[PATCH v2] usb/gadget: make composite gadget meet usb compliance for vbus draw

From: Du, Changbin
Date: Thu Jul 23 2015 - 08:08:04 EST


USB-IF compliance requirement limits the vbus current according to
current state. USB2 Spec requires that un-configured current must
be <= 100mA, for USB3 is 150mA, OTG is 2.5mA. So set corresponding
vbus draw current according to device mode.

Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx>
---
drivers/usb/gadget/composite.c | 39 ++++++++++++++++++++++++++++++++-------
drivers/usb/gadget/configfs.c | 2 +-
include/linux/usb/composite.h | 1 +
include/uapi/linux/usb/ch9.h | 9 +++++++++
4 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 4e3447b..b3896e9 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -610,6 +610,21 @@ static void device_qual(struct usb_composite_dev *cdev)
qual->bRESERVED = 0;
}

+static unsigned unconfigured_vbus_draw(struct usb_composite_dev *cdev)
+{
+ struct usb_gadget *g = cdev->gadget;
+ unsigned power;
+
+ if (gadget_is_otg(g))
+ power = USB_OTG_UNCONF_STATE_VBUS_MAX_DRAW;
+ else if (g->speed == USB_SPEED_SUPER)
+ power = USB3_UNCONF_STATE_VBUS_MAX_DRAW;
+ else
+ power = USB2_UNCONF_STATE_VBUS_MAX_DRAW;
+
+ return power;
+}
+
/*-------------------------------------------------------------------------*/

static void reset_config(struct usb_composite_dev *cdev)
@@ -634,7 +649,7 @@ static int set_config(struct usb_composite_dev *cdev,
struct usb_gadget *gadget = cdev->gadget;
struct usb_configuration *c = NULL;
int result = -EINVAL;
- unsigned power = gadget_is_otg(gadget) ? 8 : 100;
+ unsigned power = unconfigured_vbus_draw(cdev);
int tmp;

if (number) {
@@ -1829,6 +1844,15 @@ done:
return value;
}

+void composite_reset(struct usb_gadget *gadget)
+{
+ struct usb_composite_dev *cdev = get_gadget_data(gadget);
+
+ DBG(cdev, "reset\n");
+ usb_gadget_vbus_draw(gadget, unconfigured_vbus_draw(cdev));
+ composite_disconnect(gadget);
+}
+
void composite_disconnect(struct usb_gadget *gadget)
{
struct usb_composite_dev *cdev = get_gadget_data(gadget);
@@ -2095,7 +2119,7 @@ void composite_suspend(struct usb_gadget *gadget)

cdev->suspended = 1;

- usb_gadget_vbus_draw(gadget, 2);
+ usb_gadget_vbus_draw(gadget, USB_SUSPEND_STATE_VBUS_MAX_DRAW);
}

void composite_resume(struct usb_gadget *gadget)
@@ -2117,10 +2141,11 @@ void composite_resume(struct usb_gadget *gadget)
}

maxpower = cdev->config->MaxPower;
-
- usb_gadget_vbus_draw(gadget, maxpower ?
- maxpower : CONFIG_USB_GADGET_VBUS_DRAW);
- }
+ if (!maxpower)
+ maxpower = CONFIG_USB_GADGET_VBUS_DRAW;
+ } else
+ maxpower = unconfigured_vbus_draw(cdev);
+ usb_gadget_vbus_draw(gadget, maxpower);

cdev->suspended = 0;
}
@@ -2132,7 +2157,7 @@ static const struct usb_gadget_driver composite_driver_template = {
.unbind = composite_unbind,

.setup = composite_setup,
- .reset = composite_disconnect,
+ .reset = composite_reset,
.disconnect = composite_disconnect,

.suspend = composite_suspend,
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 0495c94..e16335d 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -1449,7 +1449,7 @@ static const struct usb_gadget_driver configfs_driver_template = {
.unbind = configfs_composite_unbind,

.setup = composite_setup,
- .reset = composite_disconnect,
+ .reset = composite_reset,
.disconnect = composite_disconnect,

.suspend = composite_suspend,
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 2511469..825ad39 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -506,6 +506,7 @@ extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,

extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);

+extern void composite_reset(struct usb_gadget *gadget);
extern void composite_disconnect(struct usb_gadget *gadget);
extern int composite_setup(struct usb_gadget *gadget,
const struct usb_ctrlrequest *ctrl);
diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h
index aa33fd1..ab216bf 100644
--- a/include/uapi/linux/usb/ch9.h
+++ b/include/uapi/linux/usb/ch9.h
@@ -996,4 +996,13 @@ struct usb_set_sel_req {
*/
#define USB_SELF_POWER_VBUS_MAX_DRAW 100

+/*
+ * USB2 compliance requires that un-configured current draw less than 100mA,
+ * while USB3 requires it <= 150mA, and OTG device requires it <= 2.5mA.
+ */
+#define USB2_UNCONF_STATE_VBUS_MAX_DRAW 100
+#define USB3_UNCONF_STATE_VBUS_MAX_DRAW 150
+#define USB_OTG_UNCONF_STATE_VBUS_MAX_DRAW 2
+#define USB_SUSPEND_STATE_VBUS_MAX_DRAW 2
+
#endif /* _UAPI__LINUX_USB_CH9_H */
--
2.1.4

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