Hi,
We are trying to get the GPIO toggle example running on the beaglebone
black.
At this point we succeeded in the following: running the RProc echo example
from the TI hands on lab which works. Writing and loading a custom device
tree overlay to set the pinmux although we are not sure whether the pins
get configured correctly.
We did some tests by setting the pinmode with pull-up and pull-down
resistors which we measured using a multimeter. So we are sure the device
tree overlay is loaded correctly. But we are not able to toggle pins from
the PRU.
The device tree overlay code (PRU cape dtsi file adapted to overlay):
/dts-v1/;
/plugin/;
/ {
compatible = "ti,beaglebone", "ti,beaglebone-black";
part-number = "EMS-PRU-CUSTOM";
version = "00A0";
/* This overlay uses the following resources */
exclusive-use =
"P9.30",
"P9.31",
"P9.27",
"P9.25",
"P9.29",
"P9.28",
"P8.44",
"P8.41",
"P8.42",
"pru0",
"pru1",
"pruss";
fragment@0 {
target = <&am33xx_pinmux>;
__overlay__ {
pru_pru_pins: pinmux_pru_pru_pins { // The PRU pin modes
pinctrl-single,pins = <
0x1a4 0x2e /* mcasp0_fsr, OMAP_MUX_MODE6 | AM33XX_PIN_INPUT,
PRU CAPE SW1 */
0x1ac 0x2e /* mcasp0_ahclkx, OMAP_MUX_MODE6 | AM33XX_PIN_INPUT, PRU CAPE
SW2 */
0x19c 0x05 /* mcasp0_ahclkr, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE
Red LED */
0x198 0x05 /* mcasp0_axr0, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE
Orange LED */
0x190 0x05 /* mcasp0_aclkx, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE
Blue LED */
0x194 0x05 /* mcasp0_fsx, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE
Green LED */
0x0ac 0x05 /* lcd_data3, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE RGB_0
LED, HDMI Conf. */
0x0b0 0x05 /* lcd_data4, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE RGB_1
LED, HDMI Conf. */
0x0b4 0x05 /* lcd_data5, OMAP_MUX_MODE5 | AM33XX_PIN_OUTPUT, PRU CAPE RGB_2
LED, HDMI Conf. */
>;
};
};
};
fragment@1 { // Enable the PRUSS
target = <&pruss>;
__overlay__ {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&pru_pru_pins>;
};
};
};
The code of the GPIO toggle example remained the same (toggling some bits
of R30 ). The outfile was moved to /lib/firmware and symlinked to
am335x-pru0-fw which was then loaded by removing and reloading pru_rproc.
Is there a way to check how the pinmux is configured? Also using the
uEnv.txt we prevented any universal capes from loading on boot
(cmdline=coherent_pool=1M net.ifnames=0 quiet cape_universal=disable) and
are using dtb=am335x-boneblack-overlay.dtb
We are running out of ideas why the GPIO's are not toggling. Perhaps
something is missing in the dts file? Are we overlooking something?
Thanks in advance
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/beagleboard/30f551c0-ea96-41ce-9088-f05df24ee531%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
