MVEBU A38x Regulator

[Pali Rohár]

Hello!

I think that those dmesg lines are printed when regulator is not
specified in device tree file in sata/ahci node (which is read by
sata/ahci driver).

On Sunday 24 July 2022 17:36:06 Tony Dinh wrote:
> Hi Pali Hi Stefan,
> 
> I find it odd that the Linux kernel regulator does not attempt to
> enable power to the HDD. Is the purpose of the SATA regulator to power
> up the port with GPIO (GPIO 15 in this case). The Supply AHCI is not
> found because there is no power to the port, isn't it?
> 
> [    2.415108] ahci-mvebu f10a8000.sata: supply ahci not found, using
> dummy regulator
> [    2.423601] ahci-mvebu f10a8000.sata: supply phy not found, using
> dummy regulator
> 
> If I boot with stock u-boot and then poke GPIO 15 at u-boot prompt,
> later I would get the same error in dmesg about "dummy regulator", but
> the SATA drive is spun up OK. So I guess it has nothing to do with
> whether the SATA port has powered up. Just something wrong about the
> regulator code when running with the Armada 385 SoC (or with this
> board in particular).
> 
> Thanks,
> Tony
> 
> On Sun, Jul 24, 2022 at 2:27 AM Pali Rohár <pali at kernel.org> wrote:
> >
> > On Wednesday 20 July 2022 15:47:55 Tony Dinh wrote:
> > > Hi Pali/Marek,
> > >
> > > I'm writing u-boot for the Synology DS116 (Armada 385, dual core, 1.8
> > > Ghz). I could not seem to get the DM Regulator to power up the SATA
> > > port on this board. I'm using Stefan ./board/Marvell/db-88f6820-gp as
> > > the starting point, and using the latest DTS
> > >
> > > https://github.com/torvalds/linux/blob/master/arch/arm/boot/dts/armada-385-synology-ds116.dts
> > >
> > > I noticed that the Linux kernel boot log (booted with stock Marvell
> > > u-boot) shows "supply ahci not found" error. But I can power up the
> > > SATA drive in stock u-boot by poking GPIO 15 (SATA power enable). And
> > > it works fine with this combination: stock u-boot, kernel 5.18.6.
> > >
> > > [    2.861061] usb_phy_generic usb3_0_phy: dummy supplies not allowed
> > > for exclusive requests
> > > [    2.870173] usb_phy_generic usb3_1_phy: dummy supplies not allowed
> > > for exclusive requests
> > > [    2.879296] ahci-mvebu f10a8000.sata: supply ahci not found, using
> > > dummy regulator
> > > [    2.887704] ahci-mvebu f10a8000.sata: supply phy not found, using
> > > dummy regulator
> > > [    2.896101] ahci-mvebu f10a8000.sata: masking port_map 0x3 -> 0x1
> > > [    2.902951] ahci-mvebu f10a8000.sata: AHCI 0001.0000 32 slots 2
> > > ports 6 Gbps 0x1 impl platform mode
> > > [    2.912750] ahci-mvebu f10a8000.sata: flags: 64bit ncq sntf led
> > > only pmp fbs pio slum part sxs
> > > [    2.923184] scsi host0: ahci-mvebu
> > > [    2.927693] scsi host1: ahci-mvebu
> > > [    2.931935] ata1: SATA max UDMA/133 mmio [mem
> > > 0xf10a8000-0xf10a9fff] port 0x100 irq 50
> > > [    2.940610] ata2: DUMMY
> > >
> > > My questions: does DM regulator +  DM GPIO work for Armada 38x u-boot?
> > > and is the error "ahci-mvebu f10a8000.sata: supply ahci, using dummy
> > > regulator" a real error? I've googled this and came across some past
> > > related posts from you (Pali and Marek), but it is not apparent what
> > > was the solution.
> >
> > I'm really not sure if DM regulator and DM GPIO is working in U-Boot for
> > Armada 38x. Lot of Armada boards touch pinctrl/gpio registers directory
> > to configure GPIOs, instead of using DM GPIO API.
> >
> > Stefan, any idea?
> >
> > > If you are interested in seeing more info while I'm at my new u-boot
> > > prompt (kwboot with the SPL kwb), I can post that followup.
> > >
> > > Thanks,
> > > Tony