Merge branch 'huawei_cdc_ncm'

Bjørn Mork says:

====================
The huawei_cdc_ncm driver.

Enrico has been kind enough to let me repost his driver with the changes
requested by Oliver Neukum during the last review of this series.

The changes I have made from Enricos original v5 series to this version
are:

v6:
 - fix to avoid corrupting drvstate->pmcount
 - fix error return value from huawei_cdc_ncm_suspend()
 - drop redundant testing for subdriver->suspend during resume
 - broke a few lines to keep within the 80 columns recommendation
 - rebased on top of current net-next

Enrico's orginal introduction to the v5 series follows below.  It explains
the background much better than I can.

Bjørn

[quote Enrico Mioso]

So this is a new, revised, edition of the huawei_cdc_ncm.c driver, which
supports devices resembling the NCM standard, but using it also as a mean
to encapsulate other protocols, as is the case for the Huawei E3131 and
E3251 modem devices.
Some precisations are needed however - and I encourage discussion on this: and
that's why I'm sending this message with a broader CC.
Merging those patches might change:
- the way Modem Manager interacts with those devices
- some regressions might be possible if there are some unknown firmware
  variants around (Franko?)

First of all: I observed the behaviours of two devices.
Huawei E3131: this device doesn't accept NDIS setup requests unless they're
sent via the embedded AT channel exposed by this driver.
So actually we gain funcionality in this case!

The second case, is the Huawei E3251: which works with standard NCM driver,
still exposing an AT embedded channel. Whith this patch set applied, you gain
some funcionality, loosing the ability to catch standard NCM events for now.
The device will work in both ways with no problems, but this has to be
acknowledged and discussed. Might be we can develop this driver further to
change this, when more devices are tested.

We where thinking Huawei changed their interfaces on new devices - but probably
this driver only works around a nice firmware bug present in E3131, which
prevented the modem from being used in NDIS mode.

I think committing this is definitely wortth-while, since it will allow for
more Huawei devices to be used without serial connection. Some devices like the
E3251 also, reports some status information only via the embedded AT channel,
at least in my case.
Note: I'm not subscribed to any list except the Modem Manager's one, so please
CC me, thanks!!

[/quote]

Enrico Mioso (3):
  net: cdc_ncm: Export cdc_ncm_{tx,rx}_fixup functions for re-use
  net: huawei_cdc_ncm: Introduce the huawei_cdc_ncm driver
  net: cdc_ncm: remove non-standard NCM device IDs
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 250 insertions, 13 deletions

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 40db31233313..85e4a01670f0 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -242,6 +242,21 @@ config USB_NET_CDC_NCM
             * ST-Ericsson M343 HSPA Mobile Broadband Modem (reference design)
             * Ericsson F5521gw Mobile Broadband Module
 
+config USB_NET_HUAWEI_CDC_NCM
+        tristate "Huawei NCM embedded AT channel support"
+        depends on USB_USBNET
+        select USB_WDM
+        select USB_NET_CDC_NCM
+        help
+                This driver supports huawei-style NCM devices, that use NCM as a
+                transport for other protocols, usually an embedded AT channel.
+                Good examples are:
+                * Huawei E3131
+                * Huawei E3251
+
+                To compile this driver as a module, choose M here: the module will be
+                called huawei_cdc_ncm.ko.
+
 config USB_NET_CDC_MBIM
         tristate "CDC MBIM support"
         depends on USB_USBNET
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index 8b342cf992fd..b17b5e88bbaf 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_USB_IPHETH)	+= ipheth.o
 obj-$(CONFIG_USB_SIERRA_NET)    += sierra_net.o
 obj-$(CONFIG_USB_NET_CX82310_ETH)       += cx82310_eth.o
 obj-$(CONFIG_USB_NET_CDC_NCM)   += cdc_ncm.o
+obj-$(CONFIG_USB_NET_HUAWEI_CDC_NCM)    += huawei_cdc_ncm.o
 obj-$(CONFIG_USB_VL600)         += lg-vl600.o
 obj-$(CONFIG_USB_NET_QMI_WWAN)  += qmi_wwan.o
 obj-$(CONFIG_USB_NET_CDC_MBIM)  += cdc_mbim.o
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 11c703337577..f74786aa37be 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -830,7 +830,7 @@ static void cdc_ncm_txpath_bh(unsigned long param)
         }
 }
 
-static struct sk_buff *
+struct sk_buff *
 cdc_ncm_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 {
         struct sk_buff *skb_out;
@@ -857,6 +857,7 @@ error:
 
         return NULL;
 }
+EXPORT_SYMBOL_GPL(cdc_ncm_tx_fixup);
 
 /* verify NTB header and return offset of first NDP, or negative error */
 int cdc_ncm_rx_verify_nth16(struct cdc_ncm_ctx *ctx, struct sk_buff *skb_in)
@@ -943,7 +944,7 @@ error:
 }
 EXPORT_SYMBOL_GPL(cdc_ncm_rx_verify_ndp16);
 
-static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
+int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in)
 {
         struct sk_buff *skb;
         struct cdc_ncm_ctx *ctx = (struct cdc_ncm_ctx *)dev->data[0];
@@ -1019,6 +1020,7 @@ err_ndp:
 error:
         return 0;
 }
+EXPORT_SYMBOL_GPL(cdc_ncm_rx_fixup);
 
 static void
 cdc_ncm_speed_change(struct usbnet *dev,
@@ -1184,17 +1186,6 @@ static const struct usb_device_id cdc_devs[] = {
           .driver_info = (unsigned long)&wwan_info,
         },
 
-        /* Huawei NCM devices disguised as vendor specific */
-        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
-          .driver_info = (unsigned long)&wwan_info,
-        },
-        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
-          .driver_info = (unsigned long)&wwan_info,
-        },
-        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76),
-          .driver_info = (unsigned long)&wwan_info,
-        },
-
         /* Infineon(now Intel) HSPA Modem platform */
         { USB_DEVICE_AND_INTERFACE_INFO(0x1519, 0x0443,
                 USB_CLASS_COMM,
diff --git a/drivers/net/usb/huawei_cdc_ncm.c b/drivers/net/usb/huawei_cdc_ncm.c
new file mode 100644
index 000000000000..312178d7b698
--- /dev/null
+++ b/drivers/net/usb/huawei_cdc_ncm.c
@@ -0,0 +1,230 @@
+/* huawei_cdc_ncm.c - handles Huawei devices using the CDC NCM protocol as
+ * transport layer.
+ * Copyright (C) 2013    Enrico Mioso <mrkiko.rs@gmail.com>
+ *
+ *
+ * ABSTRACT:
+ * This driver handles devices resembling the CDC NCM standard, but
+ * encapsulating another protocol inside it. An example are some Huawei 3G
+ * devices, exposing an embedded AT channel where you can set up the NCM
+ * connection.
+ * This code has been heavily inspired by the cdc_mbim.c driver, which is
+ * Copyright (c) 2012  Smith Micro Software, Inc.
+ * 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/if_vlan.h>
+#include <linux/ip.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>
+#include <linux/usb/cdc_ncm.h>
+
+/* Driver data */
+struct huawei_cdc_ncm_state {
+        struct cdc_ncm_ctx *ctx;
+        atomic_t pmcount;
+        struct usb_driver *subdriver;
+        struct usb_interface *control;
+        struct usb_interface *data;
+};
+
+static int huawei_cdc_ncm_manage_power(struct usbnet *usbnet_dev, int on)
+{
+        struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+        int rv;
+
+        if ((on && atomic_add_return(1, &drvstate->pmcount) == 1) ||
+                        (!on && atomic_dec_and_test(&drvstate->pmcount))) {
+                rv = usb_autopm_get_interface(usbnet_dev->intf);
+                usbnet_dev->intf->needs_remote_wakeup = on;
+                if (!rv)
+                        usb_autopm_put_interface(usbnet_dev->intf);
+        }
+        return 0;
+}
+
+static int huawei_cdc_ncm_wdm_manage_power(struct usb_interface *intf,
+                                           int status)
+{
+        struct usbnet *usbnet_dev = usb_get_intfdata(intf);
+
+        /* can be called while disconnecting */
+        if (!usbnet_dev)
+                return 0;
+
+        return huawei_cdc_ncm_manage_power(usbnet_dev, status);
+}
+
+
+static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
+                               struct usb_interface *intf)
+{
+        struct cdc_ncm_ctx *ctx;
+        struct usb_driver *subdriver = ERR_PTR(-ENODEV);
+        int ret = -ENODEV;
+        struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+
+        /* altsetting should always be 1 for NCM devices - so we hard-coded
+         * it here
+         */
+        ret = cdc_ncm_bind_common(usbnet_dev, intf, 1);
+        if (ret)
+                goto err;
+
+        ctx = drvstate->ctx;
+
+        if (usbnet_dev->status)
+                /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256
+                 * decimal (0x100)"
+                 */
+                subdriver = usb_cdc_wdm_register(ctx->control,
+                                                 &usbnet_dev->status->desc,
+                                                 256, /* wMaxCommand */
+                                                 huawei_cdc_ncm_wdm_manage_power);
+        if (IS_ERR(subdriver)) {
+                ret = PTR_ERR(subdriver);
+                cdc_ncm_unbind(usbnet_dev, intf);
+                goto err;
+        }
+
+        /* Prevent usbnet from using the status descriptor */
+        usbnet_dev->status = NULL;
+
+        drvstate->subdriver = subdriver;
+
+err:
+        return ret;
+}
+
+static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev,
+                                  struct usb_interface *intf)
+{
+        struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+        struct cdc_ncm_ctx *ctx = drvstate->ctx;
+
+        if (drvstate->subdriver && drvstate->subdriver->disconnect)
+                drvstate->subdriver->disconnect(ctx->control);
+        drvstate->subdriver = NULL;
+
+        cdc_ncm_unbind(usbnet_dev, intf);
+}
+
+static int huawei_cdc_ncm_suspend(struct usb_interface *intf,
+                                  pm_message_t message)
+{
+        int ret = 0;
+        struct usbnet *usbnet_dev = usb_get_intfdata(intf);
+        struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+        struct cdc_ncm_ctx *ctx = drvstate->ctx;
+
+        if (ctx == NULL) {
+                ret = -ENODEV;
+                goto error;
+        }
+
+        ret = usbnet_suspend(intf, message);
+        if (ret < 0)
+                goto error;
+
+        if (intf == ctx->control &&
+                drvstate->subdriver &&
+                drvstate->subdriver->suspend)
+                ret = drvstate->subdriver->suspend(intf, message);
+        if (ret < 0)
+                usbnet_resume(intf);
+
+error:
+        return ret;
+}
+
+static int huawei_cdc_ncm_resume(struct usb_interface *intf)
+{
+        int ret = 0;
+        struct usbnet *usbnet_dev = usb_get_intfdata(intf);
+        struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data;
+        bool callsub;
+        struct cdc_ncm_ctx *ctx = drvstate->ctx;
+
+        /* should we call subdriver's resume function? */
+        callsub =
+                (intf == ctx->control &&
+                drvstate->subdriver &&
+                drvstate->subdriver->resume);
+
+        if (callsub)
+                ret = drvstate->subdriver->resume(intf);
+        if (ret < 0)
+                goto err;
+        ret = usbnet_resume(intf);
+        if (ret < 0 && callsub)
+                drvstate->subdriver->suspend(intf, PMSG_SUSPEND);
+err:
+        return ret;
+}
+
+static int huawei_cdc_ncm_check_connect(struct usbnet *usbnet_dev)
+{
+        struct cdc_ncm_ctx *ctx;
+
+        ctx = (struct cdc_ncm_ctx *)usbnet_dev->data[0];
+
+        if (ctx == NULL)
+                return 1; /* disconnected */
+
+        return !ctx->connected;
+}
+
+static const struct driver_info huawei_cdc_ncm_info = {
+        .description = "Huawei CDC NCM device",
+        .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
+        .bind = huawei_cdc_ncm_bind,
+        .unbind = huawei_cdc_ncm_unbind,
+        .check_connect = huawei_cdc_ncm_check_connect,
+        .manage_power = huawei_cdc_ncm_manage_power,
+        .rx_fixup = cdc_ncm_rx_fixup,
+        .tx_fixup = cdc_ncm_tx_fixup,
+};
+
+static const struct usb_device_id huawei_cdc_ncm_devs[] = {
+        /* Huawei NCM devices disguised as vendor specific */
+        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
+          .driver_info = (unsigned long)&huawei_cdc_ncm_info,
+        },
+        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
+          .driver_info = (unsigned long)&huawei_cdc_ncm_info,
+        },
+        { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76),
+          .driver_info = (unsigned long)&huawei_cdc_ncm_info,
+        },
+
+        /* Terminating entry */
+        {
+        },
+};
+MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs);
+
+static struct usb_driver huawei_cdc_ncm_driver = {
+        .name = "huawei_cdc_ncm",
+        .id_table = huawei_cdc_ncm_devs,
+        .probe = usbnet_probe,
+        .disconnect = usbnet_disconnect,
+        .suspend = huawei_cdc_ncm_suspend,
+        .resume = huawei_cdc_ncm_resume,
+        .reset_resume = huawei_cdc_ncm_resume,
+        .supports_autosuspend = 1,
+        .disable_hub_initiated_lpm = 1,
+};
+module_usb_driver(huawei_cdc_ncm_driver);
+MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>");
+MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support");
+MODULE_LICENSE("GPL");