openwrt/target/linux/layerscape/patches-5.4/802-can-0025-can-flexcan-add-LPSR-mode-support-for-i.MX7D.patch

From 211c20a459a0fd4868ed22ecfc2b2186d9df6da0 Mon Sep 17 00:00:00 2001
From: Joakim Zhang <qiangqing.zhang@nxp.com>
Date: Tue, 30 Jul 2019 14:43:25 +0800
Subject: [PATCH] can: flexcan: add LPSR mode support for i.MX7D

For i.MX7D LPSR mode, the controller will lost power and got the
configuration state lost after system resume back.
So we need to set pinctrl state again and re-start chip to do
re-configuration after resume.

For wakeup case, it should not set pinctrl to sleep state by
pinctrl_pm_select_sleep_state.
For interface is not up before suspend case, we don't need
re-configure as it will be configured by user later by interface up.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/can/flexcan.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -26,6 +26,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/regmap.h>
 
 #define DRV_NAME			"flexcan"
@@ -1942,7 +1943,7 @@ static int __maybe_unused flexcan_suspen
 {
 	struct net_device *dev = dev_get_drvdata(device);
 	struct flexcan_priv *priv = netdev_priv(dev);
-	int err = 0;
+	int err;
 
 	if (netif_running(dev)) {
 		/* if wakeup is enabled, enter stop mode
@@ -1954,25 +1955,27 @@ static int __maybe_unused flexcan_suspen
 			if (err)
 				return err;
 		} else {
-			err = flexcan_chip_disable(priv);
+			flexcan_chip_stop(dev);
+
+			err = pm_runtime_force_suspend(device);
 			if (err)
 				return err;
 
-			err = pm_runtime_force_suspend(device);
+			pinctrl_pm_select_sleep_state(device);
 		}
 		netif_stop_queue(dev);
 		netif_device_detach(dev);
 	}
 	priv->can.state = CAN_STATE_SLEEPING;
 
-	return err;
+	return 0;
 }
 
 static int __maybe_unused flexcan_resume(struct device *device)
 {
 	struct net_device *dev = dev_get_drvdata(device);
 	struct flexcan_priv *priv = netdev_priv(dev);
-	int err = 0;
+	int err;
 
 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 	if (netif_running(dev)) {
@@ -1984,15 +1987,19 @@ static int __maybe_unused flexcan_resume
 			if (err)
 				return err;
 		} else {
+			pinctrl_pm_select_default_state(device);
+
 			err = pm_runtime_force_resume(device);
 			if (err)
 				return err;
 
-			err = flexcan_chip_enable(priv);
+			err = flexcan_chip_start(dev);
+			if (err)
+				return err;
 		}
 	}
 
-	return err;
+	return 0;
 }
 
 static int __maybe_unused flexcan_runtime_suspend(struct device *device)