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SubjectRe: [PATCH 2/3] phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround
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On 10/25/2016 08:52 AM, Alexandre Bailon wrote:
> If we configure the da8xx OTG phy in OTG mode, neither device or host
> mode will work. That is because the PHY is not able to detect and notify
> the driver that value of ID pin changed.
> To work despite this hardware limitation, the da8xx glue implement a
> workaround.
> But to work, the workaround require the VBUS sense and the session end
> comparator to enabled.
> Enable them if the phy is configured in OTG mode.
>
> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
> ---
> drivers/phy/phy-da8xx-usb.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/phy/phy-da8xx-usb.c b/drivers/phy/phy-da8xx-usb.c
> index 32ae78c..fd39292 100644
> --- a/drivers/phy/phy-da8xx-usb.c
> +++ b/drivers/phy/phy-da8xx-usb.c
> @@ -93,24 +93,31 @@ static int da8xx_usb20_phy_power_off(struct phy *phy)
> static int da8xx_usb20_phy_set_mode(struct phy *phy, enum phy_mode mode)
> {
> struct da8xx_usb_phy *d_phy = phy_get_drvdata(phy);
> + int ret;
> u32 val;
>
> + ret = regmap_read(d_phy->regmap, CFGCHIP(2), &val);
> + if (ret)
> + return ret;
> +
> + val &= ~CFGCHIP2_OTGMODE_MASK;
> +
> switch (mode) {
> case PHY_MODE_USB_HOST: /* Force VBUS valid, ID = 0 */
> - val = CFGCHIP2_OTGMODE_FORCE_HOST;
> + val |= CFGCHIP2_OTGMODE_FORCE_HOST;
> break;
> case PHY_MODE_USB_DEVICE: /* Force VBUS valid, ID = 1 */
> - val = CFGCHIP2_OTGMODE_FORCE_DEVICE;
> + val |= CFGCHIP2_OTGMODE_FORCE_DEVICE;
> break;
> case PHY_MODE_USB_OTG: /* Don't override the VBUS/ID comparators */
> - val = CFGCHIP2_OTGMODE_NO_OVERRIDE;
> + val |= CFGCHIP2_OTGMODE_NO_OVERRIDE |
> + CFGCHIP2_SESENDEN | CFGCHIP2_VBDTCTEN;

Do we need to clear CFGCHIP2_SESENDEN and/or CFGCHIP2_VBDTCTEN in case
PHY_MODE_USB_HOST: or case PHY_MODE_USB_DEVICE:? Or are they ignored in
those modes?

> break;
> default:
> return -EINVAL;
> }
>
> - regmap_write_bits(d_phy->regmap, CFGCHIP(2), CFGCHIP2_OTGMODE_MASK,
> - val);
> + regmap_write(d_phy->regmap, CFGCHIP(2), val);
>
> return 0;
> }
>

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