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Question asked by james lee on Mar 31, 2016
Latest reply on Apr 3, 2016 by Pavel Chubakov

Hi all,

I need to control a gpio of MPC8309twr. In my driver, I used gpio_request(38, "gpio_reset") function to request the "USBDR_TXDRXD6/GPIO_38/QE_BRG_9" I/O signal. But the function alway return a negative number.

I have configurated the kernel, added the "QE GPIO support" and "GPIO Support" and "/sys/class/gpio/... (sysfs interface)". In order to multiplex the GPIO_38, I set the SICR_2 register as 0x00080000. In mpc8390twr.dts, I add lines as follows:

gpio2: gpio-controller@d00 {

  #gpio-cells = <2>;

  compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";

  reg = <0xd00 0x100>;

  interrupts = <75 0x8>;

  interrupt-parent = <&ipic>;





Is there anything wrong in my configuration ?

I will appreciate all your comments and suggestions!