The OTG state machine needs a mechanism to start and stop the gadget controller. Add usb_gadget_start() and usb_gadget_stop().
Signed-off-by: Roger Quadros <rog...@ti.com> --- drivers/usb/gadget/udc/udc-core.c | 166 +++++++++++++++++++++++++++++++++++--- include/linux/usb/gadget.h | 3 + 2 files changed, 158 insertions(+), 11 deletions(-) diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c index 5a81cb0..69b4123 100644 --- a/drivers/usb/gadget/udc/udc-core.c +++ b/drivers/usb/gadget/udc/udc-core.c @@ -35,6 +35,8 @@ * @dev - the child device to the actual controller * @gadget - the gadget. For use by the class code * @list - for use by the udc class driver + * @running - udc is running + * @softconnect - sysfs softconnect says OK to connect * * This represents the internal data structure which is used by the UDC-class * to hold information about udc driver and gadget together. @@ -44,6 +46,8 @@ struct usb_udc { struct usb_gadget *gadget; struct device dev; struct list_head list; + bool running; + bool softconnect; }; static struct class *udc_class; @@ -187,7 +191,14 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); */ static inline int usb_gadget_udc_start(struct usb_udc *udc) { - return udc->gadget->ops->udc_start(udc->gadget, udc->driver); + int ret; + + dev_dbg(&udc->dev, "%s\n", __func__); + ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver); + if (!ret) + udc->running = 1; + + return ret; } /** @@ -204,10 +215,140 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) */ static inline void usb_gadget_udc_stop(struct usb_udc *udc) { + dev_dbg(&udc->dev, "%s\n", __func__); udc->gadget->ops->udc_stop(udc->gadget); + udc->running = 0; } /** + * usb_udc_start - Start the usb device controller only if conditions met + * @udc: The UDC to be started + * + * Start the UDC and connect to bus (enable pull) only if the + * following conditions are met + * - UDC is not already running + * - gadget function driver is loaded + * - userspace softconnect says OK to connect + * + * NOTE: udc_lock must be held by caller. + * + * Returs 0 on success or not ready to start, else negative errno. + */ +static int usb_udc_start(struct usb_udc *udc) +{ + int ret; + + if (udc->running) { + dev_err(&udc->dev, "%s: not starting as already running\n", + __func__); + return -EBUSY; + } + + if (udc->driver && udc->softconnect) { + ret = usb_gadget_udc_start(udc); + if (ret) + return ret; + + usb_gadget_connect(udc->gadget); + } + + return 0; +} + +/** + * usb_udc_stop - Stop the usb device controller + * @udc: The UDC to be stopped + * + * Disconnect from bus (disable pull) and stop the UDC. + * + * NOTE: udc_lock must be held by caller. + * + * Returs 0 on success, else negative errno. + */ +static int usb_udc_stop(struct usb_udc *udc) +{ + if (!udc->running) { + dev_err(&udc->dev, "%s: not stopping as already halted\n", + __func__); + return -EBUSY; + } + + usb_gadget_disconnect(udc->gadget); + udc->driver->disconnect(udc->gadget); + usb_gadget_udc_stop(udc); + + return 0; +} + +/** + * 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 and connect to bus (enable pull). + * There is no guarantee that the controller is started + * as we might be missing some dependencies + * i.e. gadget function driver not loaded or softconnect disabled. + */ +int usb_gadget_start(struct usb_gadget *gadget) +{ + int ret; + struct usb_udc *udc = NULL; + + dev_dbg(&gadget->dev, "%s\n", __func__); + mutex_lock(&udc_lock); + list_for_each_entry(udc, &udc_list, list) + if (udc->gadget == gadget) + goto found; + + dev_err(gadget->dev.parent, "%s: gadget not registered.\n", + __func__); + mutex_unlock(&udc_lock); + return -EINVAL; + +found: + ret = usb_udc_start(udc); + mutex_unlock(&udc_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(usb_gadget_start); + +/** + * usb_gadget_stop - stop the usb gadget + * @gadget: The gadget device we want to stop + * + * This is external API for use by OTG core. + * + * Disconnect from the bus (disable pull) and stop the + * gadget controller. + */ +int usb_gadget_stop(struct usb_gadget *gadget) +{ + int ret; + struct usb_udc *udc = NULL; + + dev_dbg(&gadget->dev, "%s\n", __func__); + mutex_lock(&udc_lock); + list_for_each_entry(udc, &udc_list, list) + if (udc->gadget == gadget) + goto found; + + dev_err(gadget->dev.parent, "%s: gadget not registered.\n", + __func__); + mutex_unlock(&udc_lock); + return -EINVAL; + +found: + ret = usb_udc_stop(udc); + mutex_unlock(&udc_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(usb_gadget_stop); + +/** * usb_udc_release - release the usb_udc struct * @dev: the dev member within usb_udc * @@ -278,6 +419,7 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, goto err3; udc->gadget = gadget; + udc->softconnect = 1; /* connect by default */ mutex_lock(&udc_lock); list_add_tail(&udc->list, &udc_list); @@ -329,10 +471,8 @@ 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); + usb_udc_stop(udc); udc->driver->unbind(udc->gadget); - usb_gadget_udc_stop(udc); udc->driver = NULL; udc->dev.driver = NULL; @@ -378,6 +518,7 @@ 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; @@ -392,12 +533,12 @@ 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); + + ret = usb_udc_start(udc); if (ret) { driver->unbind(udc->gadget); goto err1; } - usb_gadget_connect(udc->gadget); kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); return 0; @@ -510,12 +651,15 @@ static ssize_t usb_udc_softconn_store(struct device *dev, } if (sysfs_streq(buf, "connect")) { - usb_gadget_udc_start(udc); - usb_gadget_connect(udc->gadget); + mutex_lock(&udc_lock); + udc->softconnect = 1; + usb_udc_start(udc); + mutex_unlock(&udc_lock); } else if (sysfs_streq(buf, "disconnect")) { - usb_gadget_disconnect(udc->gadget); - udc->driver->disconnect(udc->gadget); - usb_gadget_udc_stop(udc); + mutex_lock(&udc_lock); + udc->softconnect = 0; + usb_udc_stop(udc); + mutex_unlock(&udc_lock); } else { dev_err(dev, "unsupported command '%s'\n", buf); return -EINVAL; diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index e2f00fd..7ada7e6 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -922,6 +922,9 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver); */ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver); +int usb_gadget_start(struct usb_gadget *gadget); +int usb_gadget_stop(struct usb_gadget *gadget); + extern int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget, void (*release)(struct device *dev)); extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html