On Tue, Oct 24, 2017 at 10:57:29AM +0200, Uwe Kleine-König wrote:
> In commit 9dba516ed282 ("usb: chipidea: imx: set over current polarity
> per dts setting") i.MX6 and i.MX7 learned the dt property
> "over-current-active-high". The difference compared to i.MX25 is that on
> the latter the default in hardware and the driver is already
> active-high. For that reason the over-current-active-high property is
> added to the imx25 template to keep the default behaviour.
>
> The obvious downside is that device trees that were compiled before this
> change don't have that property and so when run with a kernel including
> this change suddenly use active low logic. This could only be
> circumvented with another property "over-current-active-low" and
> different default handling for imx6/7 vs imx25 if none (or both) of the
> properties are present. For simplicity I stick to the easier and better
> understandable alternative at the cost of dt incompatibility.
Sorry to reply late, in order to keep compatibility, my suggestion is
add another property "over-current-active-low" and change imx25 related
code accordingly.
Peter
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koe...@pengutronix.de>
> ---
> Hello,
>
> is it ok to break compatibility here?
>
> Best regards
> Uwe
>
> arch/arm/boot/dts/imx25.dtsi | 2 ++
> drivers/usb/chipidea/usbmisc_imx.c | 15 +++++++++++++--
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/boot/dts/imx25.dtsi b/arch/arm/boot/dts/imx25.dtsi
> index 09ce8b81fafa..bb0054603846 100644
> --- a/arch/arm/boot/dts/imx25.dtsi
> +++ b/arch/arm/boot/dts/imx25.dtsi
> @@ -565,6 +565,7 @@
> fsl,usbphy = <&usbphy0>;
> phy_type = "utmi";
> dr_mode = "otg";
> + over-current-active-high;
> status = "disabled";
> };
>
> @@ -576,6 +577,7 @@
> clock-names = "ipg", "ahb", "per";
> fsl,usbmisc = <&usbmisc 1>;
> fsl,usbphy = <&usbphy1>;
> + over-current-active-high;
> status = "disabled";
> };
>
> diff --git a/drivers/usb/chipidea/usbmisc_imx.c
> b/drivers/usb/chipidea/usbmisc_imx.c
> index 9f4a0185dd60..6f3d0341357c 100644
> --- a/drivers/usb/chipidea/usbmisc_imx.c
> +++ b/drivers/usb/chipidea/usbmisc_imx.c
> @@ -125,16 +125,27 @@ static int usbmisc_imx25_init(struct imx_usbmisc_data
> *data)
> val = readl(usbmisc->base);
> val &= ~(MX25_OTG_SIC_MASK | MX25_OTG_PP_BIT);
> val |= (MX25_EHCI_INTERFACE_DIFF_UNI &
> MX25_EHCI_INTERFACE_MASK) << MX25_OTG_SIC_SHIFT;
> - val |= (MX25_OTG_PM_BIT | MX25_OTG_OCPOL_BIT);
> + val |= MX25_OTG_PM_BIT;
> +
> + if (data->oc_polarity)
> + val |= MX25_OTG_OCPOL_BIT;
> + else
> + val &= ~MX25_OTG_OCPOL_BIT;
> +
> writel(val, usbmisc->base);
> break;
> case 1:
> val = readl(usbmisc->base);
> val &= ~(MX25_H1_SIC_MASK | MX25_H1_PP_BIT |
> MX25_H1_IPPUE_UP_BIT);
> val |= (MX25_EHCI_INTERFACE_SINGLE_UNI &
> MX25_EHCI_INTERFACE_MASK) << MX25_H1_SIC_SHIFT;
> - val |= (MX25_H1_PM_BIT | MX25_H1_OCPOL_BIT | MX25_H1_TLL_BIT |
> + val |= (MX25_H1_PM_BIT | MX25_H1_TLL_BIT |
> MX25_H1_USBTE_BIT | MX25_H1_IPPUE_DOWN_BIT);
>
> + if (data->oc_polarity)
> + val |= MX25_H1_OCPOL_BIT;
> + else
> + val &= ~MX25_H1_OCPOL_BIT;
> +
> writel(val, usbmisc->base);
>
> break;
> --
> 2.11.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-ker...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Best Regards,
Peter Chen
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