New Device Tree Do not Change Pin Values

[Xsentius]

I am trying a PRU example from Derek Molloy's book, however whatever I do, pin values do not change. Could you please check what I am doing wrong?

dts file:

/* Device Tree Overlay for enabling the pins that are used in Chapter 13
* This overlay is based on the BB-PRU-01 overlay
* Written by Derek Molloy for the book "Exploring BeagleBone: Tools and
* Techniques for Building with Embedded Linux" by John Wiley & Sons, 2014
* ISBN 9781118935125. Please see the file README.md in the repository root
* directory for copyright and GNU GPLv3 license information.
*/
/dts-v1/;
/plugin/;


/ {
   compatible = "ti,beaglebone", "ti,beaglebone-black";


   part-number = "EBB-PRU-Example";
   version = "00A0";


   /* This overlay uses the following resources */
   exclusive-use =
         "P9.11", "P9.13", "P9.27", "P9.28", "pru0";


   fragment@0 {
      target = <&am33xx_pinmux>;
      __overlay__ {


         gpio_pins: pinmux_gpio_pins {         // The GPIO pins
            pinctrl-single,pins = <
               0x070 0x07  // P9_11 MODE7 | OUTPUT | GPIO pull-down
               0x074 0x27  // P9_13 MODE7 | INPUT | GPIO pull-down
            >;
         };


         pru_pru_pins: pinmux_pru_pru_pins {   // The PRU pin modes
            pinctrl-single,pins = <
               0x1a4 0x05  // P9_27 pr1_pru0_pru_r30_5, MODE5 | OUTPUT | PRU
               0x19c 0x26  // P9_28 pr1_pru0_pru_r31_3, MODE6 | INPUT | PRU
            >;
         };
      };
   };


   fragment@1 {         // Enable the PRUSS
      target = <&pruss>;
      __overlay__ {
         status = "okay";
         pinctrl-names = "default";
         pinctrl-0 = <&pru_pru_pins>;
      };
   };


   fragment@2 {         // Enable the GPIOs
      target = <&ocp>;
      __overlay__ {
         gpio_helper {
            compatible = "gpio-of-helper";
            status = "okay";
            pinctrl-names = "default";
            pinctrl-0 = <&gpio_pins>;
         };
      };
   };
};

I compile with:

dtc -O dtb -o EBB-PRU-Example-00A0.dtbo -b 0 -@ EBB-PRU-Example.dts

then copy it under /lib/firmware and do:

sudo sh ‐c "echo EBB‐PRU‐Example > $SLOTS"

Then I check:

$SLOTS output:

xsentius@beaglebone:~/chp13/overlay$ cat $SLOTS
 0: PF----  -1
 1: PF----  -1
 2: PF----  -1
 3: PF----  -1
 6: P-O-L-   0 Override Board Name,00A0,Override Manuf,EBB-PRU-Example

dmesg output:

[  701.582790] bone_capemgr bone_capemgr: slot #6: override
[  701.582839] bone_capemgr bone_capemgr: Using override eeprom data at slot 6
[  701.582892] bone_capemgr bone_capemgr: slot #6: 'Override Board Name,00A0,Override Manuf,EBB-PRU-Example'
[  701.584950] bone_capemgr bone_capemgr: slot #6: dtbo 'EBB-PRU-Example-00A0.dtbo' loaded; overlay id #0

Everything seems normal up to here, but when I check pin values:

xsentius@beaglebone:~/chp13/overlay$ sudo cat $PINS|grep '103\|105'
pin 103 (44e1099c.0) 00000027 pinctrl-single
pin 105 (44e109a4.0) 00000027 pinctrl-single

Those pins values seem not changed. They should be equal to 26 and 5.

Do you have an idea?

Here are my system properties:

xsentius@beaglebone:~/chp13/overlay$ uname -a
Linux beaglebone 4.1.18-ti-rt-r56 #1 SMP PREEMPT RT Thu Mar 31 00:22:06 UTC 2016 armv7l GNU/Linux
xsentius@beaglebone:~/chp13/overlay$ dtc --version
Version: DTC 1.4.1-g1e75ebc9

Thanks

[Robert Nelson]

On Mon, Apr 4, 2016 at 9:23 AM, frank brewer <frankth...@gmail.com> wrote:

Also now I checked whether uio_pruss is loaded:

root@beaglebone:~# lsmod
Module                  Size  Used by
c_can_platform          6564  0
c_can                   9605  1 c_can_platform
can_dev                11455  1 c_can
spidev                  6739  0
tieqep                  8510  0
pwm_tiehrpwm            4546  0
pwm_tiecap              3492  0
8021q                  17344  0
garp                    5975  1 8021q
mrp                     7322  1 8021q
stp                     1911  1 garp
llc                     5257  2 stp,garp
pru_rproc              11099  0
usb_f_acm               7180  1
u_serial               10646  3 usb_f_acm
usb_f_rndis            22734  1
g_multi                 5316  0
usb_f_mass_storage     42745  2 g_multi
u_ether                12028  2 usb_f_rndis,g_multi
libcomposite           43810  4 usb_f_acm,usb_f_rndis,g_multi,usb_f_mass_storage
pruss                  14686  1 pru_rproc
omap_rng                4358  0
rng_core                7441  1 omap_rng
snd_soc_davinci_mcasp    17352  0
snd_soc_edma            1150  1 snd_soc_davinci_mcasp
spi_omap2_mcspi        10681  0
uio_pdrv_genirq         3521  0
uio                     8467  1 uio_pdrv_genirq
cfg80211              399381  0
rfkill                 17701  2 cfg80211

Seems like it is not. I have pruss and pru_rproc but not uio_pruss. Can that be the problem?

I tried loading it:

root@beaglebone:~# modprobe uio_pruss
modprobe: FATAL: Module uio_pruss not found.

However I could not. Any ideas?

This is documented through out this forum..

In another thread you mentioned you were running:

4.1.18-ti-rt-r56

This "v4.1.x-ti" which uses remoteproc_pruss..

If you want uio_pruss, you need to use "4.1.x-bone" or "4.4.x-bone"..

cd /opt/scripts/tools/
git pull
sudo ./update_kernel.sh --bone-rt-kernel --lts-4_1

Regards,

--

Robert Nelson
https://rcn-ee.com/

[Xsentius]

So do you think that's why I cannot change pin mode settings? 

Kind Regards

[Robert Nelson]

On Mon, Apr 4, 2016 at 9:42 AM, Xsentius <satanas...@gmail.com> wrote:

So do you think that's why I cannot change pin mode settings? 

You are also assuming "sudo cat $PINS" works on 4.1.x... it doesn't currently show updates from loading overlays..

Regards,

[Xsentius]

Oh, that is a very precious information, I really appreciate it. 

So is there a way to see updates? Do you recommend me to go back to 3.8, if it is stable?

[Robert Nelson]

On Mon, Apr 4, 2016 at 9:51 AM, Xsentius <satanas...@gmail.com> wrote:

Oh, that is a very precious information, I really appreciate it. 

So is there a way to see updates? Do you recommend me to go back to 3.8, if it is stable?

Correctly set them in the overlay and don't worry about it..

[Xsentius]

I am very grateful Robert, it worked. I can change pin modes easily, time to test some PRU codes. Thank you so much!

[engka...@gmail.com]

Hi, I have the same problem with the same device tree overlay.
The setting of the PRU works when I put added the PRU pin mux in the am335x-boneblack-emmc-overlay.dts but not when I insert it to slots.

Here is my device tree that I add to the am335x-boneblack-emmc-overlay.dts.

/*
 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

&am33xx_pinmux {
    gpio_pins: gpio_pins {         // The GPIO pins
             pinctrl-single,pins = <
                0x070 0x07   // P9_11 MODE7 GPIO output pull‐down
                0x074 0x27   // P9_13 MODE7 GPIO input pull‐down
             >;
          };
 
 
 pru_cape_bone_pins: pru_cape_bone_pins {
  pinctrl-single,pins = <
   0x1a4 0x05   // P9_27 pr1_pru0_pru_r30_5, Mode5 output pull‐down
            0x19c 0x26   // P9_28 pr1_pru0_pru_r31_3, Mode6 input pull‐down
  >;
 };
};

&ocp {

   helper {
             compatible = "gpio-of-helper";
             status = "okay";
             pinctrl-names = "default";
             pinctrl-0 = <&gpio_pins>;
          };
   
};

&pruss {
        pinctrl-names = "default";
     pinctrl-0 = <&pru_cape_bone_pins>;
};

I'm not sure what is happening. But I am using kernel 4.4.9-ti-rt-r26.My my PRU code loaded to the pru is just blinking LEDs from GPIO P9_11  and pr1_pru0_pru_r30_5. However, only the P9_11 blinks. When I "sudo cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pins", the pins corresponding to the PRU pins are not changed. Why do you think this happens?


Thanks


Kister