BPI-R2 SPI Communication

(Yusuf BĂźlbĂźl) #1

Hello everyone.

I want to use SPI port of BPI-R2. I saw wiringPi support for BPI-M2 kernel. Is the kernel compatible with BPI-R2? How Can I use the Spi on BPI-R2 with C++ Spidev. I mean How can I install or enable SPI driver on DPI-R2? Is there anybody have an idea?

Thanks for all answers.

(Frank W.) #2

non-bpi-r2-kernel does not work on bpi-r2 because its a different SOC

default kernel do not have spi-support afaik. you can try to build your own and test it…

you need the SPI-Module and the dts-nodes for SPI enabled. you can try it with my 4.14 kernel, SPI-module is enabled, you have to activate the SPI-Node(s) in bananapi-r2.dts and build again

(Yusuf BĂźlbĂźl) #3

Thanks for quick answer.

Where can I find your kernel 4.14 for BPI-R2? As I understand, If I load the your kernel 4.14 to my BPI_R2, The SPI module will be enabled on this kernel and I will see the /dev/spidev0.0 on userspace. Am I right?

(Frank W.) #4

ok, i see, that i have enabled the node before:

i have not tested SPI you must look in your bootlog how the device is named (dmesg in debian/ubuntu)

as of the nodes are enabled you can also use one of my precompiled kernels

https://drive.google.com/open?id=1EGN1TvqCpDHdOAS-mjRg9ipi0kahnOUV

SPI touchscreen ads7846 (xpt2046) on UBUNTU images (BPI-R2)
(Yusuf BĂźlbĂźl) #5

Okay. Thanks for info and kernel. I will try this.

(Frank W.) #6

kernel-packages have version and branch-name…main is the right one :slight_smile:

if it does not work you have to build it by yourself…please give me feedback if you’ve got it running and how

(Yusuf BĂźlbĂźl) #7

Okay. I will turn back you after trying.

(Frank W.) #8

added spi-dev as module to 4.14.15-main…

https://drive.google.com/open?id=1EGN1TvqCpDHdOAS-mjRg9ipi0kahnOUV

(Yusuf BĂźlbĂźl) #9

Hi. Thanks for helps.

I use kernel 4.4.xx . Also, I activated the device -> driver->SPI support from kernel menuconfig. I compiled the kernel gcc-arm-linux-gnueabihf-6. It compiled succesfully. gcc-7 gives errors.

I still don’t see spidev0 or spidev1 driver in /dev directory.

Which one of the device driver Should I activate from ./build.sh option 4 for spidev?

(Frank W.) #10

spidev is under spi-support names somehow user-driver or similar…you can search in menuconfig with / for spidev

(Yusuf BĂźlbĂźl) #11

I have activeted all of SPI Support subheaders including spi user interface. But, I didn,t see /dev/spidev.

Is it necessary to enable or install spi after buildg kernel?

(Frank W.) #12

I don’t know which spi should be found…do you use gpio-spi or inside your camera? If using gpio you have to enanle it in dts(i)

(Yusuf BĂźlbĂźl) #13

I am using gpio spi. where can I enable dts?

(Frank W.) #14

Here i wrote the steps for enabling spi in dts: SPI touchscreen ads7846 (xpt2046) on UBUNTU images (BPI-R2)

(Yusuf BĂźlbĂźl) #15

The kernel which you sent me, is not booting? I have merged the compiled BPI_BOOT and BPI_ROOT directories with SD card but, it didn’t boot.

Or it has not hdmi support?

(Frank W.) #16

Kernel 4.14 has no no working hdmi yet…see the issue on github.

But you can use the nodes in dts and kernel-options from 4.14 to extend 4.4

#17

We plan to send HDMI related patches to mainline late this month and will add MIPI support if we have time to do that.

#18

If you want to use spi0: spi@1100a000 you should enable it, add the correct pinmux setting and add a device which is connected to spi0.

There are many examples in /arch/arm//boot/dts/* (for more details please grep ‘spi’ ).

Thanks

(Yusuf BĂźlbĂźl) #19

Hi Ryder. I have editted mt7623.dtsi following;

         spi0: spi@1100a000 {
                compatible = "mediatek,mt7623-spi",
                             "mediatek,mt2701-spi";
                #address-cells = <1>;
                #size-cells = <0>;
                reg = <0 0x1100a000 0 0x100>;
                interrupts = <GIC_SPI 78 IRQ_TYPE_LEVEL_LOW>;
                clocks = <&topckgen CLK_TOP_SYSPLL3_D2>,
                         <&topckgen CLK_TOP_SPI0_SEL>,
                         <&pericfg CLK_PERI_SPI0>;
                clock-names = "parent-clk", "sel-clk", "spi-clk";
                status = "disabled";
        };

Also, I added like this mt7623n_bpi_r2.dts file;

spi0_pins_a: spi0@0 {
		pins_spi {
			pinmux = <MT7623_PIN_53_SPI0_CSN_FUNC_SPI0_CS>,
				<MT7623_PIN_54_SPI0_CK_FUNC_SPI0_CK>,
				<MT7623_PIN_55_SPI0_MI_FUNC_SPI0_MI>,
				<MT7623_PIN_56_SPI0_MO_FUNC_SPI0_MO>;
			bias-disable;
		};
	};

I have checked gpio of spi are correct. But, I couldn’t see /dev/spidev.0.0 after rebuilding kernel.

#20

Did you enable it : "status = “okay”?

Please type this command: find /sys/bus | grep spi