wil6210: add support for PCIe D3hot in system suspend

In order to preserve the connection in suspend/resume flow,
wil6210 host allows going to PCIe D3hot state in suspend,
instead of performing a full wil6210 device reset. This
requires the platform ability to initiate wakeup in case of
RX data. To check that, a new platform API is added.
In addition, add cfg80211 suspend/resume callbacks
implementation.

Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 209 insertions, 19 deletions

diff --git a/drivers/net/wireless/ath/wil6210/pm.c b/drivers/net/wireless/ath/wil6210/pm.c
index 2ae4fe85cc8c..ce1f384e7f8e 100644
--- a/drivers/net/wireless/ath/wil6210/pm.c
+++ b/drivers/net/wireless/ath/wil6210/pm.c
@@ -15,6 +15,7 @@
  */
 
 #include "wil6210.h"
+#include <linux/jiffies.h>
 
 int wil_can_suspend(struct wil6210_priv *wil, bool is_runtime)
 {
@@ -61,20 +62,170 @@ 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;
 }
 
-int wil_suspend(struct wil6210_priv *wil, bool is_runtime)
+static int wil_resume_keep_radio_on(struct wil6210_priv *wil)
 {
 	int rc = 0;
-	struct net_device *ndev = wil_to_ndev(wil);
 
-	wil_dbg_pm(wil, "suspend: %s\n", is_runtime ? "runtime" : "system");
+	/* 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);
 
-	if (test_bit(wil_status_suspended, wil->status)) {
-		wil_dbg_pm(wil, "trying to suspend while suspended\n");
-		return 0;
+	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), resetting\n", rc);
+		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) {
@@ -90,7 +241,7 @@ int wil_suspend(struct wil6210_priv *wil, bool is_runtime)
 	wil_disable_irq(wil);
 
 	if (wil->platform_ops.suspend) {
-		rc = wil->platform_ops.suspend(wil->platform_handle);
+		rc = wil->platform_ops.suspend(wil->platform_handle, false);
 		if (rc) {
 			wil_enable_irq(wil);
 			goto out;
@@ -100,6 +251,50 @@ int wil_suspend(struct wil6210_priv *wil, bool is_runtime)
 	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);
 
@@ -110,29 +305,24 @@ 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;
 
 	wil_dbg_pm(wil, "resume: %s\n", is_runtime ? "runtime" : "system");
 
 	if (wil->platform_ops.resume) {
-		rc = wil->platform_ops.resume(wil->platform_handle);
+		rc = wil->platform_ops.resume(wil->platform_handle,
+					      keep_radio_on);
 		if (rc) {
 			wil_err(wil, "platform_ops.resume : %d\n", rc);
 			goto out;
 		}
 	}
 
-	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);
+	if (keep_radio_on)
+		rc = wil_resume_keep_radio_on(wil);
 	else
-		clear_bit(wil_status_suspended, wil->status);
+		rc = wil_resume_radio_off(wil);
 
 out:
 	wil_dbg_pm(wil, "resume: %s => %d\n",