/*
 * Copyright (c) 2014,2017 Qualcomm Atheros, Inc.
 * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "wil6210.h"
#include <linux/jiffies.h>
#include <linux/pm_runtime.h>

#define WIL6210_AUTOSUSPEND_DELAY_MS (1000)

static void wil_pm_wake_connected_net_queues(struct wil6210_priv *wil)
{
        int i;

        mutex_lock(&wil->vif_mutex);
        for (i = 0; i < GET_MAX_VIFS(wil); i++) {
                struct wil6210_vif *vif = wil->vifs[i];

                if (vif && test_bit(wil_vif_fwconnected, vif->status))
                        wil_update_net_queues_bh(wil, vif, NULL, false);
        }
        mutex_unlock(&wil->vif_mutex);
}

static void wil_pm_stop_all_net_queues(struct wil6210_priv *wil)
{
        int i;

        mutex_lock(&wil->vif_mutex);
        for (i = 0; i < GET_MAX_VIFS(wil); i++) {
                struct wil6210_vif *vif = wil->vifs[i];

                if (vif)
                        wil_update_net_queues_bh(wil, vif, NULL, true);
        }
        mutex_unlock(&wil->vif_mutex);
}

static bool
wil_can_suspend_vif(struct wil6210_priv *wil, struct wil6210_vif *vif,
                    bool is_runtime)
{
        struct wireless_dev *wdev = vif_to_wdev(vif);

        switch (wdev->iftype) {
        case NL80211_IFTYPE_MONITOR:
                wil_dbg_pm(wil, "Sniffer\n");
                return false;

        /* for STA-like interface, don't runtime suspend */
        case NL80211_IFTYPE_STATION:
        case NL80211_IFTYPE_P2P_CLIENT:
                if (test_bit(wil_vif_fwconnecting, vif->status)) {
                        wil_dbg_pm(wil, "Delay suspend when connecting\n");
                        return false;
                }
                if (is_runtime) {
                        wil_dbg_pm(wil, "STA-like interface\n");
                        return false;
                }
                break;
        /* AP-like interface - can't suspend */
        default:
                wil_dbg_pm(wil, "AP-like interface\n");
                return false;
        }

        return true;
}

int wil_can_suspend(struct wil6210_priv *wil, bool is_runtime)
{
        int rc = 0, i;
        bool wmi_only = test_bit(WMI_FW_CAPABILITY_WMI_ONLY,
                                 wil->fw_capabilities);
        bool active_ifaces;

        wil_dbg_pm(wil, "can_suspend: %s\n", is_runtime ? "runtime" : "system");

        if (wmi_only || debug_fw) {
                wil_dbg_pm(wil, "Deny any suspend - %s mode\n",
                           wmi_only ? "wmi_only" : "debug_fw");
                rc = -EBUSY;
                goto out;
        }
        if (is_runtime && !wil->platform_ops.suspend) {
                rc = -EBUSY;
                goto out;
        }

        mutex_lock(&wil->vif_mutex);
        active_ifaces = wil_has_active_ifaces(wil, true, false);
        mutex_unlock(&wil->vif_mutex);

        if (!active_ifaces) {
                /* can always sleep when down */
                wil_dbg_pm(wil, "Interface is down\n");
                goto out;
        }
        if (test_bit(wil_status_resetting, wil->status)) {
                wil_dbg_pm(wil, "Delay suspend when resetting\n");
                rc = -EBUSY;
                goto out;
        }
        if (wil->recovery_state != fw_recovery_idle) {
                wil_dbg_pm(wil, "Delay suspend during recovery\n");
                rc = -EBUSY;
                goto out;
        }

        /* interface is running */
        mutex_lock(&wil->vif_mutex);
        for (i = 0; i < GET_MAX_VIFS(wil); i++) {
                struct wil6210_vif *vif = wil->vifs[i];

                if (!vif)
                        continue;
                if (!wil_can_suspend_vif(wil, vif, is_runtime)) {
                        rc = -EBUSY;
                        mutex_unlock(&wil->vif_mutex);
                        goto out;
                }
        }
        mutex_unlock(&wil->vif_mutex);

out:
        wil_dbg_pm(wil, "can_suspend: %s => %s (%d)\n",
                   is_runtime ? "runtime" : "system", rc ? "No" : "Yes", rc);

        if (rc)
                wil->suspend_stats.rejected_by_host++;

        return rc;
}

static int wil_resume_keep_radio_on(struct wil6210_priv *wil)
{
        int rc = 0;

        /* wil_status_resuming will be cleared when getting
         * WMI_TRAFFIC_RESUME_EVENTID
         */
        set_bit(wil_status_resuming, wil->status);
        clear_bit(wil_status_suspended, wil->status);
        wil_c(wil, RGF_USER_CLKS_CTL_0, BIT_USER_CLKS_RST_PWGD);
        wil_unmask_irq(wil);

        wil6210_bus_request(wil, wil->bus_request_kbps_pre_suspend);

        /* Send WMI resume request to the device */
        rc = wmi_resume(wil);
        if (rc) {
                wil_err(wil, "device failed to resume (%d)\n", rc);
                if (no_fw_recovery)
                        goto out;
                rc = wil_down(wil);
                if (rc) {
                        wil_err(wil, "wil_down failed (%d)\n", rc);
                        goto out;
                }
                rc = wil_up(wil);
                if (rc) {
                        wil_err(wil, "wil_up failed (%d)\n", rc);
                        goto out;
                }
        }

        /* Wake all queues */
        wil_pm_wake_connected_net_queues(wil);

out:
        if (rc)
                set_bit(wil_status_suspended, wil->status);
        return rc;
}

static int wil_suspend_keep_radio_on(struct wil6210_priv *wil)
{
        int rc = 0;
        unsigned long data_comp_to;

        wil_dbg_pm(wil, "suspend keep radio on\n");

        /* Prevent handling of new tx and wmi commands */
        rc = down_write_trylock(&wil->mem_lock);
        if (!rc) {
                wil_err(wil,
                        "device is busy. down_write_trylock failed, returned (0x%x)\n",
                        rc);
                wil->suspend_stats.rejected_by_host++;
                return -EBUSY;
        }

        set_bit(wil_status_suspending, wil->status);
        up_write(&wil->mem_lock);

        wil_pm_stop_all_net_queues(wil);

        if (!wil_is_tx_idle(wil)) {
                wil_dbg_pm(wil, "Pending TX data, reject suspend\n");
                wil->suspend_stats.rejected_by_host++;
                goto reject_suspend;
        }

        if (!wil->txrx_ops.is_rx_idle(wil)) {
                wil_dbg_pm(wil, "Pending RX data, reject suspend\n");
                wil->suspend_stats.rejected_by_host++;
                goto reject_suspend;
        }

        if (!wil_is_wmi_idle(wil)) {
                wil_dbg_pm(wil, "Pending WMI events, reject suspend\n");
                wil->suspend_stats.rejected_by_host++;
                goto reject_suspend;
        }

        /* Send WMI suspend request to the device */
        rc = wmi_suspend(wil);
        if (rc) {
                wil_dbg_pm(wil, "wmi_suspend failed, reject suspend (%d)\n",
                           rc);
                goto reject_suspend;
        }

        /* Wait for completion of the pending RX packets */
        data_comp_to = jiffies + msecs_to_jiffies(WIL_DATA_COMPLETION_TO_MS);
        if (test_bit(wil_status_napi_en, wil->status)) {
                while (!wil->txrx_ops.is_rx_idle(wil)) {
                        if (time_after(jiffies, data_comp_to)) {
                                if (wil->txrx_ops.is_rx_idle(wil))
                                        break;
                                wil_err(wil,
                                        "TO waiting for idle RX, suspend failed\n");
                                wil->suspend_stats.r_on.failed_suspends++;
                                goto resume_after_fail;
                        }
                        wil_dbg_ratelimited(wil, "rx vring is not empty -> NAPI\n");
                        napi_synchronize(&wil->napi_rx);
                        msleep(20);
                }
        }

        /* In case of pending WMI events, reject the suspend
         * and resume the device.
         * This can happen if the device sent the WMI events before
         * approving the suspend.
         */
        if (!wil_is_wmi_idle(wil)) {
                wil_err(wil, "suspend failed due to pending WMI events\n");
                wil->suspend_stats.r_on.failed_suspends++;
                goto resume_after_fail;
        }

        wil_mask_irq(wil);

        /* Disable device reset on PERST */
        wil_s(wil, RGF_USER_CLKS_CTL_0, BIT_USER_CLKS_RST_PWGD);

        if (wil->platform_ops.suspend) {
                rc = wil->platform_ops.suspend(wil->platform_handle, true);
                if (rc) {
                        wil_err(wil, "platform device failed to suspend (%d)\n",
                                rc);
                        wil->suspend_stats.r_on.failed_suspends++;
                        wil_c(wil, RGF_USER_CLKS_CTL_0, BIT_USER_CLKS_RST_PWGD);
                        wil_unmask_irq(wil);
                        goto resume_after_fail;
                }
        }

        /* Save the current bus request to return to the same in resume */
        wil->bus_request_kbps_pre_suspend = wil->bus_request_kbps;
        wil6210_bus_request(wil, 0);

        set_bit(wil_status_suspended, wil->status);
        clear_bit(wil_status_suspending, wil->status);

        return rc;

resume_after_fail:
        set_bit(wil_status_resuming, wil->status);
        clear_bit(wil_status_suspending, wil->status);
        rc = wmi_resume(wil);
        /* if resume succeeded, reject the suspend */
        if (!rc) {
                rc = -EBUSY;
                wil_pm_wake_connected_net_queues(wil);
        }
        return rc;

reject_suspend:
        clear_bit(wil_status_suspending, wil->status);
        wil_pm_wake_connected_net_queues(wil);
        return -EBUSY;
}

static int wil_suspend_radio_off(struct wil6210_priv *wil)
{
        int rc = 0;
        bool active_ifaces;

        wil_dbg_pm(wil, "suspend radio off\n");

        rc = down_write_trylock(&wil->mem_lock);
        if (!rc) {
                wil_err(wil,
                        "device is busy. down_write_trylock failed, returned (0x%x)\n",
                        rc);
                wil->suspend_stats.rejected_by_host++;
                return -EBUSY;
        }

        set_bit(wil_status_suspending, wil->status);
        up_write(&wil->mem_lock);

        /* if netif up, hardware is alive, shut it down */
        mutex_lock(&wil->vif_mutex);
        active_ifaces = wil_has_active_ifaces(wil, true, false);
        mutex_unlock(&wil->vif_mutex);

        if (active_ifaces) {
                rc = wil_down(wil);
                if (rc) {
                        wil_err(wil, "wil_down : %d\n", rc);
                        wil->suspend_stats.r_off.failed_suspends++;
                        goto out;
                }
        }

        /* Disable PCIe IRQ to prevent sporadic IRQs when PCIe is suspending */
        wil_dbg_pm(wil, "Disabling PCIe IRQ before suspending\n");
        wil_disable_irq(wil);

        if (wil->platform_ops.suspend) {
                rc = wil->platform_ops.suspend(wil->platform_handle, false);
                if (rc) {
                        wil_enable_irq(wil);
                        wil->suspend_stats.r_off.failed_suspends++;
                        goto out;
                }
        }

        set_bit(wil_status_suspended, wil->status);

out:
        clear_bit(wil_status_suspending, wil->status);
        wil_dbg_pm(wil, "suspend radio off: %d\n", rc);

        return rc;
}

static int wil_resume_radio_off(struct wil6210_priv *wil)
{
        int rc = 0;
        bool active_ifaces;

        wil_dbg_pm(wil, "Enabling PCIe IRQ\n");
        wil_enable_irq(wil);
        /* if any netif up, bring hardware up
         * During open(), IFF_UP set after actual device method
         * invocation. This prevent recursive call to wil_up()
         * wil_status_suspended will be cleared in wil_reset
         */
        mutex_lock(&wil->vif_mutex);
        active_ifaces = wil_has_active_ifaces(wil, true, false);
        mutex_unlock(&wil->vif_mutex);
        if (active_ifaces)
                rc = wil_up(wil);
        else
                clear_bit(wil_status_suspended, wil->status);

        return rc;
}

int wil_suspend(struct wil6210_priv *wil, bool is_runtime, bool keep_radio_on)
{
        int rc = 0;

        wil_dbg_pm(wil, "suspend: %s\n", is_runtime ? "runtime" : "system");

        if (test_bit(wil_status_suspended, wil->status)) {
                wil_dbg_pm(wil, "trying to suspend while suspended\n");
                return 0;
        }

        if (!keep_radio_on)
                rc = wil_suspend_radio_off(wil);
        else
                rc = wil_suspend_keep_radio_on(wil);

        wil_dbg_pm(wil, "suspend: %s => %d\n",
                   is_runtime ? "runtime" : "system", rc);

        return rc;
}

int wil_resume(struct wil6210_priv *wil, bool is_runtime, bool keep_radio_on)
{
        int rc = 0;

        wil_dbg_pm(wil, "resume: %s\n", is_runtime ? "runtime" : "system");

        if (wil->platform_ops.resume) {
                rc = wil->platform_ops.resume(wil->platform_handle,
                                              keep_radio_on);
                if (rc) {
                        wil_err(wil, "platform_ops.resume : %d\n", rc);
                        goto out;
                }
        }

        if (keep_radio_on)
                rc = wil_resume_keep_radio_on(wil);
        else
                rc = wil_resume_radio_off(wil);

out:
        wil_dbg_pm(wil, "resume: %s => %d\n", is_runtime ? "runtime" : "system",
                   rc);
        return rc;
}

void wil_pm_runtime_allow(struct wil6210_priv *wil)
{
        struct device *dev = wil_to_dev(wil);

        pm_runtime_put_noidle(dev);
        pm_runtime_set_autosuspend_delay(dev, WIL6210_AUTOSUSPEND_DELAY_MS);
        pm_runtime_use_autosuspend(dev);
        pm_runtime_allow(dev);
}

void wil_pm_runtime_forbid(struct wil6210_priv *wil)
{
        struct device *dev = wil_to_dev(wil);

        pm_runtime_forbid(dev);
        pm_runtime_get_noresume(dev);
}

int wil_pm_runtime_get(struct wil6210_priv *wil)
{
        int rc;
        struct device *dev = wil_to_dev(wil);

        rc = pm_runtime_get_sync(dev);
        if (rc < 0) {
                wil_err(wil, "pm_runtime_get_sync() failed, rc = %d\n", rc);
                pm_runtime_put_noidle(dev);
                return rc;
        }

        return 0;
}

void wil_pm_runtime_put(struct wil6210_priv *wil)
{
        struct device *dev = wil_to_dev(wil);

        pm_runtime_mark_last_busy(dev);
        pm_runtime_put_autosuspend(dev);
}