At gadget bus, the device (udc) and the driver (gadget dirver)
will try to match between each other, the automatically
binding is designed at this patch.
The rule of auto-binding is: if the udc is not in use and the
gadget driver is not used by any udcs, it is matched successfully,
and will be binded. Each gadget driver can only be binded at one
udc. For example, there are two udcs, "udc-0" and "udc-1", and
two gadget drivers, "g_mass_storage" and "g_serial", assumed the
udcs is added to bus first, then, the "udc-0" will be binded to
"g_mass_storage", and "udc-1" will be binded to "g_seiral".
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
---
drivers/usb/gadget/udc-core.c | 192 +++++++++++++++++++++++++++--------------
1 files changed, 128 insertions(+), 64 deletions(-)
diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 86aeb8b..e2d26c6 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -20,10 +20,10 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
-#include <linux/list.h>
#include <linux/err.h>
#include <linux/dma-mapping.h>
#include <linux/workqueue.h>
+#include <linux/idr.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
@@ -33,7 +33,6 @@
* @driver - the gadget driver pointer. For use by gadget bus
* @dev - the child device to the actual controller
* @gadget - the gadget. For use by the gadget bus code
- * @list - for use by the gadget bus code
*
* This represents the internal data structure which is used by the gadget bus
* to hold information about udc driver and gadget together.
@@ -42,12 +41,11 @@ struct usb_udc {
struct usb_gadget_driver *driver;
struct usb_gadget *gadget;
struct device dev;
- struct list_head list;
};
static struct bus_type gadget_bus_type;
-static LIST_HEAD(udc_list);
static DEFINE_MUTEX(udc_lock);
+static DEFINE_IDA(udc_ida);
/* ------------------------------------------------------------------------- */
@@ -123,6 +121,38 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state);
/* ------------------------------------------------------------------------- */
+static int __find_gadget(struct device *dev, void *data)
+{
+ struct usb_gadget *gadget = data;
+ struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
+
+ if (udc->gadget == gadget)
+ return 1;
+ else
+ return 0;
+}
+
+static int __find_driver(struct device *dev, void *data)
+{
+ struct usb_gadget_driver *driver = data;
+ struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
+
+ if (udc->driver == driver)
+ return 1;
+ else
+ return 0;
+}
+
+static int __find_udc(struct device *dev, void *data)
+{
+ char *name = data;
+
+ if (strcmp(name, dev_name(dev)) == 0)
+ return 1;
+ else
+ return 0;
+}
+
/**
* usb_gadget_udc_start - tells usb device controller to start up
* @gadget: The gadget we want to get started
@@ -188,7 +218,7 @@ static void usb_udc_nop_release(struct device *dev)
* usb_add_gadget_udc_release - adds a new gadget to the udc framework
* @parent: the parent device to this udc. Usually the controller driver's
* device.
- * @gadget: the gadget to be added to the list.
+ * @gadget: the gadget to be added to the gadget bus.
* @release: a gadget release function.
*
* Returns zero on success, negative errno otherwise.
@@ -197,7 +227,11 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
void (*release)(struct device *dev))
{
struct usb_udc *udc;
- int ret = -ENOMEM;
+ int id, ret = -ENOMEM;
+
+ id = ida_simple_get(&udc_ida, 0, 0xffff, GFP_KERNEL);
+ if (id < 0)
+ return id;
udc = kzalloc(sizeof(*udc), GFP_KERNEL);
if (!udc)
@@ -227,14 +261,14 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
udc->dev.bus = &gadget_bus_type;
udc->dev.groups = usb_udc_attr_groups;
udc->dev.parent = parent;
- ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
+ udc->dev.id = id;
+ ret = dev_set_name(&udc->dev, "%s-%d", "udc", id);
if (ret)
goto err3;
udc->gadget = gadget;
mutex_lock(&udc_lock);
- list_add_tail(&udc->list, &udc_list);
ret = device_add(&udc->dev);
if (ret)
@@ -247,17 +281,15 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
return 0;
err4:
- list_del(&udc->list);
mutex_unlock(&udc_lock);
-
err3:
put_device(&udc->dev);
-
err2:
put_device(&gadget->dev);
kfree(udc);
err1:
+ ida_simple_remove(&udc_ida, id);
return ret;
}
EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
@@ -266,7 +298,7 @@ EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
* usb_add_gadget_udc - adds a new gadget to the udc framework
* @parent: the parent device to this udc. Usually the controller
* driver's device.
- * @gadget: the gadget to be added to the list
+ * @gadget: the gadget to be added to the gadget bus
*
* Returns zero on success, negative errno otherwise.
*/
@@ -287,14 +319,15 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
udc->driver->disconnect(udc->gadget);
udc->driver->unbind(udc->gadget);
usb_gadget_udc_stop(udc->gadget, NULL);
+ usb_gadget_set_state(udc->gadget,
+ USB_STATE_NOTATTACHED);
udc->driver = NULL;
- udc->dev.driver = NULL;
udc->gadget->dev.driver = NULL;
}
/**
- * usb_del_gadget_udc - deletes @udc from udc_list
+ * usb_del_gadget_udc - deletes @udc from gadget bus
* @gadget: the gadget to be removed.
*
* This, will call usb_gadget_unregister_driver() if
@@ -302,30 +335,29 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
*/
void usb_del_gadget_udc(struct usb_gadget *gadget)
{
- struct usb_udc *udc = NULL;
+ struct usb_udc *udc;
+ int id;
+ struct device *dev;
mutex_lock(&udc_lock);
- list_for_each_entry(udc, &udc_list, list)
- if (udc->gadget == gadget)
- goto found;
+ dev = bus_find_device(&gadget_bus_type, NULL, gadget, __find_gadget);
+ mutex_unlock(&udc_lock);
+ if (dev)
+ goto found;
dev_err(gadget->dev.parent, "gadget not registered.\n");
- mutex_unlock(&udc_lock);
return;
found:
dev_vdbg(gadget->dev.parent, "unregistering gadget\n");
- list_del(&udc->list);
- mutex_unlock(&udc_lock);
-
- if (udc->driver)
- usb_gadget_remove_driver(udc);
-
+ udc = container_of(dev, struct usb_udc, dev);
kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
flush_work(&gadget->work);
+ id = udc->dev.id;
device_unregister(&udc->dev);
+ ida_simple_remove(&udc_ida, id);
device_unregister(&gadget->dev);
}
EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
@@ -340,7 +372,6 @@ static int udc_bind_to_driver(struct usb_udc *udc, struct usb_gadget_driver *dri
driver->function);
udc->driver = driver;
- udc->dev.driver = &driver->driver;
udc->gadget->dev.driver = &driver->driver;
ret = driver->bind(udc->gadget, driver);
@@ -360,31 +391,38 @@ err1:
dev_err(&udc->dev, "failed to start %s: %d\n",
udc->driver->function, ret);
udc->driver = NULL;
- udc->dev.driver = NULL;
udc->gadget->dev.driver = NULL;
return ret;
}
int udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
{
- struct usb_udc *udc = NULL;
+ struct usb_udc *udc;
+ struct device *dev;
int ret = -ENODEV;
+ struct device_driver *drv;
mutex_lock(&udc_lock);
- list_for_each_entry(udc, &udc_list, list) {
- ret = strcmp(name, dev_name(&udc->dev));
- if (!ret)
- break;
- }
- if (ret) {
- ret = -ENODEV;
+
+ if (!driver || !driver->bind || !driver->setup) {
+ ret = -EINVAL;
goto out;
}
+
+ dev = bus_find_device(&gadget_bus_type,
+ NULL, (char *)name, __find_udc);
+ if (!dev)
+ goto out;
+
+ udc = container_of(dev, struct usb_udc, dev);
if (udc->driver) {
ret = -EBUSY;
goto out;
}
- ret = udc_bind_to_driver(udc, driver);
+
+ drv = &driver->driver;
+ drv->bus = &gadget_bus_type;
+ ret = driver_register(drv);
out:
mutex_unlock(&udc_lock);
return ret;
@@ -393,49 +431,28 @@ EXPORT_SYMBOL_GPL(udc_attach_driver);
int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
{
- struct usb_udc *udc = NULL;
- int ret;
+ struct device_driver *drv;
if (!driver || !driver->bind || !driver->setup)
return -EINVAL;
- mutex_lock(&udc_lock);
- list_for_each_entry(udc, &udc_list, list) {
- /* For now we take the first one */
- if (!udc->driver)
- goto found;
- }
+ drv = &driver->driver;
+ drv->bus = &gadget_bus_type;
- pr_debug("couldn't find an available UDC\n");
- mutex_unlock(&udc_lock);
- return -ENODEV;
-found:
- ret = udc_bind_to_driver(udc, driver);
- mutex_unlock(&udc_lock);
- return ret;
+ return driver_register(drv);
}
EXPORT_SYMBOL_GPL(usb_gadget_probe_driver);
int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
- struct usb_udc *udc = NULL;
- int ret = -ENODEV;
-
if (!driver || !driver->unbind)
return -EINVAL;
mutex_lock(&udc_lock);
- list_for_each_entry(udc, &udc_list, list)
- if (udc->driver == driver) {
- usb_gadget_remove_driver(udc);
- usb_gadget_set_state(udc->gadget,
- USB_STATE_NOTATTACHED);
- ret = 0;
- break;
- }
-
+ driver_unregister(&driver->driver);
mutex_unlock(&udc_lock);
- return ret;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(usb_gadget_unregister_driver);
@@ -560,9 +577,56 @@ static int usb_udc_uevent(struct device *dev, struct kobj_uevent_env *env)
return 0;
}
+static int usb_gadget_match(struct device *dev, struct device_driver *drv)
+{
+ struct usb_udc *udc;
+ struct usb_gadget_driver *driver =
+ container_of(drv, struct usb_gadget_driver, driver);
+ bool dev_not_in_use = true, driver_not_in_use = true;
+
+ dev_dbg(dev, "%s: driver: %s\n", __func__, drv->name);
+
+ udc = container_of(dev, struct usb_udc, dev);
+
+ if (udc->driver)
+ dev_not_in_use = false;
+
+ dev = bus_find_device(&gadget_bus_type, NULL, driver, __find_driver);
+ if (dev)
+ driver_not_in_use = false;
+
+ if (dev_not_in_use && driver_not_in_use)
+ return 1;
+ else
+ return 0;
+}
+
+static int usb_gadget_probe(struct device *dev)
+{
+ struct usb_udc *udc = container_of(dev, struct usb_udc, dev);
+ struct device_driver *drv = dev->driver;
+ struct usb_gadget_driver *driver =
+ container_of(drv, struct usb_gadget_driver, driver);
+
+ return udc_bind_to_driver(udc, driver);
+}
+
+static int usb_gadget_remove(struct device *dev)
+{
+ struct usb_udc *udc =
+ container_of(dev, struct usb_udc, dev);
+
+ usb_gadget_remove_driver(udc);
+
+ return 0;
+}
+
static struct bus_type gadget_bus_type = {
.name = "usb_gadget",
+ .match = usb_gadget_match,
+ .probe = usb_gadget_probe,
.uevent = usb_udc_uevent,
+ .remove = usb_gadget_remove,
};
static int __init usb_udc_init(void)
--
1.7.8
--
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