From be8c936e540fe6e60d03fa1578205c936e71335b Mon Sep 17 00:00:00 2001 From: M Chetan Kumar Date: Sun, 13 Jun 2021 18:20:18 +0530 Subject: net: iosm: power management Implements state machine to handle host & device sleep. Signed-off-by: M Chetan Kumar Signed-off-by: David S. Miller --- drivers/net/wwan/iosm/iosm_ipc_pm.c | 333 ++++++++++++++++++++++++++++++++++++ drivers/net/wwan/iosm/iosm_ipc_pm.h | 207 ++++++++++++++++++++++ 2 files changed, 540 insertions(+) create mode 100644 drivers/net/wwan/iosm/iosm_ipc_pm.c create mode 100644 drivers/net/wwan/iosm/iosm_ipc_pm.h (limited to 'drivers/net/wwan/iosm') diff --git a/drivers/net/wwan/iosm/iosm_ipc_pm.c b/drivers/net/wwan/iosm/iosm_ipc_pm.c new file mode 100644 index 000000000000..413601c72dcd --- /dev/null +++ b/drivers/net/wwan/iosm/iosm_ipc_pm.c @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020-21 Intel Corporation. + */ + +#include "iosm_ipc_protocol.h" + +/* Timeout value in MS for the PM to wait for device to reach active state */ +#define IPC_PM_ACTIVE_TIMEOUT_MS (500) + +/* Note that here "active" has the value 1, as compared to the enums + * ipc_mem_host_pm_state or ipc_mem_dev_pm_state, where "active" is 0 + */ +#define IPC_PM_SLEEP (0) +#define CONSUME_STATE (0) +#define IPC_PM_ACTIVE (1) + +void ipc_pm_signal_hpda_doorbell(struct iosm_pm *ipc_pm, u32 identifier, + bool host_slp_check) +{ + if (host_slp_check && ipc_pm->host_pm_state != IPC_MEM_HOST_PM_ACTIVE && + ipc_pm->host_pm_state != IPC_MEM_HOST_PM_ACTIVE_WAIT) { + ipc_pm->pending_hpda_update = true; + dev_dbg(ipc_pm->dev, + "Pend HPDA update set. Host PM_State: %d identifier:%d", + ipc_pm->host_pm_state, identifier); + return; + } + + if (!ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_IRQ, true)) { + ipc_pm->pending_hpda_update = true; + dev_dbg(ipc_pm->dev, "Pending HPDA update set. identifier:%d", + identifier); + return; + } + ipc_pm->pending_hpda_update = false; + + /* Trigger the irq towards CP */ + ipc_cp_irq_hpda_update(ipc_pm->pcie, identifier); + + ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_IRQ, false); +} + +/* Wake up the device if it is in low power mode. */ +static bool ipc_pm_link_activate(struct iosm_pm *ipc_pm) +{ + if (ipc_pm->cp_state == IPC_MEM_DEV_PM_ACTIVE) + return true; + + if (ipc_pm->cp_state == IPC_MEM_DEV_PM_SLEEP) { + if (ipc_pm->ap_state == IPC_MEM_DEV_PM_SLEEP) { + /* Wake up the device. */ + ipc_cp_irq_sleep_control(ipc_pm->pcie, + IPC_MEM_DEV_PM_WAKEUP); + ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE_WAIT; + + goto not_active; + } + + if (ipc_pm->ap_state == IPC_MEM_DEV_PM_ACTIVE_WAIT) + goto not_active; + + return true; + } + +not_active: + /* link is not ready */ + return false; +} + +bool ipc_pm_wait_for_device_active(struct iosm_pm *ipc_pm) +{ + bool ret_val = false; + + if (ipc_pm->ap_state != IPC_MEM_DEV_PM_ACTIVE) { + /* Complete all memory stores before setting bit */ + smp_mb__before_atomic(); + + /* Wait for IPC_PM_ACTIVE_TIMEOUT_MS for Device sleep state + * machine to enter ACTIVE state. + */ + set_bit(0, &ipc_pm->host_sleep_pend); + + /* Complete all memory stores after setting bit */ + smp_mb__after_atomic(); + + if (!wait_for_completion_interruptible_timeout + (&ipc_pm->host_sleep_complete, + msecs_to_jiffies(IPC_PM_ACTIVE_TIMEOUT_MS))) { + dev_err(ipc_pm->dev, + "PM timeout. Expected State:%d. Actual: %d", + IPC_MEM_DEV_PM_ACTIVE, ipc_pm->ap_state); + goto active_timeout; + } + } + + ret_val = true; +active_timeout: + /* Complete all memory stores before clearing bit */ + smp_mb__before_atomic(); + + /* Reset the atomic variable in any case as device sleep + * state machine change is no longer of interest. + */ + clear_bit(0, &ipc_pm->host_sleep_pend); + + /* Complete all memory stores after clearing bit */ + smp_mb__after_atomic(); + + return ret_val; +} + +static void ipc_pm_on_link_sleep(struct iosm_pm *ipc_pm) +{ + /* pending sleep ack and all conditions are cleared + * -> signal SLEEP__ACK to CP + */ + ipc_pm->cp_state = IPC_MEM_DEV_PM_SLEEP; + ipc_pm->ap_state = IPC_MEM_DEV_PM_SLEEP; + + ipc_cp_irq_sleep_control(ipc_pm->pcie, IPC_MEM_DEV_PM_SLEEP); +} + +static void ipc_pm_on_link_wake(struct iosm_pm *ipc_pm, bool ack) +{ + ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE; + + if (ack) { + ipc_pm->cp_state = IPC_MEM_DEV_PM_ACTIVE; + + ipc_cp_irq_sleep_control(ipc_pm->pcie, IPC_MEM_DEV_PM_ACTIVE); + + /* check the consume state !!! */ + if (test_bit(CONSUME_STATE, &ipc_pm->host_sleep_pend)) + complete(&ipc_pm->host_sleep_complete); + } + + /* Check for pending HPDA update. + * Pending HP update could be because of sending message was + * put on hold due to Device sleep state or due to TD update + * which could be because of Device Sleep and Host Sleep + * states. + */ + if (ipc_pm->pending_hpda_update && + ipc_pm->host_pm_state == IPC_MEM_HOST_PM_ACTIVE) + ipc_pm_signal_hpda_doorbell(ipc_pm, IPC_HP_PM_TRIGGER, true); +} + +bool ipc_pm_trigger(struct iosm_pm *ipc_pm, enum ipc_pm_unit unit, bool active) +{ + union ipc_pm_cond old_cond; + union ipc_pm_cond new_cond; + bool link_active; + + /* Save the current D3 state. */ + new_cond = ipc_pm->pm_cond; + old_cond = ipc_pm->pm_cond; + + /* Calculate the power state only in the runtime phase. */ + switch (unit) { + case IPC_PM_UNIT_IRQ: /* CP irq */ + new_cond.irq = active; + break; + + case IPC_PM_UNIT_LINK: /* Device link state. */ + new_cond.link = active; + break; + + case IPC_PM_UNIT_HS: /* Host sleep trigger requires Link. */ + new_cond.hs = active; + break; + + default: + break; + } + + /* Something changed ? */ + if (old_cond.raw == new_cond.raw) { + /* Stay in the current PM state. */ + link_active = old_cond.link == IPC_PM_ACTIVE; + goto ret; + } + + ipc_pm->pm_cond = new_cond; + + if (new_cond.link) + ipc_pm_on_link_wake(ipc_pm, unit == IPC_PM_UNIT_LINK); + else if (unit == IPC_PM_UNIT_LINK) + ipc_pm_on_link_sleep(ipc_pm); + + if (old_cond.link == IPC_PM_SLEEP && new_cond.raw) { + link_active = ipc_pm_link_activate(ipc_pm); + goto ret; + } + + link_active = old_cond.link == IPC_PM_ACTIVE; + +ret: + return link_active; +} + +bool ipc_pm_prepare_host_sleep(struct iosm_pm *ipc_pm) +{ + /* suspend not allowed if host_pm_state is not IPC_MEM_HOST_PM_ACTIVE */ + if (ipc_pm->host_pm_state != IPC_MEM_HOST_PM_ACTIVE) { + dev_err(ipc_pm->dev, "host_pm_state=%d\tExpected to be: %d", + ipc_pm->host_pm_state, IPC_MEM_HOST_PM_ACTIVE); + return false; + } + + ipc_pm->host_pm_state = IPC_MEM_HOST_PM_SLEEP_WAIT_D3; + + return true; +} + +bool ipc_pm_prepare_host_active(struct iosm_pm *ipc_pm) +{ + if (ipc_pm->host_pm_state != IPC_MEM_HOST_PM_SLEEP) { + dev_err(ipc_pm->dev, "host_pm_state=%d\tExpected to be: %d", + ipc_pm->host_pm_state, IPC_MEM_HOST_PM_SLEEP); + return false; + } + + /* Sending Sleep Exit message to CP. Update the state */ + ipc_pm->host_pm_state = IPC_MEM_HOST_PM_ACTIVE_WAIT; + + return true; +} + +void ipc_pm_set_s2idle_sleep(struct iosm_pm *ipc_pm, bool sleep) +{ + if (sleep) { + ipc_pm->ap_state = IPC_MEM_DEV_PM_SLEEP; + ipc_pm->cp_state = IPC_MEM_DEV_PM_SLEEP; + ipc_pm->device_sleep_notification = IPC_MEM_DEV_PM_SLEEP; + } else { + ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE; + ipc_pm->cp_state = IPC_MEM_DEV_PM_ACTIVE; + ipc_pm->device_sleep_notification = IPC_MEM_DEV_PM_ACTIVE; + ipc_pm->pm_cond.link = IPC_PM_ACTIVE; + } +} + +bool ipc_pm_dev_slp_notification(struct iosm_pm *ipc_pm, u32 cp_pm_req) +{ + if (cp_pm_req == ipc_pm->device_sleep_notification) + return false; + + ipc_pm->device_sleep_notification = cp_pm_req; + + /* Evaluate the PM request. */ + switch (ipc_pm->cp_state) { + case IPC_MEM_DEV_PM_ACTIVE: + switch (cp_pm_req) { + case IPC_MEM_DEV_PM_ACTIVE: + break; + + case IPC_MEM_DEV_PM_SLEEP: + /* Inform the PM that the device link can go down. */ + ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_LINK, false); + return true; + + default: + dev_err(ipc_pm->dev, + "loc-pm=%d active: confused req-pm=%d", + ipc_pm->cp_state, cp_pm_req); + break; + } + break; + + case IPC_MEM_DEV_PM_SLEEP: + switch (cp_pm_req) { + case IPC_MEM_DEV_PM_ACTIVE: + /* Inform the PM that the device link is active. */ + ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_LINK, true); + break; + + case IPC_MEM_DEV_PM_SLEEP: + break; + + default: + dev_err(ipc_pm->dev, + "loc-pm=%d sleep: confused req-pm=%d", + ipc_pm->cp_state, cp_pm_req); + break; + } + break; + + default: + dev_err(ipc_pm->dev, "confused loc-pm=%d, req-pm=%d", + ipc_pm->cp_state, cp_pm_req); + break; + } + + return false; +} + +void ipc_pm_init(struct iosm_protocol *ipc_protocol) +{ + struct iosm_imem *ipc_imem = ipc_protocol->imem; + struct iosm_pm *ipc_pm = &ipc_protocol->pm; + + ipc_pm->pcie = ipc_imem->pcie; + ipc_pm->dev = ipc_imem->dev; + + ipc_pm->pm_cond.irq = IPC_PM_SLEEP; + ipc_pm->pm_cond.hs = IPC_PM_SLEEP; + ipc_pm->pm_cond.link = IPC_PM_ACTIVE; + + ipc_pm->cp_state = IPC_MEM_DEV_PM_ACTIVE; + ipc_pm->ap_state = IPC_MEM_DEV_PM_ACTIVE; + ipc_pm->host_pm_state = IPC_MEM_HOST_PM_ACTIVE; + + /* Create generic wait-for-completion handler for Host Sleep + * and device sleep coordination. + */ + init_completion(&ipc_pm->host_sleep_complete); + + /* Complete all memory stores before clearing bit */ + smp_mb__before_atomic(); + + clear_bit(0, &ipc_pm->host_sleep_pend); + + /* Complete all memory stores after clearing bit */ + smp_mb__after_atomic(); +} + +void ipc_pm_deinit(struct iosm_protocol *proto) +{ + struct iosm_pm *ipc_pm = &proto->pm; + + complete(&ipc_pm->host_sleep_complete); +} diff --git a/drivers/net/wwan/iosm/iosm_ipc_pm.h b/drivers/net/wwan/iosm/iosm_ipc_pm.h new file mode 100644 index 000000000000..e7c00f388cb0 --- /dev/null +++ b/drivers/net/wwan/iosm/iosm_ipc_pm.h @@ -0,0 +1,207 @@ +/* SPDX-License-Identifier: GPL-2.0-only + * + * Copyright (C) 2020-21 Intel Corporation. + */ + +#ifndef IOSM_IPC_PM_H +#define IOSM_IPC_PM_H + +/* Trigger the doorbell interrupt on cp to change the PM sleep/active status */ +#define ipc_cp_irq_sleep_control(ipc_pcie, data) \ + ipc_doorbell_fire(ipc_pcie, IPC_DOORBELL_IRQ_SLEEP, data) + +/* Trigger the doorbell interrupt on CP to do hpda update */ +#define ipc_cp_irq_hpda_update(ipc_pcie, data) \ + ipc_doorbell_fire(ipc_pcie, IPC_DOORBELL_IRQ_HPDA, 0xFF & (data)) + +/** + * union ipc_pm_cond - Conditions for D3 and the sleep message to CP. + * @raw: raw/combined value for faster check + * @irq: IRQ towards CP + * @hs: Host Sleep + * @link: Device link state. + */ +union ipc_pm_cond { + unsigned int raw; + + struct { + unsigned int irq:1, + hs:1, + link:1; + }; +}; + +/** + * enum ipc_mem_host_pm_state - Possible states of the HOST SLEEP finite state + * machine. + * @IPC_MEM_HOST_PM_ACTIVE: Host is active + * @IPC_MEM_HOST_PM_ACTIVE_WAIT: Intermediate state before going to + * active + * @IPC_MEM_HOST_PM_SLEEP_WAIT_IDLE: Intermediate state to wait for idle + * before going into sleep + * @IPC_MEM_HOST_PM_SLEEP_WAIT_D3: Intermediate state to wait for D3 + * before going to sleep + * @IPC_MEM_HOST_PM_SLEEP: after this state the interface is not + * accessible host is in suspend to RAM + * @IPC_MEM_HOST_PM_SLEEP_WAIT_EXIT_SLEEP: Intermediate state before exiting + * sleep + */ +enum ipc_mem_host_pm_state { + IPC_MEM_HOST_PM_ACTIVE, + IPC_MEM_HOST_PM_ACTIVE_WAIT, + IPC_MEM_HOST_PM_SLEEP_WAIT_IDLE, + IPC_MEM_HOST_PM_SLEEP_WAIT_D3, + IPC_MEM_HOST_PM_SLEEP, + IPC_MEM_HOST_PM_SLEEP_WAIT_EXIT_SLEEP, +}; + +/** + * enum ipc_mem_dev_pm_state - Possible states of the DEVICE SLEEP finite state + * machine. + * @IPC_MEM_DEV_PM_ACTIVE: IPC_MEM_DEV_PM_ACTIVE is the initial + * power management state. + * IRQ(struct ipc_mem_device_info: + * device_sleep_notification) + * and DOORBELL-IRQ-HPDA(data) values. + * @IPC_MEM_DEV_PM_SLEEP: IPC_MEM_DEV_PM_SLEEP is PM state for + * sleep. + * @IPC_MEM_DEV_PM_WAKEUP: DOORBELL-IRQ-DEVICE_WAKE(data). + * @IPC_MEM_DEV_PM_HOST_SLEEP: DOORBELL-IRQ-HOST_SLEEP(data). + * @IPC_MEM_DEV_PM_ACTIVE_WAIT: Local intermediate states. + * @IPC_MEM_DEV_PM_FORCE_SLEEP: DOORBELL-IRQ-FORCE_SLEEP. + * @IPC_MEM_DEV_PM_FORCE_ACTIVE: DOORBELL-IRQ-FORCE_ACTIVE. + */ +enum ipc_mem_dev_pm_state { + IPC_MEM_DEV_PM_ACTIVE, + IPC_MEM_DEV_PM_SLEEP, + IPC_MEM_DEV_PM_WAKEUP, + IPC_MEM_DEV_PM_HOST_SLEEP, + IPC_MEM_DEV_PM_ACTIVE_WAIT, + IPC_MEM_DEV_PM_FORCE_SLEEP = 7, + IPC_MEM_DEV_PM_FORCE_ACTIVE, +}; + +/** + * struct iosm_pm - Power management instance + * @pcie: Pointer to iosm_pcie structure + * @dev: Pointer to device structure + * @host_pm_state: PM states for host + * @host_sleep_pend: Variable to indicate Host Sleep Pending + * @host_sleep_complete: Generic wait-for-completion used in + * case of Host Sleep + * @pm_cond: Conditions for power management + * @ap_state: Current power management state, the + * initial state is IPC_MEM_DEV_PM_ACTIVE eq. 0. + * @cp_state: PM State of CP + * @device_sleep_notification: last handled device_sleep_notfication + * @pending_hpda_update: is a HPDA update pending? + */ +struct iosm_pm { + struct iosm_pcie *pcie; + struct device *dev; + enum ipc_mem_host_pm_state host_pm_state; + unsigned long host_sleep_pend; + struct completion host_sleep_complete; + union ipc_pm_cond pm_cond; + enum ipc_mem_dev_pm_state ap_state; + enum ipc_mem_dev_pm_state cp_state; + u32 device_sleep_notification; + u8 pending_hpda_update:1; +}; + +/** + * enum ipc_pm_unit - Power management units. + * @IPC_PM_UNIT_IRQ: IRQ towards CP + * @IPC_PM_UNIT_HS: Host Sleep for converged protocol + * @IPC_PM_UNIT_LINK: Link state controlled by CP. + */ +enum ipc_pm_unit { + IPC_PM_UNIT_IRQ, + IPC_PM_UNIT_HS, + IPC_PM_UNIT_LINK, +}; + +/** + * ipc_pm_init - Allocate power management component + * @ipc_protocol: Pointer to iosm_protocol structure + */ +void ipc_pm_init(struct iosm_protocol *ipc_protocol); + +/** + * ipc_pm_deinit - Free power management component, invalidating its pointer. + * @ipc_protocol: Pointer to iosm_protocol structure + */ +void ipc_pm_deinit(struct iosm_protocol *ipc_protocol); + +/** + * ipc_pm_dev_slp_notification - Handle a sleep notification message from the + * device. This can be called from interrupt state + * This function handles Host Sleep requests too + * if the Host Sleep protocol is register based. + * @ipc_pm: Pointer to power management component + * @sleep_notification: Actual notification from device + * + * Returns: true if dev sleep state has to be checked, false otherwise. + */ +bool ipc_pm_dev_slp_notification(struct iosm_pm *ipc_pm, + u32 sleep_notification); + +/** + * ipc_pm_set_s2idle_sleep - Set PM variables to sleep/active + * @ipc_pm: Pointer to power management component + * @sleep: true to enter sleep/false to exit sleep + */ +void ipc_pm_set_s2idle_sleep(struct iosm_pm *ipc_pm, bool sleep); + +/** + * ipc_pm_prepare_host_sleep - Prepare the PM for sleep by entering + * IPC_MEM_HOST_PM_SLEEP_WAIT_D3 state. + * @ipc_pm: Pointer to power management component + * + * Returns: true on success, false if the host was not active. + */ +bool ipc_pm_prepare_host_sleep(struct iosm_pm *ipc_pm); + +/** + * ipc_pm_prepare_host_active - Prepare the PM for wakeup by entering + * IPC_MEM_HOST_PM_ACTIVE_WAIT state. + * @ipc_pm: Pointer to power management component + * + * Returns: true on success, false if the host was not sleeping. + */ +bool ipc_pm_prepare_host_active(struct iosm_pm *ipc_pm); + +/** + * ipc_pm_wait_for_device_active - Wait upto IPC_PM_ACTIVE_TIMEOUT_MS ms + * for the device to reach active state + * @ipc_pm: Pointer to power management component + * + * Returns: true if device is active, false on timeout + */ +bool ipc_pm_wait_for_device_active(struct iosm_pm *ipc_pm); + +/** + * ipc_pm_signal_hpda_doorbell - Wake up the device if it is in low power mode + * and trigger a head pointer update interrupt. + * @ipc_pm: Pointer to power management component + * @identifier: specifies what component triggered hpda update irq + * @host_slp_check: if set to true then Host Sleep state machine check will + * be performed. If Host Sleep state machine allows HP + * update then only doorbell is triggered otherwise pending + * flag will be set. If set to false then Host Sleep check + * will not be performed. This is helpful for Host Sleep + * negotiation through message ring. + */ +void ipc_pm_signal_hpda_doorbell(struct iosm_pm *ipc_pm, u32 identifier, + bool host_slp_check); +/** + * ipc_pm_trigger - Update power manager and wake up the link if needed + * @ipc_pm: Pointer to power management component + * @unit: Power management units + * @active: Device link state + * + * Returns: true if link is unchanged or active, false otherwise + */ +bool ipc_pm_trigger(struct iosm_pm *ipc_pm, enum ipc_pm_unit unit, bool active); + +#endif -- cgit v1.2.3