/*
 * Copyright (c) 2014,2017 Qualcomm Atheros, Inc.
 *
 * 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>

int wil_can_suspend(struct wil6210_priv *wil, bool is_runtime)
{
	int rc = 0;
	struct wireless_dev *wdev = wil->wdev;
	struct net_device *ndev = wil_to_ndev(wil);

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

	if (!(ndev->flags & IFF_UP)) {
		/* 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 */
	switch (wdev->iftype) {
	case NL80211_IFTYPE_MONITOR:
	case NL80211_IFTYPE_STATION:
	case NL80211_IFTYPE_P2P_CLIENT:
		if (test_bit(wil_status_fwconnecting, wil->status)) {
			wil_dbg_pm(wil, "Delay suspend when connecting\n");
			rc = -EBUSY;
			goto out;
		}
		break;
	/* AP-like interface - can't suspend */
	default:
		wil_dbg_pm(wil, "AP-like interface\n");
		rc = -EBUSY;
		break;
	}

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 */
	if (test_bit(wil_status_fwconnected, wil->status))
		wil_update_net_queues_bh(wil, NULL, false);

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 start, data_comp_to;

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

	/* Prevent handling of new tx and wmi commands */
	set_bit(wil_status_suspending, wil->status);
	wil_update_net_queues_bh(wil, NULL, true);

	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_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 */
	start = jiffies;
	data_comp_to = jiffies + msecs_to_jiffies(WIL_DATA_COMPLETION_TO_MS);
	if (test_bit(wil_status_napi_en, wil->status)) {
		while (!wil_is_rx_idle(wil)) {
			if (time_after(jiffies, data_comp_to)) {
				if (wil_is_rx_idle(wil))
					break;
				wil_err(wil,
					"TO waiting for idle RX, suspend failed\n");
				wil->suspend_stats.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.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.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;
		if (test_bit(wil_status_fwconnected, wil->status))
			wil_update_net_queues_bh(wil, NULL, false);
	}
	return rc;

reject_suspend:
	clear_bit(wil_status_suspending, wil->status);
	if (test_bit(wil_status_fwconnected, wil->status))
		wil_update_net_queues_bh(wil, NULL, false);
	return -EBUSY;
}

static int wil_suspend_radio_off(struct wil6210_priv *wil)
{
	int rc = 0;
	struct net_device *ndev = wil_to_ndev(wil);

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

	/* if netif up, hardware is alive, shut it down */
	if (ndev->flags & IFF_UP) {
		rc = wil_down(wil);
		if (rc) {
			wil_err(wil, "wil_down : %d\n", rc);
			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);
			goto out;
		}
	}

	set_bit(wil_status_suspended, wil->status);

out:
	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;
	struct net_device *ndev = wil_to_ndev(wil);

	wil_dbg_pm(wil, "Enabling PCIe IRQ\n");
	wil_enable_irq(wil);
	/* if 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
	 */
	if (ndev->flags & IFF_UP)
		rc = wil_up(wil);
	else
		clear_bit(wil_status_suspended, wil->status);

	return rc;
}

int wil_suspend(struct wil6210_priv *wil, bool is_runtime)
{
	int rc = 0;
	struct net_device *ndev = wil_to_ndev(wil);
	bool keep_radio_on = ndev->flags & IFF_UP &&
			     wil->keep_radio_on_during_sleep;

	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);

	if (!rc)
		wil->suspend_stats.suspend_start_time = ktime_get();

	return rc;
}

int wil_resume(struct wil6210_priv *wil, bool is_runtime)
{
	int rc = 0;
	struct net_device *ndev = wil_to_ndev(wil);
	bool keep_radio_on = ndev->flags & IFF_UP &&
			     wil->keep_radio_on_during_sleep;
	unsigned long long suspend_time_usec = 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);

	if (rc)
		goto out;

	suspend_time_usec =
		ktime_to_us(ktime_sub(ktime_get(),
				      wil->suspend_stats.suspend_start_time));
	wil->suspend_stats.total_suspend_time += suspend_time_usec;
	if (suspend_time_usec < wil->suspend_stats.min_suspend_time)
		wil->suspend_stats.min_suspend_time = suspend_time_usec;
	if (suspend_time_usec > wil->suspend_stats.max_suspend_time)
		wil->suspend_stats.max_suspend_time = suspend_time_usec;

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