All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ruslan Bilovol <ruslan.bilovol@gmail.com>
To: balbi@ti.com
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	k.opasiak@samsung.com, stern@rowland.harvard.edu,
	peter.chen@freescale.com, gregkh@linuxfoundation.org,
	andrzej.p@samsung.com, maxime.ripard@free-electrons.com
Subject: [PATCH v5 5/5] usb: gadget: udc-core: independent registration of gadgets and gadget drivers
Date: Tue, 23 Jun 2015 01:01:14 +0300	[thread overview]
Message-ID: <1435010474-13419-6-git-send-email-ruslan.bilovol@gmail.com> (raw)
In-Reply-To: <1435010474-13419-1-git-send-email-ruslan.bilovol@gmail.com>

Change behavior during registration of gadgets and
gadget drivers in udc-core. Instead of previous
approach when for successful probe of usb gadget driver
at least one usb gadget should be already registered
use another one where gadget drivers and gadgets
can be registered in udc-core independently.

Independent registration of gadgets and gadget drivers
is useful for built-in into kernel gadget and gadget
driver case - because it's possible that gadget is
really probed only on late_init stage (due to deferred
probe) whereas gadget driver's probe is silently failed
on module_init stage due to no any UDC added.

Also it is useful for modules case - now there is no
difference what module to insert first: gadget module
or gadget driver one.

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
---
 drivers/usb/gadget/udc/udc-core.c | 49 ++++++++++++++++++++++++++++++++-------
 include/linux/usb/gadget.h        |  2 ++
 2 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index 441877d..5a764ea 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -51,8 +51,12 @@ struct usb_udc {
 
 static struct class *udc_class;
 static LIST_HEAD(udc_list);
+static LIST_HEAD(gadget_driver_pending_list);
 static DEFINE_MUTEX(udc_lock);
 
+static int udc_bind_to_driver(struct usb_udc *udc,
+		struct usb_gadget_driver *driver);
+
 /* ------------------------------------------------------------------------- */
 
 #ifdef	CONFIG_HAS_DMA
@@ -264,6 +268,7 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 		void (*release)(struct device *dev))
 {
 	struct usb_udc		*udc;
+	struct usb_gadget_driver *driver;
 	int			ret = -ENOMEM;
 
 	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
@@ -311,6 +316,18 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
 	udc->vbus = true;
 
+	/* 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,
+						dev_name(&udc->dev)) == 0) {
+			ret = udc_bind_to_driver(udc, driver);
+			if (ret)
+				goto err4;
+			list_del(&driver->pending);
+			break;
+		}
+	}
+
 	mutex_unlock(&udc_lock);
 
 	return 0;
@@ -382,9 +399,16 @@ void usb_del_gadget_udc(struct usb_gadget *gadget)
 	list_del(&udc->list);
 	mutex_unlock(&udc_lock);
 
-	if (udc->driver)
+	if (udc->driver) {
+		struct usb_gadget_driver *driver = udc->driver;
+
 		usb_gadget_remove_driver(udc);
 
+		mutex_lock(&udc_lock);
+		list_add(&driver->pending, &gadget_driver_pending_list);
+		mutex_unlock(&udc_lock);
+	}
+
 	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
 	flush_work(&gadget->work);
 	device_unregister(&udc->dev);
@@ -442,11 +466,7 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 			if (!ret)
 				break;
 		}
-		if (ret)
-			ret = -ENODEV;
-		else if (udc->driver)
-			ret = -EBUSY;
-		else
+		if (!ret && !udc->driver)
 			goto found;
 	} else {
 		list_for_each_entry(udc, &udc_list, list) {
@@ -456,9 +476,12 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 		}
 	}
 
-	pr_debug("couldn't find an available UDC\n");
+	list_add_tail(&driver->pending, &gadget_driver_pending_list);
+	pr_info("udc-core: couldn't find an available UDC "
+			"- added [%s] to list of pending drivers\n",
+			driver->function);
 	mutex_unlock(&udc_lock);
-	return ret;
+	return 0;
 found:
 	ret = udc_bind_to_driver(udc, driver);
 	mutex_unlock(&udc_lock);
@@ -484,6 +507,16 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 			break;
 		}
 
+	if (ret) {
+		struct usb_gadget_driver *tmp;
+
+		list_for_each_entry(tmp, &gadget_driver_pending_list, pending)
+			if (tmp == driver) {
+				list_del(&driver->pending);
+				ret = 0;
+				break;
+			}
+	}
 	mutex_unlock(&udc_lock);
 	return ret;
 }
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 5482d13..9c6fe22 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -826,6 +826,7 @@ static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
  * @driver: Driver model state for this driver.
  * @udc_name: A name of UDC this driver should be bound to. If udc_name is NULL,
  * 	this driver will be bound to any available UDC.
+ * @pending: UDC core private data used for deferred probe of this driver.
  *
  * Devices are disabled till a gadget driver successfully bind()s, which
  * means the driver will handle setup() requests needed to enumerate (and
@@ -888,6 +889,7 @@ struct usb_gadget_driver {
 	struct device_driver	driver;
 
 	char			*udc_name;
+	struct list_head	pending;
 };
 
 
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at  http://www.tux.org/lkml/

  parent reply	other threads:[~2015-06-22 22:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-22 22:01 [PATCH v5 0/5] usb/gadget: independent registration of gadgets and gadget drivers Ruslan Bilovol
2015-06-22 22:01 ` [PATCH v5 1/5] usb: gadget: bind UDC by name passed via usb_gadget_driver structure Ruslan Bilovol
2015-06-22 22:01 ` [PATCH v5 2/5] usb: gadget: configfs: pass UDC name via usb_gadget_driver struct Ruslan Bilovol
2015-06-23  6:54   ` Krzysztof Opasiak
2015-06-27 14:33     ` Ruslan Bilovol
2015-06-22 22:01 ` [PATCH v5 3/5] usb: gadget: udc-core: remove unused usb_udc_attach_driver() Ruslan Bilovol
2015-06-22 22:01 ` [PATCH v5 4/5] usb: gadget: legacy: don't use __init/__exit attributes for bind/unbind path Ruslan Bilovol
2015-06-22 22:01 ` Ruslan Bilovol [this message]
2015-06-23 14:08   ` [PATCH v5 5/5] usb: gadget: udc-core: independent registration of gadgets and gadget drivers Alan Stern
2015-06-27 22:37     ` Ruslan Bilovol
2015-06-27 23:47       ` Alan Stern
2015-07-06 17:38         ` Felipe Balbi
2015-10-19  8:11 ` [PATCH v5 0/5] usb/gadget: " Maxime Ripard
2015-11-02 16:44   ` Ruslan Bilovol
2015-11-09  0:07     ` Maxime Ripard

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1435010474-13419-6-git-send-email-ruslan.bilovol@gmail.com \
    --to=ruslan.bilovol@gmail.com \
    --cc=andrzej.p@samsung.com \
    --cc=balbi@ti.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=k.opasiak@samsung.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=maxime.ripard@free-electrons.com \
    --cc=peter.chen@freescale.com \
    --cc=stern@rowland.harvard.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.