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be8c936e54
Implements state machine to handle host & device sleep. Signed-off-by: M Chetan Kumar <m.chetan.kumar@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
334 lines
8.2 KiB
C
334 lines
8.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2020-21 Intel Corporation.
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*/
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#include "iosm_ipc_protocol.h"
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/* Timeout value in MS for the PM to wait for device to reach active state */
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#define IPC_PM_ACTIVE_TIMEOUT_MS (500)
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/* Note that here "active" has the value 1, as compared to the enums
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* ipc_mem_host_pm_state or ipc_mem_dev_pm_state, where "active" is 0
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*/
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#define IPC_PM_SLEEP (0)
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#define CONSUME_STATE (0)
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#define IPC_PM_ACTIVE (1)
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void ipc_pm_signal_hpda_doorbell(struct iosm_pm *ipc_pm, u32 identifier,
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bool host_slp_check)
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{
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if (host_slp_check && ipc_pm->host_pm_state != IPC_MEM_HOST_PM_ACTIVE &&
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ipc_pm->host_pm_state != IPC_MEM_HOST_PM_ACTIVE_WAIT) {
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ipc_pm->pending_hpda_update = true;
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dev_dbg(ipc_pm->dev,
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"Pend HPDA update set. Host PM_State: %d identifier:%d",
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ipc_pm->host_pm_state, identifier);
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return;
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}
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if (!ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_IRQ, true)) {
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ipc_pm->pending_hpda_update = true;
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dev_dbg(ipc_pm->dev, "Pending HPDA update set. identifier:%d",
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identifier);
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return;
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}
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ipc_pm->pending_hpda_update = false;
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/* Trigger the irq towards CP */
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ipc_cp_irq_hpda_update(ipc_pm->pcie, identifier);
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ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_IRQ, false);
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}
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/* Wake up the device if it is in low power mode. */
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static bool ipc_pm_link_activate(struct iosm_pm *ipc_pm)
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{
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if (ipc_pm->cp_state == IPC_MEM_DEV_PM_ACTIVE)
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return true;
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if (ipc_pm->cp_state == IPC_MEM_DEV_PM_SLEEP) {
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if (ipc_pm->ap_state == IPC_MEM_DEV_PM_SLEEP) {
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/* Wake up the device. */
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ipc_cp_irq_sleep_control(ipc_pm->pcie,
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IPC_MEM_DEV_PM_WAKEUP);
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ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE_WAIT;
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goto not_active;
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}
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if (ipc_pm->ap_state == IPC_MEM_DEV_PM_ACTIVE_WAIT)
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goto not_active;
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return true;
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}
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not_active:
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/* link is not ready */
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return false;
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}
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bool ipc_pm_wait_for_device_active(struct iosm_pm *ipc_pm)
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{
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bool ret_val = false;
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if (ipc_pm->ap_state != IPC_MEM_DEV_PM_ACTIVE) {
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/* Complete all memory stores before setting bit */
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smp_mb__before_atomic();
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/* Wait for IPC_PM_ACTIVE_TIMEOUT_MS for Device sleep state
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* machine to enter ACTIVE state.
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*/
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set_bit(0, &ipc_pm->host_sleep_pend);
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/* Complete all memory stores after setting bit */
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smp_mb__after_atomic();
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if (!wait_for_completion_interruptible_timeout
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(&ipc_pm->host_sleep_complete,
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msecs_to_jiffies(IPC_PM_ACTIVE_TIMEOUT_MS))) {
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dev_err(ipc_pm->dev,
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"PM timeout. Expected State:%d. Actual: %d",
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IPC_MEM_DEV_PM_ACTIVE, ipc_pm->ap_state);
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goto active_timeout;
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}
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}
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ret_val = true;
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active_timeout:
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/* Complete all memory stores before clearing bit */
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smp_mb__before_atomic();
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/* Reset the atomic variable in any case as device sleep
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* state machine change is no longer of interest.
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*/
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clear_bit(0, &ipc_pm->host_sleep_pend);
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/* Complete all memory stores after clearing bit */
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smp_mb__after_atomic();
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return ret_val;
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}
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static void ipc_pm_on_link_sleep(struct iosm_pm *ipc_pm)
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{
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/* pending sleep ack and all conditions are cleared
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* -> signal SLEEP__ACK to CP
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*/
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ipc_pm->cp_state = IPC_MEM_DEV_PM_SLEEP;
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ipc_pm->ap_state = IPC_MEM_DEV_PM_SLEEP;
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ipc_cp_irq_sleep_control(ipc_pm->pcie, IPC_MEM_DEV_PM_SLEEP);
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}
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static void ipc_pm_on_link_wake(struct iosm_pm *ipc_pm, bool ack)
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{
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ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE;
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if (ack) {
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ipc_pm->cp_state = IPC_MEM_DEV_PM_ACTIVE;
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ipc_cp_irq_sleep_control(ipc_pm->pcie, IPC_MEM_DEV_PM_ACTIVE);
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/* check the consume state !!! */
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if (test_bit(CONSUME_STATE, &ipc_pm->host_sleep_pend))
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complete(&ipc_pm->host_sleep_complete);
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}
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/* Check for pending HPDA update.
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* Pending HP update could be because of sending message was
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* put on hold due to Device sleep state or due to TD update
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* which could be because of Device Sleep and Host Sleep
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* states.
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*/
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if (ipc_pm->pending_hpda_update &&
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ipc_pm->host_pm_state == IPC_MEM_HOST_PM_ACTIVE)
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ipc_pm_signal_hpda_doorbell(ipc_pm, IPC_HP_PM_TRIGGER, true);
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}
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bool ipc_pm_trigger(struct iosm_pm *ipc_pm, enum ipc_pm_unit unit, bool active)
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{
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union ipc_pm_cond old_cond;
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union ipc_pm_cond new_cond;
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bool link_active;
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/* Save the current D3 state. */
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new_cond = ipc_pm->pm_cond;
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old_cond = ipc_pm->pm_cond;
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/* Calculate the power state only in the runtime phase. */
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switch (unit) {
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case IPC_PM_UNIT_IRQ: /* CP irq */
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new_cond.irq = active;
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break;
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case IPC_PM_UNIT_LINK: /* Device link state. */
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new_cond.link = active;
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break;
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case IPC_PM_UNIT_HS: /* Host sleep trigger requires Link. */
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new_cond.hs = active;
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break;
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default:
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break;
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}
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/* Something changed ? */
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if (old_cond.raw == new_cond.raw) {
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/* Stay in the current PM state. */
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link_active = old_cond.link == IPC_PM_ACTIVE;
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goto ret;
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}
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ipc_pm->pm_cond = new_cond;
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if (new_cond.link)
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ipc_pm_on_link_wake(ipc_pm, unit == IPC_PM_UNIT_LINK);
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else if (unit == IPC_PM_UNIT_LINK)
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ipc_pm_on_link_sleep(ipc_pm);
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if (old_cond.link == IPC_PM_SLEEP && new_cond.raw) {
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link_active = ipc_pm_link_activate(ipc_pm);
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goto ret;
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}
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link_active = old_cond.link == IPC_PM_ACTIVE;
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ret:
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return link_active;
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}
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bool ipc_pm_prepare_host_sleep(struct iosm_pm *ipc_pm)
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{
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/* suspend not allowed if host_pm_state is not IPC_MEM_HOST_PM_ACTIVE */
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if (ipc_pm->host_pm_state != IPC_MEM_HOST_PM_ACTIVE) {
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dev_err(ipc_pm->dev, "host_pm_state=%d\tExpected to be: %d",
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ipc_pm->host_pm_state, IPC_MEM_HOST_PM_ACTIVE);
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return false;
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}
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ipc_pm->host_pm_state = IPC_MEM_HOST_PM_SLEEP_WAIT_D3;
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return true;
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}
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bool ipc_pm_prepare_host_active(struct iosm_pm *ipc_pm)
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{
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if (ipc_pm->host_pm_state != IPC_MEM_HOST_PM_SLEEP) {
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dev_err(ipc_pm->dev, "host_pm_state=%d\tExpected to be: %d",
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ipc_pm->host_pm_state, IPC_MEM_HOST_PM_SLEEP);
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return false;
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}
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/* Sending Sleep Exit message to CP. Update the state */
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ipc_pm->host_pm_state = IPC_MEM_HOST_PM_ACTIVE_WAIT;
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return true;
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}
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void ipc_pm_set_s2idle_sleep(struct iosm_pm *ipc_pm, bool sleep)
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{
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if (sleep) {
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ipc_pm->ap_state = IPC_MEM_DEV_PM_SLEEP;
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ipc_pm->cp_state = IPC_MEM_DEV_PM_SLEEP;
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ipc_pm->device_sleep_notification = IPC_MEM_DEV_PM_SLEEP;
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} else {
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ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE;
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ipc_pm->cp_state = IPC_MEM_DEV_PM_ACTIVE;
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ipc_pm->device_sleep_notification = IPC_MEM_DEV_PM_ACTIVE;
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ipc_pm->pm_cond.link = IPC_PM_ACTIVE;
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}
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}
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bool ipc_pm_dev_slp_notification(struct iosm_pm *ipc_pm, u32 cp_pm_req)
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{
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if (cp_pm_req == ipc_pm->device_sleep_notification)
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return false;
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ipc_pm->device_sleep_notification = cp_pm_req;
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/* Evaluate the PM request. */
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switch (ipc_pm->cp_state) {
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case IPC_MEM_DEV_PM_ACTIVE:
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switch (cp_pm_req) {
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case IPC_MEM_DEV_PM_ACTIVE:
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break;
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case IPC_MEM_DEV_PM_SLEEP:
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/* Inform the PM that the device link can go down. */
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ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_LINK, false);
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return true;
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default:
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dev_err(ipc_pm->dev,
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"loc-pm=%d active: confused req-pm=%d",
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ipc_pm->cp_state, cp_pm_req);
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break;
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}
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break;
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case IPC_MEM_DEV_PM_SLEEP:
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switch (cp_pm_req) {
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case IPC_MEM_DEV_PM_ACTIVE:
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/* Inform the PM that the device link is active. */
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ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_LINK, true);
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break;
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case IPC_MEM_DEV_PM_SLEEP:
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break;
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default:
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dev_err(ipc_pm->dev,
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"loc-pm=%d sleep: confused req-pm=%d",
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ipc_pm->cp_state, cp_pm_req);
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break;
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}
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break;
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default:
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dev_err(ipc_pm->dev, "confused loc-pm=%d, req-pm=%d",
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ipc_pm->cp_state, cp_pm_req);
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break;
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}
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return false;
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}
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void ipc_pm_init(struct iosm_protocol *ipc_protocol)
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{
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struct iosm_imem *ipc_imem = ipc_protocol->imem;
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struct iosm_pm *ipc_pm = &ipc_protocol->pm;
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ipc_pm->pcie = ipc_imem->pcie;
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ipc_pm->dev = ipc_imem->dev;
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ipc_pm->pm_cond.irq = IPC_PM_SLEEP;
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ipc_pm->pm_cond.hs = IPC_PM_SLEEP;
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ipc_pm->pm_cond.link = IPC_PM_ACTIVE;
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ipc_pm->cp_state = IPC_MEM_DEV_PM_ACTIVE;
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ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE;
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ipc_pm->host_pm_state = IPC_MEM_HOST_PM_ACTIVE;
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/* Create generic wait-for-completion handler for Host Sleep
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* and device sleep coordination.
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*/
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init_completion(&ipc_pm->host_sleep_complete);
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/* Complete all memory stores before clearing bit */
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smp_mb__before_atomic();
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clear_bit(0, &ipc_pm->host_sleep_pend);
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/* Complete all memory stores after clearing bit */
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smp_mb__after_atomic();
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}
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void ipc_pm_deinit(struct iosm_protocol *proto)
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{
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struct iosm_pm *ipc_pm = &proto->pm;
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complete(&ipc_pm->host_sleep_complete);
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}
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