Re: [PATCH v3] ARM: zynq: DT: Add USB to device tree

["Sören Brinkmann" <soren.brinkmann@xilinx.com>]

On Tue, 2015-01-27 at 02:14AM +0100, Andreas Färber wrote:
> + linux-gpio, linux-usb, Felipe Balbi
> 
> Am 26.01.2015 um 19:44 schrieb Sören Brinkmann:
> > On Mon, 2015-01-26 at 08:23AM -0800, Sören Brinkmann wrote:
> >> On Mon, 2015-01-26 at 05:21PM +0100, Andreas Färber wrote:
> >>> Am 26.01.2015 um 16:50 schrieb Sören Brinkmann:
> >>>> On Mon, 2015-01-26 at 10:35AM +0100, Andreas Färber wrote:
> >>>>> Am 26.01.2015 um 09:33 schrieb Andreas Färber:
> >>>>>> Am 26.01.2015 um 09:23 schrieb Michal Simek:
> >>>>>>> On 01/26/2015 09:19 AM, Andreas Färber wrote:
> >>>>>>>> And if I apply it to my -next based tree, adding corresponding nodes to
> >>>>>>>> zynq-parallella.dts, I get repeatedly:
> >>>>>>>>
> >>>>>>>> [  +0,012242] ci_hdrc ci_hdrc.0: no of_node; not parsing pinctrl DT
> >>>>>>>> [  +0,000157] ci_hdrc ci_hdrc.0: ChipIdea HDRC found, lpm: 0; cap:
> >>>>>>>> f090e100 op: f090e140
> >>>>>>>> [  +0,000081] platform ci_hdrc.0: Driver ci_hdrc requests probe deferral
> >>>>>>>> [  +0,005360] ci_hdrc ci_hdrc.1: no of_node; not parsing pinctrl DT
> >>>>>>>> [  +0,000120] ci_hdrc ci_hdrc.1: ChipIdea HDRC found, lpm: 0; cap:
> >>>>>>>> f0910100 op: f0910140
> >>>>>>>> [  +0,001810] platform ci_hdrc.1: Driver ci_hdrc requests probe deferral
> >>>>>>>>
> >>>>>>>> Am I missing any other patches or config options?
> [...]
> >>>>>>> Why is it deferred? Is it because of pinmuxing stuff?
> >>>>>>
> >>>>>> No, happened without as well.
> >>>>>>
> >>>>>> Looking at a different place in dmesg, I spot this:
> >>>>>>
> >>>>>> [  +0,003988] usb_phy_generic phy0: GPIO lookup for consumer reset-gpios
> >>>>>> [  +0,000012] usb_phy_generic phy0: using device tree for GPIO lookup
> >>>>>> [  +0,000015] of_get_named_gpiod_flags: can't parse 'reset-gpios-gpios'
> >>>>>> property
> >>>>>>  of node '/phy0[0]'
> >>>>>> [  +0,000013] of_get_named_gpiod_flags: can't parse 'reset-gpios-gpio'
> >>>>>> property
> >>>>>> of node '/phy0[0]'
> >>>>>> [  +0,000010] usb_phy_generic phy0: using lookup tables for GPIO lookup
> >>>>>> [  +0,000153] usb_phy_generic phy0: lookup for GPIO reset-gpios failed
> >>>>>> [  +0,000012] usb_phy_generic phy0: Error requesting RESET GPIO
> >>>>>> [  +0,004360] usb_phy_generic: probe of phy0 failed with error -2
> >>>>>> [  +0,004991] usb_phy_generic phy1: GPIO lookup for consumer reset-gpios
> >>>>>> [  +0,000012] usb_phy_generic phy1: using device tree for GPIO lookup
> >>>>>> [  +0,000013] of_get_named_gpiod_flags: can't parse 'reset-gpios-gpios'
> >>>>>> property
> >>>>>>  of node '/phy1[0]'
> >>>>>> [  +0,000013] of_get_named_gpiod_flags: can't parse 'reset-gpios-gpio'
> >>>>>> property of node '/phy1[0]'
> >>>>>> [  +0,000010] usb_phy_generic phy1: using lookup tables for GPIO lookup
> >>>>>> [  +0,000012] usb_phy_generic phy1: lookup for GPIO reset-gpios failed
> >>>>>> [  +0,000011] usb_phy_generic phy1: Error requesting RESET GPIO
> >>>>>> [  +0,004337] usb_phy_generic: probe of phy1 failed with error -2
> >>>>>>
> >>>>>> So, I guess the chipidea driver is deferring because the phys want a
> >>>>>> property that neither me nor you are specifying? [...]
> [...]
> >>>>> In my manuals and notes I can't find any GPIO being used as reset for
> >>>>> the USB PHYs. Any thoughts appreciated.
> >>>>
> >>>> Such a connection is optional. The platform might rely on its reset
> >>>> circuit, though it might not work for warm reboots.
> >>>> I haven't looked at parallela docs, but if there is a schematic
> >>>> available, that should tell you if/what is connected to the PHY reset
> >>>> pin.
> >>>
> >>> I do have the schematic, and the way I read it, only the on-board reset
> >>> button resets the PHYs.
> >>>
> >>> Yet it looks as if usb-nop-xceiv insists on a reset-gpios above, no?
> >>> Does it work on your boards with linux-next?
> >>
> >> I haven't re-tested it since I submitted the patches, but at that time
> >> it worked. But I also didn't test USB with the pinctrl patches together.
> >> I'll do some testing later today.
> > 
> > So, just did a test. I took all the pinctrl stuff and this patch and ran
> > it on a zc702. I plugged in a thumb drive and that worked just fine. So,
> > basically this patch could go in, despite missing pinctrl properties.
> 
> For my board I needed the following workaround:
> 
> diff --git a/drivers/usb/phy/phy-generic.c b/drivers/usb/phy/phy-generic.c
> index dd05254241fb..96c7c36e22a6 100644
> --- a/drivers/usb/phy/phy-generic.c
> +++ b/drivers/usb/phy/phy-generic.c
> @@ -218,13 +218,13 @@ int usb_phy_gen_create_phy(struct device *dev,
> struct usb_phy_generic *nop,
>                         clk_rate = 0;
> 
>                 needs_vcc = of_property_read_bool(node, "vcc-supply");
> -               nop->gpiod_reset = devm_gpiod_get(dev, "reset-gpios");
> +               /*nop->gpiod_reset = devm_gpiod_get(dev, "reset-gpios");
>                 err = PTR_ERR(nop->gpiod_reset);
>                 if (!err) {
>                         nop->gpiod_vbus = devm_gpiod_get(dev,
> 
> "vbus-detect-gpio");
>                         err = PTR_ERR(nop->gpiod_vbus);
> -               }
> +               }*/
>         } else if (pdata) {
>                 type = pdata->type;
>                 clk_rate = pdata->clk_rate;
> 
> [  +0,004738] usb_phy_generic phy0: Looking up vcc-supply from device tree
> [  +0,000018] usb_phy_generic phy0: Looking up vcc-supply property in
> node /phy0 failed
> [  +0,000011] phy0 supply vcc not found, using dummy regulator
> [  +0,004844] usb_phy_generic phy1: Looking up vcc-supply from device tree
> [  +0,000017] usb_phy_generic phy1: Looking up vcc-supply property in
> node /phy1 failed
> [  +0,000008] phy1 supply vcc not found, using dummy regulator
> 
> Basically, usb-nop-xceiv fails to probe when reset-gpios property is
> absent (and probably also when vbus-detect-gpio property is absent).
> So I don't understand why it would work for your boards without such
> properties on today's linux-next... sounds like you tested a different tree?

I tested on the 3.19 tip, not on next. I see the problems you see on
next though. Haven't really dug deeper yet.

> 
> Take a look at __gpiod_get_index() called from devm_gpiod_get():
> http://lxr.free-electrons.com/source/drivers/gpio/gpiolib.c#L1648
> 
> !desc || desc == ERR_PTR(-ENOENT) results in the above "using lookup
> tables for GPIO lookup", then IS_ERR(desc) in "lookup for GPIO %s failed".
> 
> My interpretation is that this gpiolib code is probably okay but that
> the generic usb phy code fails to check for specific error codes such as
> absent property (as opposed to deferred resolution of a phandle, where
> we do want to return -EDEFER early).

Sounds like you're already close.

	Sören