Linux/AM3352: GPIO read error

Part Number:AM3352

Tool/software: Linux

Hi all,

1,Now my dts as below:

nandflash_pins_default: nandflash_pins_default {
pinctrl-single,pins = <
0x0 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad0.gpmc_ad0 */
0x4 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad1.gpmc_ad1 */
0x8 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad2.gpmc_ad2 */
0xc (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad3.gpmc_ad3 */
0x10 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad4.gpmc_ad4 */
0x14 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad5.gpmc_ad5 */
0x18 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad6.gpmc_ad6 */
0x1c (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_ad7.gpmc_ad7 */
0x70 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_wait0.gpmc_wait0 */
0x74 (PIN_INPUT_PULLUP | MUX_MODE7) /* gpmc_wpn.gpio0_30 */
0x7c (PIN_OUTPUT | MUX_MODE0) /* gpmc_csn0.gpmc_csn0 */
0x90 (PIN_OUTPUT | MUX_MODE0) /* gpmc_advn_ale.gpmc_advn_ale */
0x94 (PIN_OUTPUT | MUX_MODE0) /* gpmc_oen_ren.gpmc_oen_ren */
0x98 (PIN_OUTPUT | MUX_MODE0) /* gpmc_wen.gpmc_wen */
0x9c (PIN_OUTPUT | MUX_MODE0) /* gpmc_be0n_cle.gpmc_be0n_cle */
>;
};

gpio0_pins_default: gpio0_pins_default {
pinctrl-single,pins = <
AM33XX_IOPAD(0x20, PIN_OUTPUT | MUX_MODE7) /* (U10) gpmc_ad8.gpio0[22] */
AM33XX_IOPAD(0x24, PIN_OUTPUT | MUX_MODE7) /* (T10) gpmc_ad9.gpio0[23] */
AM33XX_IOPAD(0x28, PIN_INPUT | MUX_MODE7) /* (T11) gpmc_ad10.gpio0[26] */
AM33XX_IOPAD(0x2c, PIN_INPUT | MUX_MODE7) /* (U12) gpmc_ad11.gpio0[27] */
>;
};

gpio1_pins_default: gpio1_pins_default {
pinctrl-single,pins = <
AM33XX_IOPAD(0x30, PIN_INPUT | MUX_MODE7) /* (T12) gpmc_ad12.gpio1[12] */
AM33XX_IOPAD(0x34, PIN_INPUT | MUX_MODE7) /* (R12) gpmc_ad13.gpio1[13] */
AM33XX_IOPAD(0x38, PIN_INPUT | MUX_MODE7) /* (V13) gpmc_ad14.gpio1[14] */
AM33XX_IOPAD(0x3c, PIN_INPUT | MUX_MODE7) /* (U13) gpmc_ad15.gpio1[15] */
AM33XX_IOPAD(0x80, PIN_OUTPUT | MUX_MODE7) /* (U9) gpmc_csn1.gpio1[30] */
AM33XX_IOPAD(0x84, PIN_OUTPUT | MUX_MODE7) /* (V9) gpmc_csn2.gpio1[31] */
>;
};

2,my nand is 8bit-data bus.

3,notice that I use these pin as input gpio:

(T11) gpmc_ad10.gpio0[26] 

(U12) gpmc_ad11.gpio0[27]

(T12) gpmc_ad12.gpio1[12] 

 (R12) gpmc_ad13.gpio1[13]

(V13) gpmc_ad14.gpio1[14]

(U13) gpmc_ad15.gpio1[15]

4,operations as below:

1,when boot by sd card.I read the gpio value, it is ok.

2,when boot by nand flash,I read the gpio value,it wrong.

3,read actions:

cd /sys/class/gpio

echo 26 > export

cd gpio26

echo "in" > direction

cat value

4,the nand flash is made by the sdcard,

What is the problem?

Best regards