-----Original Message-----
From: Joakim Zhang
Sent: 2019年7月31日 13:57
To: mkl@pengutronix.de; linux-can@vger.kernel.org
Cc: wg@grandegger.com; netdev@vger.kernel.org; dl-linux-imx
[off-list ref]; Joakim Zhang [off-list ref]
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. (coming i.MX8QM/QXP will also
completely power off the domain, the controller state will be lost and needs
restore).
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 <redacted>
---
 drivers/net/can/flexcan.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index

c21b3507123e..228d07e84ddc 100644

--- 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"

@@ -1889,7 +1890,7 @@ static int __maybe_unused flexcan_suspend(struct

device *device)  {
 	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 @@ -1899,25 +1900,27

@@ static int __maybe_unused flexcan_suspend(struct device *device)
 			enable_irq_wake(dev->irq);
 			flexcan_enter_stop_mode(priv);
 		} 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)) {

@@ -1926,15 +1929,19 @@ static int __maybe_unused

flexcan_resume(struct device *device)
 		if (device_may_wakeup(device)) {
 			disable_irq_wake(dev->irq);
 		} 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)
--
2.17.1