[PATCH v6 3/8] usb: dwc3: Add support for role-switch-default-mode binding

From: John Stultz
Date: Thu Nov 28 2019 - 00:10:15 EST


Support the new role-switch-default-mode binding for configuring
the default role the controller assumes as when the usb role is
USB_ROLE_NONE

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

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
CC: ShuFan Lee <shufan_lee@xxxxxxxxxxx>
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: Jack Pham <jackp@xxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
Change-Id: Ic6e4df1109b350deaecdc69f667d49ce91d599f3
---
v3: Split this patch out from addition of usb-role-switch
handling
v5: Reworked to use string based role-switch-default-mode
---
drivers/usb/dwc3/core.h | 3 +++
drivers/usb/dwc3/drd.c | 25 ++++++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)

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 3b57d2ddda93..865341facece 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -491,7 +491,10 @@ 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;
}

@@ -517,7 +520,10 @@ 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);
@@ -527,6 +533,19 @@ static enum usb_role dwc3_usb_role_switch_get(struct device *dev)
static int dwc3_setup_role_switch(struct dwc3 *dwc)
{
struct usb_role_switch_desc dwc3_role_switch = {NULL};
+ const char *str;
+ u32 mode;
+ int ret;
+
+ ret = device_property_read_string(dwc->dev, "role-switch-default-mode",
+ &str);
+ if (ret >= 0 && !strncmp(str, "host", strlen("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;
@@ -535,7 +554,7 @@ static int dwc3_setup_role_switch(struct dwc3 *dwc)
if (IS_ERR(dwc->role_sw))
return PTR_ERR(dwc->role_sw);

- dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
+ dwc3_set_mode(dwc, mode);
return 0;
}
#else
--
2.17.1