topic Re: spidev not listed in /dev in i.MX Processors

spidev not listed in /dev

moose — Fri, 02 Dec 2022 17:47:15 GMT

Hello, we cannot see our spidev device under the "dev" directory. We can see it under "devices" in the "sys/bus/spi" directory as well as spidev driver. Please see below console output for reference. The devicetree node description is listed.

root@board:~# ls /dev/spidev*
ls: cannot access '/dev/spidev*': No such file or directory
root@board:~# ls /sys/bus/spi/devices/
spi1.0
root@board:~# ls /sys/bus/spi/drivers/spidev*
bind uevent unbind

------------------------------------------------

#include "freescale/imx8mn.dtsi"

&ecspi2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi2>;
status = "okay";

spidev@0{
compatible = "spidev";
reg = <0>;
spi-max-frequency = <4000000>;
};
};

Re: spidev not listed in /dev

Zhiming_Liu — Mon, 05 Dec 2022 03:13:57 GMT

Please check if you open the config.You can compare your config and official config.

:~# ls /dev/spidev1.0 /dev/spidev1.0

Re: spidev not listed in /dev

moose — Tue, 06 Dec 2022 17:00:58 GMT

I checked the config file, and I see all related config statements to be enabled, including CONFG_SPI, CONFIG_SPI_MASTER, CONFIG_SPI_IMX and CONFIG_SPI_SPIDEV. I attached the config file for your reference.

If there are specific configuration parameters that I am missing, could you please list them? Thank you!

Re: spidev not listed in /dev

Zhiming_Liu — Fri, 09 Dec 2022 01:08:55 GMT

Have you checked the kernel log about SPI driver? Maybe the driver does not be loaded correctly.

Re: spidev not listed in /dev

moose — Sat, 10 Dec 2022 14:18:08 GMT

Yes, I checked the kernel log, and there are no errors related to SPI.

Re: spidev not listed in /dev

Sanket_Parekh — Mon, 12 Dec 2022 07:36:38 GMT

Hi @moose

I hope you are doing well.

Can you please share the board DTS file?

Can you please share the log files?

Thanks & Regards

Sanket Parekh

Re: spidev not listed in /dev

moose — Tue, 13 Dec 2022 00:20:09 GMT

Hi @Sanket_Parekh, files have been shared. Thank you.

Re: spidev not listed in /dev

Sanket_Parekh — Tue, 13 Dec 2022 07:26:07 GMT

Hi @moose

I am sorry, But attachment is missing in your last reply.

Thanks & Regards

Sanket Parekh

Re: spidev not listed in /dev

moose — Tue, 13 Dec 2022 14:31:40 GMT

I sent them in a private message. Did you not receive the message?

Re: spidev not listed in /dev

Sanket_Parekh — Wed, 14 Dec 2022 07:30:20 GMT

Hi @moose

I got the attachments.

I found that few properties are missing from your board DTS file. Please add "fsl,spi-num-chipselects" and "cs-gpios" in ecspi node as per your board design. For more details please refer Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt.

Thanks & Regards

Sanket Parekh

Re: spidev not listed in /dev

moose — Thu, 15 Dec 2022 07:06:31 GMT

Hi @Sanket_Parekh, I did add "fsl,spi-num-chipselects" and "cs-gpios" proprties and I was hoping this would be it but I still don't see spidev under "/dev". I do see the following new message in the kernel log:

spidev@0 enforce active low on chipselect handle

Below is the ecspi node definition. How should we proceed? Thx!

&ecspi2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi2>;
status = "okay";
fsl,spi-num-chipselects = <1>;
cs-gpios = <&gpio5 13 0>;

spidev@0{
compatible = "spidev";
reg = <0>;
spi-max-frequency = <4000000>;
};
};

Re: spidev not listed in /dev

_angelo_ — Thu, 15 Dec 2022 08:20:13 GMT

What cpu are you using ? Sometimes spi is not visible at all, and not probed at all, since resource is allocated to m4 or scmfw.

Re: spidev not listed in /dev

Sanket_Parekh — Thu, 15 Dec 2022 09:56:42 GMT

Hi @moose

I went through the kernel configuration file and found that lots of other options related to SPI are enabled in kernel configuration file. Please disable all the options and enable only the below mentioned options and check the same.

CONFIG_SPI=y

CONFIG_SPI_MASTER=y

CONFIG_SPI_BITBANG=y

CONFIG_SPI_IMX=y

CONFIG_SPI_SPIDEV=y

Thanks & Regards

Sanket Parekh

Re: spidev not listed in /dev

moose — Fri, 16 Dec 2022 05:08:44 GMT

Hi @Sanket_Parekh,

I removed the SPI configs as instructed, but I still can't see spidev. I attached the fragmentation file that removes the unnecessary SPI configs you mentioned as well as the final config file. If you see anything that I am supposed to remove, please let me know. Otherwise, please let me know how we should proceed. Thanks!

Re: spidev not listed in /dev

Sanket_Parekh — Fri, 16 Dec 2022 07:55:39 GMT

Hi @moose

Configuration changes looks good.

Can you please check the M4 core configuration like is M4 core using the SPI device or not? Because in this case it is possible to not create the SPIDEV at A53 core.

Thanks & Regards

Sanket Parekh

Re: spidev not listed in /dev

moose — Fri, 16 Dec 2022 08:22:08 GMT

@Sanket_Parekh I am using imx8mn with builtin M7. I personally do not use the M7 for now, but my bsp is based on the imx8mn DDR3 EVK bsp. I am not as familiar with using the M7, but it seems that EVK code is assigning SAI3, GPT1, and UART4 to M7. I see this in the imx-boot code:

+ mcu_rdc {

+ compatible = "imx8m,mcu_rdc";

+ /* rdc config when MCU starts

+ * master

+ * SDMA3p --> domain 1

+ * SDMA3b --> domian 1

+ * SDMA3_SPBA2 --> domian 1

+ * peripheral:

+ * SAI3 --> Only Domian 1 can access

+ * UART4 --> Only Domian 1 can access

+ * GPT1 --> Only Domian 1 can access

+ * memory:

+ * no MRC should be configured when GPU3D is disabled.

+ * end.

+ */

+ start-config = <

+ RDC_MDA RDC_MDA_SDMA3p DID1 0x0 0x0

+ RDC_MDA RDC_MDA_SDMA3b DID1 0x0 0x0

+ RDC_MDA RDC_MDA_SDMA3_SPBA2 DID1 0x0 0x0

+ RDC_PDAP RDC_PDAP_SAI3 PDAP_D1_ACCESS 0x0 0x0

+ RDC_PDAP RDC_PDAP_UART4 PDAP_D1_ACCESS 0x0 0x0

+ RDC_PDAP RDC_PDAP_GPT1 PDAP_D1_ACCESS 0x0 0x0

+ 0x0 0x0 0x0 0x0 0x0

+ >;

+ /* rdc config when MCU stops

+ * memory:

+ * no MRC should be configured when GPU3D is disabled.

+ * end.

+ */

+ stop-config = <

+ 0x0 0x0 0x0 0x0 0x0

+ >;

+ };

In the machine.conf, we are loading the following firmware in M7:

WKS_FILE_DEPENDS:append = " imx-m7-demos"

IMAGE_BOOT_FILES += " \

imx8mnddr3l_m7_TCM_hello_world.bin \

imx8mnddr3l_m7_TCM_rpmsg_lite_pingpong_rtos_linux_remote.bin \

imx8mnddr3l_m7_TCM_rpmsg_lite_str_echo_rtos.bin \

imx8mnddr3l_m7_TCM_sai_low_power_audio.bin \

It doesn't seem to me that the M7 is using SPI.

Re: spidev not listed in /dev

moose — Mon, 19 Dec 2022 08:45:10 GMT

Hello @Sanket_Parekh, any input on how to proceed? Thank you.

Re: spidev not listed in /dev

Sanket_Parekh — Mon, 19 Dec 2022 09:34:23 GMT

Hi @moose

We can use UART4 pads as a ECSPI2. And the same UART4 is enabled and used in M7. This might be the reason why SPI line is not working. Please find the reference from below.

One can disable all the peripherals which are enable in M7 core and check the status of ECSPI2.

Thanks & Regards

Sanket Parekh

Re: spidev not listed in /dev

_angelo_ — Mon, 19 Dec 2022 14:19:10 GMT

So as i said in my intial post. When there is no sign of probe, generally the resource is allocated (partitioned) to the other M core.

Re: spidev not listed in /dev

moose — Thu, 22 Dec 2022 05:46:48 GMT

Hello @Sanket_Parekh, we disabled the M7 allocation per your instructions but still no spidev under the dev directory. Below is the patch we used to disable the M7 allocation, which applies only to u-boot-imx dts files. We didn't see any reference to M7 in the linux-imx dts files. We also commented out the lines loading the M7 related binaries. We are assuming that this disables the M7 core but let me know if we missed anything. If not, please let us know how we should proceed. Thank you.

u-boot-imx

Subject: [PATCH] Remove M7 UART4 to enable SPI
---
arch/arm/dts/imx8mn-550p2-rev4.dts | 34 -------------------------
arch/arm/dts/imx8mn-evk-u-boot.dtsi | 39 -----------------------------
2 files changed, 73 deletions(-)

diff --git a/arch/arm/dts/imx8mn-550p2-rev4.dts b/arch/arm/dts/imx8mn-550p2-rev4.dts
index 90cae733c1..4530e7bfd2 100644
--- a/arch/arm/dts/imx8mn-550p2-rev4.dts
+++ b/arch/arm/dts/imx8mn-550p2-rev4.dts
@@ -8,40 +8,6 @@

/ {
model = "Rivieh 550.2V4";
-
- mcu_rdc {
- compatible = "imx8m,mcu_rdc";
- /* rdc config when MCU starts
- * master
- * SDMA3p --> domain 1
- * SDMA3b --> domian 1
- * SDMA3_SPBA2 --> domian 1
- * peripheral:
- * SAI3 --> Only Domian 1 can access
- * UART4 --> Only Domian 1 can access
- * GPT1 --> Only Domian 1 can access
- * memory:
- * no MRC should be configured when GPU3D is disabled.
- * end.
- */
- start-config = <
- RDC_MDA RDC_MDA_SDMA3p DID1 0x0 0x0
- RDC_MDA RDC_MDA_SDMA3b DID1 0x0 0x0
- RDC_MDA RDC_MDA_SDMA3_SPBA2 DID1 0x0 0x0
- RDC_PDAP RDC_PDAP_SAI3 PDAP_D1_ACCESS 0x0 0x0
- RDC_PDAP RDC_PDAP_UART4 PDAP_D1_ACCESS 0x0 0x0
- RDC_PDAP RDC_PDAP_GPT1 PDAP_D1_ACCESS 0x0 0x0
- 0x0 0x0 0x0 0x0 0x0
- >;
- /* rdc config when MCU stops
- * memory:
- * no MRC should be configured when GPU3D is disabled.
- * end.
- */
- stop-config = <
- 0x0 0x0 0x0 0x0 0x0
- >;
- };
};

&ddrc {
diff --git a/arch/arm/dts/imx8mn-evk-u-boot.dtsi b/arch/arm/dts/imx8mn-evk-u-boot.dtsi
index 2e2ba3e36e..a29f9f54e6 100644
--- a/arch/arm/dts/imx8mn-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mn-evk-u-boot.dtsi
@@ -29,45 +29,6 @@
method = "smc";
};
};
- mcu_rdc {
- compatible = "imx8m,mcu_rdc";
- /* rdc config when MCU starts
- * master
- * SDMA3p --> domain 1
- * SDMA3b --> domian 1
- * SDMA3_SPBA2 --> domian 1
- * peripheral:
- * SAI3 --> Only Domian 1 can access
- * UART4 --> Only Domian 1 can access
- * GPT1 --> Only Domian 1 can access
- * memory:
- * TCM --> Only Domian 1 can access (0x7E0000~0x81FFFF)
- * DDR --> Only Domian 1 can access (0x80000000~0x81000000)
- * end.
- */
- start-config = <
- RDC_MDA RDC_MDA_SDMA3p DID1 0x0 0x0
- RDC_MDA RDC_MDA_SDMA3b DID1 0x0 0x0
- RDC_MDA RDC_MDA_SDMA3_SPBA2 DID1 0x0 0x0
- RDC_PDAP RDC_PDAP_SAI3 PDAP_D1_ACCESS 0x0 0x0
- RDC_PDAP RDC_PDAP_UART4 PDAP_D1_ACCESS 0x0 0x0
- RDC_PDAP RDC_PDAP_GPT1 PDAP_D1_ACCESS 0x0 0x0
- RDC_MEM_REGION 26 TCM_START TCM_END MEM_D1_ACCESS
- RDC_MEM_REGION 0 M4_EVK_DDR4_START M4_EVK_DDR4_END MEM_D1_ACCESS
- 0x0 0x0 0x0 0x0 0x0
- >;
- /* rdc config when MCU stops
- * memory:
- * TCM --> domain 0/1 can access (0x7E0000~0x81FFFF)
- * DDR --> domain 0/1 can access (0x80000000~0x81000000)
- * end.
- */
- stop-config = <
- RDC_MEM_REGION 26 TCM_START TCM_END MEM_D0D1_ACCESS
- RDC_MEM_REGION 0 M4_EVK_DDR4_START M4_EVK_DDR4_END MEM_D0D1_ACCESS
- 0x0 0x0 0x0 0x0 0x0
- >;
- };
};

&{/soc@0} {
--
2.38.1

machine file M7 statements

WKS_FILE_DEPENDS:append = " imx-m7-demos"
# IMAGE_BOOT_FILES += " \
# imx8mnddr3l_m7_TCM_hello_world.bin \
# imx8mnddr3l_m7_TCM_rpmsg_lite_pingpong_rtos_linux_remote.bin \
# imx8mnddr3l_m7_TCM_rpmsg_lite_str_echo_rtos.bin \
# imx8mnddr3l_m7_TCM_sai_low_power_audio.bin \
# "