utility for pin in BBB: PX.Y --> pin_mode, pin_name

[Nicola Mingotti]

On 08/29/18 22:26, Nicola Mingotti wrote:
>
>
> On 08/29/18 20:46, Ian Lepore wrote:
>> On Wed, 2018-08-29 at 20:01 +0200, Nicola Mingotti wrote:
>>> Thank you for suggestion Russel,
>>>
>>> but unfortunately, at best of my knowldege,
>>> $> man 3 gpio_open
>>> and its shell command brother
>>> $> man 8 gpioctl
>>>
>>> are not appropriate, they are useful only if a pin
>>> has been configured as GPIO pin.
>>>
>>> The program i look for would be useful instead to esablish
>>> which physical pin has been configured as GPIO pin or
>>> PWM, PRU, I2C etc.
>>>
>>> I asked also in the Forum, but the only one aswering
>>> (@Phishry) has given me your same suggestion.
>>>
>>> If nobody knows of such a program i will start the implementation,
>>> maybe
>>> tomorrow.
>>>
>>> bye
>>> Nicola
>>>
>> Please bottom-post when replying to freebsd mailing lists.
> ok !
>> There is no interface defined for getting an fdt_pinctrl driver to
>> return info about the current configuration. Even if such an interface
>> existed, there would also need to be a new driver providing a cdev so
>> that userland can access the information.
> ok, no interface.
>> There is also nothing in freebsd equivelent to the linux devmem2
>> program. A driver would have to be written to provide access to device-
>> mapped memory before such a program could be written. You can't access
>> arm hardware registers via /dev/mem or /dev/kmem.
>>
>> -- Ian
> I just compiled devmem2 and it seems to work. I did silly modifications.
> The code is here: http://euriscom.it/data/dm2.c
> (forget the first comment lines, they are poor, I did not intend to 
> share this, it is my working copy)
>
> if i run it:
> ---------------------------------
> #> ./dm2 0x44e10998 b
> /dev/mem opened.
> Memory mapped at address 0x20221000.
> Value at address 0x44E10998 (0x20221998): 0x5
> ---------------------------------
>
> Whic corresponds to what i wrote in the DTO.
> -----
>            pru_pru_pins: pinmux_pru_pru_pins {
>                       pinctrl-single,pins = <
>                           // 0x1a4 0x05   /* P9.27 pr1_pru0_pru_r30_5, 
> Mode 5 output pull-down   */
>                           0x19c 0x26   /* P9.28 pr1_pru0_pru_r31_3, 
> Mode 6 input pull-down    */
>                           0x198 0x05    /* PRU0-2 -- P9.30 -- 
> pr1_pru0_pru_r30_2 ... se in MODE-5  */
>                           >;
>                   };
> -----
>
> This is the only test i made but it seems improbable I got the same 
> value by chance;)
>
> It goes without saying that I don't understand all what i wrote,
> so, i could be boldly wrong ;)
>
> If it turns out it works let me know, i can make the port.
>
> bye
> n.
>
>
>
>
>
> -- 
> --------------------------
> Dr. Nicola Mingotti
> R&D - Borghi Srl
> CTO - BondInsider
> --------------------------

I did other experiments, with pins i used in the last days so I am sure
they perform in the mode i am setting them in the DTO. (except for 
mode-6 in P9.30,
wich is just a variation respect to the previous example.)

I load 2 overlays where i define :
---------------
       pinctrl-single,pins = <
              0x154 0x03        /* P9.21 */
              0x150 0x03        /* P9.22 */
         >;
   .....
              0x198 0x06    /* PRU0-2 -- P9.30
---------------

Now i devmem all the 3 pin:
----------
root at bbb-FBS-12-APLHA:~/code/devmem2 # ./dm2 0x44e10954 b
/dev/mem opened.
Memory mapped at address 0x20221000.
Value at address 0x44E10954 (0x20221954): 0x3

./dm2 0x44e10950 b
/dev/mem opened.
Memory mapped at address 0x20221000.
Value at address 0x44E10950 (0x20221950): 0x3

root at bbb-FBS-12-APLHA:~/code/devmem2 # ./dm2 0x44e10998 b
/dev/mem opened.
Memory mapped at address 0x20221000.
Value at address 0x44E10998 (0x20221998): 0x6
---------

I think devmem2 is working.

Don't ask me why, i modified other people code, that's it ;)

bye
n.

-- 
--------------------------
Dr. Nicola Mingotti
R&D - Borghi Srl
CTO - BondInsider
--------------------------