On 16.07.20 10:22, Roger Quadros wrote:
> AM654x PG1.0 has a silicon bug that D+ is pulled high after POR, which
> could cause enumeration failure with some USB hubs. Disabling the
> USB2_PHY Charger Detect function will put D+ into the normal state.
>
> Using property "ti,disable-charger-det" in the DT usb2-phy node to
> enable this workaround for AM654x PG1.0.
>
> This addresses Silicon Errata:
> i2075 - "USB2PHY: USB2PHY Charger Detect is Enabled by Default Without VBUS
> Presence"
>
> Signed-off-by: Bin Liu <b-liu@xxxxxx>
> Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> ---
> drivers/phy/ti/phy-omap-usb2.c | 35 +++++++++++++++++++++++++++-------
> 1 file changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/phy/ti/phy-omap-usb2.c b/drivers/phy/ti/phy-omap-usb2.c
> index cb2dd3230fa7..21c3904d4efc 100644
> --- a/drivers/phy/ti/phy-omap-usb2.c
> +++ b/drivers/phy/ti/phy-omap-usb2.c
> @@ -26,6 +26,10 @@
> #define USB2PHY_ANA_CONFIG1 0x4c
> #define USB2PHY_DISCON_BYP_LATCH BIT(31)
>
> +#define USB2PHY_CHRG_DET 0x14
> +#define USB2PHY_CHRG_DET_USE_CHG_DET_REG BIT(29)
> +#define USB2PHY_CHRG_DET_DIS_CHG_DET BIT(28)
> +
> /* SoC Specific USB2_OTG register definitions */
> #define AM654_USB2_OTG_PD BIT(8)
> #define AM654_USB2_VBUS_DET_EN BIT(5)
> @@ -43,6 +47,7 @@
> #define OMAP_USB2_HAS_START_SRP BIT(0)
> #define OMAP_USB2_HAS_SET_VBUS BIT(1)
> #define OMAP_USB2_CALIBRATE_FALSE_DISCONNECT BIT(2)
> +#define OMAP_USB2_DISABLE_CHRG_DET BIT(3)
>
> struct omap_usb {
> struct usb_phy phy;
> @@ -236,6 +241,13 @@ static int omap_usb_init(struct phy *x)
> omap_usb_writel(phy->phy_base, USB2PHY_ANA_CONFIG1, val);
> }
>
> + if (phy->flags & OMAP_USB2_DISABLE_CHRG_DET) {
> + val = omap_usb_readl(phy->phy_base, USB2PHY_CHRG_DET);
> + val |= USB2PHY_CHRG_DET_USE_CHG_DET_REG |
> + USB2PHY_CHRG_DET_DIS_CHG_DET;
> + omap_usb_writel(phy->phy_base, USB2PHY_CHRG_DET, val);
> + }
> +
> return 0;
> }
>
> @@ -366,14 +378,12 @@ static int omap_usb2_probe(struct platform_device *pdev)
> phy->mask = phy_data->mask;
> phy->power_on = phy_data->power_on;
> phy->power_off = phy_data->power_off;
> + phy->flags = phy_data->flags;
>
> - if (phy_data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(phy->phy_base))
> - return PTR_ERR(phy->phy_base);
> - phy->flags |= OMAP_USB2_CALIBRATE_FALSE_DISCONNECT;
> - }
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(phy->phy_base))
> + return PTR_ERR(phy->phy_base);
>
> phy->syscon_phy_power = syscon_regmap_lookup_by_phandle(node,
> "syscon-phy-power");
> @@ -405,6 +415,17 @@ static int omap_usb2_probe(struct platform_device *pdev)
> }
> }
>
> + /*
> + * Errata i2075: USB2PHY: USB2PHY Charger Detect is Enabled by
> + * Default Without VBUS Presence.
> + *
> + * AM654x SR1.0 has a silicon bug due to which D+ is pulled high after
> + * POR, which could cause enumeration failure with some USB hubs.
> + * Disabling the USB2_PHY Charger Detect function will put D+
> + * into the normal state.
> + */
> + if (of_property_read_bool(node, "ti,disable-charger-det"))
> + phy->flags |= OMAP_USB2_DISABLE_CHRG_DET;
>
> phy->wkupclk = devm_clk_get(phy->dev, "wkupclk");
> if (IS_ERR(phy->wkupclk)) {
>
Why a property, rather than SoC detection like in [1] and your previous
downstream version?
Jan
[1] https://patchwork.kernel.org/patch/11710643/
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
