd->ring.rp != mhi_cmd->ring.wp) + mhi_ring_cmd_db(mhi_cntrl, mhi_cmd); + spin_unlock_irq(&mhi_cmd->lock); + } + + /* Ring channel DB registers */ + mhi_chan = mhi_cntrl->mhi_chan; + for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) { + struct mhi_ring *tre_ring = &mhi_chan->tre_ring; + + if (mhi_chan->db_cfg.reset_req) { + write_lock_irq(&mhi_chan->lock); + mhi_chan->db_cfg.db_mode = true; + write_unlock_irq(&mhi_chan->lock); + } + + read_lock_irq(&mhi_chan->lock); + + /* Only ring DB if ring is not empty */ + if (tre_ring->base && tre_ring->wp != tre_ring->rp && + mhi_chan->ch_state == MHI_CH_STATE_ENABLED) + mhi_ring_chan_db(mhi_cntrl, mhi_chan); + read_unlock_irq(&mhi_chan->lock); + } + + mhi_cntrl->wake_put(mhi_cntrl, false); + read_unlock_bh(&mhi_cntrl->pm_lock); + wake_up_all(&mhi_cntrl->state_event); + + return 0; +} + +/* + * After receiving the MHI state change event from the device indicating the + * transition to M1 state, the host can transition the device to M2 state + * for keeping it in low power state. + */ +void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl) +{ + enum mhi_pm_state state; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + + write_lock_irq(&mhi_cntrl->pm_lock); + state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M2); + if (state == MHI_PM_M2) { + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M2); + mhi_cntrl->dev_state = MHI_STATE_M2; + + write_unlock_irq(&mhi_cntrl->pm_lock); + + mhi_cntrl->M2++; + wake_up_all(&mhi_cntrl->state_event); + + /* If there are any pending resources, exit M2 immediately */ + if (unlikely(atomic_read(&mhi_cntrl->pending_pkts) || + atomic_read(&mhi_cntrl->dev_wake))) { + dev_dbg(dev, + "Exiting M2, pending_pkts: %d dev_wake: %d\n", + atomic_read(&mhi_cntrl->pending_pkts), + atomic_read(&mhi_cntrl->dev_wake)); + read_lock_bh(&mhi_cntrl->pm_lock); + mhi_cntrl->wake_get(mhi_cntrl, true); + mhi_cntrl->wake_put(mhi_cntrl, true); + read_unlock_bh(&mhi_cntrl->pm_lock); + } else { + mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_IDLE); + } + } else { + write_unlock_irq(&mhi_cntrl->pm_lock); + } +} + +/* MHI M3 completion handler */ +int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl) +{ + enum mhi_pm_state state; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + + write_lock_irq(&mhi_cntrl->pm_lock); + mhi_cntrl->dev_state = MHI_STATE_M3; + state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (state != MHI_PM_M3) { + dev_err(dev, "Unable to transition to M3 state\n"); + return -EIO; + } + + mhi_cntrl->M3++; + wake_up_all(&mhi_cntrl->state_event); + + return 0; +} + +/* Handle device Mission Mode transition */ +static int mhi_pm_mission_mode_transition(struct mhi_controller *mhi_cntrl) +{ + struct mhi_event *mhi_event; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_ee_type current_ee = mhi_cntrl->ee; + int i, ret; + + dev_dbg(dev, "Processing Mission Mode transition\n"); + + write_lock_irq(&mhi_cntrl->pm_lock); + if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) + mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl); + write_unlock_irq(&mhi_cntrl->pm_lock); + + if (!MHI_IN_MISSION_MODE(mhi_cntrl->ee)) + return -EIO; + + wake_up_all(&mhi_cntrl->state_event); + + device_for_each_child(&mhi_cntrl->mhi_dev->dev, ¤t_ee, + mhi_destroy_device); + mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_MISSION_MODE); + + /* Force MHI to be in M0 state before continuing */ + ret = __mhi_device_get_sync(mhi_cntrl); + if (ret) + return ret; + + read_lock_bh(&mhi_cntrl->pm_lock); + + if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { + ret = -EIO; + goto error_mission_mode; + } + + /* Add elements to all HW event rings */ + mhi_event = mhi_cntrl->mhi_event; + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { + struct mhi_ring *ring = &mhi_event->ring; + + if (mhi_event->offload_ev || !mhi_event->hw_ring) + continue; + + ring->wp = ring->base + ring->len - ring->el_size; + *ring->ctxt_wp = ring->iommu_base + ring->len - ring->el_size; + /* Update to all cores */ + smp_wmb(); + + spin_lock_irq(&mhi_event->lock); + if (MHI_DB_ACCESS_VALID(mhi_cntrl)) + mhi_ring_er_db(mhi_event); + spin_unlock_irq(&mhi_event->lock); + } + + read_unlock_bh(&mhi_cntrl->pm_lock); + + /* + * The MHI devices are only created when the client device switches its + * Execution Environment (EE) to either SBL or AMSS states + */ + mhi_create_devices(mhi_cntrl); + + read_lock_bh(&mhi_cntrl->pm_lock); + +error_mission_mode: + mhi_cntrl->wake_put(mhi_cntrl, false); + read_unlock_bh(&mhi_cntrl->pm_lock); + + return ret; +} + +/* Handle SYS_ERR and Shutdown transitions */ +static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, + enum mhi_pm_state transition_state) +{ + enum mhi_pm_state cur_state, prev_state; + struct mhi_event *mhi_event; + struct mhi_cmd_ctxt *cmd_ctxt; + struct mhi_cmd *mhi_cmd; + struct mhi_event_ctxt *er_ctxt; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret, i; + + dev_dbg(dev, "Transitioning from PM state: %s to: %s\n", + to_mhi_pm_state_str(mhi_cntrl->pm_state), + to_mhi_pm_state_str(transition_state)); + + /* We must notify MHI control driver so it can clean up first */ + if (transition_state == MHI_PM_SYS_ERR_PROCESS) + mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR); + + mutex_lock(&mhi_cntrl->pm_mutex); + write_lock_irq(&mhi_cntrl->pm_lock); + prev_state = mhi_cntrl->pm_state; + cur_state = mhi_tryset_pm_state(mhi_cntrl, transition_state); + if (cur_state == transition_state) { + mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION; + mhi_cntrl->dev_state = MHI_STATE_RESET; + } + write_unlock_irq(&mhi_cntrl->pm_lock); + + /* Wake up threads waiting for state transition */ + wake_up_all(&mhi_cntrl->state_event); + + if (cur_state != transition_state) { + dev_err(dev, "Failed to transition to state: %s from: %s\n", + to_mhi_pm_state_str(transition_state), + to_mhi_pm_state_str(cur_state)); + mutex_unlock(&mhi_cntrl->pm_mutex); + return; + } + + /* Trigger MHI RESET so that the device will not access host memory */ + if (MHI_REG_ACCESS_VALID(prev_state)) { + u32 in_reset = -1; + unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms); + + /* Skip MHI RESET if in RDDM state */ + if (mhi_cntrl->rddm_image && mhi_get_exec_env(mhi_cntrl) == MHI_EE_RDDM) + goto skip_mhi_reset; + + dev_dbg(dev, "Triggering MHI Reset in device\n"); + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET); + + /* Wait for the reset bit to be cleared by the device */ + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_read_reg_field(mhi_cntrl, + mhi_cntrl->regs, + MHICTRL, + MHICTRL_RESET_MASK, + MHICTRL_RESET_SHIFT, + &in_reset) || + !in_reset, timeout); + if ((!ret || in_reset) && cur_state == MHI_PM_SYS_ERR_PROCESS) { + dev_err(dev, "Device failed to exit MHI Reset state\n"); + mutex_unlock(&mhi_cntrl->pm_mutex); + return; + } + + /* + * Device will clear BHI_INTVEC as a part of RESET processing, + * hence re-program it + */ + mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0); + } + +skip_mhi_reset: + dev_dbg(dev, + "Waiting for all pending event ring processing to complete\n"); + mhi_event = mhi_cntrl->mhi_event; + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { + if (mhi_event->offload_ev) + continue; + tasklet_kill(&mhi_event->task); + } + + /* Release lock and wait for all pending threads to complete */ + mutex_unlock(&mhi_cntrl->pm_mutex); + 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->cntrl_dev, NULL, mhi_destroy_device); + + mutex_lock(&mhi_cntrl->pm_mutex); + + WARN_ON(atomic_read(&mhi_cntrl->dev_wake)); + WARN_ON(atomic_read(&mhi_cntrl->pending_pkts)); + + /* Reset the ev rings and cmd rings */ + dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n"); + mhi_cmd = mhi_cntrl->mhi_cmd; + cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt; + for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) { + struct mhi_ring *ring = &mhi_cmd->ring; + + ring->rp = ring->base; + ring->wp = ring->base; + cmd_ctxt->rp = cmd_ctxt->rbase; + cmd_ctxt->wp = cmd_ctxt->rbase; + } + + mhi_event = mhi_cntrl->mhi_event; + er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt; + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++, + mhi_event++) { + struct mhi_ring *ring = &mhi_event->ring; + + /* Skip offload events */ + if (mhi_event->offload_ev) + continue; + + ring->rp = ring->base; + ring->wp = ring->base; + er_ctxt->rp = er_ctxt->rbase; + er_ctxt->wp = er_ctxt->rbase; + } + + if (cur_state == MHI_PM_SYS_ERR_PROCESS) { + mhi_ready_state_transition(mhi_cntrl); + } else { + /* Move to disable state */ + write_lock_irq(&mhi_cntrl->pm_lock); + cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (unlikely(cur_state != MHI_PM_DISABLE)) + dev_err(dev, "Error moving from PM state: %s to: %s\n", + to_mhi_pm_state_str(cur_state), + to_mhi_pm_state_str(MHI_PM_DISABLE)); + } + + dev_dbg(dev, "Exiting 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)); + + mutex_unlock(&mhi_cntrl->pm_mutex); +} + +/* Queue a new work item and schedule work */ +int mhi_queue_state_transition(struct mhi_controller *mhi_cntrl, + enum dev_st_transition state) +{ + struct state_transition *item = kmalloc(sizeof(*item), GFP_ATOMIC); + unsigned long flags; + + if (!item) + return -ENOMEM; + + item->state = state; + spin_lock_irqsave(&mhi_cntrl->transition_lock, flags); + list_add_tail(&item->node, &mhi_cntrl->transition_list); + spin_unlock_irqrestore(&mhi_cntrl->transition_lock, flags); + + schedule_work(&mhi_cntrl->st_worker); + + return 0; +} + +/* SYS_ERR worker */ +void mhi_pm_sys_err_handler(struct mhi_controller *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + + /* skip if controller supports RDDM */ + if (mhi_cntrl->rddm_image) { + dev_dbg(dev, "Controller supports RDDM, skip SYS_ERROR\n"); + return; + } + + mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_SYS_ERR); +} + +/* Device State Transition worker */ +void mhi_pm_st_worker(struct work_struct *work) +{ + struct state_transition *itr, *tmp; + LIST_HEAD(head); + struct mhi_controller *mhi_cntrl = container_of(work, + struct mhi_controller, + st_worker); + struct device *dev = &mhi_cntrl->mhi_dev->dev; + + spin_lock_irq(&mhi_cntrl->transition_lock); + list_splice_tail_init(&mhi_cntrl->transition_list, &head); + spin_unlock_irq(&mhi_cntrl->transition_lock); + + list_for_each_entry_safe(itr, tmp, &head, node) { + list_del(&itr->node); + dev_dbg(dev, "Handling state transition: %s\n", + TO_DEV_STATE_TRANS_STR(itr->state)); + + switch (itr->state) { + case DEV_ST_TRANSITION_PBL: + write_lock_irq(&mhi_cntrl->pm_lock); + if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) + mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (MHI_IN_PBL(mhi_cntrl->ee)) + mhi_fw_load_handler(mhi_cntrl); + break; + case DEV_ST_TRANSITION_SBL: + write_lock_irq(&mhi_cntrl->pm_lock); + mhi_cntrl->ee = MHI_EE_SBL; + write_unlock_irq(&mhi_cntrl->pm_lock); + /* + * The MHI devices are only created when the client + * device switches its Execution Environment (EE) to + * either SBL or AMSS states + */ + mhi_create_devices(mhi_cntrl); + break; + case DEV_ST_TRANSITION_MISSION_MODE: + mhi_pm_mission_mode_transition(mhi_cntrl); + break; + case DEV_ST_TRANSITION_READY: + mhi_ready_state_transition(mhi_cntrl); + break; + case DEV_ST_TRANSITION_SYS_ERR: + mhi_pm_disable_transition + (mhi_cntrl, MHI_PM_SYS_ERR_PROCESS); + break; + case DEV_ST_TRANSITION_DISABLE: + mhi_pm_disable_transition + (mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS); + break; + default: + break; + } + kfree(itr); + } +} + +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) || + atomic_read(&mhi_cntrl->pending_pkts)) + 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) || + atomic_read(&mhi_cntrl->pending_pkts)) { + 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_cntrl->dev_state == MHI_STATE_M2 || + 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; + + /* Wake up the device */ + read_lock_bh(&mhi_cntrl->pm_lock); + mhi_cntrl->wake_get(mhi_cntrl, true); + if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) + mhi_trigger_resume(mhi_cntrl); + read_unlock_bh(&mhi_cntrl->pm_lock); + + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_cntrl->pm_state == MHI_PM_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)) { + read_lock_bh(&mhi_cntrl->pm_lock); + mhi_cntrl->wake_put(mhi_cntrl, false); + read_unlock_bh(&mhi_cntrl->pm_lock); + return -EIO; + } + + return 0; +} + +/* Assert device wake db */ +static void mhi_assert_dev_wake(struct mhi_controller *mhi_cntrl, bool force) +{ + unsigned long flags; + + /* + * If force flag is set, then increment the wake count value and + * ring wake db + */ + if (unlikely(force)) { + spin_lock_irqsave(&mhi_cntrl->wlock, flags); + atomic_inc(&mhi_cntrl->dev_wake); + if (MHI_WAKE_DB_FORCE_SET_VALID(mhi_cntrl->pm_state) && + !mhi_cntrl->wake_set) { + mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 1); + mhi_cntrl->wake_set = true; + } + spin_unlock_irqrestore(&mhi_cntrl->wlock, flags); + } else { + /* + * If resources are already requested, then just increment + * the wake count value and return + */ + if (likely(atomic_add_unless(&mhi_cntrl->dev_wake, 1, 0))) + return; + + spin_lock_irqsave(&mhi_cntrl->wlock, flags); + if ((atomic_inc_return(&mhi_cntrl->dev_wake) == 1) && + MHI_WAKE_DB_SET_VALID(mhi_cntrl->pm_state) && + !mhi_cntrl->wake_set) { + mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 1); + mhi_cntrl->wake_set = true; + } + spin_unlock_irqrestore(&mhi_cntrl->wlock, flags); + } +} + +/* De-assert device wake db */ +static void mhi_deassert_dev_wake(struct mhi_controller *mhi_cntrl, + bool override) +{ + unsigned long flags; + + /* + * Only continue if there is a single resource, else just decrement + * and return + */ + if (likely(atomic_add_unless(&mhi_cntrl->dev_wake, -1, 1))) + return; + + spin_lock_irqsave(&mhi_cntrl->wlock, flags); + if ((atomic_dec_return(&mhi_cntrl->dev_wake) == 0) && + MHI_WAKE_DB_CLEAR_VALID(mhi_cntrl->pm_state) && !override && + mhi_cntrl->wake_set) { + mhi_write_db(mhi_cntrl, mhi_cntrl->wake_db, 0); + mhi_cntrl->wake_set = false; + } + spin_unlock_irqrestore(&mhi_cntrl->wlock, flags); +} + +int mhi_async_power_up(struct mhi_controller *mhi_cntrl) +{ + enum mhi_state state; + enum mhi_ee_type current_ee; + enum dev_st_transition next_state; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + u32 val; + int ret; + + dev_info(dev, "Requested to power ON\n"); + + if (mhi_cntrl->nr_irqs < 1) + return -EINVAL; + + /* Supply default wake routines if not provided by controller driver */ + if (!mhi_cntrl->wake_get || !mhi_cntrl->wake_put || + !mhi_cntrl->wake_toggle) { + mhi_cntrl->wake_get = mhi_assert_dev_wake; + mhi_cntrl->wake_put = mhi_deassert_dev_wake; + mhi_cntrl->wake_toggle = (mhi_cntrl->db_access & MHI_PM_M2) ? + mhi_toggle_dev_wake_nop : mhi_toggle_dev_wake; + } + + mutex_lock(&mhi_cntrl->pm_mutex); + mhi_cntrl->pm_state = MHI_PM_DISABLE; + + if (!mhi_cntrl->pre_init) { + /* Setup device context */ + ret = mhi_init_dev_ctxt(mhi_cntrl); + if (ret) + goto error_dev_ctxt; + } + + ret = mhi_init_irq_setup(mhi_cntrl); + if (ret) + goto error_setup_irq; + + /* Setup BHI offset & INTVEC */ + write_lock_irq(&mhi_cntrl->pm_lock); + ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIOFF, &val); + if (ret) { + write_unlock_irq(&mhi_cntrl->pm_lock); + goto error_bhi_offset; + } + + mhi_cntrl->bhi = mhi_cntrl->regs + val; + + /* Setup BHIE offset */ + if (mhi_cntrl->fbc_download) { + ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF, &val); + if (ret) { + write_unlock_irq(&mhi_cntrl->pm_lock); + dev_err(dev, "Error reading BHIE offset\n"); + goto error_bhi_offset; + } + + mhi_cntrl->bhie = mhi_cntrl->regs + val; + } + + mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0); + mhi_cntrl->pm_state = MHI_PM_POR; + mhi_cntrl->ee = MHI_EE_MAX; + current_ee = mhi_get_exec_env(mhi_cntrl); + write_unlock_irq(&mhi_cntrl->pm_lock); + + /* Confirm that the device is in valid exec env */ + if (!MHI_IN_PBL(current_ee) && current_ee != MHI_EE_AMSS) { + dev_err(dev, "Not a valid EE for power on\n"); + ret = -EIO; + goto error_bhi_offset; + } + + state = mhi_get_mhi_state(mhi_cntrl); + if (state == MHI_STATE_SYS_ERR) { + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET); + ret = wait_event_timeout(mhi_cntrl->state_event, + MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) || + mhi_read_reg_field(mhi_cntrl, + mhi_cntrl->regs, + MHICTRL, + MHICTRL_RESET_MASK, + MHICTRL_RESET_SHIFT, + &val) || + !val, + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + if (!ret) { + ret = -EIO; + dev_info(dev, "Failed to reset MHI due to syserr state\n"); + goto error_bhi_offset; + } + + /* + * device cleares INTVEC as part of RESET processing, + * re-program it + */ + mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0); + } + + /* Transition to next state */ + next_state = MHI_IN_PBL(current_ee) ? + DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY; + + mhi_queue_state_transition(mhi_cntrl, next_state); + + mutex_unlock(&mhi_cntrl->pm_mutex); + + dev_info(dev, "Power on setup success\n"); + + return 0; + +error_bhi_offset: + mhi_deinit_free_irq(mhi_cntrl); + +error_setup_irq: + if (!mhi_cntrl->pre_init) + mhi_deinit_dev_ctxt(mhi_cntrl); + +error_dev_ctxt: + mutex_unlock(&mhi_cntrl->pm_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_async_power_up); + +void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful) +{ + enum mhi_pm_state cur_state; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + + /* If it's not a graceful shutdown, force MHI to linkdown state */ + if (!graceful) { + mutex_lock(&mhi_cntrl->pm_mutex); + write_lock_irq(&mhi_cntrl->pm_lock); + cur_state = mhi_tryset_pm_state(mhi_cntrl, + MHI_PM_LD_ERR_FATAL_DETECT); + write_unlock_irq(&mhi_cntrl->pm_lock); + mutex_unlock(&mhi_cntrl->pm_mutex); + if (cur_state != MHI_PM_LD_ERR_FATAL_DETECT) + dev_dbg(dev, "Failed to move to state: %s from: %s\n", + to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT), + to_mhi_pm_state_str(mhi_cntrl->pm_state)); + } + + mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE); + + /* Wait for shutdown to complete */ + flush_work(&mhi_cntrl->st_worker); + + mhi_deinit_free_irq(mhi_cntrl); + + if (!mhi_cntrl->pre_init) { + /* Free all allocated resources */ + if (mhi_cntrl->fbc_image) { + mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image); + mhi_cntrl->fbc_image = NULL; + } + mhi_deinit_dev_ctxt(mhi_cntrl); + } +} +EXPORT_SYMBOL_GPL(mhi_power_down); + +int mhi_sync_power_up(struct mhi_controller *mhi_cntrl) +{ + int ret = mhi_async_power_up(mhi_cntrl); + + if (ret) + return ret; + + wait_event_timeout(mhi_cntrl->state_event, + MHI_IN_MISSION_MODE(mhi_cntrl->ee) || + MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state), + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + + ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT; + if (ret) + mhi_power_down(mhi_cntrl, false); + + return ret; +} +EXPORT_SYMBOL(mhi_sync_power_up); + +int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl) +{ + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret; + + /* Check if device is already in RDDM */ + if (mhi_cntrl->ee == MHI_EE_RDDM) + return 0; + + dev_dbg(dev, "Triggering SYS_ERR to force RDDM state\n"); + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR); + + /* Wait for RDDM event */ + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_cntrl->ee == MHI_EE_RDDM, + msecs_to_jiffies(mhi_cntrl->timeout_ms)); + ret = ret ? 0 : -EIO; + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_force_rddm_mode); + +void mhi_device_get(struct mhi_device *mhi_dev) +{ + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; + + mhi_dev->dev_wake++; + read_lock_bh(&mhi_cntrl->pm_lock); + if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) + mhi_trigger_resume(mhi_cntrl); + + mhi_cntrl->wake_get(mhi_cntrl, true); + read_unlock_bh(&mhi_cntrl->pm_lock); +} +EXPORT_SYMBOL_GPL(mhi_device_get); + +int mhi_device_get_sync(struct mhi_device *mhi_dev) +{ + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; + int ret; + + ret = __mhi_device_get_sync(mhi_cntrl); + if (!ret) + mhi_dev->dev_wake++; + + return ret; +} +EXPORT_SYMBOL_GPL(mhi_device_get_sync); + +void mhi_device_put(struct mhi_device *mhi_dev) +{ + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; + + mhi_dev->dev_wake--; + read_lock_bh(&mhi_cntrl->pm_lock); + if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) + mhi_trigger_resume(mhi_cntrl); + + mhi_cntrl->wake_put(mhi_cntrl, false); + read_unlock_bh(&mhi_cntrl->pm_lock); +} +EXPORT_SYMBOL_GPL(mhi_device_put); |