diff options
Diffstat (limited to 'net/caif/caif_usb.c')
| -rw-r--r-- | net/caif/caif_usb.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/net/caif/caif_usb.c b/net/caif/caif_usb.c new file mode 100644 index 000000000..bf61ea4b8 --- /dev/null +++ b/net/caif/caif_usb.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CAIF USB handler + * Copyright (C) ST-Ericsson AB 2011 + * Author: Sjur Brendeland + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ + +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/slab.h> +#include <linux/mii.h> +#include <linux/usb.h> +#include <linux/usb/usbnet.h> +#include <linux/etherdevice.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 0x230f /* 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 too 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); +} + +static struct cflayer *cfusbl_create(int phyid, const u8 ethaddr[ETH_ALEN], + u8 braddr[ETH_ALEN]) +{ + struct cfusbl *this = kmalloc(sizeof(struct cfusbl), GFP_ATOMIC); + + if (!this) + return NULL; + + caif_assert(offsetof(struct cfusbl, layer) == 0); + + memset(&this->layer, 0, sizeof(this->layer)); + 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 + */ + ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], braddr); + ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], ethaddr); + 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 void cfusbl_release(struct cflayer *layer) +{ + kfree(layer); +} + +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 *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct caif_dev_common common; + struct cflayer *layer, *link_support; + struct usbnet *usbnet; + struct usb_device *usbdev; + int res; + + if (what == NETDEV_UNREGISTER && dev->reg_state >= NETREG_UNREGISTERED) + return 0; + + /* Check whether we have a NCM device, and find its VID/PID. */ + if (!(dev->dev.parent && dev->dev.parent->driver && + strcmp(dev->dev.parent->driver->name, "cdc_ncm") == 0)) + return 0; + + usbnet = netdev_priv(dev); + usbdev = usbnet->udev; + + 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"); + + res = caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN, + &layer, &caif_usb_type.func); + if (res) + goto err; + + if (!pack_added) + dev_add_pack(&caif_usb_type); + pack_added = true; + + strscpy(layer->name, dev->name, sizeof(layer->name)); + + return 0; +err: + cfusbl_release(link_support); + return res; +} + +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); |