[RFC][PATCH v3 07/11] usb: dwc3: Registering a role switch in the DRD code.

John Stultz
2019-10-16T03:33:59Z

From: Yu Chen <chenyu56@huawei.com>

The Type-C drivers use USB role switch API to inform the
system about the negotiated data role, so registering a role
switch in the DRD code in order to support platforms with
USB Type-C connectors.

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
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Yu Chen <chenyu56@huawei.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2: Fix role_sw and role_switch_default_mode descriptions as
reported by kbuild test robot <lkp@intel.com>

v3: Split out the role-switch-default-host logic into its own
patch
---
drivers/usb/dwc3/Kconfig | 1 +
drivers/usb/dwc3/core.h | 3 ++
drivers/usb/dwc3/drd.c | 66 +++++++++++++++++++++++++++++++++++++++-
3 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 89abc6078703..1104745c41a9 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -44,6 +44,7 @@ config USB_DWC3_DUAL_ROLE
bool "Dual Role mode"
depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
depends on (EXTCON=y || EXTCON=USB_DWC3)
+ select USB_ROLE_SWITCH
help
This is the default mode of working of DWC3 controller where
both host and gadget features are enabled.
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 1c8b349379af..6f19e9891767 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -25,6 +25,7 @@
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/otg.h>
+#include <linux/usb/role.h>
#include <linux/ulpi/interface.h>

#include <linux/phy/phy.h>
@@ -951,6 +952,7 @@ struct dwc3_scratchpad_array {
* @hsphy_mode: UTMI phy mode, one of following:
* - USBPHY_INTERFACE_MODE_UTMI
* - USBPHY_INTERFACE_MODE_UTMIW
+ * @role_sw: usb_role_switch handle
* @usb2_phy: pointer to USB2 PHY
* @usb3_phy: pointer to USB3 PHY
* @usb2_generic_phy: pointer to USB2 PHY
@@ -1084,6 +1086,7 @@ struct dwc3 {
struct extcon_dev *edev;
struct notifier_block edev_nb;
enum usb_phy_interface hsphy_mode;
+ struct usb_role_switch *role_sw;

u32 fladj;
u32 irq_gadget;
diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index c946d64142ad..61d4fd8aead4 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -476,6 +476,52 @@ static struct extcon_dev *dwc3_get_extcon(struct dwc3 *dwc)
return edev;
}

+static int dwc3_usb_role_switch_set(struct device *dev, enum usb_role role)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+ u32 mode;
+
+ switch (role) {
+ case USB_ROLE_HOST:
+ mode = DWC3_GCTL_PRTCAP_HOST;
+ break;
+ case USB_ROLE_DEVICE:
+ mode = DWC3_GCTL_PRTCAP_DEVICE;
+ break;
+ default:
+ mode = DWC3_GCTL_PRTCAP_DEVICE;
+ break;
+ }
+
+ dwc3_set_mode(dwc, mode);
+ return 0;
+}
+
+static enum usb_role dwc3_usb_role_switch_get(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+ unsigned long flags;
+ enum usb_role role;
+
+ spin_lock_irqsave(&dwc->lock, flags);
+ switch (dwc->current_dr_role) {
+ case DWC3_GCTL_PRTCAP_HOST:
+ role = USB_ROLE_HOST;
+ break;
+ case DWC3_GCTL_PRTCAP_DEVICE:
+ role = USB_ROLE_DEVICE;
+ break;
+ case DWC3_GCTL_PRTCAP_OTG:
+ role = dwc->current_otg_role;
+ break;
+ default:
+ role = USB_ROLE_DEVICE;
+ break;
+ }
+ spin_unlock_irqrestore(&dwc->lock, flags);
+ return role;
+}
+
int dwc3_drd_init(struct dwc3 *dwc)
{
int ret, irq;
@@ -484,7 +530,22 @@ int dwc3_drd_init(struct dwc3 *dwc)
if (IS_ERR(dwc->edev))
return PTR_ERR(dwc->edev);

- if (dwc->edev) {
+ if (device_property_read_bool(dwc->dev, "usb-role-switch")) {
+ struct usb_role_switch_desc dwc3_role_switch = {NULL};
+ u32 mode;
+
+ 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;
+ dwc->role_sw = usb_role_switch_register(dwc->dev,
+ &dwc3_role_switch);
+ if (IS_ERR(dwc->role_sw))
+ return PTR_ERR(dwc->role_sw);
+
+ dwc3_set_mode(dwc, mode);
+ } else if (dwc->edev) {
dwc->edev_nb.notifier_call = dwc3_drd_notifier;
ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
&dwc->edev_nb);
@@ -531,6 +592,9 @@ void dwc3_drd_exit(struct dwc3 *dwc)
{
unsigned long flags;

+ if (dwc->role_sw)
+ usb_role_switch_unregister(dwc->role_sw);
+
if (dwc->edev)
extcon_unregister_notifier(dwc->edev, EXTCON_USB_HOST,
&dwc->edev_nb);
--
2.17.1