https://community.nxp.com/t5/i-MX-Processors/i-MX8xQuadPlus-UART1-RX-GPIO-usage/m-p/1395771#M185488 <P>I'm trying to use UART1_RX (ball L31) on an i.MX8XQuadPlus processor. I have the device tree pinctrl setup as follows:</P><P>IMX8QXP_UART1_RX_LSIO_GPT1_CLK 0x26000060 // IMX8_FREQ_IN</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_0-1641498866484.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166932i31F4FD0C84640758/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_0-1641498866484.png" alt="nlbutts_0-1641498866484.png" /></span></P><P>&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_1-1641498873578.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166933iB6CA2768161609FA/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_1-1641498873578.png" alt="nlbutts_1-1641498873578.png" /></span></P><P>This should be GPIO0 pin 22:</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_2-1641498891607.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166934i5F046BA36E3D8F3E/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_2-1641498891607.png" alt="nlbutts_2-1641498891607.png" /></span></P><P>&nbsp;</P><P>I have a 1 Hz square wave being fed into this pin.&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_3-1641498954455.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166935iD25A9E83FA6D7256/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_3-1641498954455.png" alt="nlbutts_3-1641498954455.png" /></span></P><P>&nbsp;</P><P>But when I try to read this pin in Linux it always reads low:</P><LI-CODE lang="markup">root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0</LI-CODE><P>I looked through the errata and didn't see any mention of a GPIO pin.&nbsp;</P><P>Any ideas?</P> Thu, 06 Jan 2022 19:57:07 GMT nlbutts 2022-01-06T19:57:07Z https://community.nxp.com/t5/i-MX-Processors/i-MX8xQuadPlus-UART1-RX-GPIO-usage/m-p/1395771#M185488 <P>I'm trying to use UART1_RX (ball L31) on an i.MX8XQuadPlus processor. I have the device tree pinctrl setup as follows:</P><P>IMX8QXP_UART1_RX_LSIO_GPT1_CLK 0x26000060 // IMX8_FREQ_IN</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_0-1641498866484.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166932i31F4FD0C84640758/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_0-1641498866484.png" alt="nlbutts_0-1641498866484.png" /></span></P><P>&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_1-1641498873578.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166933iB6CA2768161609FA/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_1-1641498873578.png" alt="nlbutts_1-1641498873578.png" /></span></P><P>This should be GPIO0 pin 22:</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_2-1641498891607.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166934i5F046BA36E3D8F3E/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_2-1641498891607.png" alt="nlbutts_2-1641498891607.png" /></span></P><P>&nbsp;</P><P>I have a 1 Hz square wave being fed into this pin.&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="nlbutts_3-1641498954455.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/166935iD25A9E83FA6D7256/image-size/medium?v=v2&amp;px=400" role="button" title="nlbutts_3-1641498954455.png" alt="nlbutts_3-1641498954455.png" /></span></P><P>&nbsp;</P><P>But when I try to read this pin in Linux it always reads low:</P><LI-CODE lang="markup">root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0 root@imx8qxpdeere:~# gpioget gpiochip0 22 0</LI-CODE><P>I looked through the errata and didn't see any mention of a GPIO pin.&nbsp;</P><P>Any ideas?</P> Thu, 06 Jan 2022 19:57:07 GMT https://community.nxp.com/t5/i-MX-Processors/i-MX8xQuadPlus-UART1-RX-GPIO-usage/m-p/1395771#M185488 nlbutts 2022-01-06T19:57:07Z https://community.nxp.com/t5/i-MX-Processors/i-MX8xQuadPlus-UART1-RX-GPIO-usage/m-p/1395792#M185491 <P>I had copied and pasted the wrong #define:</P><P>#define IMX8QXP_UART1_RX_LSIO_GPT1_CLK IMX8QXP_UART1_RX 3<BR />#define IMX8QXP_UART1_RX_LSIO_GPIO0_IO22 IMX8QXP_UART1_RX 4</P><P>I used the former, when I meant to use the later.</P> Thu, 06 Jan 2022 22:04:00 GMT https://community.nxp.com/t5/i-MX-Processors/i-MX8xQuadPlus-UART1-RX-GPIO-usage/m-p/1395792#M185491 nlbutts 2022-01-06T22:04:00Z