iwlwifi: add support for suspend-resume flow for new device generation

The new device generation has a slightly different suspend resume flow
Currently, the way the driver instruct the device to move to D3 is by
sending D3_CONFIG_CMD.
Instead of using the host command the indication is by writing to the
doorbell interrupt.
The FW will respond with interrupt to indicate transition completion.
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-prph.h

@@ -451,6 +451,8 @@ enum {
 
 #define UREG_DOORBELL_TO_ISR6		0xA05C04
 #define UREG_DOORBELL_TO_ISR6_NMI_BIT	BIT(0)
+#define UREG_DOORBELL_TO_ISR6_SUSPEND	BIT(18)
+#define UREG_DOORBELL_TO_ISR6_RESUME	BIT(19)
 
 #define FSEQ_ERROR_CODE			0xA340C8
 #define FSEQ_TOP_INIT_VERSION		0xA34038
@@ -460,4 +462,7 @@ enum {
 #define FSEQ_ALIVE_TOKEN		0xA340F0
 #define FSEQ_CNVI_ID			0xA3408C
 #define FSEQ_CNVR_ID			0xA34090
+
+#define IWL_D3_SLEEP_STATUS_SUSPEND	0xD3
+#define IWL_D3_SLEEP_STATUS_RESUME	0xD0
 #endif				/* __iwl_prph_h__ */

drivers/net/wireless/intel/iwlwifi/iwl-trans.h

@@ -537,7 +537,7 @@ struct iwl_trans_ops {
 	void (*fw_alive)(struct iwl_trans *trans, u32 scd_addr);
 	void (*stop_device)(struct iwl_trans *trans);
 
-	void (*d3_suspend)(struct iwl_trans *trans, bool test, bool reset);
+	int (*d3_suspend)(struct iwl_trans *trans, bool test, bool reset);
 	int (*d3_resume)(struct iwl_trans *trans, enum iwl_d3_status *status,
 			 bool test, bool reset);
 
@@ -883,12 +883,14 @@ static inline void iwl_trans_stop_device(struct iwl_trans *trans)
 	trans->state = IWL_TRANS_NO_FW;
 }
 
-static inline void iwl_trans_d3_suspend(struct iwl_trans *trans, bool test,
+static inline int iwl_trans_d3_suspend(struct iwl_trans *trans, bool test,
 				       bool reset)
 {
 	might_sleep();
-	if (trans->ops->d3_suspend)
-		trans->ops->d3_suspend(trans, test, reset);
+	if (!trans->ops->d3_suspend)
+		return 0;
+
+	return trans->ops->d3_suspend(trans, test, reset);
 }
 
 static inline int iwl_trans_d3_resume(struct iwl_trans *trans,

drivers/net/wireless/intel/iwlwifi/mvm/d3.c

@@ -1068,7 +1068,7 @@ static int __iwl_mvm_suspend(struct ieee80211_hw *hw,
 
 	clear_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status);
 
-	iwl_trans_d3_suspend(mvm->trans, test, !unified_image);
+	ret = iwl_trans_d3_suspend(mvm->trans, test, !unified_image);
  out:
 	if (ret < 0) {
 		iwl_mvm_free_nd(mvm);
@@ -1930,15 +1930,6 @@ static int __iwl_mvm_resume(struct iwl_mvm *mvm, bool test)
 	if (IS_ERR_OR_NULL(vif))
 		goto err;
 
-	ret = iwl_trans_d3_resume(mvm->trans, &d3_status, test, !unified_image);
-	if (ret)
-		goto err;
-
-	if (d3_status != IWL_D3_STATUS_ALIVE) {
-		IWL_INFO(mvm, "Device was reset during suspend\n");
-		goto err;
-	}
-
 	iwl_fw_dbg_read_d3_debug_data(&mvm->fwrt);
 
 	if (iwl_mvm_check_rt_status(mvm, vif)) {
@@ -1950,6 +1941,15 @@ static int __iwl_mvm_resume(struct iwl_mvm *mvm, bool test)
 		goto err;
 	}
 
+	ret = iwl_trans_d3_resume(mvm->trans, &d3_status, test, !unified_image);
+	if (ret)
+		goto err;
+
+	if (d3_status != IWL_D3_STATUS_ALIVE) {
+		IWL_INFO(mvm, "Device was reset during suspend\n");
+		goto err;
+	}
+
 	if (d0i3_first) {
 		ret = iwl_mvm_send_cmd_pdu(mvm, D0I3_END_CMD, 0, 0, NULL);
 		if (ret < 0) {

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

@@ -558,8 +558,10 @@ struct iwl_trans_pcie {
 	void __iomem *hw_base;
 
 	bool ucode_write_complete;
+	bool sx_complete;
 	wait_queue_head_t ucode_write_waitq;
 	wait_queue_head_t wait_command_queue;
+	wait_queue_head_t sx_waitq;
 
 	u8 page_offs, dev_cmd_offs;
 
@@ -1117,4 +1119,6 @@ void _iwl_trans_pcie_gen2_stop_device(struct iwl_trans *trans);
 void iwl_pcie_gen2_txq_unmap(struct iwl_trans *trans, int txq_id);
 void iwl_pcie_gen2_tx_free(struct iwl_trans *trans);
 void iwl_pcie_gen2_tx_stop(struct iwl_trans *trans);
+void iwl_pcie_d3_complete_suspend(struct iwl_trans *trans,
+				  bool test, bool reset);
 #endif /* __iwl_trans_int_pcie_h__ */

drivers/net/wireless/intel/iwlwifi/pcie/rx.c

@@ -2196,6 +2196,16 @@ irqreturn_t iwl_pcie_irq_msix_handler(int irq, void *dev_id)
 			iwl_pcie_irq_handle_error(trans);
 		}
 	} else if (inta_hw & MSIX_HW_INT_CAUSES_REG_WAKEUP) {
+		u32 sleep_notif =
+			le32_to_cpu(trans_pcie->prph_info->sleep_notif);
+		if (sleep_notif == IWL_D3_SLEEP_STATUS_SUSPEND ||
+		    sleep_notif == IWL_D3_SLEEP_STATUS_RESUME) {
+			IWL_DEBUG_ISR(trans,
+				      "Sx interrupt: sleep notification = 0x%x\n",
+				      sleep_notif);
+			trans_pcie->sx_complete = true;
+			wake_up(&trans_pcie->sx_waitq);
+		} else {
 			/* uCode wakes up after power-down sleep */
 			IWL_DEBUG_ISR(trans, "Wakeup interrupt\n");
 			iwl_pcie_rxq_check_wrptr(trans);
@@ -2203,6 +2213,7 @@ irqreturn_t iwl_pcie_irq_msix_handler(int irq, void *dev_id)
 
 			isr_stats->wakeup++;
 		}
+	}
 
 	if (inta_hw & MSIX_HW_INT_CAUSES_REG_IML) {
 		/* Reflect IML transfer status */

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

@@ -1478,15 +1478,9 @@ void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state)
 	}
 }
 
-static void iwl_trans_pcie_d3_suspend(struct iwl_trans *trans, bool test,
-				      bool reset)
+void iwl_pcie_d3_complete_suspend(struct iwl_trans *trans,
+				  bool test, bool reset)
 {
-	if (!reset) {
-		/* Enable persistence mode to avoid reset */
-		iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
-			    CSR_HW_IF_CONFIG_REG_PERSIST_MODE);
-	}
-
 	iwl_disable_interrupts(trans);
 
 	/*
@@ -1517,6 +1511,42 @@ static void iwl_trans_pcie_d3_suspend(struct iwl_trans *trans, bool test,
 	iwl_pcie_set_pwr(trans, true);
 }
 
+static int iwl_trans_pcie_d3_suspend(struct iwl_trans *trans, bool test,
+				     bool reset)
+{
+	int ret;
+	struct iwl_trans_pcie *trans_pcie =  IWL_TRANS_GET_PCIE_TRANS(trans);
+
+	/*
+	 * Family IWL_DEVICE_FAMILY_AX210 and above persist mode is set by FW.
+	 */
+	if (!reset && trans->trans_cfg->device_family < IWL_DEVICE_FAMILY_AX210) {
+		/* Enable persistence mode to avoid reset */
+		iwl_set_bit(trans, CSR_HW_IF_CONFIG_REG,
+			    CSR_HW_IF_CONFIG_REG_PERSIST_MODE);
+	}
+
+	if (trans->trans_cfg->device_family >= IWL_DEVICE_FAMILY_AX210) {
+		iwl_write_umac_prph(trans, UREG_DOORBELL_TO_ISR6,
+				    UREG_DOORBELL_TO_ISR6_SUSPEND);
+
+		ret = wait_event_timeout(trans_pcie->sx_waitq,
+					 trans_pcie->sx_complete, 2 * HZ);
+		/*
+		 * Invalidate it toward resume.
+		 */
+		trans_pcie->sx_complete = false;
+
+		if (!ret) {
+			IWL_ERR(trans, "Timeout entering D3\n");
+			return -ETIMEDOUT;
+		}
+	}
+	iwl_pcie_d3_complete_suspend(trans, test, reset);
+
+	return 0;
+}
+
 static int iwl_trans_pcie_d3_resume(struct iwl_trans *trans,
 				    enum iwl_d3_status *status,
 				    bool test,  bool reset)
@@ -1528,7 +1558,7 @@ static int iwl_trans_pcie_d3_resume(struct iwl_trans *trans,
 	if (test) {
 		iwl_enable_interrupts(trans);
 		*status = IWL_D3_STATUS_ALIVE;
-		return 0;
+		goto out;
 	}
 
 	iwl_set_bit(trans, CSR_GP_CNTRL,
@@ -1575,6 +1605,25 @@ static int iwl_trans_pcie_d3_resume(struct iwl_trans *trans,
 	else
 		*status = IWL_D3_STATUS_ALIVE;
 
+out:
+	if (*status == IWL_D3_STATUS_ALIVE &&
+	    trans->trans_cfg->device_family >= IWL_DEVICE_FAMILY_AX210) {
+		trans_pcie->sx_complete = false;
+		iwl_write_umac_prph(trans, UREG_DOORBELL_TO_ISR6,
+				    UREG_DOORBELL_TO_ISR6_RESUME);
+
+		ret = wait_event_timeout(trans_pcie->sx_waitq,
+					 trans_pcie->sx_complete, 2 * HZ);
+		/*
+		 * Invalidate it toward next suspend.
+		 */
+		trans_pcie->sx_complete = false;
+
+		if (!ret) {
+			IWL_ERR(trans, "Timeout exiting D3\n");
+			return -ETIMEDOUT;
+		}
+	}
 	return 0;
 }
 
@@ -3514,6 +3563,8 @@ struct iwl_trans *iwl_trans_pcie_alloc(struct pci_dev *pdev,
 	/* Initialize the wait queue for commands */
 	init_waitqueue_head(&trans_pcie->wait_command_queue);
 
+	init_waitqueue_head(&trans_pcie->sx_waitq);
+
 	if (trans_pcie->msix_enabled) {
 		ret = iwl_pcie_init_msix_handler(pdev, trans_pcie);
 		if (ret)