Messages in this thread | | | From | Martin Blumenstingl <> | Date | Fri, 18 Jun 2021 22:01:33 +0200 | Subject | Re: [RFCv1 4/8] phy: amlogic: meson8b-usb2: Use phy set_mode callback function |
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Hi Anand,
On Fri, Jun 18, 2021 at 3:19 PM Anand Moon <linux.amoon@gmail.com> wrote: [...] > > I suggest dropping this patch until we know for sure if and which > > registers need to be updated based on the DR mode. > > Yes, I have observed this, Can you give these small changes a try? > With the below changes, I got the PHY_MODE_USB_DEVICE support working. first of all: sorry that I have not linked my source of information previously: - Meson8b: [0] - Meson8 and Meson8m2: [1]
Unfortunately I don't have any datasheet or "better documentation" of how the registers should be programmed. This is why I am a bit defensive when I am asked to change something there - as I simply have no way of knowing if the changes are good or not. I can only tell whether they're "identical" or "different" from what the vendor kernel does.
[...] > + case PHY_MODE_USB_DEVICE: > + case PHY_MODE_USB_OTG: > + regmap_update_bits(priv->regmap, REG_ADP_BC, > + REG_ADP_BC_DCD_ENABLE, > + REG_ADP_BC_DCD_ENABLE); > + > + udelay(ACA_ENABLE_COMPLETE_TIME); > + > + regmap_read(priv->regmap, REG_ADP_BC, ®); > + if (reg & REG_ADP_BC_ACA_PIN_FLOAT) { > + dev_warn(&phy->dev, "USB ID detect failed!\n"); > + return -EINVAL; > + } > + regmap_update_bits(priv->regmap, REG_ADP_BC, > + REG_ADP_BC_ID_PULLUP, REG_ADP_BC_ID_PULLUP); > + break; According to the vendor kernel this should only be applied to "host-only" USB_PORT_IDX_B (which is usb1 in the mainline .dtsi). Based on that I think it's not correct to apply this for DEVICE and OTG modes.
The vendor kernel does not configure REG_ADP_BC_ID_PULLUP anywhere. Also DCD_ENABLE is only ever set to 0 (while you are enabling it now), see [2].
As mentioned before: all I can say about this patch is that it programs the registers differently than the vendor kernel does. From your description I am not sure if you are now getting different behavior on Odroid-C1 with this patch (compared to what we had before).
Best regards, Martin
[0] https://github.com/endlessm/linux-meson/blob/03393bb8e8478626e03ee93b0a2a225d6de242b5/arch/arm/mach-meson8b/usbclock.c#L120 [1] https://github.com/endlessm/linux-meson/blob/03393bb8e8478626e03ee93b0a2a225d6de242b5/arch/arm/mach-meson8/usbclock.c#L120 [2] https://github.com/endlessm/linux-meson/blob/d6e13c220931110fe676ede6da69fc61a7cb04b6/drivers/amlogic/usb/dwc_otg/310/dwc_otg_pcd.c#L71
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