Hello everyone,
I have a jetson-nano production module. Basically the title says it all.
I want to set the pin 181 (PCIE0_RST) manually to high or low.
Is that possible? And if so, how can it be done?
Didn’t find any information about something linke that online.
Any help is appreciated.
Is this related to PCIe driver issue or you just want to toggle the pin?
Generally, the software driver should handle it.
Not related to PCIe driver, it is our custom board, where the PCIE_RST is connected to our modem’s reset pin.
So basically i just want to toggle the pin :)
I am a little not sure about the usage here.
Is this issue related to PCIe or you just want to treat this pin as a GPIO and let your modem to use?
NOT releated to PCIe.
I want to treat the PIN as a GPIO, just set it manually to high or low.
Then please use the pinmux spreadsheet to configure dtsi files which enable this pin as GPIO.
And then you can use sysfs to control this GPIO.
Thanks for your fast answer.
Will try it and comeback if there were any problems.
I’m a little bit confused.
I found 2 dtsi files which are looking intresting to me.
pex_l0_rst_n_pa0 {
nvidia,pins = "pex_l0_rst_n_pa0";
nvidia,function = "pe0";
nvidia,pull = <TEGRA_PIN_PULL_NONE>;
nvidia,tristate = <TEGRA_PIN_DISABLE>;
nvidia,enable-input = <TEGRA_PIN_DISABLE>;
nvidia,io-high-voltage = <TEGRA_PIN_ENABLE>;
};
gpio-output-low = <
TEGRA_GPIO(S, 7)
TEGRA_GPIO(T, 0)
TEGRA_GPIO(H, 0)
TEGRA_GPIO(H, 3)
TEGRA_GPIO(H, 4)
TEGRA_GPIO(H, 7)
TEGRA_GPIO(I, 0)
TEGRA_GPIO(I, 2)
>;
gpio-output-high = <
TEGRA_GPIO(A, 6)
TEGRA_GPIO(X, 3)
TEGRA_GPIO(I, 1)
TEGRA_GPIO(CC, 7)
>;
};
I read this post to get a better understanding how to enable a new GPIO: TEGRA_GPIO("port", "offset")? - #2 by JamieBasil
According the table you sent above, the pin i’m intrested about looks like that:
PCIE0_RST* 181 PEX_L0_RST_N GPIO3_PA.00
That corresponds to TEGRA_GPIO(A,0) according the post mentioned above…
So my approach would be to add this line to the outputs above(tegra-210-porg-gpio-p3448-0000-b00.dts).
But i should also disable the pin for the PCIe driver. How can i achieve that? Remove it from the tegra-210-porg-pinmux-p3448-0000-b00.dtsi file?
Can you tell me if i’m going in the right direction?
No, the pinmux spreadsheet is the one to change the function… you should run it on a windows machine, open the spreadsheet, select the function you want your pin to be used in the excel.
And the dtsi generated will be what you want. You shouldn’t need to “modify the dts” file again after using the spreadsheet.
I didn’t mean you cannot modify the dtsi files. I just want to say it should be done by the excel .
And this spreadsheet only cares about “pinmux”. It is not the full dts we flashed to the board.
It is not possible our system can just boot with these few lines. There are other dts files in separate files. If you want to check them, download the public source from the L4T archive.
Ty. I didn’t see the button at the top of excel to generate the dtsi file at the beginning sorry :D.
Okay now that i have generated the two dtsi files with the spread sheet.
How can i apply this overlay? Do i need to replace the two files mentioned above with the newly generated ones?
And build the kernel again.
Or is there a way to directly apply this overlay?
Greetings Marco
You have to replace these two files to the dts file and rebuild the dtb out.
Put the dtb to Linux_for_Tegra/kernel/dtb and full flash the board.
Thanks again .
Really appreciate your fast answering.
Okay now i build the kernel, copied the resulting dtb file to the correct location and flashed the board.
However, if i run the following commands:
echo 0 > /sys/class/gpio/export
echo 0 > /sys/class/gpio/gpio0/value
-bash: echo: write error: Operation not permitted
It says that the operation is not permitted.
According to the table PCIE0_RST is GPIO3_PA.00. So export GPIO Pin 0 is correct right?
What am I missing?
Please share
sudo cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 0-255, parent: platform/6000d000.gpio, tegra-gpio:
gpio-0 ( |sysfs ) in lo
gpio-1 ( )
gpio-2 ( |pcie_wake ) in hi
gpio-3 ( )
gpio-4 ( )
gpio-5 ( )
gpio-6 ( |system-suspend-gpio ) out hi
gpio-7 ( )
gpio-8 ( )
gpio-9 ( )
gpio-10 ( )
gpio-11 ( )
gpio-12 (SPI1_MOSI )
gpio-13 (SPI1_MISO )
gpio-14 (SPI1_SCK )
gpio-15 (SPI1_CS0 )
gpio-16 (SPI0_MOSI )
gpio-17 (SPI0_MISO )
gpio-18 (SPI0_SCK )
gpio-19 (SPI0_CS0 )
gpio-20 (SPI0_CS1 )
gpio-21 ( )
gpio-22 ( )
gpio-23 ( )
gpio-24 ( )
gpio-25 ( )
gpio-26 ( )
gpio-27 ( )
gpio-28 ( )
gpio-29 ( )
gpio-30 ( )
gpio-31 ( )
gpio-32 ( )
gpio-33 ( )
gpio-34 ( )
gpio-35 ( )
gpio-36 ( )
gpio-37 ( )
gpio-38 (GPIO13 )
gpio-39 ( )
gpio-40 ( )
gpio-41 ( )
gpio-42 ( )
gpio-43 ( )
gpio-44 ( )
gpio-45 ( )
gpio-46 ( )
gpio-47 ( )
gpio-48 ( )
gpio-49 ( )
gpio-50 (UART1_RTS )
gpio-51 (UART1_CTS )
gpio-52 ( )
gpio-53 ( )
gpio-54 ( )
gpio-55 ( )
gpio-56 ( )
gpio-57 ( )
gpio-58 ( )
gpio-59 ( )
gpio-60 ( )
gpio-61 ( )
gpio-62 ( )
gpio-63 ( )
gpio-64 ( |i2c-mux-gpio ) out hi
gpio-65 ( |? ) out hi
gpio-66 ( )
gpio-67 ( )
gpio-68 ( )
gpio-69 ( )
gpio-70 ( )
gpio-71 ( )
gpio-72 ( )
gpio-73 ( )
gpio-74 ( )
gpio-75 ( )
gpio-76 (I2S0_FS )
gpio-77 (I2S0_DIN )
gpio-78 (I2S0_DOUT )
gpio-79 (I2S0_SCLK )
gpio-80 ( )
gpio-81 ( )
gpio-82 ( )
gpio-83 ( )
gpio-84 ( )
gpio-85 ( )
gpio-86 ( )
gpio-87 ( )
gpio-88 ( )
gpio-89 ( )
gpio-90 ( )
gpio-91 ( )
gpio-92 ( )
gpio-93 ( )
gpio-94 ( )
gpio-95 ( )
gpio-96 ( )
gpio-97 ( )
gpio-98 ( )
gpio-99 ( )
gpio-100 ( )
gpio-101 ( )
gpio-102 ( )
gpio-103 ( )
gpio-104 ( )
gpio-105 ( )
gpio-106 ( )
gpio-107 ( )
gpio-108 ( )
gpio-109 ( )
gpio-110 ( )
gpio-111 ( )
gpio-112 ( )
gpio-113 ( )
gpio-114 ( )
gpio-115 ( )
gpio-116 ( )
gpio-117 ( )
gpio-118 ( )
gpio-119 ( )
gpio-120 ( )
gpio-121 ( )
gpio-122 ( )
gpio-123 ( )
gpio-124 ( )
gpio-125 ( )
gpio-126 ( )
gpio-127 ( )
gpio-128 ( )
gpio-129 ( )
gpio-130 ( )
gpio-131 ( )
gpio-132 ( )
gpio-133 ( )
gpio-134 ( )
gpio-135 ( )
gpio-136 ( )
gpio-137 ( )
gpio-138 ( )
gpio-139 ( )
gpio-140 ( )
gpio-141 ( )
gpio-142 ( )
gpio-143 ( )
gpio-144 ( )
gpio-145 ( )
gpio-146 ( )
gpio-147 ( )
gpio-148 ( )
gpio-149 (GPIO01 )
gpio-150 ( )
gpio-151 ( )
gpio-152 ( )
gpio-153 ( )
gpio-154 ( )
gpio-155 ( )
gpio-156 ( )
gpio-157 ( )
gpio-158 ( )
gpio-159 ( )
gpio-160 ( )
gpio-161 ( )
gpio-162 ( )
gpio-163 ( )
gpio-164 ( )
gpio-165 ( )
gpio-166 ( )
gpio-167 ( )
gpio-168 (GPIO07 )
gpio-169 ( )
gpio-170 ( )
gpio-171 ( )
gpio-172 ( )
gpio-173 ( )
gpio-174 ( )
gpio-175 ( )
gpio-176 ( )
gpio-177 ( )
gpio-178 ( )
gpio-179 ( )
gpio-180 ( )
gpio-181 ( )
gpio-182 ( )
gpio-183 ( )
gpio-184 ( )
gpio-185 ( )
gpio-186 ( )
gpio-187 ( )
gpio-188 ( )
gpio-189 ( |Power ) in hi IRQ
gpio-190 ( |Forcerecovery ) in hi IRQ
gpio-191 ( )
gpio-192 ( )
gpio-193 ( )
gpio-194 (GPIO12 )
gpio-195 ( )
gpio-196 ( )
gpio-197 ( )
gpio-198 ( )
gpio-199 ( )
gpio-200 (GPIO11 )
gpio-201 ( )
gpio-202 ( |pwm-fan-tach ) in lo IRQ
gpio-203 ( |vdd-3v3-sd ) out lo
gpio-204 ( )
gpio-205 ( )
gpio-206 ( )
gpio-207 ( )
gpio-208 ( )
gpio-209 ( )
gpio-210 ( )
gpio-211 ( )
gpio-212 ( )
gpio-213 ( )
gpio-214 ( )
gpio-215 ( )
gpio-216 (GPIO09 )
gpio-217 ( )
gpio-218 ( )
gpio-219 ( )
gpio-220 ( )
gpio-221 ( )
gpio-222 ( )
gpio-223 ( )
gpio-224 ( )
gpio-225 ( |hdmi2.0_hpd ) in lo IRQ
gpio-226 ( )
gpio-227 ( )
gpio-228 ( |extcon:extcon@1 ) in hi IRQ
gpio-229 ( )
gpio-230 ( )
gpio-231 ( |? ) out hi
gpio-232 (SPI1_CS1 )
gpio-233 ( )
gpio-234 ( )
gpio-235 ( )
gpio-236 ( )
gpio-237 ( )
gpio-238 ( )
gpio-239 ( )
gpiochip1: GPIOs 504-511, parent: platform/max77620-gpio, max77620-gpio, can sleep:
gpio-505 ( |spmic-default-output) out hi
gpio-507 ( |vdd-3v3-sys ) out hi
gpio-510 ( |enable ) out lo
gpio-511 ( |avdd-io-edp-1v05 ) out lo
Hi,
You set your gpio as input pin. So you cannot directly ask it with echo 0/1. That is output pin’s function.
Here when unexporting gpio-0 again
gpio-0 ( )
gpio-1 ( )
gpio-2 ( |pcie_wake ) in hi
gpio-3 ( )
gpio-4 ( )
gpio-5 ( )
gpio-6 ( |system-suspend-gpio ) out hi
gpio-7 ( )
gpio-8 ( )
gpio-9 ( )
gpio-10 ( )
gpio-11 ( )
gpio-12 (SPI1_MOSI )
gpio-13 (SPI1_MISO )
gpio-14 (SPI1_SCK )
gpio-15 (SPI1_CS0 )
gpio-16 (SPI0_MOSI )
gpio-17 (SPI0_MISO )
gpio-18 (SPI0_SCK )
gpio-19 (SPI0_CS0 )
gpio-20 (SPI0_CS1 )
gpio-21 ( )
gpio-22 ( )
gpio-23 ( )
gpio-24 ( )
gpio-25 ( )
gpio-26 ( )
gpio-27 ( )
gpio-28 ( )
gpio-29 ( )
gpio-30 ( )
gpio-31 ( )
gpio-32 ( )
gpio-33 ( )
gpio-34 ( )
gpio-35 ( )
gpio-36 ( )
gpio-37 ( )
gpio-38 (GPIO13 )
gpio-39 ( )
gpio-40 ( )
gpio-41 ( )
gpio-42 ( )
gpio-43 ( )
gpio-44 ( )
gpio-45 ( )
gpio-46 ( )
gpio-47 ( )
gpio-48 ( )
gpio-49 ( )
gpio-50 (UART1_RTS )
gpio-51 (UART1_CTS )
gpio-52 ( )
gpio-53 ( )
gpio-54 ( )
gpio-55 ( )
gpio-56 ( )
gpio-57 ( )
gpio-58 ( )
gpio-59 ( )
gpio-60 ( )
gpio-61 ( )
gpio-62 ( )
gpio-63 ( )
gpio-64 ( |i2c-mux-gpio ) out hi
gpio-65 ( |? ) out hi
gpio-66 ( )
gpio-67 ( )
gpio-68 ( )
gpio-69 ( )
gpio-70 ( )
gpio-71 ( )
gpio-72 ( )
gpio-73 ( )
gpio-74 ( )
gpio-75 ( )
gpio-76 (I2S0_FS )
gpio-77 (I2S0_DIN )
gpio-78 (I2S0_DOUT )
gpio-79 (I2S0_SCLK )
gpio-80 ( )
gpio-81 ( )
gpio-82 ( )
gpio-83 ( )
gpio-84 ( )
gpio-85 ( )
gpio-86 ( )
gpio-87 ( )
gpio-88 ( )
gpio-89 ( )
gpio-90 ( )
gpio-91 ( )
gpio-92 ( )
gpio-93 ( )
gpio-94 ( )
gpio-95 ( )
gpio-96 ( )
gpio-97 ( )
gpio-98 ( )
gpio-99 ( )
gpio-100 ( )
gpio-101 ( )
gpio-102 ( )
gpio-103 ( )
gpio-104 ( )
gpio-105 ( )
gpio-106 ( )
gpio-107 ( )
gpio-108 ( )
gpio-109 ( )
gpio-110 ( )
gpio-111 ( )
gpio-112 ( )
gpio-113 ( )
gpio-114 ( )
gpio-115 ( )
gpio-116 ( )
gpio-117 ( )
gpio-118 ( )
gpio-119 ( )
gpio-120 ( )
gpio-121 ( )
gpio-122 ( )
gpio-123 ( )
gpio-124 ( )
gpio-125 ( )
gpio-126 ( )
gpio-127 ( )
gpio-128 ( )
gpio-129 ( )
gpio-130 ( )
gpio-131 ( )
gpio-132 ( )
gpio-133 ( )
gpio-134 ( )
gpio-135 ( )
gpio-136 ( )
gpio-137 ( )
gpio-138 ( )
gpio-139 ( )
gpio-140 ( )
gpio-141 ( )
gpio-142 ( )
gpio-143 ( )
gpio-144 ( )
gpio-145 ( )
gpio-146 ( )
gpio-147 ( )
gpio-148 ( )
gpio-149 (GPIO01 )
gpio-150 ( )
gpio-151 ( )
gpio-152 ( )
gpio-153 ( )
gpio-154 ( )
gpio-155 ( )
gpio-156 ( )
gpio-157 ( )
gpio-158 ( )
gpio-159 ( )
gpio-160 ( )
gpio-161 ( )
gpio-162 ( )
gpio-163 ( )
gpio-164 ( )
gpio-165 ( )
gpio-166 ( )
gpio-167 ( )
gpio-168 (GPIO07 )
gpio-169 ( )
gpio-170 ( )
gpio-171 ( )
gpio-172 ( )
gpio-173 ( )
gpio-174 ( )
gpio-175 ( )
gpio-176 ( )
gpio-177 ( )
gpio-178 ( )
gpio-179 ( )
gpio-180 ( )
gpio-181 ( )
gpio-182 ( )
gpio-183 ( )
gpio-184 ( )
gpio-185 ( )
gpio-186 ( )
gpio-187 ( )
gpio-188 ( )
gpio-189 ( |Power ) in hi IRQ
gpio-190 ( |Forcerecovery ) in hi IRQ
gpio-191 ( )
gpio-192 ( )
gpio-193 ( )
gpio-194 (GPIO12 )
gpio-195 ( )
gpio-196 ( )
gpio-197 ( )
gpio-198 ( )
gpio-199 ( )
gpio-200 (GPIO11 )
gpio-201 ( )
gpio-202 ( |pwm-fan-tach ) in lo IRQ
gpio-203 ( |vdd-3v3-sd ) out lo
gpio-204 ( )
gpio-205 ( )
gpio-206 ( )
gpio-207 ( )
gpio-208 ( )
gpio-209 ( )
gpio-210 ( )
gpio-211 ( )
gpio-212 ( )
gpio-213 ( )
gpio-214 ( )
gpio-215 ( )
gpio-216 (GPIO09 )
gpio-217 ( )
gpio-218 ( )
gpio-219 ( )
gpio-220 ( )
gpio-221 ( )
gpio-222 ( )
gpio-223 ( )
gpio-224 ( )
gpio-225 ( |hdmi2.0_hpd ) in lo IRQ
gpio-226 ( )
gpio-227 ( )
gpio-228 ( |extcon:extcon@1 ) in hi IRQ
gpio-229 ( )
gpio-230 ( )
gpio-231 ( |? ) out hi
gpio-232 (SPI1_CS1 )
gpio-233 ( )
gpio-234 ( )
gpio-235 ( )
gpio-236 ( )
gpio-237 ( )
gpio-238 ( )
gpio-239 ( )
gpiochip1: GPIOs 504-511, parent: platform/max77620-gpio, max77620-gpio, can sleep:
gpio-505 ( |spmic-default-output) out hi
gpio-507 ( |vdd-3v3-sys ) out hi
gpio-510 ( |enable ) out lo
gpio-511 ( |avdd-io-edp-1v05 ) out lo
There is a “direction” in the gpio sysfs. You can set it.
