Re: [PATCH v3 2/2] usb: dwc2: add 'mode' which based on Kconfig select or dts setting

[Doug Anderson]

Kever,

On Mon, Aug 4, 2014 at 6:45 AM, Kever Yang <kever.yang@xxxxxxxxxxxxxx> wrote:
> According to the "dr_mode", the otg controller can work as
> device role during firmware period, and work as host role in
> the kernel, without use of usb_id pin. As the commit "usb: dwc3:
> set 'mode' based on selected Kconfig choices".

I don't think you need to mention firmware / kernel here.  Just say
that on some boards we always want to use host mode and on other
boards we want to use gadget mode.  ...and that we don't necessarily
have the ID pin hooked up to make this automatic.


> Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>

Normally I'd say that you should have added Paul's "Acked-by" since
you fixed his nit and he told you to include his Acked-by when his nit
was fixed, but...


> ---
>
> Changes in v3:
> - fix the odd spacing in dwc2_hsotg struct
> - From Jingoo's suggestion:
>     change the commit message

You did more than just this.  You also added some (incorrect) Kconfig
things.  See below.


> Changes in v2:
> - put spaces around '+' operator
> - expand the comment for dr_mode
> - handle dr_mode is USB_DR_MODE_OTG
>
>  drivers/usb/dwc2/core.c     | 18 ++++++++++++++++++
>  drivers/usb/dwc2/core.h     |  5 +++++
>  drivers/usb/dwc2/platform.c | 12 ++++++++++++
>  3 files changed, 35 insertions(+)
>
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index 27d2c9b..738bec2 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -118,6 +118,7 @@ static int dwc2_core_reset(struct dwc2_hsotg *hsotg)
>  {
>         u32 greset;
>         int count = 0;
> +       u32 gusbcfg;
>
>         dev_vdbg(hsotg->dev, "%s()\n", __func__);
>
> @@ -148,6 +149,23 @@ static int dwc2_core_reset(struct dwc2_hsotg *hsotg)
>                 }
>         } while (greset & GRSTCTL_CSFTRST);
>
> +       if (hsotg->dr_mode == USB_DR_MODE_HOST) {
> +               gusbcfg = readl(hsotg->regs + GUSBCFG);
> +               gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
> +               gusbcfg |= GUSBCFG_FORCEHOSTMODE;
> +               writel(gusbcfg, hsotg->regs + GUSBCFG);
> +       } else if (hsotg->dr_mode == USB_DR_MODE_PERIPHERAL) {
> +               gusbcfg = readl(hsotg->regs + GUSBCFG);
> +               gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
> +               gusbcfg |= GUSBCFG_FORCEDEVMODE;
> +               writel(gusbcfg, hsotg->regs + GUSBCFG);
> +       } else if (hsotg->dr_mode == USB_DR_MODE_OTG) {
> +               gusbcfg = readl(hsotg->regs + GUSBCFG);
> +               gusbcfg &= ~GUSBCFG_FORCEHOSTMODE;
> +               gusbcfg &= ~GUSBCFG_FORCEDEVMODE;
> +               writel(gusbcfg, hsotg->regs + GUSBCFG);
> +       }
> +
>         /*
>          * NOTE: This long sleep is _very_ important, otherwise the core will
>          * not stay in host mode after a connector ID change!
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> index 1efd10c..52a4fd2 100644
> --- a/drivers/usb/dwc2/core.h
> +++ b/drivers/usb/dwc2/core.h
> @@ -501,6 +501,10 @@ struct dwc2_hw_params {
>   *                      a_peripheral and b_device=>b_host) this may not match
>   *                      the core, but allows the software to determine
>   *                      transitions
> + * @dr_mode:            Requested mode of operation, one of following:
> + *                      - USB_DR_MODE_PERIPHERAL
> + *                      - USB_DR_MODE_HOST
> + *                      - USB_DR_MODE_OTG
>   * @queuing_high_bandwidth: True if multiple packets of a high-bandwidth
>   *                      transfer are in process of being queued
>   * @srp_success:        Stores status of SRP request in the case of a FS PHY
> @@ -592,6 +596,7 @@ struct dwc2_hsotg {
>         /** Params to actually use */
>         struct dwc2_core_params *core_params;
>         enum usb_otg_state op_state;
> +       enum usb_dr_mode dr_mode;
>
>         unsigned int queuing_high_bandwidth:1;
>         unsigned int srp_success:1;
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index a10e7a3..4d2c738 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -42,6 +42,8 @@
>  #include <linux/of_device.h>
>  #include <linux/platform_device.h>
>
> +#include <linux/usb/of.h>
> +
>  #include "core.h"
>  #include "hcd.h"
>
> @@ -171,6 +173,16 @@ static int dwc2_driver_probe(struct platform_device *dev)
>         dev_dbg(&dev->dev, "mapped PA %08lx to VA %p\n",
>                 (unsigned long)res->start, hsotg->regs);
>
> +       hsotg->dr_mode = of_usb_get_dr_mode(dev->dev.of_node);
> +
> +       if (IS_ENABLED(CONFIG_USB_DWC2_HOST))
> +               hsotg->dr_mode = USB_DR_MODE_HOST;
> +       else if (IS_ENABLED(CONFIG_USB_DWC2_GADGET))
> +               hsotg->dr_mode = USB_DR_MODE_PERIPHERAL;
> +
> +       if (hsotg->dr_mode == USB_DR_MODE_UNKNOWN)
> +               hsotg->dr_mode = USB_DR_MODE_OTG;
> +

Please remove this whole chunk.  Specifically:

* CONFIG_USB_DWC2_GADGET is not a config option and is nowhere in any
KConfig files.

* CONFIG_USB_DWC2_HOST claims in Kconfig that we'll be in "host only"
mode, but I don't think that's right.  The only way you'll get any
host functionality is if CONFIG_USB_DWC2_HOST is defined, so we'd need
that defined even for OTG mode.
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