Hi,
I use an i.mx6 board and am configuring a device tree.
I changed a dts file and put the dtb file in a boot partition.
I set GPIO4_IO19 in dts file as follows.
&iomuxc {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_hog_1>;
imx6ul-evk {
pinctrl_hog_1: hoggrp-1 {
fsl,pins = <
...
MX6UL_PAD_CSI_VSYNC__GPIO4_IO19 0x0000B0B0
...
>;
};
...
At first MX6UL_PAD_CSI_VSYNC__GPIO4_IO19 was defined in other group (usdhcgrp) but I commented out them.
After booting, I checked if gpio is successfully determined as I set.
The result is
echo 115 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
So I checked this.
cat /sys/kernel/debug/gpio
GPIOs 0-31, platform/209c000.gpio, 209c000.gpio:
gpio-10 (phy-reset ) out lo
GPIOs 32-63, platform/20a0000.gpio, 20a0000.gpio:
GPIOs 64-95, platform/20a4000.gpio, 20a4000.gpio:
gpio-68 (ft5x06_irq_gpio ) in hi
GPIOs 96-127, platform/20a8000.gpio, 20a8000.gpio:
gpio-109 (? ) out lo
gpio-115 (cd ) in lo
gpio-116 (? ) out lo
gpio-117 (? ) out lo
gpio-118 (sysfs ) in hi
GPIOs 128-159, platform/20ac000.gpio, 20ac000.gpio:
gpio-128 (phy-reset ) out lo
gpio-115 is used by cd. What is cd ?
I want to use it as sysfs to read the state. Any other way to read it ?
Furthermore, gpio-10, 68, 109, 116, 117 is used by other device.
How can I use them by sysfs?
Thank you for your cooperation.
