drivers: Backport cdc-wdm and new qmi_wwan

Backport is based on Aleksander Morgado's backport for OpenWrt to the
3.2 kernel[1], so it's a backport of a backport. I added the device
IDs for MDM9x15.

[1] https://gitorious.org/lanedo/linux-stable?p=lanedo:linux-stable.git;a=shortlog;h=refs/heads/v3.2.5-qmi

Signed-off-by: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>

1 files changed, 479 insertions, 0 deletions

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
new file mode 100644
index 0000000..7156bc7
--- /dev/null
+++ b/drivers/net/usb/qmi_wwan.c
@@ -0,0 +1,479 @@
+/*
+ * Copyright (c) 2012  Bjørn Mork <bjorn@mork.no>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/ethtool.h>
+#include <linux/mii.h>
+#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"
+
+/*
+ * This driver supports wwan (3G/LTE/?) devices using a vendor
+ * specific management protocol called Qualcomm MSM Interface (QMI) -
+ * in addition to the more common AT commands over serial interface
+ * management
+ *
+ * QMI is wrapped in CDC, using CDC encapsulated commands on the
+ * control ("master") interface of a two-interface CDC Union
+ * resembling standard CDC ECM.  The devices do not use the control
+ * interface for any other CDC messages.  Most likely because the
+ * management protocol is used in place of the standard CDC
+ * notifications NOTIFY_NETWORK_CONNECTION and NOTIFY_SPEED_CHANGE
+ *
+ * Handling a protocol like QMI is out of the scope for any driver.
+ * It can be exported as a character device using the cdc-wdm driver,
+ * which will enable userspace applications ("modem managers") to
+ * handle it.  This may be required to use the network interface
+ * provided by the driver.
+ *
+ * These devices may alternatively/additionally be configured using AT
+ * commands on any of the serial interfaces driven by the option driver
+ *
+ * This driver binds only to the data ("slave") interface to enable
+ * the cdc-wdm driver to bind to the control interface.  It still
+ * parses the CDC functional descriptors on the control interface to
+ *  a) verify that this is indeed a handled interface (CDC Union
+ *     header lists it as slave)
+ *  b) get MAC address and other ethernet config from the CDC Ethernet
+ *     header
+ *  c) enable user bind requests against the control interface, which
+ *     is the common way to bind to CDC Ethernet Control Model type
+ *     interfaces
+ *  d) provide a hint to the user about which interface is the
+ *     corresponding management interface
+ */
+
+static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	int status = -1;
+	struct usb_interface *control = NULL;
+	u8 *buf = intf->cur_altsetting->extra;
+	int len = intf->cur_altsetting->extralen;
+	struct usb_interface_descriptor *desc = &intf->cur_altsetting->desc;
+	struct usb_cdc_union_desc *cdc_union = NULL;
+	struct usb_cdc_ether_desc *cdc_ether = NULL;
+	u32 required = 1 << USB_CDC_HEADER_TYPE | 1 << USB_CDC_UNION_TYPE;
+	u32 found = 0;
+	atomic_t *pmcount = (void *)&dev->data[1];
+
+	atomic_set(pmcount, 0);
+
+	/*
+	 * assume a data interface has no additional descriptors and
+	 * that the control and data interface are numbered
+	 * consecutively - this holds for the Huawei device at least
+	 */
+	if (len == 0 && desc->bInterfaceNumber > 0) {
+		control = usb_ifnum_to_if(dev->udev, desc->bInterfaceNumber - 1);
+		if (!control)
+			goto err;
+
+		buf = control->cur_altsetting->extra;
+		len = control->cur_altsetting->extralen;
+		dev_dbg(&intf->dev, "guessing \"control\" => %s, \"data\" => this\n",
+			dev_name(&control->dev));
+	}
+
+	while (len > 3) {
+		struct usb_descriptor_header *h = (void *)buf;
+
+		/* ignore any misplaced descriptors */
+		if (h->bDescriptorType != USB_DT_CS_INTERFACE)
+			goto next_desc;
+
+		/* buf[2] is CDC descriptor subtype */
+		switch (buf[2]) {
+		case USB_CDC_HEADER_TYPE:
+			if (found & 1 << USB_CDC_HEADER_TYPE) {
+				dev_dbg(&intf->dev, "extra CDC header\n");
+				goto err;
+			}
+			if (h->bLength != sizeof(struct usb_cdc_header_desc)) {
+				dev_dbg(&intf->dev, "CDC header len %u\n", h->bLength);
+				goto err;
+			}
+			break;
+		case USB_CDC_UNION_TYPE:
+			if (found & 1 << USB_CDC_UNION_TYPE) {
+				dev_dbg(&intf->dev, "extra CDC union\n");
+				goto err;
+			}
+			if (h->bLength != sizeof(struct usb_cdc_union_desc)) {
+				dev_dbg(&intf->dev, "CDC union len %u\n", h->bLength);
+				goto err;
+			}
+			cdc_union = (struct usb_cdc_union_desc *)buf;
+			break;
+		case USB_CDC_ETHERNET_TYPE:
+			if (found & 1 << USB_CDC_ETHERNET_TYPE) {
+				dev_dbg(&intf->dev, "extra CDC ether\n");
+				goto err;
+			}
+			if (h->bLength != sizeof(struct usb_cdc_ether_desc)) {
+				dev_dbg(&intf->dev, "CDC ether len %u\n",  h->bLength);
+				goto err;
+			}
+			cdc_ether = (struct usb_cdc_ether_desc *)buf;
+			break;
+		}
+
+		/*
+		 * Remember which CDC functional descriptors we've seen.  Works
+		 * for all types we care about, of which USB_CDC_ETHERNET_TYPE
+		 * (0x0f) is the highest numbered
+		 */
+		if (buf[2] < 32)
+			found |= 1 << buf[2];
+
+next_desc:
+		len -= h->bLength;
+		buf += h->bLength;
+	}
+
+	/* did we find all the required ones? */
+	if ((found & required) != required) {
+		dev_err(&intf->dev, "CDC functional descriptors missing\n");
+		goto err;
+	}
+
+	/* give the user a helpful hint if trying to bind to the wrong interface */
+	if (cdc_union && desc->bInterfaceNumber == cdc_union->bMasterInterface0) {
+		dev_err(&intf->dev, "leaving \"control\" interface for " DM_DRIVER " - try binding to %s instead!\n",
+			dev_name(&usb_ifnum_to_if(dev->udev, cdc_union->bSlaveInterface0)->dev));
+		goto err;
+	}
+
+	/* errors aren't fatal - we can live with the dynamic address */
+	if (cdc_ether) {
+		dev->hard_mtu = le16_to_cpu(cdc_ether->wMaxSegmentSize);
+		usbnet_get_ethernet_addr(dev, cdc_ether->iMACAddress);
+	}
+
+	/* success! point the user to the management interface */
+	if (control)
+		dev_info(&intf->dev, "Use \"" DM_DRIVER "\" for QMI interface %s\n",
+			dev_name(&control->dev));
+
+	/* XXX: add a sysfs symlink somewhere to help management applications find it? */
+
+	/* collect bulk endpoints now that we know intf == "data" interface */
+	status = usbnet_get_endpoints(dev, intf);
+
+err:
+	return status;
+}
+
+/* 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)
+{
+	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;
+	atomic_t *pmcount = (void *)&dev->data[1];
+
+	/* ZTE makes devices where the interface descriptors and endpoint
+	 * configurations of two or more interfaces are identical, even
+	 * though the functions are completely different.  If set, then
+	 * driver_info->data is a bitmap of acceptable interface numbers
+	 * allowing us to bind to one such interface without binding to
+	 * all of them
+	 */
+	if (dev->driver_info->data &&
+	    !test_bit(intf->cur_altsetting->desc.bInterfaceNumber, &dev->driver_info->data)) {
+		dev_info(&intf->dev, "not on our whitelist - ignored");
+		rv = -ENODEV;
+		goto err;
+	}
+
+	atomic_set(pmcount, 0);
+
+	/* 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;
+}
+
+/* Gobi devices uses identical class/protocol codes for all interfaces regardless
+ * of function. Some of these are CDC ACM like and have the exact same endpoints
+ * we are looking for. This leaves two possible strategies for identifying the
+ * correct interface:
+ *   a) hardcoding interface number, or
+ *   b) use the fact that the wwan interface is the only one lacking additional
+ *      (CDC functional) descriptors
+ *
+ * Let's see if we can get away with the generic b) solution.
+ */
+static int qmi_wwan_bind_gobi(struct usbnet *dev, struct usb_interface *intf)
+{
+	int rv = -EINVAL;
+
+	/* ignore any interface with additional descriptors */
+	if (intf->cur_altsetting->extralen)
+		goto err;
+
+	rv = qmi_wwan_bind_shared(dev, intf);
+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,
+	.bind		= qmi_wwan_bind,
+	.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,
+};
+
+static const struct driver_info	qmi_wwan_gobi = {
+	.description	= "Qualcomm Gobi wwan/QMI device",
+	.flags		= FLAG_WWAN,
+	.bind		= qmi_wwan_bind_gobi,
+	.unbind		= qmi_wwan_unbind_shared,
+	.manage_power	= qmi_wwan_manage_power,
+};
+
+/* ZTE suck at making USB descriptors */
+static const struct driver_info	qmi_wwan_force_int4 = {
+	.description	= "Qualcomm Gobi wwan/QMI device",
+	.flags		= FLAG_WWAN,
+	.bind		= qmi_wwan_bind_gobi,
+	.unbind		= qmi_wwan_unbind_shared,
+	.manage_power	= qmi_wwan_manage_power,
+	.data		= BIT(4), /* interface whitelist bitmap */
+};
+
+
+#define HUAWEI_VENDOR_ID	0x12D1
+#define QMI_GOBI_DEVICE(vend, prod) \
+	USB_DEVICE(vend, prod), \
+	.driver_info = (unsigned long)&qmi_wwan_gobi
+
+static const struct usb_device_id products[] = {
+	{	/* Huawei E392, E398 and possibly others sharing both device id and more... */
+		.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 = 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,
+	},
+	{	/* Pantech UML290 */
+		.match_flags	    = USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_INT_INFO,
+		.idVendor           = 0x106c,
+		.idProduct          = 0x3718,
+		.bInterfaceClass    = 0xff,
+		.bInterfaceSubClass = 0xf0,
+		.bInterfaceProtocol = 0xff,
+		.driver_info        = (unsigned long)&qmi_wwan_shared,
+	},
+	{	/* ZTE MF820D */
+		.match_flags	    = USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_INT_INFO,
+		.idVendor           = 0x19d2,
+		.idProduct          = 0x0167,
+		.bInterfaceClass    = 0xff,
+		.bInterfaceSubClass = 0xff,
+		.bInterfaceProtocol = 0xff,
+		.driver_info        = (unsigned long)&qmi_wwan_force_int4,
+	},
+	{QMI_GOBI_DEVICE(0x05c6, 0x9212)},	/* Acer Gobi Modem Device */
+	{QMI_GOBI_DEVICE(0x03f0, 0x1f1d)},	/* HP un2400 Gobi Modem Device */
+	{QMI_GOBI_DEVICE(0x03f0, 0x371d)},	/* HP un2430 Mobile Broadband Module */
+	{QMI_GOBI_DEVICE(0x04da, 0x250d)},	/* Panasonic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x413c, 0x8172)},	/* Dell Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x1410, 0xa001)},	/* Novatel Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x0b05, 0x1776)},	/* Asus Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x19d2, 0xfff3)},	/* ONDA Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9001)},	/* Generic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9002)},	/* Generic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9202)},	/* Generic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9203)},	/* Generic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9222)},	/* Generic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9009)},	/* Generic Gobi Modem device */
+	{QMI_GOBI_DEVICE(0x413c, 0x8186)},	/* Dell Gobi 2000 Modem device (N0218, VU936) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x920b)},	/* Generic Gobi 2000 Modem device */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9225)},	/* Sony Gobi 2000 Modem device (N0279, VU730) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9245)},	/* Samsung Gobi 2000 Modem device (VL176) */
+	{QMI_GOBI_DEVICE(0x03f0, 0x251d)},	/* HP Gobi 2000 Modem device (VP412) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9215)},	/* Acer Gobi 2000 Modem device (VP413) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9265)},	/* Asus Gobi 2000 Modem device (VR305) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9235)},	/* Top Global Gobi 2000 Modem device (VR306) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9275)},	/* iRex Technologies Gobi 2000 Modem device (VR307) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9001)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9002)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9003)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9004)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9005)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9006)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9007)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9008)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9009)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x900a)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{QMI_GOBI_DEVICE(0x1199, 0x9011)},	/* Sierra Wireless Gobi 2000 Modem device (MC8305) */
+	{QMI_GOBI_DEVICE(0x16d8, 0x8002)},	/* CMDTech Gobi 2000 Modem device (VU922) */
+	{QMI_GOBI_DEVICE(0x05c6, 0x9205)},	/* Gobi 2000 Modem device */
+	{QMI_GOBI_DEVICE(0x1199, 0x9013)},	/* Sierra Wireless Gobi 3000 Modem device (MC8355) */
+        {QMI_GOBI_DEVICE(0x05c6, 0x904c)},	/* MDM9x15 */
+	{ }					/* END */
+};
+MODULE_DEVICE_TABLE(usb, products);
+
+static struct usb_driver qmi_wwan_driver = {
+	.name		      = "qmi_wwan",
+	.id_table	      = products,
+	.probe		      =	usbnet_probe,
+	.disconnect	      = usbnet_disconnect,
+	.suspend	      = qmi_wwan_suspend,
+	.resume		      =	qmi_wwan_resume,
+	.reset_resume         = qmi_wwan_resume,
+	.supports_autosuspend = 1,
+};
+
+static int __init qmi_wwan_init(void)
+{
+	return usb_register(&qmi_wwan_driver);
+}
+module_init(qmi_wwan_init);
+
+static void __exit qmi_wwan_exit(void)
+{
+	usb_deregister(&qmi_wwan_driver);
+}
+module_exit(qmi_wwan_exit);
+
+MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
+MODULE_DESCRIPTION("Qualcomm MSM Interface (QMI) WWAN driver");
+MODULE_LICENSE("GPL");