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authorGreg Suarez <gpsuarez2512@gmail.com>2012-10-08 14:30:23 +0200
committerBjørn Mork <bjorn@mork.no>2012-10-09 16:25:13 +0200
commit96dbdb1e30e4dee76562ebd49fc0888d5621e2e5 (patch)
tree5d556267e78edb12f0cacee65e25defdc0ab519a
parent6ac9fa6ef19a4c1392654bae34b8553b98040051 (diff)
net: cdc_mbim: adding MBIM driver
Implementing a basic MBIM driver supporting only IPS sessions with SessionID 0. Signed-off-by: Bjørn Mork <bjorn@mork.no>
-rw-r--r--drivers/net/usb/cdc_mbim.c364
-rw-r--r--include/linux/usb/cdc_ncm.h10
2 files changed, 374 insertions, 0 deletions
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
new file mode 100644
index 00000000000..93c16678c6c
--- /dev/null
+++ b/drivers/net/usb/cdc_mbim.c
@@ -0,0 +1,364 @@
+/*
+ * Copyright (c) 2012 Greg Suarez <gpsuarez2512@gmail.com>
+ * Copyright (c) 2012 Bjørn Mork <bjorn@mork.no>
+ *
+ * This driver is based on and reuse most of cdc_ncm, which is
+ * Copyright (C) ST-Ericsson 2010-2012
+ *
+ * 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/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 specific data - must match cdc_ncm usage */
+struct cdc_mbim_state {
+ struct cdc_ncm_ctx *ctx;
+ atomic_t pmcount;
+ struct usb_driver *subdriver;
+ struct usb_interface *control;
+ struct usb_interface *data;
+};
+
+/* using a counter to merge subdriver requests with our own into a combined state */
+static int cdc_mbim_manage_power(struct usbnet *dev, int on)
+{
+ struct cdc_mbim_state *info = (void *)&dev->data;
+ int rv = 0;
+
+ dev_dbg(&dev->intf->dev, "%s() pmcount=%d, on=%d\n", __func__, atomic_read(&info->pmcount), on);
+
+ if ((on && atomic_add_return(1, &info->pmcount) == 1) || (!on && atomic_dec_and_test(&info->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 cdc_mbim_wdm_manage_power(struct usb_interface *intf, int status)
+{
+ struct usbnet *dev = usb_get_intfdata(intf);
+
+ /* can be called while disconnecting */
+ if (!dev)
+ return 0;
+
+ return cdc_mbim_manage_power(dev, status);
+}
+
+
+static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+ struct cdc_ncm_ctx *ctx;
+ struct usb_driver *subdriver = ERR_PTR(-ENODEV);
+ int ret = -ENODEV;
+ u8 data_altsetting = CDC_NCM_DATA_ALTSETTING_NCM;
+ struct cdc_mbim_state *info = (void *)&dev->data;
+
+ /* see if interface supports MBIM alternate setting */
+ if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting)) {
+ if (!usb_set_interface(dev->udev,
+ intf->cur_altsetting->desc.bInterfaceNumber,
+ CDC_NCM_COMM_ALTSETTING_MBIM))
+ data_altsetting = CDC_NCM_DATA_ALTSETTING_MBIM;
+ }
+
+ /* Probably NCM, defer for cdc_ncm_bind */
+ if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
+ goto err;
+
+ ret = cdc_ncm_bind_common(dev, intf, data_altsetting);
+ if (ret)
+ goto err;
+
+ ctx = info->ctx;
+
+ /* The MBIM descriptor and the status endpoint are required */
+ if (ctx->mbim_desc && dev->status)
+ subdriver = usb_cdc_wdm_register(ctx->control,
+ &dev->status->desc,
+ le16_to_cpu(ctx->mbim_desc->wMaxControlMessage),
+ cdc_mbim_wdm_manage_power);
+ if (IS_ERR(subdriver)) {
+ ret = PTR_ERR(subdriver);
+ cdc_ncm_unbind(dev, intf);
+ goto err;
+ }
+
+ /* can't let usbnet use the interrupt endpoint */
+ dev->status = NULL;
+ info->subdriver = subdriver;
+
+ /* MBIM cannot do ARP */
+ dev->net->flags |= IFF_NOARP;
+err:
+ return ret;
+}
+
+static void cdc_mbim_unbind(struct usbnet *dev, struct usb_interface *intf)
+{
+ struct cdc_mbim_state *info = (void *)&dev->data;
+ struct cdc_ncm_ctx *ctx = info->ctx;
+
+ /* disconnect subdriver from control interface */
+ if (info->subdriver && info->subdriver->disconnect)
+ info->subdriver->disconnect(ctx->control);
+ info->subdriver = NULL;
+
+ /* let NCM unbind clean up both control and data interface */
+ cdc_ncm_unbind(dev, intf);
+}
+
+
+static struct sk_buff *cdc_mbim_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
+{
+ struct sk_buff *skb_out;
+ struct cdc_mbim_state *info = (void *)&dev->data;
+ struct cdc_ncm_ctx *ctx = info->ctx;
+
+ if (!ctx)
+ goto error;
+
+ if (skb) {
+ if (skb->len <= sizeof(ETH_HLEN))
+ goto error;
+
+ skb_reset_mac_header(skb);
+ switch (eth_hdr(skb)->h_proto) {
+ case htons(ETH_P_IP):
+ case htons(ETH_P_IPV6):
+ skb_pull(skb, ETH_HLEN);
+ break;
+ default:
+ goto error;
+ }
+ }
+
+ spin_lock_bh(&ctx->mtx);
+ skb_out = cdc_ncm_fill_tx_frame(ctx, skb, cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN));
+ spin_unlock_bh(&ctx->mtx);
+ return skb_out;
+
+error:
+ if (skb)
+ dev_kfree_skb_any(skb);
+
+ return NULL;
+}
+
+static struct sk_buff *cdc_mbim_process_dgram(struct usbnet *dev, u8 *buf, size_t len)
+{
+ __be16 proto;
+ struct sk_buff *skb = NULL;
+
+ switch (*buf & 0xf0) {
+ case 0x40:
+ proto = htons(ETH_P_IP);
+ break;
+ case 0x60:
+ proto = htons(ETH_P_IPV6);
+ break;
+ default:
+ goto err;
+ }
+
+ skb = netdev_alloc_skb_ip_align(dev->net, len + ETH_HLEN);
+ if (!skb)
+ goto err;
+
+ /* add an ethernet header */
+ skb_put(skb, ETH_HLEN);
+ skb_reset_mac_header(skb);
+ eth_hdr(skb)->h_proto = proto;
+ memset(eth_hdr(skb)->h_source, 0, ETH_ALEN);
+ memcpy(eth_hdr(skb)->h_dest, dev->net->dev_addr, ETH_ALEN);
+
+ /* add datagram */
+ memcpy(skb_put(skb, len), buf, len);
+err:
+ return skb;
+}
+
+static int cdc_mbim_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];
+ int len;
+ int nframes;
+ int x;
+ int offset;
+ struct usb_cdc_ncm_ndp16 *ndp16;
+ struct usb_cdc_ncm_dpe16 *dpe16;
+ int ndpoffset;
+ int loopcount = 50; /* arbitrary max preventing infinite loop */
+
+ ndpoffset = cdc_ncm_rx_verify_nth16(ctx, skb_in);
+ if (ndpoffset < 0)
+ goto error;
+
+next_ndp:
+ nframes = cdc_ncm_rx_verify_ndp16(skb_in, ndpoffset);
+ if (nframes < 0)
+ goto error;
+
+ ndp16 = (struct usb_cdc_ncm_ndp16 *)(skb_in->data + ndpoffset);
+
+ /* only supporting IPS Session #0 for now */
+ switch (ndp16->dwSignature) {
+ case cpu_to_le32(USB_CDC_MBIM_NDP16_IPS_SIGN):
+ break;
+ default:
+ netif_dbg(dev, rx_err, dev->net,
+ "unsupported NDP signature <0x%08x>\n",
+ le32_to_cpu(ndp16->dwSignature));
+ goto err_ndp;
+
+ }
+
+ dpe16 = ndp16->dpe16;
+ for (x = 0; x < nframes; x++, dpe16++) {
+ offset = le16_to_cpu(dpe16->wDatagramIndex);
+ len = le16_to_cpu(dpe16->wDatagramLength);
+
+ /*
+ * CDC NCM ch. 3.7
+ * All entries after first NULL entry are to be ignored
+ */
+ if ((offset == 0) || (len == 0)) {
+ if (!x)
+ goto err_ndp; /* empty NTB */
+ break;
+ }
+
+ /* sanity checking */
+ if (((offset + len) > skb_in->len) || (len > ctx->rx_max) ||
+ (len < sizeof(struct iphdr))) {
+ netif_dbg(dev, rx_err, dev->net,
+ "invalid frame detected (ignored) offset[%u]=%u, length=%u, skb=%p\n",
+ x, offset, len, skb_in);
+ if (!x)
+ goto err_ndp;
+ break;
+ } else {
+ skb = cdc_mbim_process_dgram(dev, skb_in->data + offset, len);
+ if (!skb)
+ goto error;
+ usbnet_skb_return(dev, skb);
+ }
+ }
+err_ndp:
+ /* are there more NDPs to process? */
+ ndpoffset = le16_to_cpu(ndp16->wNextNdpIndex);
+ if (ndpoffset && loopcount--)
+ goto next_ndp;
+
+ return 1;
+error:
+ return 0;
+}
+
+static int cdc_mbim_suspend(struct usb_interface *intf, pm_message_t message)
+{
+ int ret = 0;
+ struct usbnet *dev = usb_get_intfdata(intf);
+ struct cdc_mbim_state *info = (void *)&dev->data;
+ struct cdc_ncm_ctx *ctx = info->ctx;
+
+ if (ctx == NULL) {
+ ret = -1;
+ goto error;
+ }
+
+ ret = usbnet_suspend(intf, message);
+ if (ret < 0)
+ goto error;
+
+ if (intf == ctx->control && info->subdriver && info->subdriver->suspend)
+ ret = info->subdriver->suspend(intf, message);
+ if (ret < 0)
+ usbnet_resume(intf);
+
+error:
+ return ret;
+}
+
+static int cdc_mbim_resume(struct usb_interface *intf)
+{
+ int ret = 0;
+ struct usbnet *dev = usb_get_intfdata(intf);
+ struct cdc_mbim_state *info = (void *)&dev->data;
+ struct cdc_ncm_ctx *ctx = info->ctx;
+ bool callsub = (intf == ctx->control && info->subdriver && info->subdriver->resume);
+
+ if (callsub)
+ ret = info->subdriver->resume(intf);
+ if (ret < 0)
+ goto err;
+ ret = usbnet_resume(intf);
+ if (ret < 0 && callsub && info->subdriver->suspend)
+ info->subdriver->suspend(intf, PMSG_SUSPEND);
+err:
+ return ret;
+}
+
+static const struct driver_info cdc_mbim_info = {
+ .description = "CDC MBIM",
+ .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
+ .bind = cdc_mbim_bind,
+ .unbind = cdc_mbim_unbind,
+ .manage_power = cdc_mbim_manage_power,
+ .rx_fixup = cdc_mbim_rx_fixup,
+ .tx_fixup = cdc_mbim_tx_fixup,
+};
+
+static const struct usb_device_id mbim_devs[] = {
+ /* This duplicate NCM entry is intentional. MBIM devices can
+ * be disguised as NCM by default, and this is necessary to
+ * allow us to bind the correct driver_info to such devices.
+ *
+ * bind() will sort out this for us, selecting the correct
+ * entry and reject the other
+ */
+ { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_NCM, USB_CDC_PROTO_NONE),
+ .driver_info = (unsigned long)&cdc_mbim_info,
+ },
+ { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
+ .driver_info = (unsigned long)&cdc_mbim_info,
+ },
+ {
+ },
+};
+MODULE_DEVICE_TABLE(usb, mbim_devs);
+
+static struct usb_driver cdc_mbim_driver = {
+ .name = "cdc_mbim",
+ .id_table = mbim_devs,
+ .probe = usbnet_probe,
+ .disconnect = usbnet_disconnect,
+ .suspend = cdc_mbim_suspend,
+ .resume = cdc_mbim_resume,
+ .reset_resume = cdc_mbim_resume,
+ .supports_autosuspend = 1,
+ .disable_hub_initiated_lpm = 1,
+};
+module_usb_driver(cdc_mbim_driver);
+
+MODULE_AUTHOR("Greg Suarez <gpsuarez2512@gmail.com>");
+MODULE_AUTHOR("Bjørn Mork <bjorn@mork.no>");
+MODULE_DESCRIPTION("USB CDC MBIM host driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index e7ef5ce37be..fde2cc02b5f 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -36,6 +36,12 @@
* SUCH DAMAGE.
*/
+#define CDC_NCM_COMM_ALTSETTING_NCM 0
+#define CDC_NCM_COMM_ALTSETTING_MBIM 1
+
+#define CDC_NCM_DATA_ALTSETTING_NCM 1
+#define CDC_NCM_DATA_ALTSETTING_MBIM 2
+
/* CDC NCM subclass 3.2.1 */
#define USB_CDC_NCM_NDP16_LENGTH_MIN 0x10
@@ -74,6 +80,10 @@
(sizeof(struct usb_cdc_ncm_ndp16) + \
(CDC_NCM_DPT_DATAGRAMS_MAX + 1) * sizeof(struct usb_cdc_ncm_dpe16))
+#define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \
+ (x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE)
+#define cdc_ncm_data_intf_is_mbim(x) ((x)->desc.bInterfaceProtocol == USB_CDC_MBIM_PROTO_NTB)
+
struct cdc_ncm_ctx {
struct usb_cdc_ncm_ntb_parameters ncm_parm;
struct hrtimer tx_timer;