iwlwifi: pcie: add RTPM support when wifi is enabled

Enable runtime power management (RTPM) for PCIe devices and implement
the corresponding functions to enable D0i3 mode when the device is
idle.

Additionally, remove some unnecessary #ifdef's because the RTPM code
will not be called if runtime PM is not configured.
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

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

@@ -736,6 +736,11 @@ enum iwl_plat_pm_mode {
 	IWL_PLAT_PM_MODE_D0I3,
 };
 
+/* Max time to wait for trans to become idle/non-idle on d0i3
+ * enter/exit (in msecs).
+ */
+#define IWL_TRANS_IDLE_TIMEOUT 2000
+
 /**
  * struct iwl_trans - transport common data
  *

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

@@ -67,9 +67,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/module.h>
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
 #include <linux/pm_runtime.h>
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
 #include <linux/pci.h>
 #include <linux/pci-aspm.h>
 #include <linux/acpi.h>
@@ -627,13 +625,15 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret)
 		goto out_free_drv;
 
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
+	/* if RTPM is in use, enable it in our device */
+	if (iwl_trans->runtime_pm_mode != IWL_PLAT_PM_MODE_DISABLED) {
 		pm_runtime_set_active(&pdev->dev);
 		pm_runtime_set_autosuspend_delay(&pdev->dev,
 					 iwlwifi_mod_params.d0i3_entry_delay);
 		pm_runtime_use_autosuspend(&pdev->dev);
 		pm_runtime_allow(&pdev->dev);
-#endif
+	}
+
 	return 0;
 
 out_free_drv:
@@ -700,17 +700,90 @@ static int iwl_pci_resume(struct device *device)
 	return 0;
 }
 
+int iwl_pci_fw_enter_d0i3(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	int ret;
+
+	if (test_bit(STATUS_FW_ERROR, &trans->status))
+		return 0;
+
+	set_bit(STATUS_TRANS_GOING_IDLE, &trans->status);
+
+	/* config the fw */
+	ret = iwl_op_mode_enter_d0i3(trans->op_mode);
+	if (ret == 1) {
+		IWL_DEBUG_RPM(trans, "aborting d0i3 entrance\n");
+		clear_bit(STATUS_TRANS_GOING_IDLE, &trans->status);
+		return -EBUSY;
+	}
+	if (ret)
+		goto err;
+
+	ret = wait_event_timeout(trans_pcie->d0i3_waitq,
+				 test_bit(STATUS_TRANS_IDLE, &trans->status),
+				 msecs_to_jiffies(IWL_TRANS_IDLE_TIMEOUT));
+	if (!ret) {
+		IWL_ERR(trans, "Timeout entering D0i3\n");
+		ret = -ETIMEDOUT;
+		goto err;
+	}
+
+	clear_bit(STATUS_TRANS_GOING_IDLE, &trans->status);
+
+	return 0;
+err:
+	clear_bit(STATUS_TRANS_GOING_IDLE, &trans->status);
+	iwl_trans_fw_error(trans);
+	return ret;
+}
+
+int iwl_pci_fw_exit_d0i3(struct iwl_trans *trans)
+{
+	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+	int ret;
+
+	/* sometimes a D0i3 entry is not followed through */
+	if (!test_bit(STATUS_TRANS_IDLE, &trans->status))
+		return 0;
+
+	/* config the fw */
+	ret = iwl_op_mode_exit_d0i3(trans->op_mode);
+	if (ret)
+		goto err;
+
+	/* we clear STATUS_TRANS_IDLE only when D0I3_END command is completed */
+
+	ret = wait_event_timeout(trans_pcie->d0i3_waitq,
+				 !test_bit(STATUS_TRANS_IDLE, &trans->status),
+				 msecs_to_jiffies(IWL_TRANS_IDLE_TIMEOUT));
+	if (!ret) {
+		IWL_ERR(trans, "Timeout exiting D0i3\n");
+		ret = -ETIMEDOUT;
+		goto err;
+	}
+
+	return 0;
+err:
+	clear_bit(STATUS_TRANS_IDLE, &trans->status);
+	iwl_trans_fw_error(trans);
+	return ret;
+}
+
 #ifdef CONFIG_IWLWIFI_PCIE_RTPM
 static int iwl_pci_runtime_suspend(struct device *device)
 {
 	struct pci_dev *pdev = to_pci_dev(device);
 	struct iwl_trans *trans = pci_get_drvdata(pdev);
+	int ret;
 
 	IWL_DEBUG_RPM(trans, "entering runtime suspend\n");
 
-	/* For now we only allow D0I3 if the device is off */
-	if (test_bit(STATUS_DEVICE_ENABLED, &trans->status))
-		return -EBUSY;
+	if (test_bit(STATUS_DEVICE_ENABLED, &trans->status)) {
+		ret = iwl_pci_fw_enter_d0i3(trans);
+		if (ret < 0)
+			return ret;
+	}
 
 	trans->system_pm_mode = IWL_PLAT_PM_MODE_D0I3;
 
@@ -729,7 +802,8 @@ static int iwl_pci_runtime_resume(struct device *device)
 
 	iwl_trans_d3_resume(trans, &d3_status, false);
 
-	trans->system_pm_mode = IWL_PLAT_PM_MODE_D3;
+	if (test_bit(STATUS_DEVICE_ENABLED, &trans->status))
+		return iwl_pci_fw_exit_d0i3(trans);
 
 	return 0;
 }

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

@@ -2,6 +2,7 @@
  *
  * Copyright(c) 2003 - 2015 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
+ * Copyright(c) 2016 Intel Deutschland GmbH
  *
  * Portions of this file are derived from the ipw3945 project, as well
  * as portions of the ieee80211 subsystem header files.
@@ -374,6 +375,7 @@ struct iwl_trans_pcie {
 	bool ucode_write_complete;
 	wait_queue_head_t ucode_write_waitq;
 	wait_queue_head_t wait_command_queue;
+	wait_queue_head_t d0i3_waitq;
 
 	u8 cmd_queue;
 	u8 cmd_fifo;
@@ -594,4 +596,7 @@ static inline int iwl_trans_pcie_dbgfs_register(struct iwl_trans *trans)
 }
 #endif
 
+int iwl_pci_fw_exit_d0i3(struct iwl_trans *trans);
+int iwl_pci_fw_enter_d0i3(struct iwl_trans *trans);
+
 #endif /* __iwl_trans_int_pcie_h__ */

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

@@ -72,9 +72,7 @@
 #include <linux/bitops.h>
 #include <linux/gfp.h>
 #include <linux/vmalloc.h>
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
 #include <linux/pm_runtime.h>
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
 
 #include "iwl-drv.h"
 #include "iwl-trans.h"
@@ -1197,9 +1195,6 @@ static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans, bool low_power)
 	if (hw_rfkill != was_hw_rfkill)
 		iwl_trans_pcie_rf_kill(trans, hw_rfkill);
 
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
-	pm_runtime_put_sync(trans->dev);
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
 	/* re-take ownership to prevent other users from stealing the deivce */
 	iwl_pcie_prepare_card_hw(trans);
 }
@@ -1359,9 +1354,10 @@ static int _iwl_trans_pcie_start_hw(struct iwl_trans *trans, bool low_power)
 	/* ... rfkill can call stop_device and set it false if needed */
 	iwl_trans_pcie_rf_kill(trans, hw_rfkill);
 
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
-	pm_runtime_get_sync(trans->dev);
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
+	/* Make sure we sync here, because we'll need full access later */
+	if (low_power)
+		pm_runtime_resume(trans->dev);
+
 	return 0;
 }
 
@@ -1485,10 +1481,9 @@ void iwl_trans_pcie_free(struct iwl_trans *trans)
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	int i;
 
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
 	/* TODO: check if this is really needed */
 	pm_runtime_disable(trans->dev);
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
+
 	synchronize_irq(trans_pcie->pci_dev->irq);
 
 	iwl_pcie_tx_free(trans);
@@ -1844,9 +1839,7 @@ void iwl_trans_pcie_ref(struct iwl_trans *trans)
 	spin_lock_irqsave(&trans_pcie->ref_lock, flags);
 	IWL_DEBUG_RPM(trans, "ref_counter: %d\n", trans_pcie->ref_count);
 	trans_pcie->ref_count++;
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
 	pm_runtime_get(&trans_pcie->pci_dev->dev);
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
 	spin_unlock_irqrestore(&trans_pcie->ref_lock, flags);
 }
 
@@ -1865,10 +1858,9 @@ void iwl_trans_pcie_unref(struct iwl_trans *trans)
 		return;
 	}
 	trans_pcie->ref_count--;
-#ifdef CONFIG_IWLWIFI_PCIE_RTPM
+
 	pm_runtime_mark_last_busy(&trans_pcie->pci_dev->dev);
 	pm_runtime_put_autosuspend(&trans_pcie->pci_dev->dev);
-#endif /* CONFIG_IWLWIFI_PCIE_RTPM */
 
 	spin_unlock_irqrestore(&trans_pcie->ref_lock, flags);
 }
@@ -2536,6 +2528,22 @@ static struct iwl_trans_dump_data
 	return dump_data;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int iwl_trans_pcie_suspend(struct iwl_trans *trans)
+{
+	if (trans->runtime_pm_mode == IWL_PLAT_PM_MODE_D0I3)
+		return iwl_pci_fw_enter_d0i3(trans);
+
+	return 0;
+}
+
+static void iwl_trans_pcie_resume(struct iwl_trans *trans)
+{
+	if (trans->runtime_pm_mode == IWL_PLAT_PM_MODE_D0I3)
+		iwl_pci_fw_exit_d0i3(trans);
+}
+#endif /* CONFIG_PM_SLEEP */
+
 static const struct iwl_trans_ops trans_ops_pcie = {
 	.start_hw = iwl_trans_pcie_start_hw,
 	.op_mode_leave = iwl_trans_pcie_op_mode_leave,
@@ -2546,6 +2554,11 @@ static const struct iwl_trans_ops trans_ops_pcie = {
 	.d3_suspend = iwl_trans_pcie_d3_suspend,
 	.d3_resume = iwl_trans_pcie_d3_resume,
 
+#ifdef CONFIG_PM_SLEEP
+	.suspend = iwl_trans_pcie_suspend,
+	.resume = iwl_trans_pcie_resume,
+#endif /* CONFIG_PM_SLEEP */
+
 	.send_cmd = iwl_trans_pcie_send_hcmd,
 
 	.tx = iwl_trans_pcie_tx,
@@ -2735,6 +2748,8 @@ 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->d0i3_waitq);
+
 	ret = iwl_pcie_alloc_ict(trans);
 	if (ret)
 		goto out_pci_disable_msi;

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

 /******************************************************************************
  *
  * Copyright(c) 2003 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
+ * Copyright(c) 2016 Intel Deutschland GmbH
  *
  * Portions of this file are derived from the ipw3945 project, as well
  * as portions of the ieee80211 subsystem header files.
@@ -1727,6 +1728,20 @@ void iwl_pcie_hcmd_complete(struct iwl_trans *trans,
 		wake_up(&trans_pcie->wait_command_queue);
 	}
 
+	if (meta->flags & CMD_MAKE_TRANS_IDLE) {
+		IWL_DEBUG_INFO(trans, "complete %s - mark trans as idle\n",
+			       iwl_get_cmd_string(trans, cmd->hdr.cmd));
+		set_bit(STATUS_TRANS_IDLE, &trans->status);
+		wake_up(&trans_pcie->d0i3_waitq);
+	}
+
+	if (meta->flags & CMD_WAKE_UP_TRANS) {
+		IWL_DEBUG_INFO(trans, "complete %s - clear trans idle flag\n",
+			       iwl_get_cmd_string(trans, cmd->hdr.cmd));
+		clear_bit(STATUS_TRANS_IDLE, &trans->status);
+		wake_up(&trans_pcie->d0i3_waitq);
+	}
+
 	meta->flags = 0;
 
 	spin_unlock_bh(&txq->lock);