imx6ul GPIO pin multiplexing

1. GPIO Pin Allocation

SNO	BALL	PAD NAME	DEFAULT	DEFAULT  DIRECTION	DEFAULT VALUE	LINUX PIN NO	TESDED
1	B9	LCD_DATA00	GPIO3_IO05	IN	0	69	OK
2	E10	LCD_DATA02	GPIO3_IO07	IN	0	71	OK
3	D10	LCD_DATA03	GPIO3_IO08	IN	0	72	OK
4	B10	LCD_DATA05	GPIO3_IO10	IN	0	74	OK
5	D11	LCD_DATA07	GPIO3_IO12	IN	0	76	OK

2. Probing piont (Development Board)

3. DTS File Configuration

pinctrl_lcdif_dat: lcdifdatgrp {

                        fsl,pins = <

                                    MX6UL_PAD_LCD_DATA00__GPIO3_IO05    0xb0

                                    MX6UL_PAD_LCD_DATA01__LCDIF_DATA01  0x79

                                    MX6UL_PAD_LCD_DATA02__GPIO3_IO07    0xb0

                                    MX6UL_PAD_LCD_DATA03__GPIO3_IO08    0xb0

                                    MX6UL_PAD_LCD_DATA04__LCDIF_DATA04  0x79

                                    MX6UL_PAD_LCD_DATA05__GPIO3_IO10    0xb0

                                    MX6UL_PAD_LCD_DATA06__LCDIF_DATA06  0x79

                                    MX6UL_PAD_LCD_DATA07__GPIO3_IO12    0xb0

                                    MX6UL_PAD_LCD_DATA08__LCDIF_DATA08  0x79

                                    MX6UL_PAD_LCD_DATA09__LCDIF_DATA09  0x79

                                    MX6UL_PAD_LCD_DATA10__LCDIF_DATA10  0x79

                                    MX6UL_PAD_LCD_DATA11__LCDIF_DATA11  0x79

                                    MX6UL_PAD_LCD_DATA12__LCDIF_DATA12  0x79

                                    MX6UL_PAD_LCD_DATA13__LCDIF_DATA13  0x79

                                    MX6UL_PAD_LCD_DATA14__LCDIF_DATA14  0x79

                                    MX6UL_PAD_LCD_DATA15__LCDIF_DATA15  0x79

                                    MX6UL_PAD_LCD_DATA16__LCDIF_DATA16  0x79

                                    MX6UL_PAD_LCD_DATA17__LCDIF_DATA17  0x79

                                    MX6UL_PAD_LCD_DATA18__LCDIF_DATA18  0x79

                                    MX6UL_PAD_LCD_DATA19__LCDIF_DATA19  0x79

                                    MX6UL_PAD_LCD_DATA20__LCDIF_DATA20  0x79

                                    MX6UL_PAD_LCD_DATA21__LCDIF_DATA21  0x79

                                    MX6UL_PAD_LCD_DATA22__LCDIF_DATA22  0x79

                                    MX6UL_PAD_LCD_DATA23__LCDIF_DATA23  0x79

                        >;

           };

4. Linux File Location

 File         :   imx6ul-14x14-evk.dts

5. Linux commands to test GPIO

 5.1 Gpio Status

           cat /sys/kernel/debug/gpio

 5.2 To export GPIO port

          echo 1 > /sys/class/gpio/export

 5.3 To check GPIO value:

          cat /sys/class/gpio/gpio1/value

 5.4 To check direction:

           cat /sys/class/gpio/gpio1/direction

 5.5 To change  GPIO Direction:

          a) echo "out" > /sys/class/gpio/gpio1/direction

          b) echo "in" > /sys/class/gpio/gpio1/direction

5.6       To change  GPIO Value:  

         a) echo 1 > /sys/class/gpio/gpio1/value

         b) echo 0 > /sys/class/gpio/gpio1/value