Linux/AM5728: SPIDEV test fails

Xinping Yang

Part Number: AM5728

Tool/software: Linux

Hi TI Experts,

I want to test the SPI interface for the AM5728 IDK board, I have configured the spidev driver and can get the spi device.

Details is as bellow:

In am57xx-beagle-x15.dts:

spi3_pins_default: spi3_pins_default {
	pinctrl-single,pins = <
		0x2d4 (PIN_INPUT | MUX_MODE3)  /*mcspi3_sclk  spi3_sclk.gpio6_30 */
		0x2d8 (PIN_INPUT | MUX_MODE3)  /* mcspi3_miso spi3_d1.gpio6_31*/
		0x2dc (PIN_OUTPUT | MUX_MODE3)  /*mcspi3_mosi spi3_d0.gpio7_0*/			
		0x2e0 (PIN_OUTPUT | MUX_MODE3)  /*mcspi3_cs0  spi3_cs0.gpio7_1*/
	>;	
};

&mcspi3 {
        status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&spi3_pins_default>;
        /*ti,pindir-do-out-d1-in=<1>;*/	
	spidev@0 {
		compatible ="rohm,dh2228fv";	
		spi-max-frequency =<24000000>;
		reg = <0>;
	};
};

Config:

#
# SPI Protocol Masters
#
CONFIG_SPI_SPIDEV=m
# CONFIG_SPI_TLE62X0 is not set
# CONFIG_SPMI is not set
# CONFIG_HSI is not set

During the test :

root@am57xx-evm:~/temp# ./spidev_test -D /dev/spidev1.0 
[   85.502933] Nemo spidev_open
[   85.505842] Nemo spidev_ioctl: cmd SPI_IOC_WR_MODE
[   85.510893] Nemo spidev_ioctl: cmd SPI_IOC_RD_MODE32
[   85.515892] Nemo spidev_ioctl: cmd SPI_IOC_RD_BITS_PER_WORD
[   85.521618] Nemo spidev_ioctl: cmd SPI_IOC_WR_MAX_SPEED_HZ
[   85.527132] Nemo spidev_ioctl: cmd SPI_IOC_RD_MAX_SPEED_HZ
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 KHz)
[   85.532895] Nemo spidev_message
[   85.541795] Nemo spidev tx_buffer: 
[   85.545297] Nemo spidev rx_buffer: 
[   85.548800] Nemo  xfer len 32 rx tx 8bits 0 usec 500000Hz
RX | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  | ................................[   85e

I have connect the mcspi3_miso and mcspi3_mosi, and use the spidev_test to test the spidev driver. It is not get any data from the spidev driver from the up test result.

What is the problem? Can you give some suggestion in here?

Many Thanks!

Nemo

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Dwarakesh Radhakrishnan over 8 years ago in reply to Biser Gatchev-XID

Guru 13660 points

Hi,

Do you see any other spidev* node in in /dev/ ? Kernel doc says /dev/spidevB.C, where B is bus and C is Chipselect. So I am assuming in your case /dev/spidev3.x

0 Xinping Yang over 8 years ago in reply to Dwarakesh Radhakrishnan

Prodigy 240 points

Hi Dwarakesh,

I have seen the spidev1.0 in /dev. I am not sure about the B which is the bus. For example, I used the mcspi3, the bus number should be 3?

for my device tree:

&mcspi3 {
        status = "okay";
    pinctrl-names = "default";
    pinctrl-0 = <&spi3_pins_default>;
        /*ti,pindir-do-out-d1-in=<1>;*/   
    spidev@0 {
        compatible ="rohm,dh2228fv";    
        spi-max-frequency =<24000000>;
        reg = <0>;
    }


How to write the device tree to map the spi bus 3?

0 Dwarakesh Radhakrishnan over 8 years ago in reply to Xinping Yang

Guru 13660 points

Hi,

Looks like your device tree entry specific to spidev seems to be fine. Can you check related to pinmux ? May I know what SPI device is being connected ?

0 Yordan Kovachev over 8 years ago in reply to Dwarakesh Radhakrishnan

TI__Guru**** 161600 points

Hi,

Which SDK (kernel) version are you using?

Best Regards,
Yordan

0 Xinping Yang over 8 years ago in reply to Yordan Kovachev

Prodigy 240 points

Hi Yordan,

I used the latest SDK. Linux kernel 4.4.41.

0 Prabhakar Lad over 8 years ago

Guru 11260 points

Hello,

Looking at you dt node and comments you are configuring, MOSI as output and MISO as input, In that case you also need to have following line as well in mcspi3 node,

ti,pindir-d0-out-d1-in;

Also to check, can also scope the clk and data pins and see if there is something ?

Cheers,
--Prabhakar Lad

0 Xinping Yang over 8 years ago in reply to Prabhakar Lad

Prodigy 240 points

Hi Cheers,
I just test the SPI itself, I connected the MOSI and MISO pins in the board, it shows the result as up. That is problem what I meet.

0 Prabhakar Lad over 8 years ago in reply to Xinping Yang

Guru 11260 points

Hello,

Even if you short (/connect) both the pins MOSI and MISO you should have 'ti,pindir-d0-out-d1-in;' in your mcspi3 node.

Cheers,
--Prabhakar Lad

0 Dwarakesh Radhakrishnan over 8 years ago in reply to Xinping Yang

Guru 13660 points

Hi,

Ok, please check what Prabhakar has suggested.

Also make sure Ball numbers for SPI3_D0 and SPI3_D1 matches with what pin you are trying to configure.

0 Xinping Yang over 8 years ago in reply to Prabhakar Lad

Prodigy 240 points

Hi Prabhakar,
Many thanks for your feedback. I have tested this before, but it did not work.
/*ti,pindir-do-out-d1-in=<1>;*/
Then I check this comment, it should be "ti, pindir-d0-out-d1-in", I have make a mistake "do" but not "d0".
Yes, after the direction set, it works for me now.
root@am57xx-evm:~/temp# ./spidev_test
[ 56.071108] Nemo spidev_open
[ 56.074015] Nemo spidev_ioctl: cmd SPI_IOC_WR_MODE
[ 56.080458] Nemo spidev_ioctl: cmd SPI_IOC_RD_MODE32
[ 56.085445] Nemo spidev_ioctl: cmd SPI_IOC_WR_BITS_PER_WORD
[ 56.102226] Nemo spidev_ioctl: cmd SPI_IOC_RD_BITS_PER_WORD
[ 56.107824] Nemo spidev_ioctl: cmd SPI_IOC_WR_MAX_SPEED_HZ
[ 56.114793] Nemo spidev_ioctl: cmd SPI_IOC_RD_MAX_SPEED_HZ
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 KHz)
RX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF Fe

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Linux/AM5728: SPIDEV test fails