can: flexcan: disable transceiver during system PM

During system PM, if no wakeup requirement, disable transceiver to
save power.

Fixes: 4de349e ("can: flexcan: fix resume function")
Cc: [email protected]
Reviewed-by: Frank Li <[email protected]>
Signed-off-by: Haibo Chen <[email protected]>
Link: https://patch.msgid.link/[email protected]
[mkl: add newlines]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: Haibo Chen

drivers/net/can/flexcan/flexcan-core.c

@@ -2260,6 +2260,10 @@ static int __maybe_unused flexcan_suspend(struct device *device)
 
 			flexcan_chip_interrupts_disable(dev);
 
+			err = flexcan_transceiver_disable(priv);
+			if (err)
+				return err;
+
 			err = pinctrl_pm_select_sleep_state(device);
 			if (err)
 				return err;
@@ -2292,10 +2296,16 @@ static int __maybe_unused flexcan_resume(struct device *device)
 			if (err)
 				return err;
 
-			err = flexcan_chip_start(dev);
+			err = flexcan_transceiver_enable(priv);
 			if (err)
 				return err;
 
+			err = flexcan_chip_start(dev);
+			if (err) {
+				flexcan_transceiver_disable(priv);
+				return err;
+			}
+
 			flexcan_chip_interrupts_enable(dev);
 		}