usb: gadget: Properly configure the device for remote wakeup

The wakeup bit in the bmAttributes field indicates whether the device
is configured for remote wakeup. But this field should be allowed to
set only if the UDC supports such wakeup mechanism. So configure this
field based on UDC capability. Also inform the UDC whether the device
is configured for remote wakeup by implementing a gadget op.

Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
Link: https://lore.kernel.org/r/1679694482-16430-2-git-send-email-quic_eserrao@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 53 insertions, 0 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f1ecd12b62c3..00c89571de2a 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -513,6 +513,19 @@ static u8 encode_bMaxPower(enum usb_device_speed speed,
 		return min(val, 900U) / 8;
 }
 
+void check_remote_wakeup_config(struct usb_gadget *g,
+				struct usb_configuration *c)
+{
+	if (USB_CONFIG_ATT_WAKEUP & c->bmAttributes) {
+		/* Reset the rw bit if gadget is not capable of it */
+		if (!g->wakeup_capable && g->ops->set_remote_wakeup) {
+			WARN(c->cdev, "Clearing wakeup bit for config c.%d\n",
+			     c->bConfigurationValue);
+			c->bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
+		}
+	}
+}
+
 static int config_buf(struct usb_configuration *config,
 		enum usb_device_speed speed, void *buf, u8 type)
 {
@@ -994,6 +1007,11 @@ static int set_config(struct usb_composite_dev *cdev,
 		power = min(power, 500U);
 	else
 		power = min(power, 900U);
+
+	if (USB_CONFIG_ATT_WAKEUP & c->bmAttributes)
+		usb_gadget_set_remote_wakeup(gadget, 1);
+	else
+		usb_gadget_set_remote_wakeup(gadget, 0);
 done:
 	if (power <= USB_SELF_POWER_VBUS_MAX_DRAW)
 		usb_gadget_set_selfpowered(gadget);
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index b9f1136aa0a2..4c639e9ddedc 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -1761,6 +1761,9 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
 		if (gadget_is_otg(gadget))
 			c->descriptors = otg_desc;
 
+		/* Properly configure the bmAttributes wakeup bit */
+		check_remote_wakeup_config(gadget, c);
+
 		cfg = container_of(c, struct config_usb_cfg, c);
 		if (!list_empty(&cfg->string_list)) {
 			i = 0;
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 23b0629a8774..3dcbba739db6 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -514,6 +514,33 @@ out:
 EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
 
 /**
+ * usb_gadget_set_remote_wakeup - configures the device remote wakeup feature.
+ * @gadget:the device being configured for remote wakeup
+ * @set:value to be configured.
+ *
+ * set to one to enable remote wakeup feature and zero to disable it.
+ *
+ * returns zero on success, else negative errno.
+ */
+int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
+{
+	int ret = 0;
+
+	if (!gadget->ops->set_remote_wakeup) {
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	ret = gadget->ops->set_remote_wakeup(gadget, set);
+
+out:
+	trace_usb_gadget_set_remote_wakeup(gadget, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(usb_gadget_set_remote_wakeup);
+
+/**
  * usb_gadget_set_selfpowered - sets the device selfpowered feature.
  * @gadget:the device being declared as self-powered
  *
diff --git a/drivers/usb/gadget/udc/trace.h b/drivers/usb/gadget/udc/trace.h
index abdbcb1bacb0..a5ed26fbc2da 100644
--- a/drivers/usb/gadget/udc/trace.h
+++ b/drivers/usb/gadget/udc/trace.h
@@ -91,6 +91,11 @@ DEFINE_EVENT(udc_log_gadget, usb_gadget_wakeup,
 	TP_ARGS(g, ret)
 );
 
+DEFINE_EVENT(udc_log_gadget, usb_gadget_set_remote_wakeup,
+	TP_PROTO(struct usb_gadget *g, int ret),
+	TP_ARGS(g, ret)
+);
+
 DEFINE_EVENT(udc_log_gadget, usb_gadget_set_selfpowered,
 	TP_PROTO(struct usb_gadget *g, int ret),
 	TP_ARGS(g, ret)