Re: [RFC][PATCH 3/3] usb: dwc3: Registering a role switch in the DRD code.
From: Roger Quadros
Date: Tue Oct 15 2019 - 04:25:50 EST
Hi,
On 03/10/2019 02:16, John Stultz wrote:
From: Yu Chen <chenyu56@xxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Cc: Yu Chen <chenyu56@xxxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Cc: Jun Li <lijun.kernel@xxxxxxxxx>
Cc: Valentin Schneider <valentin.schneider@xxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Suggested-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Yu Chen <chenyu56@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/usb/dwc3/Kconfig | 1 +
drivers/usb/dwc3/core.h | 6 ++++
drivers/usb/dwc3/drd.c | 78 +++++++++++++++++++++++++++++++++++++++-
3 files changed, 84 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 b3cb6eec3f8f..83728157b3e9 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 +952,9 @@ 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
+ * 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
@@ -1085,6 +1089,8 @@ struct dwc3 {
struct extcon_dev *edev;
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 726100d1ac0d..95b466a7faa0 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -479,6 +479,58 @@ 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:
+ if (dwc->role_switch_default_mode == USB_DR_MODE_HOST)
+ mode = DWC3_GCTL_PRTCAP_HOST;
+ else
+ 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:
+ 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);
+ return role;
+}
+
int dwc3_drd_init(struct dwc3 *dwc)
{
int ret, irq;
@@ -487,7 +539,28 @@ 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")) {
I think we should use role switch unconditionally and get rid of the
debugfs role status/change mechanism.
+ struct usb_role_switch_desc dwc3_role_switch = {0};
+ u32 mode;
+
+ 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;
+ 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) {
Role switch should exist regardless if dwc->edev is present or not.
dwc->edev_nb.notifier_call = dwc3_drd_notifier;
ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
&dwc->edev_nb);
@@ -534,6 +607,9 @@ 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);
--
cheers,
-roger
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
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