can: flexcan: disable transceiver during system PM

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

Fixes: 4de349e786 ("can: flexcan: fix resume function")
Cc: stable@vger.kernel.org
Reviewed-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://patch.msgid.link/20250314110145.899179-2-haibo.chen@nxp.com
[mkl: add newlines]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

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);
 		}