The OTG state machine needs a mechanism to start and
stop the gadget controller as well as connect/disconnect
from the bus. Add usb_gadget_start(), usb_gadget_stop()
and usb_gadget_connect_control().
Introduce usb_otg_add_gadget_udc() to allow controller drivers
to register a gadget controller that is part of an OTG instance.
Register with OTG core when UDC is added in usb_add_gadget_udc_release()
and unregister on usb_del_gadget_udc().
Notify the OTG core when gadget function driver is available on
udc_bind_to_driver() and when it is removed in usb_gadget_remove_driver().
We need to unlock the usb_lock mutex before calling
usb_otg_register_gadget() else it will cause a circular
locking dependency.
Ignore softconnect sysfs control when we're in OTG
mode as OTG FSM should care of gadget softconnect using
the b_bus_req mechanism.
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
drivers/usb/gadget/udc/core.c | 202 +++++++++++++++++++++++++++++++++++++++---
include/linux/usb/gadget.h | 4 +
2 files changed, 196 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 42756d7..9d8a1d0 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -28,6 +28,11 @@
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/of.h>
+
+#include <linux/of.h>
+#include <linux/of_platform.h>
#include "trace.h"
@@ -1060,6 +1065,113 @@ static inline void usb_gadget_udc_stop(struct usb_udc *udc)
}
/**
+ * usb_gadget_to_udc - get the UDC owning the gadget
+ *
+ * udc_lock must be held.
+ * Returs NULL if UDC is not found.
+ */
+static struct usb_udc *usb_gadget_to_udc(struct usb_gadget *gadget)
+{
+ struct usb_udc *udc;
+
+ list_for_each_entry(udc, &udc_list, list)
+ if (udc->gadget == gadget)
+ return udc;
+
+ return NULL;
+}
+
+/**
+ * usb_gadget_start - start the usb gadget controller
+ * @gadget: the gadget device to start
+ *
+ * This is external API for use by OTG core.
+ *
+ * Start the usb device controller. Does not connect to the bus.
+ */
+static int usb_gadget_start(struct usb_gadget *gadget)
+{
+ int ret;
+ struct usb_udc *udc;
+
+ mutex_lock(&udc_lock);
+ udc = usb_gadget_to_udc(gadget);
+ if (!udc) {
+ dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
+ __func__);
+ mutex_unlock(&udc_lock);
+ return -EINVAL;
+ }
+
+ ret = usb_gadget_udc_start(udc);
+ if (ret)
+ dev_err(&udc->dev, "USB Device Controller didn't start: %d\n",
+ ret);
+
+ mutex_unlock(&udc_lock);
+
+ return ret;
+}
+
+/**
+ * usb_gadget_stop - stop the usb gadget controller
+ * @gadget: the gadget device we want to stop
+ *
+ * This is external API for use by OTG core.
+ *
+ * Stop the gadget controller. Does not disconnect from the bus.
+ * Caller must ensure that gadget has disconnected from the bus
+ * before calling usb_gadget_stop().
+ */
+static int usb_gadget_stop(struct usb_gadget *gadget)
+{
+ struct usb_udc *udc;
+
+ mutex_lock(&udc_lock);
+ udc = usb_gadget_to_udc(gadget);
+ if (!udc) {
+ dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
+ __func__);
+ mutex_unlock(&udc_lock);
+ return -EINVAL;
+ }
+
+ if (gadget->connected)
+ dev_dbg(gadget->dev.parent,
+ "%s: called while still connected\n", __func__);
+
+ usb_gadget_udc_stop(udc);
+ mutex_unlock(&udc_lock);
+
+ return 0;
+}
+
+static int usb_gadget_connect_control(struct usb_gadget *gadget, bool connect)
+{
+ struct usb_udc *udc;
+
+ mutex_lock(&udc_lock);
+ udc = usb_gadget_to_udc(gadget);
+ if (!udc) {
+ dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
+ __func__);
+ mutex_unlock(&udc_lock);
+ return -EINVAL;
+ }
+
+ if (connect) {
+ usb_gadget_connect(udc->gadget);
+ } else {
+ usb_gadget_disconnect(udc->gadget);
+ udc->driver->disconnect(udc->gadget);
+ }
+
+ mutex_unlock(&udc_lock);
+
+ return 0;
+}
+
+/**
* usb_udc_release - release the usb_udc struct
* @dev: the dev member within usb_udc
*
@@ -1082,6 +1194,12 @@ static void usb_udc_nop_release(struct device *dev)
dev_vdbg(dev, "%s\n", __func__);
}
+struct otg_gadget_ops otg_gadget_intf = {
+ .start = usb_gadget_start,
+ .stop = usb_gadget_stop,
+ .connect_control = usb_gadget_connect_control,
+};
+
/**
* usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
* @parent: the parent device to this udc. Usually the controller driver's
@@ -1137,6 +1255,14 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
udc->vbus = true;
+ if (gadget->otg_dev) {
+ mutex_unlock(&udc_lock);
+ ret = usb_otg_register_gadget(gadget, &otg_gadget_intf);
+ mutex_lock(&udc_lock);
+ if (ret)
+ goto err5;
+ }
+
/* pick up one of pending gadget drivers */
list_for_each_entry(driver, &gadget_driver_pending_list, pending) {
if (!driver->udc_name || strcmp(driver->udc_name,
@@ -1145,7 +1271,7 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
if (ret != -EPROBE_DEFER)
list_del(&driver->pending);
if (ret)
- goto err4;
+ goto err5;
break;
}
}
@@ -1154,6 +1280,8 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
return 0;
+err5:
+ device_del(&udc->dev);
err4:
list_del(&udc->list);
mutex_unlock(&udc_lock);
@@ -1215,6 +1343,33 @@ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
}
EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
+/**
+ * usb_otg_add_gadget_udc - adds a new gadget to the udc class driver list
+ * @parent: the parent device to this udc. Usually the controller
+ * driver's device.
+ * @gadget: the gadget to be added to the list
+ * @otg_dev: the OTG controller device
+ *
+ * If otg_dev is NULL then device tree node is checked
+ * for OTG controller via the otg-controller property.
+ * Returns zero on success, negative errno otherwise.
+ */
+int usb_otg_add_gadget_udc(struct device *parent, struct usb_gadget *gadget,
+ struct device *otg_dev)
+{
+ if (!otg_dev) {
+ gadget->otg_dev = of_usb_get_otg(parent->of_node);
+ if (!gadget->otg_dev)
+ return -ENODEV;
+ } else {
+ gadget->otg_dev = otg_dev;
+ }
+
+ return usb_add_gadget_udc_release(parent, gadget, NULL);
+}
+EXPORT_SYMBOL_GPL(usb_otg_add_gadget_udc);
+
+/* udc_lock must be held */
static void usb_gadget_remove_driver(struct usb_udc *udc)
{
dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
@@ -1222,10 +1377,18 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
- usb_gadget_disconnect(udc->gadget);
- udc->driver->disconnect(udc->gadget);
+ /* If OTG/dual-role, the otg core manages UDC start/stop */
+ if (udc->gadget->otg_dev) {
+ mutex_unlock(&udc_lock);
+ usb_otg_gadget_ready(udc->gadget, false);
+ mutex_lock(&udc_lock);
+ } else {
+ usb_gadget_disconnect(udc->gadget);
+ udc->driver->disconnect(udc->gadget);
+ usb_gadget_udc_stop(udc);
+ }
+
udc->driver->unbind(udc->gadget);
- usb_gadget_udc_stop(udc);
udc->driver = NULL;
udc->dev.driver = NULL;
@@ -1259,6 +1422,9 @@ void usb_del_gadget_udc(struct usb_gadget *gadget)
}
mutex_unlock(&udc_lock);
+ if (gadget->otg_dev)
+ usb_otg_unregister_gadget(gadget);
+
kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
flush_work(&gadget->work);
device_unregister(&udc->dev);
@@ -1268,6 +1434,7 @@ EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
/* ------------------------------------------------------------------------- */
+/* udc_lock must be held */
static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *driver)
{
int ret;
@@ -1282,17 +1449,26 @@ static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *dri
ret = driver->bind(udc->gadget, driver);
if (ret)
goto err1;
- ret = usb_gadget_udc_start(udc);
- if (ret) {
- driver->unbind(udc->gadget);
- goto err1;
+
+ /* If OTG/dual-role, the otg core manages UDC start/stop */
+ if (udc->gadget->otg_dev) {
+ mutex_unlock(&udc_lock);
+ usb_otg_gadget_ready(udc->gadget, true);
+ mutex_lock(&udc_lock);
+ } else {
+ ret = usb_gadget_udc_start(udc);
+ if (ret) {
+ mutex_unlock(&udc_lock);
+ driver->unbind(udc->gadget);
+ goto err1;
+ }
+ usb_udc_connect_control(udc);
}
- usb_udc_connect_control(udc);
kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
return 0;
err1:
- if (ret != -EISNAM)
+ if ((ret != -EISNAM) && (ret != -EPROBE_DEFER))
dev_err(&udc->dev, "failed to start %s: %d\n",
udc->driver->function, ret);
udc->driver = NULL;
@@ -1389,6 +1565,12 @@ static ssize_t usb_udc_softconn_store(struct device *dev,
return -EOPNOTSUPP;
}
+ /* In OTG/dual-role mode, soft-connect should be handled by OTG core */
+ if (udc->gadget->otg_dev) {
+ dev_err(dev, "soft-connect not supported in OTG mode\n");
+ return -EOPNOTSUPP;
+ }
+
if (sysfs_streq(buf, "connect")) {
usb_gadget_udc_start(udc);
usb_gadget_connect(udc->gadget);
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 1d74fb8..8c6880d 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -701,6 +701,10 @@ extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
extern void usb_del_gadget_udc(struct usb_gadget *gadget);
extern char *usb_get_gadget_udc_name(void);
+extern int usb_otg_add_gadget_udc(struct device *parent,
+ struct usb_gadget *gadget,
+ struct device *otg_dev);
+
/*-------------------------------------------------------------------------*/
/* utility to simplify dealing with string descriptors */
--
2.7.4
--
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