[PATCH v7 10/18] usb: dwc3: Add support for usb-conn-gpio connectors

Bryan O'Donoghue
2020-03-03T17:12:51Z

This patch adds the ability to probe and enumerate a connector based on
usb-conn-gpio.

You would use usb-conn-gpio when a regulator in your system provides VBUS
directly to the connector instead of supplying via the USB PHY.

The parent device must have the "usb-role-switch" property, so that when
the usb-conn-gpio driver calls usb_role_switch_set_role() the notification
in dwc3 will run and the block registers will be updated to match the state
detected at the connector.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
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: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
drivers/usb/dwc3/drd.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/drivers/usb/dwc3/drd.c b/drivers/usb/dwc3/drd.c
index 331c6e997f0c..2ec1ae30bcc5 100644
--- a/drivers/usb/dwc3/drd.c
+++ b/drivers/usb/dwc3/drd.c
@@ -11,6 +11,7 @@
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/property.h>
+#include <linux/of_platform.h>

#include "debug.h"
#include "core.h"
@@ -538,9 +539,30 @@ static int dwc3_setup_role_switch(struct dwc3 *dwc)
dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
return 0;
}
+
+static int dwc3_register_gpio_usb_connector(struct dwc3 *dwc)
+{
+ struct device *dev = dwc->dev;
+ struct device_node *np = dev->of_node, *conn_np;
+ int ret = 0;
+
+ conn_np = of_get_child_by_name(np, "connector");
+ if (!conn_np) {
+ dev_dbg(dev, "no connector child node specified\n");
+ goto done;
+ }
+
+ if (of_device_is_compatible(conn_np, "gpio-usb-b-connector"))
+ ret = of_platform_populate(np, NULL, NULL, dev);
+done:
+ of_node_put(conn_np);
+ return ret;
+}
+
#else
#define ROLE_SWITCH 0
#define dwc3_setup_role_switch(x) 0
+#define dwc3_register_gpio_usb_connector(x) 0
#endif

int dwc3_drd_init(struct dwc3 *dwc)
@@ -556,6 +578,9 @@ int dwc3_drd_init(struct dwc3 *dwc)
ret = dwc3_setup_role_switch(dwc);
if (ret < 0)
return ret;
+ ret = dwc3_register_gpio_usb_connector(dwc);
+ if (ret < 0)
+ return ret;
} else if (dwc->edev) {
dwc->edev_nb.notifier_call = dwc3_drd_notifier;
ret = extcon_register_notifier(dwc->edev, EXTCON_USB_HOST,
--
2.25.1