Rpi5 alternate pin function support

[acidtech]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

[ame]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

I'm sure if you received an early unit you are in close and constant communication with Raspberry Pi.

[aBUGSworstnightmare]

And if you've read some of the comments on Pi5 you should know that
- powering from GPIO is possible
- DPI is supported for sure ( 5 display multihead is possible now)
- PWM on the GPIO is supported, for audio you will need additional filter HW. If it's realy working - test it and report back, as you'll have to test that yourself - and maybe that's why you've received some HW

Anyhow strange that people with 6 posts here have HW on hands to test with.

[Gavinmc42]

Anyhow strange that people with 6 posts here have HW on hands to test with.

Must have yt ch.

Check the Linux source, search for RP1

[aBUGSworstnightmare]

Anyhow strange that people with 6 posts here have HW on hands to test with.

Must have yt ch.

Check the Linux source, search for RP1

Joined:Sat Nov 09, 2019 2:36 am
+1 on OP checking the kernel source code!

[jamesh]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

How and where did you get your early unit?

[Gavinmc42]

How and where did you get your early unit?

Amazon of course

A very good question Eben will want to know the answer to that.
Especially considering how careful those 150 or so white box Pi's were locked down and tracked.

+1 on OP checking the kernel source code!

Took me two days of reading all the comments to see a link to the Linux source by 6by9.
Duh, slap head moment for me

[acidtech]

And if you've read some of the comments on Pi5 you should know that
- powering from GPIO is possible
- DPI is supported for sure ( 5 display multihead is possible now)
- PWM on the GPIO is supported, for audio you will need additional filter HW. If it's realy working - test it and report back, as you'll have to test that yourself - and maybe that's why you've received some HW

Anyhow strange that people with 6 posts here have HW on hands to test with.

Yes, I later found the thread about Pi 5 with more details. Still didnt answer everything.

Yes, we can still power the boards through the GPIO header.

Yes, DPI is supported but no confirmation all old DPI modes are still supported(we use the alternate 666 mode pinout so we could use GPIO 18 and 19 for audio.

I have not seen confirmation on AUDIO through the PWM pins but I did see confirmation GPIO 18 and 19 support PWM still.

It may be strange to you, but I asked most of my questions in the past through the Raspberry Pi Firmware github, not here, because they were more responsive.

[acidtech]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

I'm sure if you received an early unit you are in close and constant communication with Raspberry Pi.

If? We got a kit with accessories 1 or 2 weeks before the announcement. Don't see why there would be any question about whether people got preview kits or not since it is a well known fact. And why would you care if someone posted as if they got a kit but didnt?

My companies Sales people have direct communications with RPi Foundation. I do not. I am, however, the one that has to figure out how to update our hardware to work with the Pi5. I also found talking to a sales person doesnt give me the facts atleast 50% of the time(whatever company they are from) so I am asking here.

[acidtech]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

How and where did you get your early unit?

RPi Foundation sent us a kit with the Pi5 and accessories. We were a little surprised ourselves. Im guessing they sent out a lot of review kits for companies that manfacture hats/cases/accessories.

[acidtech]

How and where did you get your early unit?

Amazon of course

A very good question Eben will want to know the answer to that.
Especially considering how careful those 150 or so white box Pi's were locked down and tracked.

+1 on OP checking the kernel source code!

Took me two days of reading all the comments to see a link to the Linux source by 6by9.
Duh, slap head moment for me

If it was really only 150 kits I would be amazed.

[aBUGSworstnightmare]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

I'm sure if you received an early unit you are in close and constant communication with Raspberry Pi.

If? We got a kit with accessories 1 or 2 weeks before the announcement. Don't see why there would be any question about whether people got preview kits or not since it is a well known fact. And why would you care if someone posted as if they got a kit but didnt?

My companies Sales people have direct communications with RPi Foundation. I do not. I am, however, the one that has to figure out how to update our hardware to work with the Pi5. I also found talking to a sales person doesnt give me the facts atleast 50% of the time(whatever company they are from) so I am asking here.

you will have to check the sources and/or wait for somebody who has a Pi5 on hands as well to replay.

Most people here will have to wait until they are able to buy one, not being able to answer your questions now.

[6by9]

RPi Foundation sent us a kit with the Pi5 and accessories. We were a little surprised ourselves. Im guessing they sent out a lot of review kits for companies that manfacture hats/cases/accessories.

RPi Foundation (the educational charity side), or RPi Ltd (the bit that makes the Pi)?
If Ltd, then you should also have had access to the Pi5 alpha tester forum, which is where these questions could all be asked prior to the announcement.
You don't say who your company is, so there's no way to check at this end.

If Foundation, then I'm confused as to why they were involved at all!

DPI is supported
MEDIA_BUS_FMT_RGB888_1X24
MEDIA_BUS_FMT_BGR888_1X24
MEDIA_BUS_FMT_RGB666_1x24_CPADHI
MEDIA_BUS_FMT_BGR666_1x24_CPADHI
MEDIA_BUS_FMT_RGB565_1X24_CPADHI
all work as before.

However modes
MEDIA_BUS_FMT_RGB565_1X16
MEDIA_BUS_FMT_RGB666_1X18
MEDIA_BUS_FMT_BGR666_1X18
have limitations on colour depth due to a hardware gremlin.
https://github.com/raspberrypi/linux/bl ... #L288-L328

PWM audio is discussed elsewhere. No, it's not supported.

Yes you can power the Pi5 via the 5V header. You'll need to configure the Pi via config.txt if your supply can provide 5A, otherwise it will limit the current available to USB peripherals in the same way a 5V 3A USB PSU would.

[ame]

We received an early unit and would like to get started but there appears to be fairly little data availalbe on what we can do. Is DPI mode still supported(all or partial mode options). Is pwm audio still supported(we used them directly not throught the old audio jack, with our own amplifier)? Can we power the RPI5 directly from the gpio headers 5v pins like the old models(yes our power circuit can supp.y upto 5 amps at 5v)?

Those are the minimum information we need to get started working on updates. It would be great if you have this documented somewhere.

I'm sure if you received an early unit you are in close and constant communication with Raspberry Pi.

If? We got a kit with accessories 1 or 2 weeks before the announcement. Don't see why there would be any question about whether people got preview kits or not since it is a well known fact. And why would you care if someone posted as if they got a kit but didnt?

My companies Sales people have direct communications with RPi Foundation. I do not. I am, however, the one that has to figure out how to update our hardware to work with the Pi5. I also found talking to a sales person doesnt give me the facts atleast 50% of the time(whatever company they are from) so I am asking here.

The more you write, the stranger it sounds.

[aBUGSworstnightmare]

..
DPI is supported
MEDIA_BUS_FMT_RGB888_1X24
MEDIA_BUS_FMT_BGR888_1X24
MEDIA_BUS_FMT_RGB666_1x24_CPADHI
MEDIA_BUS_FMT_BGR666_1x24_CPADHI
MEDIA_BUS_FMT_RGB565_1X24_CPADHI
all work as before.

However modes
MEDIA_BUS_FMT_RGB565_1X16
MEDIA_BUS_FMT_RGB666_1X18
MEDIA_BUS_FMT_BGR666_1X18
have limitations on colour depth due to a hardware gremlin.
https://github.com/raspberrypi/linux/bl ... #L288-L328
..

thanks for the info! Very valuable.

[acidtech]

RPi Foundation sent us a kit with the Pi5 and accessories. We were a little surprised ourselves. Im guessing they sent out a lot of review kits for companies that manfacture hats/cases/accessories.

However modes
MEDIA_BUS_FMT_RGB565_1X16
MEDIA_BUS_FMT_RGB666_1X18
MEDIA_BUS_FMT_BGR666_1X18
have limitations on colour depth due to a hardware gremlin.
https://github.com/raspberrypi/linux/bl ... #L288-L328

PWM audio is discussed elsewhere. No, it's not supported.

Yes you can power the Pi5 via the 5V header. You'll need to configure the Pi via config.txt if your supply can provide 5A, otherwise it will limit the current available to USB peripherals in the same way a 5V 3A USB PSU would.

So no 18bit DPI, effectively, and no PWM audio. I am with Experimental Pi. And that pretty much ends any chances of getting our existing models working with the RPi5.

Just to be absolutely sure, DPI mode 6 can only display 12bit color on the Pi5 and there is no way to output PWM audio(787khz) on GPIO 18 and 19 like you could on earlier models?

[cleverca22]

So no 18bit DPI, effectively, and no PWM audio. I am with Experimental Pi. And that pretty much ends any chances of getting our existing models working with the RPi5.

18bit can always be emulated by going to a wider mode like 24bit, and then just not muxing some of the low-order bits
but youll have to wire properly to deal with that

pwm audio seems to be replaced by a new audio_out peripheral, that does the audio->1bit digital in hardware, but its not yet known which pins its in

[6by9]

RPi Foundation sent us a kit with the Pi5 and accessories. We were a little surprised ourselves. Im guessing they sent out a lot of review kits for companies that manfacture hats/cases/accessories.

However modes
MEDIA_BUS_FMT_RGB565_1X16
MEDIA_BUS_FMT_RGB666_1X18
MEDIA_BUS_FMT_BGR666_1X18
have limitations on colour depth due to a hardware gremlin.
https://github.com/raspberrypi/linux/bl ... #L288-L328

PWM audio is discussed elsewhere. No, it's not supported.

Yes you can power the Pi5 via the 5V header. You'll need to configure the Pi via config.txt if your supply can provide 5A, otherwise it will limit the current available to USB peripherals in the same way a 5V 3A USB PSU would.

So no 18bit DPI, effectively, and no PWM audio. I am with Experimental Pi. And that pretty much ends any chances of getting our existing models working with the RPi5.

Just to be absolutely sure, DPI mode 6 can only display 12bit color on the Pi5 and there is no way to output PWM audio(787khz) on GPIO 18 and 19 like you could on earlier models?

What used to be referred to as mode 6 (666 on GPIOs 4-9, 12-17, and 20-25) is MEDIA_BUS_FMT_RGB666_1x24_CPADHI (or MEDIA_BUS_FMT_BGR666_1x24_CPADHI depending which way you wired red and blue), and that is fully supported.

MEDIA_BUS_FMT_RGB565_1X16 is the old mode 2. MEDIA_BUS_FMT_RGB666_1X18 is the old mode 5. Those are the ones that have issues on RP1.

[dickon]

Yes you can power the Pi5 via the 5V header. You'll need to configure the Pi via config.txt if your supply can provide 5A, otherwise it will limit the current available to USB peripherals in the same way a 5V 3A USB PSU would.

Can I assume that the new PoE HAT will supply 5A, and will the board auto-detect this and behave accordingly, or will it still need a config.txt entry?

[cleverca22]

Yes you can power the Pi5 via the 5V header. You'll need to configure the Pi via config.txt if your supply can provide 5A, otherwise it will limit the current available to USB peripherals in the same way a 5V 3A USB PSU would.

Can I assume that the new PoE HAT will supply 5A, and will the board auto-detect this and behave accordingly, or will it still need a config.txt entry?

ive found this in the firmware:

Code: Select all

  switch(gp->power_source) {
  case 1:
  case 2:
  case 3:
    pcVar1 = "USB-C";
    break;
  case 4:
    if (gp->field_0x1fd4 == 0x2e8a) {
      pcVar1 = "RPi USB-PD";
    }
    else {
      pcVar1 = "USB-PD";
    }
    break;
  case 5:
    pcVar1 = "Custom";
    break;
  case 6:
    pcVar1 = "POE";
    break;
  default:
    pcVar1 = "Unknown";
  }
  snprintf(acStack288,0x20,"%s %d mA",pcVar1,gp->available_ma);
  ...
        if ((local_1e & 4) == 0) {
        if ((local_1e & 2) == 0) {
          if ((local_1e & 1) != 0) {
            gp->power_source = 1;
            gp->available_ma = 900;
          }
        }
        else {
          gp->power_source = 2;
          gp->available_ma = 1500;
        }
      }
      else {
        gp->available_ma = 3000;
        gp->power_source = 3;
      }

it looks like the firmware is aware of where the power is coming from, and can detect generic usb-pd, the official psu, dumb usb-c, or other
and t has support to keep track of how many mA its got available, so i would assume it also knows what the PoE hat is supplying

but the PoE hat has also not been announced yet, and the design may still be in the works
so i could assume when it does get finished, the firmware will be updated to fill in available_ma correctly

[acidtech]

However modes
MEDIA_BUS_FMT_RGB565_1X16
MEDIA_BUS_FMT_RGB666_1X18
MEDIA_BUS_FMT_BGR666_1X18
have limitations on colour depth due to a hardware gremlin.
https://github.com/raspberrypi/linux/bl ... #L288-L328

PWM audio is discussed elsewhere. No, it's not supported.

Yes you can power the Pi5 via the 5V header. You'll need to configure the Pi via config.txt if your supply can provide 5A, otherwise it will limit the current available to USB peripherals in the same way a 5V 3A USB PSU would.

So no 18bit DPI, effectively, and no PWM audio. I am with Experimental Pi. And that pretty much ends any chances of getting our existing models working with the RPi5.

Just to be absolutely sure, DPI mode 6 can only display 12bit color on the Pi5 and there is no way to output PWM audio(787khz) on GPIO 18 and 19 like you could on earlier models?

What used to be referred to as mode 6 (666 on GPIOs 4-9, 12-17, and 20-25) is MEDIA_BUS_FMT_RGB666_1x24_CPADHI (or MEDIA_BUS_FMT_BGR666_1x24_CPADHI depending which way you wired red and blue), and that is fully supported.

MEDIA_BUS_FMT_RGB565_1X16 is the old mode 2. MEDIA_BUS_FMT_RGB666_1X18 is the old mode 5. Those are the ones that have issues on RP1.

Good to know. I thought I may be misunderstanding.

That just leaves audio as an issue. The RP1 data sheet shows AUDIO_OUT_L and AUDIO_OUT_R on GPIO 12 and 13. But there is no explanation on what they are. I would assumed Audio PWM but you said PWM doesnt support audio output so.... Not that we could use 12 or 13 if it is audio pwm outputs, since all DPI modes use those pins already(hence why we used 18 and 19 on older Pis).

Any thoughts on how to get audio out of the Pi while using DPI mode 6?

[cleverca22]

But there is no explanation on what they are. I would assumed Audio PWM but you said PWM doesnt support audio output so

pi1-pi4 all had a complex stack of software using a DSP to convert ~48khz 16bit audio into ~781khz 7bit audio
and that was then fed into the PWM block

from what ive heard, the audio_out block in the RP1 does all of that in hardware, so it just directly turns 48khz 16bit into a PWM like signal, with all of the fancy math hidden in hardware