The flexcan driver has function pointer transceiver_switch defined in
flexcan_platform_data for platform codes to hook up their transceiver
switch implementation.  However this does not cope with device tree
probe.

It's been observed that platforms mostly use gpios to control the
switch of flexcan transceiver, like enable and standby.  The patch
adds transceiver switch gpios support into flexcan driver, so that
platforms booting from device tree can just define properties
phy-enable-gpios and phy-standby-gpios to have flexcan driver control
the gpios.

Signed-off-by: Shawn Guo <redacted>
---
 .../devicetree/bindings/net/can/fsl-flexcan.txt    |    2 +
 drivers/net/can/flexcan.c                          |   62 ++++++++++++++++++++
 2 files changed, 64 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
index 8ff324e..e0dbac7 100644
--- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
+++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt

@@ -15,6 +15,8 @@ Required properties:
 Optional properties:
 
 - clock-frequency : The oscillator frequency driving the flexcan device
+- phy-enable-gpios : Specify the gpio used to enable phy
+- phy-standby-gpios : Specify the gpio used to put phy into STANDBY mode