usb: gadget: udc-core: add "new-style" registration interface

udc_start() should only trigger the internal state machine and make
minimal house keeping. Before that call udc-core calls the bind()
callback and after the callback the pullup().

udc_stop() is simillar, udc-core calls pullup(), unbind() and finally
udc_stop().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 77 insertions, 4 deletions

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 83e9e5f99b4a..2ddb7c8b5b3d 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -73,6 +73,26 @@ static inline int usb_gadget_start(struct usb_gadget *gadget,
 }
 
 /**
+ * usb_gadget_udc_start - tells usb device controller to start up
+ * @gadget: The gadget we want to get started
+ * @driver: The driver we want to bind to @gadget
+ *
+ * This call is issued by the UDC Class driver when it's about
+ * to register a gadget driver to the device controller, before
+ * calling gadget driver's bind() method.
+ *
+ * It allows the controller to be powered off until strictly
+ * necessary to have it powered on.
+ *
+ * Returns zero on success, else negative errno.
+ */
+static inline int usb_gadget_udc_start(struct usb_gadget *gadget,
+                struct usb_gadget_driver *driver)
+{
+        return gadget->ops->udc_start(gadget, driver);
+}
+
+/**
  * usb_gadget_stop - tells usb device controller we don't need it anymore
  * @gadget: The device we want to stop activity
  * @driver: The driver to unbind from @gadget
@@ -91,6 +111,24 @@ static inline void usb_gadget_stop(struct usb_gadget *gadget,
 }
 
 /**
+ * usb_gadget_udc_stop - tells usb device controller we don't need it anymore
+ * @gadget: The device we want to stop activity
+ * @driver: The driver to unbind from @gadget
+ *
+ * This call is issued by the UDC Class driver after calling
+ * gadget driver's unbind() method.
+ *
+ * The details are implementation specific, but it can go as
+ * far as powering off UDC completely and disable its data
+ * line pullups.
+ */
+static inline void usb_gadget_udc_stop(struct usb_gadget *gadget,
+                struct usb_gadget_driver *driver)
+{
+        gadget->ops->udc_stop(gadget, driver);
+}
+
+/**
  * usb_udc_release - release the usb_udc struct
  * @dev: the dev member within usb_udc
  *
@@ -155,6 +193,14 @@ err1:
 }
 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
 
+static int udc_is_newstyle(struct usb_udc *udc)
+{
+        if (udc->gadget->ops->udc_start && udc->gadget->ops->udc_stop)
+                return 1;
+        return 0;
+}
+
+
 static void usb_gadget_remove_driver(struct usb_udc *udc)
 {
         dev_dbg(&udc->dev, "unregistering UDC driver [%s]\n",
@@ -162,7 +208,14 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
 
         kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 
-        usb_gadget_stop(udc->gadget, udc->driver);
+        if (udc_is_newstyle(udc)) {
+                usb_gadget_disconnect(udc->gadget);
+                udc->driver->unbind(udc->gadget);
+                usb_gadget_udc_stop(udc->gadget, udc->driver);
+
+        } else {
+                usb_gadget_stop(udc->gadget, udc->driver);
+        }
 
         udc->driver = NULL;
         udc->dev.driver = NULL;
@@ -232,9 +285,23 @@ found:
         udc->driver = driver;
         udc->dev.driver = &driver->driver;
 
-        ret = usb_gadget_start(udc->gadget, driver, bind);
-        if (ret)
-                goto err1;
+        if (udc_is_newstyle(udc)) {
+                ret = bind(udc->gadget);
+                if (ret)
+                        goto err1;
+                ret = usb_gadget_udc_start(udc->gadget, driver);
+                if (ret) {
+                        driver->unbind(udc->gadget);
+                        goto err1;
+                }
+                usb_gadget_connect(udc->gadget);
+        } else {
+
+                ret = usb_gadget_start(udc->gadget, driver, bind);
+                if (ret)
+                        goto err1;
+
+        }
 
         kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
         mutex_unlock(&udc_lock);
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index afb67d997f0c..087f4b931833 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -459,6 +459,12 @@ struct usb_gadget_ops {
         int     (*ioctl)(struct usb_gadget *,
                                 unsigned code, unsigned long param);
         void    (*get_config_params)(struct usb_dcd_config_params *);
+        int     (*udc_start)(struct usb_gadget *,
+                        struct usb_gadget_driver *);
+        int     (*udc_stop)(struct usb_gadget *,
+                        struct usb_gadget_driver *);
+
+        /* Those two are deprecated */
         int     (*start)(struct usb_gadget_driver *,
                         int (*bind)(struct usb_gadget *));
         int     (*stop)(struct usb_gadget_driver *);