path: root/drivers/net/usb/cdc_ncm.c

/*
 * cdc_ncm.c
 *
 * Copyright (C) ST-Ericsson 2010-2012
 * Contact: Alexey Orishko <alexey.orishko@stericsson.com>
 * Original author: Hans Petter Selasky <hans.petter.selasky@stericsson.com>
 *
 * USB Host Driver for Network Control Model (NCM)
 * http://www.usb.org/developers/devclass_docs/NCM10.zip
 *
 * The NCM encoding, decoding and initialization logic
 * derives from FreeBSD 8.x. if_cdce.c and if_cdcereg.h
 *
 * This software is available to you under a choice of one of two
 * licenses. You may choose this file to be licensed under the terms
 * of the GNU General Public License (GPL) Version 2 or the 2-clause
 * BSD license listed below:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/ctype.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/crc32.h>
#include <linux/usb.h>
#include <linux/hrtimer.h>
#include <linux/atomic.h>
#include <linux/usb/usbnet.h>
#include <linux/usb/cdc.h>

#define	DRIVER_VERSION				"14-Mar-2012"

/* CDC NCM subclass 3.2.1 */
#define USB_CDC_NCM_NDP16_LENGTH_MIN		0x10

/* Maximum NTB length */
#define	CDC_NCM_NTB_MAX_SIZE_TX			32768	/* bytes */
#define	CDC_NCM_NTB_MAX_SIZE_RX			32768	/* bytes */

/* Minimum value for MaxDatagramSize, ch. 6.2.9 */
#define	CDC_NCM_MIN_DATAGRAM_SIZE		1514	/* bytes */

#define	CDC_NCM_MIN_TX_PKT			512	/* bytes */

/* Default value for MaxDatagramSize */
#define	CDC_NCM_MAX_DATAGRAM_SIZE		8192	/* bytes */

/*
 * Maximum amount of datagrams in NCM Datagram Pointer Table, not counting
 * the last NULL entry.
 */
#define	CDC_NCM_DPT_DATAGRAMS_MAX		40

/* Restart the timer, if amount of datagrams is less than given value */
#define	CDC_NCM_RESTART_TIMER_DATAGRAM_CNT	3
#define	CDC_NCM_TIMER_PENDING_CNT		2
#define CDC_NCM_TIMER_INTERVAL			(400UL * NSEC_PER_USEC)

/* The following macro defines the minimum header space */
#define	CDC_NCM_MIN_HDR_SIZE \
	(sizeof(struct usb_cdc_ncm_nth16) + sizeof(struct usb_cdc_ncm_ndp16) + \
	(CDC_NCM_DPT_DATAGRAMS_MAX + 1) * sizeof(struct usb_cdc_ncm_dpe16))

struct cdc_ncm_data {
	struct usb_cdc_ncm_nth16 nth16;
	struct usb_cdc_ncm_ndp16 ndp16;
	struct usb_cdc_ncm_dpe16 dpe16[CDC_NCM_DPT_DATAGRAMS_MAX + 1];
};

struct cdc_ncm_ctx {
	struct cdc_ncm_data tx_ncm;
	struct usb_cdc_ncm_ntb_parameters ncm_parm;
	struct hrtimer tx_timer;
	struct tasklet_struct bh;

	const struct usb_cdc_ncm_desc *func_desc;
	const struct usb_cdc_header_desc *header_desc;
	const struct usb_cdc_union_desc *union_desc;
	const struct usb_cdc_ether_desc *ether_desc;

	struct net_device *netdev;
	struct usb_device *udev;
	struct usb_host_endpoint *in_ep;
	struct usb_host_endpoint *out_ep;
	struct usb_host_endpoint *status_ep;
	struct usb_interface *intf;
	struct usb_interface *control;
	struct usb_interface *data;

	struct sk_buff *tx_curr_skb;
	struct sk_buff *tx_rem_skb;

	spinlock_t mtx;
	atomic_t stop;

	u32 tx_timer_pending;
	u32 tx_curr_offset;
	u32 tx_curr_last_offset;
	u32 tx_curr_frame_num;
	u32 rx_speed;
	u32 tx_speed;
	u32 rx_max;
	u32 tx_max;
	u32 max_datagram_size;
	u16 tx_max_datagrams;
	u16 tx_remainder;
	u16 tx_modulus;
	u16 tx_ndp_modulus;
	u16 tx_seq;
	u16 rx_seq;
	u16 connected;
};

static void cdc_ncm_txpath_bh(unsigned long param);
static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct