John,
On Wed, Dec 2, 2015 at 11:14 AM, John Youn <John.Youn@xxxxxxxxxxxx> wrote:
> Added functions to set force mode for host and device. These functions
> will check the current mode and only force if needed.
>
> Signed-off-by: John Youn <johnyoun@xxxxxxxxxxxx>
> ---
> drivers/usb/dwc2/core.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
>
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index 7090050..caaff42 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -3105,6 +3105,60 @@ void dwc2_set_parameters(struct dwc2_hsotg *hsotg,
> dwc2_set_param_hibernation(hsotg, params->hibernation);
> }
>
> +/*
> + * Force host mode if not in host mode. Returns true if the mode was
> + * forced.
> + */
> +static bool dwc2_force_host_if_needed(struct dwc2_hsotg *hsotg)
> +{
> + u32 gusbcfg;
> +
> + if (dwc2_is_host_mode(hsotg))
> + return false;
> +
> + gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
> + gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
> + gusbcfg |= GUSBCFG_FORCEHOSTMODE;
> + dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
> + usleep_range(25000, 50000);
> +
> + return true;
> +}
> +
> +/*
> + * Force device mode if not in device mode. Returns true if the mode
> + * was forced.
> + */
> +static bool dwc2_force_device_if_needed(struct dwc2_hsotg *hsotg)
> +{
> + u32 gusbcfg;
> +
> + if (dwc2_is_device_mode(hsotg))
> + return false;
> +
> + gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
> + gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
> + gusbcfg |= GUSBCFG_FORCEDEVMODE;
> + dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
> + usleep_range(25000, 50000);
> +
> + return true;
> +}
> +
> +/*
> + * Clears the force mode bits.
> + */
> +static void dwc2_clear_force_mode(struct dwc2_hsotg *hsotg)
> +{
> + u32 gusbcfg;
> +
> + gusbcfg = dwc2_readl(hsotg->regs + GUSBCFG);
> + gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
> + gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
> + dwc2_writel(gusbcfg, hsotg->regs + GUSBCFG);
> + usleep_range(25000, 50000);
> +}
> +
Other than same comments as "usb: dwc2: Reduce delay when forcing mode
in reset" (decrease range to 25000, 30000 or use msleep), this looks
good to me.
Optionally I'd think it might be worth it to add:
WARN_ON(hsotg->dr_mode == USB_DR_MODE_HOST)
...in dwc2_force_device_if_needed() and in dwc2_clear_force_mode()
...and
WARN_ON(hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)
...in dwc2_force_host_if_needed() and in dwc2_clear_force_mode()
AKA: make it clear that the caller was expected to check these things.
This is tested on some rk3288-based devices with a 3.14 kernel.
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
-Doug
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