3 files changed, 395 insertions, 0 deletions

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 9d4f9117260f..84d4608153c9 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -385,6 +385,16 @@ config USB_NET_CX82310_ETH
           router with USB ethernet port. This driver is for routers only,
           it will not work with ADSL modems (use cxacru driver instead).
 
+config USB_NET_KALMIA
+        tristate "Samsung Kalmia based LTE USB modem"
+        depends on USB_USBNET
+        help
+          Choose this option if you have a Samsung Kalmia based USB modem
+          as Samsung GT-B3730.
+
+          To compile this driver as a module, choose M here: the
+          module will be called kalmia.
+
 config USB_HSO
         tristate "Option USB High Speed Mobile Devices"
         depends on USB && RFKILL
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index c7ec8a5f0a90..c203fa21f6b1 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_USB_NET_MCS7830)	+= mcs7830.o
 obj-$(CONFIG_USB_USBNET)        += usbnet.o
 obj-$(CONFIG_USB_NET_INT51X1)   += int51x1.o
 obj-$(CONFIG_USB_CDC_PHONET)    += cdc-phonet.o
+obj-$(CONFIG_USB_NET_KALMIA)    += kalmia.o
 obj-$(CONFIG_USB_IPHETH)        += ipheth.o
 obj-$(CONFIG_USB_SIERRA_NET)    += sierra_net.o
 obj-$(CONFIG_USB_NET_CX82310_ETH)       += cx82310_eth.o
diff --git a/drivers/net/usb/kalmia.c b/drivers/net/usb/kalmia.c
new file mode 100644
index 000000000000..d965fb1e013e
--- /dev/null
+++ b/drivers/net/usb/kalmia.c
@@ -0,0 +1,384 @@
+/*
+ * USB network interface driver for Samsung Kalmia based LTE USB modem like the
+ * Samsung GT-B3730 and GT-B3710.
+ *
+ * Copyright (C) 2011 Marius Bjoernstad Kotsbak <marius@kotsbak.com>
+ *
+ * Sponsored by Quicklink Video Distribution Services Ltd.
+ *
+ * Based on the cdc_eem module.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ctype.h>
+#include <linux/ethtool.h>
+#include <linux/workqueue.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/crc32.h>
+#include <linux/usb/cdc.h>
+#include <linux/usb/usbnet.h>
+#include <linux/gfp.h>
+
+/*
+ * The Samsung Kalmia based LTE USB modems have a CDC ACM port for modem control
+ * handled by the "option" module and an ethernet data port handled by this
+ * module.
+ *
+ * The stick must first be switched into modem mode by usb_modeswitch
+ * or similar tool. Then the modem gets sent two initialization packets by
+ * this module, which gives the MAC address of the device. User space can then
+ * connect the modem using AT commands through the ACM port and then use
+ * DHCP on the network interface exposed by this module. Network packets are
+ * sent to and from the modem in a proprietary format discovered after watching
+ * the behavior of the windows driver for the modem.
+ *
+ * More information about the use of the modem is available in usb_modeswitch
+ * forum and the project page:
+ *
+ * http://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?t=465
+ * https://github.com/mkotsbak/Samsung-GT-B3730-linux-driver
+ */
+
+/* #define      DEBUG */
+/* #define      VERBOSE */
+
+#define KALMIA_HEADER_LENGTH 6
+#define KALMIA_ALIGN_SIZE 4
+#define KALMIA_USB_TIMEOUT 10000
+
+/*-------------------------------------------------------------------------*/
+
+static int
+kalmia_send_init_packet(struct usbnet *dev, u8 *init_msg, u8 init_msg_len,
+        u8 *buffer, u8 expected_len)
+{
+        int act_len;
+        int status;
+
+        netdev_dbg(dev->net, "Sending init packet");
+
+        status = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 0x02),
+                init_msg, init_msg_len, &act_len, KALMIA_USB_TIMEOUT);
+        if (status != 0) {
+                netdev_err(dev->net,
+                        "Error sending init packet. Status %i, length %i\n",
+                        status, act_len);
+                return status;
+        }
+        else if (act_len != init_msg_len) {
+                netdev_err(dev->net,
+                        "Did not send all of init packet. Bytes sent: %i",
+                        act_len);
+        }
+        else {
+                netdev_dbg(dev->net, "Successfully sent init packet.");
+        }
+
+        status = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 0x81),
+                buffer, expected_len, &act_len, KALMIA_USB_TIMEOUT);
+
+        if (status != 0)
+                netdev_err(dev->net,
+                        "Error receiving init result. Status %i, length %i\n",
+                        status, act_len);
+        else if (act_len != expected_len)
+                netdev_err(dev->net, "Unexpected init result length: %i\n",
+                        act_len);
+
+        return status;
+}
+
+static int
+kalmia_init_and_get_ethernet_addr(struct usbnet *dev, u8 *ethernet_addr)
+{
+        char init_msg_1[] =
+                { 0x57, 0x50, 0x04, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00,
+                0x00, 0x00 };
+        char init_msg_2[] =
+                { 0x57, 0x50, 0x04, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0xf4,
+                0x00, 0x00 };
+        char receive_buf[28];
+        int status;
+
+        status = kalmia_send_init_packet(dev, init_msg_1, sizeof(init_msg_1)
+                / sizeof(init_msg_1[0]), receive_buf, 24);
+        if (status != 0)
+                return status;
+
+        status = kalmia_send_init_packet(dev, init_msg_2, sizeof(init_msg_2)
+                / sizeof(init_msg_2[0]), receive_buf, 28);
+        if (status != 0)
+                return status;
+
+        memcpy(ethernet_addr, receive_buf + 10, ETH_ALEN);
+
+        return status;
+}
+
+static int
+kalmia_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+        u8 status;
+        u8 ethernet_addr[ETH_ALEN];
+
+        /* Don't bind to AT command interface */
+        if (intf->cur_altsetting->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+                return -EINVAL;
+
+        dev->in = usb_rcvbulkpipe(dev->udev, 0x81 & USB_ENDPOINT_NUMBER_MASK);
+        dev->out = usb_sndbulkpipe(dev->udev, 0x02 & USB_ENDPOINT_NUMBER_MASK);
+        dev->status = NULL;
+
+        dev->net->hard_header_len += KALMIA_HEADER_LENGTH;
+        dev->hard_mtu = 1400;
+        dev->rx_urb_size = dev->hard_mtu * 10; // Found as optimal after testing
+
+        status = kalmia_init_and_get_ethernet_addr(dev, ethernet_addr);
+
+        if (status < 0) {
+                usb_set_intfdata(intf, NULL);
+                usb_driver_release_interface(driver_of(intf), intf);
+                return status;
+        }
+
+        memcpy(dev->net->dev_addr, ethernet_addr, ETH_ALEN);
+        memcpy(dev->net->perm_addr, ethernet_addr, ETH_ALEN);
+
+        return status;
+}
+
+static struct sk_buff *
+kalmia_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
+{
+        struct sk_buff *skb2 = NULL;
+        u16 content_len;
+        unsigned char *header_start;
+        unsigned char ether_type_1, ether_type_2;
+        u8 remainder, padlen = 0;
+
+        if (!skb_cloned(skb)) {
+                int headroom = skb_headroom(skb);
+                int tailroom = skb_tailroom(skb);
+
+                if ((tailroom >= KALMIA_ALIGN_SIZE) && (headroom
+                        >= KALMIA_HEADER_LENGTH))
+                        goto done;
+
+                if ((headroom + tailroom) > (KALMIA_HEADER_LENGTH
+                        + KALMIA_ALIGN_SIZE)) {
+                        skb->data = memmove(skb->head + KALMIA_HEADER_LENGTH,
+                                skb->data, skb->len);
+                        skb_set_tail_pointer(skb, skb->len);
+                        goto done;
+                }
+        }
+
+        skb2 = skb_copy_expand(skb, KALMIA_HEADER_LENGTH,
+                KALMIA_ALIGN_SIZE, flags);
+        if (!skb2)
+                return NULL;
+
+        dev_kfree_skb_any(skb);
+        skb = skb2;
+
+        done: header_start = skb_push(skb, KALMIA_HEADER_LENGTH);
+        ether_type_1 = header_start[KALMIA_HEADER_LENGTH + 12];
+        ether_type_2 = header_start[KALMIA_HEADER_LENGTH + 13];
+
+        netdev_dbg(dev->net, "Sending etherType: %02x%02x", ether_type_1,
+                ether_type_2);
+
+        /* According to empiric data for data packages */
+        header_start[0] = 0x57;
+        header_start[1] = 0x44;
+        content_len = skb->len - KALMIA_HEADER_LENGTH;
+        header_start[2] = (content_len & 0xff); /* low byte */
+        header_start[3] = (content_len >> 8); /* high byte */
+
+        header_start[4] = ether_type_1;
+        header_start[5] = ether_type_2;
+
+        /* Align to 4 bytes by padding with zeros */
+        remainder = skb->len % KALMIA_ALIGN_SIZE;
+        if (remainder > 0) {
+                padlen = KALMIA_ALIGN_SIZE - remainder;
+                memset(skb_put(skb, padlen), 0, padlen);
+        }
+
+        netdev_dbg(
+                dev->net,
+                "Sending package with length %i and padding %i. Header: %02x:%02x:%02x:%02x:%02x:%02x.",
+                content_len, padlen, header_start[0], header_start[1],
+                header_start[2], header_start[3], header_start[4],
+                header_start[5]);
+
+        return skb;
+}
+
+static int
+kalmia_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
+{
+        /*
+         * Our task here is to strip off framing, leaving skb with one
+         * data frame for the usbnet framework code to process.
+         */
+        const u8 HEADER_END_OF_USB_PACKET[] =
+                { 0x57, 0x5a, 0x00, 0x00, 0x08, 0x00 };
+        const u8 EXPECTED_UNKNOWN_HEADER_1[] =
+                { 0x57, 0x43, 0x1e, 0x00, 0x15, 0x02 };
+        const u8 EXPECTED_UNKNOWN_HEADER_2[] =
+                { 0x57, 0x50, 0x0e, 0x00, 0x00, 0x00 };
+        u8 i = 0;
+
+        /* incomplete header? */
+        if (skb->len < KALMIA_HEADER_LENGTH)
+                return 0;
+
+        do {
+                struct sk_buff *skb2 = NULL;
+                u8 *header_start;
+                u16 usb_packet_length, ether_packet_length;
+                int is_last;
+
+                header_start = skb->data;
+
+                if (unlikely(header_start[0] != 0x57 || header_start[1] != 0x44)) {
+                        if (!memcmp(header_start, EXPECTED_UNKNOWN_HEADER_1,
+                                sizeof(EXPECTED_UNKNOWN_HEADER_1)) || !memcmp(
+                                header_start, EXPECTED_UNKNOWN_HEADER_2,
+                                sizeof(EXPECTED_UNKNOWN_HEADER_2))) {
+                                netdev_dbg(
+                                        dev->net,
+                                        "Received expected unknown frame header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n",
+                                        header_start[0], header_start[1],
+                                        header_start[2], header_start[3],
+                                        header_start[4], header_start[5],
+                                        skb->len - KALMIA_HEADER_LENGTH);
+                        }
+                        else {
+                                netdev_err(
+                                        dev->net,
+                                        "Received unknown frame header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n",
+                                        header_start[0], header_start[1],
+                                        header_start[2], header_start[3],
+                                        header_start[4], header_start[5],
+                                        skb->len - KALMIA_HEADER_LENGTH);
+                                return 0;
+                        }
+                }
+                else
+                        netdev_dbg(
+                                dev->net,
+                                "Received header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n",
+                                header_start[0], header_start[1], header_start[2],
+                                header_start[3], header_start[4], header_start[5],
+                                skb->len - KALMIA_HEADER_LENGTH);
+
+                /* subtract start header and end header */
+                usb_packet_length = skb->len - (2 * KALMIA_HEADER_LENGTH);
+                ether_packet_length = header_start[2] + (header_start[3] << 8);
+                skb_pull(skb, KALMIA_HEADER_LENGTH);
+
+                /* Some small packets misses end marker */
+                if (usb_packet_length < ether_packet_length) {
+                        ether_packet_length = usb_packet_length
+                                + KALMIA_HEADER_LENGTH;
+                        is_last = true;
+                }
+                else {
+                        netdev_dbg(dev->net, "Correct package length #%i", i
+                                + 1);
+
+                        is_last = (memcmp(skb->data + ether_packet_length,
+                                HEADER_END_OF_USB_PACKET,
+                                sizeof(HEADER_END_OF_USB_PACKET)) == 0);
+                        if (!is_last) {
+                                header_start = skb->data + ether_packet_length;
+                                netdev_dbg(
+                                        dev->net,
+                                        "End header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n",
+                                        header_start[0], header_start[1],
+                                        header_start[2], header_start[3],
+                                        header_start[4], header_start[5],
+                                        skb->len - KALMIA_HEADER_LENGTH);
+                        }
+                }
+
+                if (is_last) {
+                        skb2 = skb;
+                }
+                else {
+                        skb2 = skb_clone(skb, GFP_ATOMIC);
+                        if (unlikely(!skb2))
+                                return 0;
+                }
+
+                skb_trim(skb2, ether_packet_length);
+
+                if (is_last) {
+                        return 1;
+                }
+                else {
+                        usbnet_skb_return(dev, skb2);
+                        skb_pull(skb, ether_packet_length);
+                }
+
+                i++;
+        }
+        while (skb->len);
+
+        return 1;
+}
+
+static const struct driver_info kalmia_info = {
+        .description = "Samsung Kalmia LTE USB dongle",
+        .flags = FLAG_WWAN,
+        .bind = kalmia_bind,
+        .rx_fixup = kalmia_rx_fixup,
+        .tx_fixup = kalmia_tx_fixup
+};
+
+/*-------------------------------------------------------------------------*/
+
+static const struct usb_device_id products[] = {
+        /* The unswitched USB ID, to get the module auto loaded: */
+        { USB_DEVICE(0x04e8, 0x689a) },
+        /* The stick swithed into modem (by e.g. usb_modeswitch): */
+        { USB_DEVICE(0x04e8, 0x6889),
+                .driver_info = (unsigned long) &kalmia_info, },
+        { /* EMPTY == end of list */} };
+MODULE_DEVICE_TABLE( usb, products);
+
+static struct usb_driver kalmia_driver = {
+        .name = "kalmia",
+        .id_table = products,
+        .probe = usbnet_probe,
+        .disconnect = usbnet_disconnect,
+        .suspend = usbnet_suspend,
+        .resume = usbnet_resume
+};
+
+static int __init kalmia_init(void)
+{
+        return usb_register(&kalmia_driver);
+}
+module_init( kalmia_init);
+
+static void __exit kalmia_exit(void)
+{
+        usb_deregister(&kalmia_driver);
+}
+module_exit( kalmia_exit);
+
+MODULE_AUTHOR("Marius Bjoernstad Kotsbak <marius@kotsbak.com>");
+MODULE_DESCRIPTION("Samsung Kalmia USB network driver");
+MODULE_LICENSE("GPL");