How to switch AGPIO (GPIO 18/19) - Omega2 FW vs LEDE build



  • @sza2-sza2 Your analysis is correct, the problem affects pin 14 through 29, and is easily fixed is in the bootloader:

    diff --git a/drivers/rt2880_eth.c b/drivers/rt2880_eth.c
    index 7c83a46..9b6f1ec 100644
    --- a/drivers/rt2880_eth.c
    +++ b/drivers/rt2880_eth.c
    @@ -2134,6 +2134,8 @@ void rt305x_esw_init(void)
     /*TODO: Init MT7628 ASIC PHY HERE*/
            i = RALINK_REG(RT2880_AGPIOCFG_REG);
            i = i & ~(MT7628_EPHY_EN);
    +       // only enable PHY 0
    +       i = i | (0x1e << 16);
            RALINK_REG(RT2880_AGPIOCFG_REG) = i;
    
            printf("Resetting MT7628 PHY.\n");
    
    


  • @wdu cool, thanks for figuring that out!

    @Lazar-Demin that should be fixed in the Omega2 bootloader. Only Phy0 is usable in the Omega2, so it makes no sense to enable Phy1..4 at all. With the Omega2S, the other Phys can be used but still I think the bootloader should only enable the port it actually uses (Phy0) and leave the others in GPIO mode.



  • @luz @wdu Thank you for your analysis and solution for this issue. This thread has served me a great purpose for a similar issue.

    I need to use phy0 as WAN, phy1 as LAN and other three phy ports as GPIO pins. When I tried the solution that is mentioned in this thread, it disables all the lan ports (except phy0).

    When I need only phy1 to be used as LAN, what is the registry value that I should use?

    Following, is the change I tried.

    volatile uint32_t *reg = (volatile uint32_t*) (gpio_mmap_reg + 0x3c);
    unsigned int v;
    v = *reg;
    v |= 0x1e << 16;
    *(volatile uint32_t*) (reg) = v;
    


  • @Siddharth-Velappan Unfortunately, it is not possible to switch on phy1..4 individually. Only phy0 can be switched independently; the other 4 always are all in phy or all in GPIO mode.

    The AGPIO_CFG register layout suggests that there is a separate disable bit for each phy, but that's not the case. See the note in the MT7688 datasheet on page 59 reading "When any bit of bit[20:17] is set to 1, P1 ~ P4 will be swiched to digital PADs together."

    It seems to me that this is one of the small oversights in the MT7688 that probably happened when MediaTek had to "IoT-ze" a former router chip design (too) quickly. Other examples of this are the SPI not working correctly in full duplex mode and the PWM units that are not connected to DMA...



  • @luz Hello! This topic is very interesting for me! I'm using an omega2s and I wanted to use eth0 and eth1 (with a custom board). I've recompiled the official firmware adding devmem, installed it and ran:

    devmem 0x1000003C 32 0x00E001FF
    

    Now, the registry has the 'correct' value but the switch isn't working. I've ran:

    root@Omega-89C9:~# swconfig dev switch0 show
    Global attributes:
    	enable_vlan: 0
    	alternate_vlan_disable: 0
    	bc_storm_protect: 0
    	led_frequency: 0
    Port 0:
    	disable: 0
    	doubletag: 1
    	untag: 1
    	led: 5
    	lan: 1
    	recv_bad: 0
    	recv_good: 845
    	tr_bad: 0
    	tr_good: 816
    	pvid: 0
    	link: port:0 link:up speed:100baseT full-duplex 
    Port 1:
    	disable: 0
    	doubletag: 1
    	untag: 1
    	led: 5
    	lan: 1
    	recv_bad: 0
    	recv_good: 0
    	tr_bad: 0
    	tr_good: 0
    	pvid: 0
    	link: port:1 link:down
    Port 2:
    	disable: 0
    	doubletag: 1
    	untag: 1
    	led: 5
    	lan: 1
    	recv_bad: 0
    	recv_good: 0
    	tr_bad: 0
    	tr_good: 0
    	pvid: 0
    	link: port:2 link:down
    Port 3:
    	disable: 0
    	doubletag: 1
    	untag: 1
    	led: 5
    	lan: 1
    	recv_bad: 0
    	recv_good: 0
    	tr_bad: 0
    	tr_good: 0
    	pvid: 0
    	link: port:3 link:down
    Port 4:
    	disable: 0
    	doubletag: 1
    	untag: 1
    	led: 5
    	lan: 1
    	recv_bad: 0
    	recv_good: 0
    	tr_bad: 0
    	tr_good: 0
    	pvid: 0
    	link: port:4 link:down
    Port 5:
    	disable: 1
    	doubletag: 1
    	untag: 1
    	led: ???
    	lan: 1
    	recv_bad: 0
    	recv_good: 0
    	tr_bad: 0
    	tr_good: 0
    	pvid: 0
    	link: port:5 link:down
    Port 6:
    	disable: 0
    	doubletag: 1
    	untag: 1
    	led: ???
    	lan: ???
    	recv_bad: ???
    	recv_good: ???
    	tr_bad: ???
    	tr_good: ???
    	pvid: 0
    	link: port:6 link:up speed:1000baseT full-duplex 
    VLAN 0:
    	ports: 0 1 2 3 4 5 6 
    root@Omega-89C9:~#
    

    but the output is the same as before running devmem and if I connect an ethernet cable on the second port, I don't see any link. What am I missing? Maybe the custom board is not working properly? Or Do I have to configure something in /etc/config/network? Or with swconfig? Sorry for all these questions but I'm relatively new to omega2 and swconfig :)

    Thank you so much for your support,
    Paolo



  • @Paolo-Ciuffetti it seems that this is related to @Dino-Ciuffetti 's question on another thread, is it?

    As you say, I also guess it's a matter of getting /etc/config/network right, and understand swconfig. Most probably (but I'm not sure), enabling/disabling the switch is not something that can be done while up and running, but must be set up in the startup sequence.

    I would try to glean information from existing MT7688 based router's firmware (Minibox V2.0, androegg.de...).



  • Yes @luz, we are working on the same project. I'm using informations taken from this thread and this link. I'm rebuilding a new firmware with modifications on sd.c (like /sza2 wrote in this thread) and 02.network (see the linked link) to enable 2 lans (1 wan, 1 lan) and see what happens.

    On very first message you wrote that the address modification (devmem 0x1000003C 32 0x00E001FF) worked for you, but super ugly. It's not working for us, so I asked on this thread more informations on how to make it works for us too.. :)

    I'll post my results on this topic when the new firmware will be ready and installed on my omega2s :)



  • @luz what did you end up doing to resolve this issue? I'm not too excited about rebuilding the boot loader with a change but I'm also using this pin to control an external relay and the relay is activating during boot time when GPIO18 is in analog mode and goes to ~1.65V.

    I'm thinking about moving to another available GPIO that doesn't exhibit this behavior but wanted to hear what you had to say first.



  • Hi @Chris-Morgan, I did not rebuild the boot loader so far, but just avoided using PHY pins for outputs that need to be stable during powerup in the projects I did since.

    Would be nice though if @onion would (or maybe already has?) fix this in their bootloader, such that newer Omega2's would no longer suffer from that problem.



  • @luz I'm still seeing it here with a pretty new Omega2+ and the latest firmware, although I'm not sure if the oupgrade process upgrades the boot loader or not.


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