UART3 and UART4 are not working on customised carrier board with modified device tree

Hi all,

I am working with VF50 module with a custom carrier board.I have modified the device tree for enabling the UART3 and UART4.But the UARt3 and UART4 are not responding.The other 3 UARTs(0,1,2) are working fine.
I have made following changes to the device tree file “vf-colibri-eval-v3.dtsi”.
The changes are:-

&uart3 {
	      pinctrl-names = "default";
	      pinctrl-0 = <&pinctrl_uart3>;
	      status = "okay";
       };

&uart4 {
	      pinctrl-names = "default";
	      pinctrl-0 = <&pinctrl_uart4>;
	      status = "okay";
       };


/*******under MUX settings following changes are done********/
pinctrl_uart3:uart3group
		           {
	                       fsl,pins = <
	                                       VF610_PAD_PTA20__UART3_TX       0x21a2     
 	                                       VF610_PAD_PTA31__UART3_RX       0x21a1    
	                                  >;     	  
		           };
		  
		         pinctrl_uart4:uart4group
		           {
		               fsl,pins = <
		                             VF610_PAD_PTA28__UART4_TX       0x21a2
		                             VF610_PAD_PTA29__UART4_RX       0x21a1
		                          >;
		           };

All of my serial interfaces are available under # cat /proc/iomem/.

3f000000-3f03ffff : 3f000000.sram
3f040000-3f07ffff : 3f040000.sram
3f400000-3f47ffff : 3f400000.sram
3f480000-3f4fffff : 3f480000.sram
40001800-40001bff : mscm-ir
40018000-40019fff : /soc/aips-bus@40000000/dma-controller@40018000
40020000-40023fff : /soc/aips-bus@40000000/flexcan@40020000
40024000-40024fff : /soc/aips-bus@40000000/dma-controller@40018000
40025000-40025fff : /soc/aips-bus@40000000/dma-controller@40018000
40027000-40027fff : /soc/aips-bus@40000000/serial@40027000
40028000-40028fff : /soc/aips-bus@40000000/serial@40028000
40029000-40029fff : /soc/aips-bus@40000000/serial@40029000
4002a000-4002afff : /soc/aips-bus@40000000/serial@4002a000
4002d000-4002dfff : /soc/aips-bus@40000000/dspi1@4002d000
40034000-400347ff : /soc/aips-bus@40000000/usb@40034000
  40034000-400347ff : /soc/aips-bus@40000000/usb@40034000
40034800-400349ff : /soc/aips-bus@40000000/usb@40034800
40038000-40038fff : /soc/aips-bus@40000000/pwm@40038000
40039000-40039fff : /soc/aips-bus@40000000/pwm@40039000
4003b000-4003bfff : /soc/aips-bus@40000000/adc@4003b000
4003d000-4003dfff : /soc/aips-bus@40000000/timing-controller@4003d000
4003e000-4003efff : /soc/aips-bus@40000000/wdog@4003e000
40048000-40048fff : /soc/aips-bus@40000000/iomuxc@40048000
40049000-40049fff : /soc/aips-bus@40000000/gpio@40049000
4004a000-4004afff : /soc/aips-bus@40000000/gpio@4004a000
4004b000-4004bfff : /soc/aips-bus@40000000/gpio@4004b000
4004c000-4004cfff : /soc/aips-bus@40000000/gpio@4004c000
4004d000-4004dfff : /soc/aips-bus@40000000/gpio@4004d000
40050800-40050bff : /soc/aips-bus@40000000/usbphy@40050800
40050c00-40050fff : /soc/aips-bus@40000000/usbphy@40050c00
40058000-400591ff : /soc/aips-bus@40000000/dcu@40058000
40066000-40066fff : /soc/aips-bus@40000000/i2c@40066000
4006a000-4006afff : /soc/aips-bus@40000000/wkpu@4006a000
4006c000-4006cfff : gpc
40098000-40099fff : /soc/aips-bus@40080000/dma-controller@40098000
400a1000-400a1fff : /soc/aips-bus@40080000/dma-controller@40098000
400a2000-400a2fff : /soc/aips-bus@40080000/dma-controller@40098000
400a5000-400a5cef : /soc/aips-bus@40080000/ocotp@400a5000
400a9000-400a9fff : /soc/aips-bus@40080000/serial@400a9000
400b2000-400b2fff : mmc0
400b4000-400b47ff : /soc/aips-bus@40080000/usb@400b4000
  400b4000-400b47ff : /soc/aips-bus@40080000/usb@400b4000
400b4800-400b49ff : /soc/aips-bus@40080000/usb@400b4800
400bb000-400bbfff : /soc/aips-bus@40080000/adc@400bb000
400d1000-400d1fff : /soc/aips-bus@40080000/ethernet@400d1000
400d4000-400d7fff : /soc/aips-bus@40080000/flexcan@400d4000
400e0000-400e3fff : /soc/aips-bus@40080000/nand@400e0000
400ff000-400ff03f : /soc/aips-bus@40000000/gpio@40049000
400ff040-400ff07f : /soc/aips-bus@40000000/gpio@4004a000
400ff080-400ff0bf : /soc/aips-bus@40000000/gpio@4004b000
400ff0c0-400ff0ff : /soc/aips-bus@40000000/gpio@4004c000
400ff100-400ff13f : /soc/aips-bus@40000000/gpio@4004d000
80000000-87dfffff : System RAM
  80008000-8080c023 : Kernel code
  80846000-808a8337 : Kernel data

Any suggestions are welcome. Plzz suggest.

PTA20 and PTA31 are multiplexed as GPIOs here. Those entries need to be removed from pinctrl_additionalgpio. PTA28 and PTA29 are used for esdhc1 viz. SD card. If you do not plan on using SD card, it should be fine but then you need to disable esdhc1.