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authorBjørn Mork <bjorn@mork.no>2012-03-06 17:29:22 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-03-08 13:06:48 -0800
commit3cc3615749dbd1b891512d5c9a5bf4559cfa9741 (patch)
tree9e6d3b095c521d7114ac0b74ee280b31d2809d94 /drivers/usb/class
parentb0c13860808a528cd580fdca61aef9f73352a331 (diff)
usb: cdc-wdm: adding usb_cdc_wdm_register subdriver support
This driver can be used as a subdriver of another USB driver, allowing it to export a Device Managment interface consisting of a single interrupt endpoint with no dedicated USB interface. Some devices provide a Device Management function combined with a wwan function in a single USB interface having three endpoints (bulk in/out + interrupt). If the interrupt endpoint is used exclusively for DM notifications, then this driver can support that as a subdriver provided that the wwan driver calls the appropriate entry points on probe, suspend, resume, pre_reset, post_reset and disconnect. The main driver must have full control over all interface related settings, including the needs_remote_wakeup flag. A manage_power function must be provided by the main driver. A manage_power stub doing direct flag manipulation is used in normal driver mode. Signed-off-by: Bjørn Mork <bjorn@mork.no> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/class')
-rw-r--r--drivers/usb/class/cdc-wdm.c63
1 files changed, 59 insertions, 4 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 46827373ecf9..c6f6560d436c 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -23,6 +23,7 @@
#include <linux/usb/cdc.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
+#include <linux/usb/cdc-wdm.h>
/*
* Version Information
@@ -116,6 +117,7 @@ struct wdm_device {
int rerr;
struct list_head device_list;
+ int (*manage_power)(struct usb_interface *, int);
};
static struct usb_driver wdm_driver;
@@ -580,7 +582,6 @@ static int wdm_open(struct inode *inode, struct file *file)
dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
goto out;
}
- intf->needs_remote_wakeup = 1;
/* using write lock to protect desc->count */
mutex_lock(&desc->wlock);
@@ -597,6 +598,8 @@ static int wdm_open(struct inode *inode, struct file *file)
rv = 0;
}
mutex_unlock(&desc->wlock);
+ if (desc->count == 1)
+ desc->manage_power(intf, 1);
usb_autopm_put_interface(desc->intf);
out:
mutex_unlock(&wdm_mutex);
@@ -618,7 +621,7 @@ static int wdm_release(struct inode *inode, struct file *file)
dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
kill_urbs(desc);
if (!test_bit(WDM_DISCONNECTING, &desc->flags))
- desc->intf->needs_remote_wakeup = 0;
+ desc->manage_power(desc->intf, 0);
}
mutex_unlock(&wdm_mutex);
return 0;
@@ -665,7 +668,8 @@ static void wdm_rxwork(struct work_struct *work)
/* --- hotplug --- */
-static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep, u16 bufsize)
+static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
+ u16 bufsize, int (*manage_power)(struct usb_interface *, int))
{
int rv = -ENOMEM;
struct wdm_device *desc;
@@ -750,6 +754,8 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
desc
);
+ desc->manage_power = manage_power;
+
spin_lock(&wdm_device_list_lock);
list_add(&desc->device_list, &wdm_device_list);
spin_unlock(&wdm_device_list_lock);
@@ -766,6 +772,19 @@ err:
return rv;
}
+static int wdm_manage_power(struct usb_interface *intf, int on)
+{
+ /* need autopm_get/put here to ensure the usbcore sees the new value */
+ int rv = usb_autopm_get_interface(intf);
+ if (rv < 0)
+ goto err;
+
+ intf->needs_remote_wakeup = on;
+ usb_autopm_put_interface(intf);
+err:
+ return rv;
+}
+
static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
int rv = -EINVAL;
@@ -809,12 +828,48 @@ next_desc:
goto err;
ep = &iface->endpoint[0].desc;
- rv = wdm_create(intf, ep, maxcom);
+ rv = wdm_create(intf, ep, maxcom, &wdm_manage_power);
err:
return rv;
}
+/**
+ * usb_cdc_wdm_register - register a WDM subdriver
+ * @intf: usb interface the subdriver will associate with
+ * @ep: interrupt endpoint to monitor for notifications
+ * @bufsize: maximum message size to support for read/write
+ *
+ * Create WDM usb class character device and associate it with intf
+ * without binding, allowing another driver to manage the interface.
+ *
+ * The subdriver will manage the given interrupt endpoint exclusively
+ * and will issue control requests referring to the given intf. It
+ * will otherwise avoid interferring, and in particular not do
+ * usb_set_intfdata/usb_get_intfdata on intf.
+ *
+ * The return value is a pointer to the subdriver's struct usb_driver.
+ * The registering driver is responsible for calling this subdriver's
+ * disconnect, suspend, resume, pre_reset and post_reset methods from
+ * its own.
+ */
+struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
+ struct usb_endpoint_descriptor *ep,
+ int bufsize,
+ int (*manage_power)(struct usb_interface *, int))
+{
+ int rv = -EINVAL;
+
+ rv = wdm_create(intf, ep, bufsize, manage_power);
+ if (rv < 0)
+ goto err;
+
+ return &wdm_driver;
+err:
+ return ERR_PTR(rv);
+}
+EXPORT_SYMBOL(usb_cdc_wdm_register);
+
static void wdm_disconnect(struct usb_interface *intf)
{
struct wdm_device *desc;