topic Re: IMX6 Linux SPI Slave mode not running in i.MX Processors

IMX6 Linux SPI Slave mode not running

Yavuz — Wed, 30 Sep 2020 08:12:01 GMT

Hi everybody,

I have an IMX6 linux system which is compiled via yocto provided by nxp.

I want to use SPI Slave mode. My IMX6 is an SPI slave with CPHA=1, CPOL=0 and external system has a Clock of 15MHz.

My Device tree is as follows:

imx6qdl.dtsi:

ecspi3: spi@2010000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx6q-ecspi", "fsl,imx51-ecspi";
reg = <0x02010000 0x4000>;
interrupts = <0 33 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6QDL_CLK_ECSPI3>,
<&clks IMX6QDL_CLK_ECSPI3>;
clock-names = "ipg", "per";
dmas = <&sdma 7 7 1>, <&sdma 8 7 2>;
dma-names = "rx", "tx";
status = "disabled";
};

imx6qdl-sabresd.dtsi

&ecspi3 {
/*fsl,spi-num-chipselects = <1>;*/
cs-gpios = <&gpio4 24 0>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi3>;
spi-slave; /*empty attriute to mark spi as slave*/
status = "okay";
};

I added spidev_test -> to yocto recipes

I added slave :

- echo spidev > /sys/class/spi_slave/spi2/slave

the by using the spidev_test I tried to test:

- spidev_test -v -D /dev/spidev2.0 -s 15000000 -p abc

but the transfer is blocked.

spi mode: 0x1

bits per word: 8

max speed: 15000000 Hz (15000 KHz)

Any suggestions ? ?

Best Regards

Re: IMX6 Linux SPI Slave mode not running

igorpadykov — Wed, 30 Sep 2020 10:19:33 GMT

Hi Yavuz

what bsp used in the case, one can try latest as described on link

https://community.nxp.com/t5/i-MX-Processors/Which-imx-linux-version-shall-be-selected-for-porting-SPI-SLAVE/m-p/1161140#M162735

Best regards
igor

Re: IMX6 Linux SPI Slave mode not running

Yavuz — Wed, 30 Sep 2020 11:14:20 GMT

Hi,

uname -a gives

Linux imx6dlsabresd 5.4.3+gf8118585ee3c #9 SMP PREEMPT Wed Sep 30 04:23:27 PDT 2020 arm71 GNU/Linux

Regards

Re: IMX6 Linux SPI Slave mode not running

Yavuz — Wed, 30 Sep 2020 11:25:43 GMT

Hi,

linux kernel 5.4.3,

i guess that is the correct version which supports linux spi slave mode support for imx6.

Do you agree ?

Regards

Re: IMX6 Linux SPI Slave mode not running

igorpadykov — Wed, 30 Sep 2020 12:11:06 GMT

it is not kernel 5.4.3 :

L5.4.24

https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/spi/spi-imx.c?h=imx_5.4.24_2.1.0

Best regards
igor

Re: IMX6 Linux SPI Slave mode not running

Yavuz — Thu, 01 Oct 2020 07:07:50 GMT

Hello ,

The spi-imx.c content was exactly the same (linux diff result) but anyway i have followed the path you suggest to switch to kernel 5.4.24_2.1.0.

I have downloaded the the git repository :

https://source.codeaurora.org/external/imx/linux-imx and checkout the branch "imx_5.4.24_2.1.0"

build the kernel, get the zImage then loaded that to my target

now "uname -a gives the following result" :

Linux imx6dlsabresd 5.4.24-00060-gbabac008e5cf #1 SMP PREEMPT Wed Sep 30 23:12:33 PDT 2020 arm71 GNU/Linux

the only difference i see after using this new kernel is:

when i perform:

# echo spidev > /sys/class/spi_slave/spi2/slave

The output is:

imx6q-pcie lffc00.pcie: could not get pcie-phy

imx_usb 2184200.usb: No overcurrent polarity is defined

first line is new, second line was existent on previous kernel version also

So the problem seems to continue.

Any Suggestions

Regards.

Re: IMX6 Linux SPI Slave mode not running

igorpadykov — Thu, 01 Oct 2020 11:05:57 GMT

for ecspi slave one also can look at:

https://community.nxp.com/t5/i-MX-Processors/i-MX6-SPI-Slave-mode/m-p/289544

https://www.digi.com/resources/documentation/digidocs/90001547/reference/bsp/v4-1_6ul/r_spi_v4-1.htm?TocPath=Additional%20resources%7CLinux%20v4.1%20Board%20Support%20Package%7C_____19

http://billauer.co.il/blog/2017/08/nxp-freescale-spi-slave/

Best regards
igor

Re: IMX6 Linux SPI Slave mode not running

Yavuz — Tue, 06 Oct 2020 07:46:00 GMT

Hello,

I finally succeeded to read something from spi in slave mode, although there is still problem with the content of the data, I think for this topic the issue is solved.

Thank you very much @igorpadykov .

Best Regards.