Hi Jan,
So I put a simple wire between pin 18 and 21 and try to run the
spidev_test... Same result... FF only.... I also check with an
oscilloscope. I see nothing... I am not able to see my data.
root@beaglebone:~# ./spidev_test -D /dev/spidev1.0
> spi mode: 0
> bits per word: 8
> max speed: 500000 Hz (500 KHz)
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF FF FF FF FF
> FF FF
So first I am currently using my own dtc file from input on the web :
/dts-v1/;
> /plugin/;
> / {
> compatible = "ti,beaglebone", "ti,beaglebone-black";
> /* identification */
> part-number = "spi0pinmux";
> fragment@0 {
> target = <&am33xx_pinmux>;
> __overlay__ {
> spi0_pins_s0: spi0_pins_s0 {
> pinctrl-single,pins = <
> 0x150 0x30 /* spi0_sclk, INPUT_PULLUP | MODE0 */
> 0x154 0x30 /* spi0_d0, INPUT_PULLUP | MODE0 */
> 0x158 0x10 /* spi0_d1, OUTPUT_PULLUP | MODE0 */
> 0x15c 0x10 /* spi0_cs0, OUTPUT_PULLUP | MODE0 */
> >;
> };
> };
> };
> fragment@1 {
> target = <&spi0>;
> __overlay__ {
> #address-cells = <1>;
> #size-cells = <0>;
> status = "okay";
> pinctrl-names = "default";
> pinctrl-0 = <&spi0_pins_s0>;
> spidev@0 {
> spi-max-frequency = <24000000>;
> reg = <0>;
> compatible = "linux,spidev";
> };
> };
> };
> };
So I build the dtbo file :
dtc -O dtb -o /lib/firmware/BB-ARTHUR-SPI0-00A0.dtbo -b 0 -@
> BB-ARTHUR-SPI0-00A0.dts
> echo BB-ARTHUR-SPI0 > /sys/devices/bone_capemgr.9/slots
Then I run uname -r to get the current linux version : 3.8.13-bone47
I download kernel source from kernel.org to get the spidev_test.c file. I
compile it on the board and I run it.
Do I wrong somewhere ? I am currently running the original EMMC
distribution of the beaglebone black ( The board was ordered few weeks ago,
so I can guess that I used a very recent version of the beagleboard
binary).
I also found in your link something about patching the kernel :
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
> index 911e9e0..622adf5 100644
> --- a/drivers/spi/spidev.c
> +++ b/drivers/spi/spidev.c
> @@ -646,6 +646,7 @@ static int spidev_remove(struct spi_device *spi)
>
> static const struct of_device_id spidev_dt_ids[] = {
> { .compatible = "rohm,dh2228fv" },
> + { .compatible = "linux,spidev" },
> {},
> };
Do I have to download my own source to build a beagleboard image and to
patch the kernel before with this patch to be able to use SPI ?
Thanks & Regards,
Arthur.
Le mardi 11 novembre 2014 00:54:29 UTC+1, [email protected] a écrit :
>
> Hi,
>
> Following the links: http://elinux.org/BeagleBone_Black_Enable_SPIDEV
> and
> http://www.nagavenkat.adurthi.com/2014/02/spi-communication-beaglebone-black-as-master-to-arduino-as-slave/
>
> I was able to make it work, but I have a SS too long (1.4ms) for my need.
> For easy test connect MOSI and MISO with a wire (loopback) to eliminate
> connection problem with you SPI slave.
> Hope this will help. When you done, can you measure the timing a let me
> know?
> I can post you my code if you need it.
>
> Jan
>
> On Tuesday, November 11, 2014 5:03:38 AM UTC+11, [email protected]
> wrote:
>>
>> Hi,
>>
>> I am trying to communicate with a device (ADS1299à by using the
>> Beaglebone black but without success. First I have to enable spi dev
>> entries in /dev. There are plenty of blog/tuto which are giving dtc file to
>> generate our own dtbo. But dtc files seems to not be always the same.
>>
>> In fact I can see that there are already some dtbo files in /lib/firmware
>> :
>> root@beaglebone:~# ls /lib/firmware/ | grep SPI
>> ADAFRUIT-SPI0-00A0.dtbo
>> ADAFRUIT-SPI1-00A0.dtbo
>> BB-SPIDEV0-00A0.dtbo
>> BB-SPIDEV1-00A0.dtbo
>> BB-SPIDEV1A1-00A0.dtbo
>>
>> So I want to use only SPI0 because I know that SPI1 is already used by
>> HDMI. Can I used theses dtbo files ? Is it better to write my own ? It is
>> quite strange, when I enable one of theses dtbo files, I get not only one
>> but two entries in /dev ??
>>
>> Currently I want to validate my wiring between the two boards. I found a
>> piece of code to read the device id in register of the device though SPI.
>> But when I try to read this register, I can only get 1 or only get 0
>> (depends of the dtbo files)
>>
>> Any advice of the good way to process here ?
>>
>> Thanks & Regards,
>> Arthur.
>>
>>
>>
>>
>>
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