Patchwork [PATCHv3,net-next,2/4] caif: Add support for CAIF over CDC NCM USB interface

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Submitter sjur.brandeland@stericsson.com
Date Dec. 4, 2011, 9:22 p.m.
Message ID <1323033775-3496-2-git-send-email-sjur.brandeland@stericsson.com>
Download mbox | patch
Permalink /patch/129195/
State Accepted
Delegated to: David Miller
Headers show

Comments

sjur.brandeland@stericsson.com - Dec. 4, 2011, 9:22 p.m.
NCM 1.0 does not support anything but Ethernet framing, hence
CAIF payload will be put into Ethernet frames.

Discovery is based on fixed USB vendor 0x04cc (ST-Ericsson),
product-id 0x230f (NCM). In this variant only CAIF payload is sent over
the NCM interface.

The CAIF stack (cfusbl.c) will when USB interface register first check if
we got a CDC NCM USB interface with the right VID, PID.
It will then read the device's Ethernet address and create a 'template'
Ethernet TX header, using a broadcast address as the destination address,
and EthType 0x88b5 (802.1 Local Experimental - vendor specific).

A protocol handler for 0x88b5 is setup for reception of CAIF frames from
the CDC NCM USB interface.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
---
Hi Dave,

>Please make this feature a tristate and make the init and exit
>routines executed via the normal modula_init()/module_exit()
>mechanisms.
>That way you don't need that dopey header file to export the
>init and exit routines, and you don't need to ifdef crap up the
>code CAIF code to invoke them.
Done.

Changes from V2:
o As suggested: Killed of header file and ifdefs, and made it tristate
o Renamed module name to caif_usb
o Exported a few functions
o Had to handle refcnt for caif_usb module when USB NCM device registers 
  and unregisters.

Regards,
Sjur

 net/caif/Kconfig        |   11 +++
 net/caif/Makefile       |    1 +
 net/caif/caif_dev.c     |    1 +
 net/caif/caif_usb.c     |  208 +++++++++++++++++++++++++++++++++++++++++++++++
 net/caif/cfpkt_skbuff.c |   12 +--
 5 files changed, 224 insertions(+), 9 deletions(-)
 create mode 100644 net/caif/caif_usb.c
David Miller - Dec. 5, 2011, 11:46 p.m.
From: Sjur Brændeland <sjur.brandeland@stericsson.com>
Date: Sun,  4 Dec 2011 22:22:53 +0100

> NCM 1.0 does not support anything but Ethernet framing, hence
> CAIF payload will be put into Ethernet frames.
> 
> Discovery is based on fixed USB vendor 0x04cc (ST-Ericsson),
> product-id 0x230f (NCM). In this variant only CAIF payload is sent over
> the NCM interface.
> 
> The CAIF stack (cfusbl.c) will when USB interface register first check if
> we got a CDC NCM USB interface with the right VID, PID.
> It will then read the device's Ethernet address and create a 'template'
> Ethernet TX header, using a broadcast address as the destination address,
> and EthType 0x88b5 (802.1 Local Experimental - vendor specific).
> 
> A protocol handler for 0x88b5 is setup for reception of CAIF frames from
> the CDC NCM USB interface.
> 
> Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>

Applied.
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Patch

diff --git a/net/caif/Kconfig b/net/caif/Kconfig
index 529750d..936361e 100644
--- a/net/caif/Kconfig
+++ b/net/caif/Kconfig
@@ -40,3 +40,14 @@  config CAIF_NETDEV
 	If you select to build it as a built-in then the main CAIF device must
 	also be a built-in.
 	If unsure say Y.
+
+config CAIF_USB
+	tristate "CAIF USB support"
+	depends on CAIF
+	default n
+	---help---
+	Say Y if you are using CAIF over USB CDC NCM.
+	This can be either built-in or a loadable module,
+	If you select to build it as a built-in then the main CAIF device must
+	also be a built-in.
+	If unsure say N.
diff --git a/net/caif/Makefile b/net/caif/Makefile
index ebcd4e7..cc2b511 100644
--- a/net/caif/Makefile
+++ b/net/caif/Makefile
@@ -10,5 +10,6 @@  caif-y := caif_dev.o \
 obj-$(CONFIG_CAIF) += caif.o
 obj-$(CONFIG_CAIF_NETDEV) += chnl_net.o
 obj-$(CONFIG_CAIF) += caif_socket.o
+obj-$(CONFIG_CAIF_USB) += caif_usb.o
 
 export-y := caif.o
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index f7e8c70..6acec19 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -262,6 +262,7 @@  void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
 	if (rcv_func)
 		*rcv_func = receive;
 }
+EXPORT_SYMBOL(caif_enroll_dev);
 
 /* notify Caif of device events */
 static int caif_device_notify(struct notifier_block *me, unsigned long what,
diff --git a/net/caif/caif_usb.c b/net/caif/caif_usb.c
new file mode 100644
index 0000000..f5db57c
--- /dev/null
+++ b/net/caif/caif_usb.c
@@ -0,0 +1,208 @@ 
+/*
+ * CAIF USB handler
+ * Copyright (C) ST-Ericsson AB 2011
+ * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/usbnet.h>
+#include <net/netns/generic.h>
+#include <net/caif/caif_dev.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+
+MODULE_LICENSE("GPL");
+
+#define CFUSB_PAD_DESCR_SZ 1	/* Alignment descriptor length */
+#define CFUSB_ALIGNMENT 4	/* Number of bytes to align. */
+#define CFUSB_MAX_HEADLEN (CFUSB_PAD_DESCR_SZ + CFUSB_ALIGNMENT-1)
+#define STE_USB_VID 0x04cc	/* USB Product ID for ST-Ericsson */
+#define STE_USB_PID_CAIF 0x2306	/* Product id for CAIF Modems */
+
+struct cfusbl {
+	struct cflayer layer;
+	u8 tx_eth_hdr[ETH_HLEN];
+};
+
+static bool pack_added;
+
+static int cfusbl_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 hpad;
+
+	/* Remove padding. */
+	cfpkt_extr_head(pkt, &hpad, 1);
+	cfpkt_extr_head(pkt, NULL, hpad);
+	return layr->up->receive(layr->up, pkt);
+}
+
+static int cfusbl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct caif_payload_info *info;
+	u8 hpad;
+	u8 zeros[CFUSB_ALIGNMENT];
+	struct sk_buff *skb;
+	struct cfusbl *usbl = container_of(layr, struct cfusbl, layer);
+
+	skb = cfpkt_tonative(pkt);
+
+	skb_reset_network_header(skb);
+	skb->protocol = htons(ETH_P_IP);
+
+	info = cfpkt_info(pkt);
+	hpad = (info->hdr_len + CFUSB_PAD_DESCR_SZ) & (CFUSB_ALIGNMENT - 1);
+
+	if (skb_headroom(skb) < ETH_HLEN + CFUSB_PAD_DESCR_SZ + hpad) {
+		pr_warn("Headroom to small\n");
+		kfree_skb(skb);
+		return -EIO;
+	}
+	memset(zeros, 0, hpad);
+
+	cfpkt_add_head(pkt, zeros, hpad);
+	cfpkt_add_head(pkt, &hpad, 1);
+	cfpkt_add_head(pkt, usbl->tx_eth_hdr, sizeof(usbl->tx_eth_hdr));
+	return layr->dn->transmit(layr->dn, pkt);
+}
+
+static void cfusbl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+					int phyid)
+{
+	if (layr->up && layr->up->ctrlcmd)
+		layr->up->ctrlcmd(layr->up, ctrl, layr->id);
+}
+
+struct cflayer *cfusbl_create(int phyid, u8 ethaddr[ETH_ALEN],
+					u8 braddr[ETH_ALEN])
+{
+	struct cfusbl *this = kmalloc(sizeof(struct cfusbl), GFP_ATOMIC);
+
+	if (!this) {
+		pr_warn("Out of memory\n");
+		return NULL;
+	}
+	caif_assert(offsetof(struct cfusbl, layer) == 0);
+
+	memset(this, 0, sizeof(struct cflayer));
+	this->layer.receive = cfusbl_receive;
+	this->layer.transmit = cfusbl_transmit;
+	this->layer.ctrlcmd = cfusbl_ctrlcmd;
+	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "usb%d", phyid);
+	this->layer.id = phyid;
+
+	/*
+	 * Construct TX ethernet header:
+	 *	0-5	destination address
+	 *	5-11	source address
+	 *	12-13	protocol type
+	 */
+	memcpy(&this->tx_eth_hdr[ETH_ALEN], braddr, ETH_ALEN);
+	memcpy(&this->tx_eth_hdr[ETH_ALEN], ethaddr, ETH_ALEN);
+	this->tx_eth_hdr[12] = cpu_to_be16(ETH_P_802_EX1) & 0xff;
+	this->tx_eth_hdr[13] = (cpu_to_be16(ETH_P_802_EX1) >> 8) & 0xff;
+	pr_debug("caif ethernet TX-header dst:%pM src:%pM type:%02x%02x\n",
+			this->tx_eth_hdr, this->tx_eth_hdr + ETH_ALEN,
+			this->tx_eth_hdr[12], this->tx_eth_hdr[13]);
+
+	return (struct cflayer *) this;
+}
+
+static struct packet_type caif_usb_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_802_EX1),
+};
+
+static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
+			      void *arg)
+{
+	struct net_device *dev = arg;
+	struct caif_dev_common common;
+	struct cflayer *layer, *link_support;
+	struct usbnet	*usbnet = netdev_priv(dev);
+	struct usb_device	*usbdev = usbnet->udev;
+	struct ethtool_drvinfo drvinfo;
+
+	/*
+	 * Quirks: High-jack ethtool to find if we have a NCM device,
+	 * and find it's VID/PID.
+	 */
+	if (dev->ethtool_ops == NULL || dev->ethtool_ops->get_drvinfo == NULL)
+		return 0;
+
+	dev->ethtool_ops->get_drvinfo(dev, &drvinfo);
+	if (strncmp(drvinfo.driver, "cdc_ncm", 7) != 0)
+		return 0;
+
+	pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n",
+		le16_to_cpu(usbdev->descriptor.idVendor),
+		le16_to_cpu(usbdev->descriptor.idProduct));
+
+	/* Check for VID/PID that supports CAIF */
+	if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID &&
+		le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF))
+		return 0;
+
+	if (what == NETDEV_UNREGISTER)
+		module_put(THIS_MODULE);
+
+	if (what != NETDEV_REGISTER)
+		return 0;
+
+	__module_get(THIS_MODULE);
+
+	memset(&common, 0, sizeof(common));
+	common.use_frag = false;
+	common.use_fcs = false;
+	common.use_stx = false;
+	common.link_select = CAIF_LINK_HIGH_BANDW;
+	common.flowctrl = NULL;
+
+	link_support = cfusbl_create(dev->ifindex, dev->dev_addr,
+					dev->broadcast);
+
+	if (!link_support)
+		return -ENOMEM;
+
+	if (dev->num_tx_queues > 1)
+		pr_warn("USB device uses more than one tx queue\n");
+
+	caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
+			&layer, &caif_usb_type.func);
+	if (!pack_added)
+		dev_add_pack(&caif_usb_type);
+	pack_added = 1;
+
+	strncpy(layer->name, dev->name,
+			sizeof(layer->name) - 1);
+	layer->name[sizeof(layer->name) - 1] = 0;
+
+	return 0;
+}
+
+static struct notifier_block caif_device_notifier = {
+	.notifier_call = cfusbl_device_notify,
+	.priority = 0,
+};
+
+static int __init cfusbl_init(void)
+{
+	return register_netdevice_notifier(&caif_device_notifier);
+}
+
+static void __exit cfusbl_exit(void)
+{
+	unregister_netdevice_notifier(&caif_device_notifier);
+	dev_remove_pack(&caif_usb_type);
+}
+
+module_init(cfusbl_init);
+module_exit(cfusbl_exit);
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
index de53907..e335ba8 100644
--- a/net/caif/cfpkt_skbuff.c
+++ b/net/caif/cfpkt_skbuff.c
@@ -63,7 +63,6 @@  static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
 	return (struct cfpkt *) skb;
 }
 
-
 struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
 {
 	struct cfpkt *pkt = skb_to_pkt(nativepkt);
@@ -105,14 +104,12 @@  void cfpkt_destroy(struct cfpkt *pkt)
 	kfree_skb(skb);
 }
 
-
 inline bool cfpkt_more(struct cfpkt *pkt)
 {
 	struct sk_buff *skb = pkt_to_skb(pkt);
 	return skb->len > 0;
 }
 
-
 int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len)
 {
 	struct sk_buff *skb = pkt_to_skb(pkt);
@@ -148,6 +145,7 @@  int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
 		memcpy(data, from, len);
 	return 0;
 }
+EXPORT_SYMBOL(cfpkt_extr_head);
 
 int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
 {
@@ -171,13 +169,11 @@  int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
 	return 0;
 }
 
-
 int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
 {
 	return cfpkt_add_body(pkt, NULL, len);
 }
 
-
 int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
 {
 	struct sk_buff *skb = pkt_to_skb(pkt);
@@ -256,21 +252,19 @@  int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
 	memcpy(to, data, len);
 	return 0;
 }
-
+EXPORT_SYMBOL(cfpkt_add_head);
 
 inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
 {
 	return cfpkt_add_body(pkt, data, len);
 }
 
-
 inline u16 cfpkt_getlen(struct cfpkt *pkt)
 {
 	struct sk_buff *skb = pkt_to_skb(pkt);
 	return skb->len;
 }
 
-
 inline u16 cfpkt_iterate(struct cfpkt *pkt,
 			    u16 (*iter_func)(u16, void *, u16),
 			    u16 data)
@@ -288,7 +282,6 @@  inline u16 cfpkt_iterate(struct cfpkt *pkt,
 	return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
 }
 
-
 int cfpkt_setlen(struct cfpkt *pkt, u16 len)
 {
 	struct sk_buff *skb = pkt_to_skb(pkt);
@@ -400,3 +393,4 @@  struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
 {
 	return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
 }
+EXPORT_SYMBOL(cfpkt_info);