[v4,9/9] usb: dwc3: Add host-mode as default support

Message ID 20191028215919.83697-10-john.stultz@linaro.org
State New
Headers show
Series
  • Prereqs for HiKey960 USB support
Related show

Commit Message

John Stultz Oct. 28, 2019, 9:59 p.m.
Support configuring the default role the controller assumes as
host mode when the usb role is USB_ROLE_NONE

This patch was split out from a larger patch originally by
Yu Chen <chenyu56@huawei.com>

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
CC: ShuFan Lee <shufan_lee@richtek.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Yu Chen <chenyu56@huawei.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jun Li <lijun.kernel@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jack Pham <jackp@codeaurora.org>
Cc: linux-usb@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: John Stultz <john.stultz@linaro.org>

---
v3: Split this patch out from addition of usb-role-switch
    handling
---
 drivers/usb/dwc3/core.h |  3 +++
 drivers/usb/dwc3/drd.c  | 20 ++++++++++++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)

-- 
2.17.1

Comments

John Stultz Nov. 7, 2019, 10:23 p.m. | #1
On Tue, Oct 29, 2019 at 2:25 AM Felipe Balbi <balbi@kernel.org> wrote:
> John Stultz <john.stultz@linaro.org> writes:

> > diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c

> > index 61d4fd8aead4..0e3466fe5ac4 100644

> > --- a/drivers/usb/dwc3/drd.c

> > +++ b/drivers/usb/dwc3/drd.c

> > @@ -489,7 +489,10 @@ static int dwc3_usb_role_switch_set(struct device *dev, enum usb_role role)

> >               mode = DWC3_GCTL_PRTCAP_DEVICE;

> >               break;

> >       default:

> > -             mode = DWC3_GCTL_PRTCAP_DEVICE;

> > +             if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)

> > +                     mode = DWC3_GCTL_PRTCAP_HOST;

> > +             else

> > +                     mode = DWC3_GCTL_PRTCAP_DEVICE;

> >               break;

> >       }

> >

> > @@ -515,7 +518,10 @@ static enum usb_role dwc3_usb_role_switch_get(struct device *dev)

> >               role = dwc->current_otg_role;

> >               break;

> >       default:

> > -             role = USB_ROLE_DEVICE;

> > +             if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)

> > +                     role = USB_ROLE_HOST;

>

> look at this, we now have 3 different encodings for role which DWC3

> needs to understand. One is its own PRTCAP_DIR, then there USB_DR_MODE_*

> and now USB_ROLE_*, can we make it so that we only have one private

> encoding and one generic encoding?


And you left out the DWC3_OTG_ROLE_* set too!

So I agree it can be easy to muddle up.  The enums are *almost* equivalent:

include/linux/usb/role.h:
enum usb_role {
        USB_ROLE_NONE,
        USB_ROLE_HOST,
        USB_ROLE_DEVICE,
};

include/linux/usb/otg.h:
enum usb_dr_mode {
        USB_DR_MODE_UNKNOWN,
        USB_DR_MODE_HOST,
        USB_DR_MODE_PERIPHERAL,
        USB_DR_MODE_OTG,
};

But both are widely used:
$ git grep USB_ROLE_ | wc -l
123
$ git grep USB_DR_MODE_ | wc -l
190

So I'm not sure how easy it will be to condense down, since the usage
is coming from different usb subsystems (otg and role switching)  and
I worry assuming them equivalent in just one driver may run into
trouble eventually if the values diverge (ie someone adds
USB_ROLE_BRICK or something).

Heikki/Greg: Any thoughts on this? Does it make sense to try to drop
the usb_role enum and users and replace it with usb_dr_mode?

thanks
-john

Patch

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6f19e9891767..3c879c9ab1aa 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -953,6 +953,8 @@  struct dwc3_scratchpad_array {
  *		- USBPHY_INTERFACE_MODE_UTMI
  *		- USBPHY_INTERFACE_MODE_UTMIW
  * @role_sw: usb_role_switch handle
+ * @role_switch_default_mode: default operation mode of controller while
+ *			usb role is USB_ROLE_NONE.
  * @usb2_phy: pointer to USB2 PHY
  * @usb3_phy: pointer to USB3 PHY
  * @usb2_generic_phy: pointer to USB2 PHY
@@ -1087,6 +1089,7 @@  struct dwc3 {
 	struct notifier_block	edev_nb;
 	enum usb_phy_interface	hsphy_mode;
 	struct usb_role_switch	*role_sw;
+	enum usb_dr_mode	role_switch_default_mode;
 
 	u32			fladj;
 	u32			irq_gadget;
diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index 61d4fd8aead4..0e3466fe5ac4 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -489,7 +489,10 @@  static int dwc3_usb_role_switch_set(struct device *dev, enum usb_role role)
 		mode = DWC3_GCTL_PRTCAP_DEVICE;
 		break;
 	default:
-		mode = DWC3_GCTL_PRTCAP_DEVICE;
+		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+			mode = DWC3_GCTL_PRTCAP_HOST;
+		else
+			mode = DWC3_GCTL_PRTCAP_DEVICE;
 		break;
 	}
 
@@ -515,7 +518,10 @@  static enum usb_role dwc3_usb_role_switch_get(struct device *dev)
 		role = dwc->current_otg_role;
 		break;
 	default:
-		role = USB_ROLE_DEVICE;
+		if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+			role = USB_ROLE_HOST;
+		else
+			role = USB_ROLE_DEVICE;
 		break;
 	}
 	spin_unlock_irqrestore(&dwc->lock, flags);
@@ -534,8 +540,14 @@  int dwc3_drd_init(struct dwc3 *dwc)
 		struct usb_role_switch_desc dwc3_role_switch = {NULL};
 		u32 mode;
 
-		mode = DWC3_GCTL_PRTCAP_DEVICE;
-
+		if (device_property_read_bool(dwc->dev,
+					      "role-switch-default-host")) {
+			dwc->role_switch_default_mode = USB_DR_MODE_HOST;
+			mode = DWC3_GCTL_PRTCAP_HOST;
+		} else {
+			dwc->role_switch_default_mode = USB_DR_MODE_PERIPHERAL;
+			mode = DWC3_GCTL_PRTCAP_DEVICE;
+		}
 		dwc3_role_switch.fwnode = dev_fwnode(dwc->dev);
 		dwc3_role_switch.set = dwc3_usb_role_switch_set;
 		dwc3_role_switch.get = dwc3_usb_role_switch_get;