Use the new cdc-wdm subdriver interface to create a device management
device even for USB devices having a single combined QMI/wwan USB
interface with three endpoints (int, bulk in, bulk out) instead of
separate data and control interfaces.
Signed-off-by: Bjørn Mork <bjorn@xxxxxxx>
---
drivers/net/usb/qmi_wwan.c | 146 ++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 140 insertions(+), 6 deletions(-)
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 739e6de..5a9f08d 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -13,6 +13,7 @@
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>
+#include <linux/usb/cdc-wdm.h>
/* The name of the CDC Device Management driver */
#define DM_DRIVER "cdc_wdm"
@@ -170,13 +171,126 @@ err:
return status;
}
-/* stolen from cdc_ether.c */
+/* using a counter to merge subdriver requests with our own into a combined state */
static int qmi_wwan_manage_power(struct usbnet *dev, int on)
{
- dev->intf->needs_remote_wakeup = on;
- return 0;
+ atomic_t *pmcount = (void *)&dev->data[1];
+ int rv = 0;
+
+ dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(pmcount), on);
+
+ if ((on && atomic_add_return(1, pmcount) == 1) || (!on && atomic_dec_and_test(pmcount))) {
+ /* need autopm_get/put here to ensure the usbcore sees the new value */
+ rv = usb_autopm_get_interface(dev->intf);
+ if (rv < 0)
+ goto err;
+ dev->intf->needs_remote_wakeup = on;
+ usb_autopm_put_interface(dev->intf);
+ }
+err:
+ return rv;
+}
+
+static int qmi_wwan_cdc_wdm_manage_power(struct usb_interface *intf, int on)
+{
+ struct usbnet *dev = usb_get_intfdata(intf);
+ return qmi_wwan_manage_power(dev, on);
+}
+
+/*
+ * Some devices combine the "control" and "data" functions into a single
+ * interface with all three endpoints: interrupt + bulk in and out
+ *
+ * Setting up cdc-wdm as a subdriver owning the interrupt endpoint will
+ * let it provide userspace access to the encapsulated QMI protocol
+ * without interfering with the usbnet operations.
+ *
+ */
+static int qmi_wwan_bind_shared(struct usbnet *dev, struct usb_interface *intf)
+{
+ int rv;
+ struct usb_driver *subdriver = NULL;
+
+ /* collect all three endpoints */
+ rv = usbnet_get_endpoints(dev, intf);
+ if (rv < 0)
+ goto err;
+
+ /* require interrupt endpoint for subdriver */
+ if (!dev->status) {
+ rv = -EINVAL;
+ goto err;
+ }
+
+ subdriver = usb_cdc_wdm_register(intf, &dev->status->desc, 512, &qmi_wwan_cdc_wdm_manage_power);
+ if (IS_ERR(subdriver)) {
+ rv = PTR_ERR(subdriver);
+ goto err;
+ }
+
+ /* can't let usbnet use the interrupt endpoint */
+ dev->status = NULL;
+
+ /* save subdriver struct for suspend/resume wrappers */
+ dev->data[0] = (unsigned long)subdriver;
+
+err:
+ return rv;
+}
+
+static void qmi_wwan_unbind_shared(struct usbnet *dev, struct usb_interface *intf)
+{
+ struct usb_driver *subdriver = (void *)dev->data[0];
+
+ if (subdriver && subdriver->disconnect)
+ subdriver->disconnect(intf);
+
+ dev->data[0] = (unsigned long)NULL;
+}
+
+/*
+ * suspend/resume wrappers calling both usbnet and the cdc-wdm subdriver if
+ * present.
+ *
+ * NOTE: cdc-wdm also supports pre/post_reset, but we cannot provide
+ * wrappers for those without adding usbnet reset support first.
+ */
+static int qmi_wwan_suspend(struct usb_interface *intf, pm_message_t message)
+{
+ struct usbnet *dev = usb_get_intfdata(intf);
+ struct usb_driver *subdriver = (void *)dev->data[0];
+ int ret;
+
+ ret = usbnet_suspend(intf, message);
+ if (ret < 0)
+ goto err;
+
+ if (subdriver && subdriver->suspend)
+ ret = subdriver->suspend(intf, message);
+ if (ret < 0)
+ usbnet_resume(intf);
+err:
+ return ret;
+}
+
+static int qmi_wwan_resume(struct usb_interface *intf)
+{
+ struct usbnet *dev = usb_get_intfdata(intf);
+ struct usb_driver *subdriver = (void *)dev->data[0];
+ int ret = 0;
+
+ if (subdriver && subdriver->resume)
+ ret = subdriver->resume(intf);
+ if (ret < 0)
+ goto err;
+ ret = usbnet_resume(intf);
+ if (ret < 0 && subdriver && subdriver->resume && subdriver->suspend)
+ subdriver->suspend(intf, PMSG_SUSPEND);
+err:
+ return ret;
}
+
static const struct driver_info qmi_wwan_info = {
.description = "QMI speaking wwan device",
.flags = FLAG_WWAN,
@@ -184,6 +298,14 @@ static const struct driver_info qmi_wwan_info = {
.manage_power = qmi_wwan_manage_power,
};
+static const struct driver_info qmi_wwan_shared = {
+ .description = "QMI speaking wwan device with combined interface",
+ .flags = FLAG_WWAN,
+ .bind = qmi_wwan_bind_shared,
+ .unbind = qmi_wwan_unbind_shared,
+ .manage_power = qmi_wwan_manage_power,
+};
+
#define HUAWEI_VENDOR_ID 0x12D1
static const struct usb_device_id products[] = {
@@ -196,6 +318,18 @@ static const struct usb_device_id products[] = {
.bInterfaceProtocol = 8, /* NOTE: This is the *slave* interface of the CDC Union! */
.driver_info = (unsigned long)&qmi_wwan_info,
}, {
+ /*
+ * Huawei E392, E398 and possibly others in "Windows mode"
+ * using a combined control and data interface without any CDC
+ * functional descriptors
+ */
+ .match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_INT_INFO,
+ .idVendor = HUAWEI_VENDOR_ID,
+ .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
+ .bInterfaceSubClass = 1,
+ .bInterfaceProtocol = 17,
+ .driver_info = (unsigned long)&qmi_wwan_shared,
+}, {
}, /* END */
};
MODULE_DEVICE_TABLE(usb, products);
@@ -205,9 +339,9 @@ static struct usb_driver qmi_wwan_driver = {
.id_table = products,
.probe = usbnet_probe,
.disconnect = usbnet_disconnect,
- .suspend = usbnet_suspend,
- .resume = usbnet_resume,
- .reset_resume = usbnet_resume,
+ .suspend = qmi_wwan_suspend,
+ .resume = qmi_wwan_resume,
+ .reset_resume = qmi_wwan_resume,
.supports_autosuspend = 1,
};
--
1.7.8.3
--
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