AnsweredAssumed Answered

Missing ttymxc on Yocto 1.6

Question asked by Pak Woon on Oct 6, 2014
Latest reply on Feb 23, 2016 by chandini indavara basavaraju

Hello Community,

 

We are in the process of moving from the LTIB build system to a Yocto one and have noticed missing UARTs on the iMX6DL. (We are using a Congatec qmx6 PN16111 and code from their git repository)

 

On the old LTIB build, the kernel detects 3 UARTS:

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[    2.212509] imx-uart.1: ttymxc1 at MMIO 0x21e8000 (irq = 59) is a IMX

[    2.268576] console [ttymxc1] enabled, bootconsole disabled

[    2.268576] console [ttymxc1] enabled, bootconsole disabled

[    2.280442] imx-uart.2: ttymxc2 at MMIO 0x21ec000 (irq = 60) is a IMX

[    2.287378] imx-uart.4: ttymxc4 at MMIO 0x21f4000 (irq = 62) is a IMX

[    2.302894] brd: module loaded

...

root@linaro:/sys/class/tty# ls -las ttymx*

0 lrwxrwxrwx 1 root root 0 2014-09-30 02:23 ttymxc1 -> ../../devices/platform/imx-uart.1/tty/ttymxc1

0 lrwxrwxrwx 1 root root 0 2014-09-30 02:23 ttymxc2 -> ../../devices/platform/imx-uart.2/tty/ttymxc2

0 lrwxrwxrwx 1 root root 0 2014-09-30 02:23 ttymxc4 -> ../../devices/platform/imx-uart.4/tty/ttymxc4

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But on the newer Yocto 1.6 build, there is only 1 and the class path is different.

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VGEN6: 1800 mV

Serial: IMX driver

21e8000.serial: ttymxc1 at MMIO 0x21e8000 (irq = 59) is a IMX

console [ttymxc1] enabled

serial: Freescale lpuart driver

...

root@cgtqmx6:/sys/class/tty# ls -las

0 lrwxrwxrwx  1 root root 0 Sep 30 02:25 ttymxc1 -> ../../devices/soc0/soc.1/2100000.aips-bus/21e8000.serial/tty/ttymxc1

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From what I can tell (and I am no means an expert) the newer build extracts the machine info from the dtb file, while in the older build it can't find a dtb file. The dtb file contains all the UART information, but for some reason, the kernel just doesn't see the other UARTs. Am I missing a configuration setting somewhere else? Do I need something in uboot?

 

Thanks in advance.

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