Hi all,
I'm trying to activate a new input on my i.MX35 device MX35_PAD_SD2_DATA3__GPIO2_4 and activating the pull up mode to this input.
But I'm a bit confused with the device tree configuration :
gpio_exporter: gpio-exporter {
compatible = "linux,gpio-exporter";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gpio_exporter>;
GPIO_IN {
gpios = <&gpio3 13 GPIO_ACTIVE_HIGH>;
};
GPIO_OUT {
gpios = <&gpio3 12 GPIO_ACTIVE_HIGH>;
output;
initial-state = <0>;
};
...
GPIO_NEWINPUT {
gpios = <&gpio2 4 GPIO_ACTIVE_HIGH>;
};
};
pinctrl_gpio_exporter: gpioexportergrp {
fsl,pins = <
MX35_PAD_RTS2__GPIO3_12 0x80000000
MX35_PAD_CTS2__GPIO3_13 0x80000000
...
MX35_PAD_SD2_DATA2__GPIO2_4 0x80000000
>;
};
Others GPIOs use the 0x80000000 value but what is it's meaning?
I have take a look to Table 301: Register: IOMUXC_SW_MUX_CTL_PAD_SD2_DATA2 but this subject is not clear enough for me.
I also have check in my include/dt-bindings/gpio/gpio.h file and no reference to pull up configuration.
Solved! Go to Solution.
Hi frk
0x80000000 means that settings are inherited from uboot ( pin does not need config.)
More details can be found in AN5078
Influence of Pin Setting on System Function and Performance
Field "PULL_KEEP_CTL" Register: IOMUXC_SW_PAD_CTL_PAD_SD2_DATA3 configures
pull settings, described on p.2900 i.MX35 (MCIMX35) Multimedia Applications Processor Reference
Best regards
igor
Thanks for your support.
Things are clearer now.
Hi frk
0x80000000 means that settings are inherited from uboot ( pin does not need config.)
More details can be found in AN5078
Influence of Pin Setting on System Function and Performance
Field "PULL_KEEP_CTL" Register: IOMUXC_SW_PAD_CTL_PAD_SD2_DATA3 configures
pull settings, described on p.2900 i.MX35 (MCIMX35) Multimedia Applications Processor Reference
Best regards
igor
So if 0x80000000 is used and nothing come from the bootloader, state can be considered as unknown/invalid?
I'll check the documentation, AN5078 seems pretty usefull.
>So if 0x80000000 is used and nothing come from the bootloader, state can be considered as unknown/invalid?
it is set as default state (after reset)
~igor