[RFC,3/3] huawei_cdc_ncm base skeleton

Message ID	alpine.LNX.2.02.1307022213380.26010@eeeadesso
State	Superseded, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> Date: Tue, 2 Jul 2013 22:15:49 +0200 (CEST) From: Enrico Mioso <mrkiko.rs@gmail.com> To: Enrico Mioso <mrkiko.rs@gmail.com> cc: netdev@vger.kernel.org, =?ISO-8859-15?Q?Bj=F8rn_Mork?= <bjorn@mork.no> Subject: Re: [PATCH RFC 3/3] huawei_cdc_ncm base skeleton In-Reply-To: <alpine.LNX.2.02.1307022210470.26010@eeeadesso> Message-ID: <alpine.LNX.2.02.1307022213380.26010@eeeadesso> References: <alpine.LNX.2.02.1307021241380.8884@eeeadesso> <87wqp9xja5.fsf@nemi.mork.no> <alpine.LNX.2.02.1307021855270.19053@eeeadesso> <alpine.LNX.2.02.1307022202570.26010@eeeadesso> <alpine.LNX.2.02.1307022207060.26010@eeeadesso> <alpine.LNX.2.02.1307022210470.26010@eeeadesso> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: netdev-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/net/usb/huawei_cdc_ncm.c b/drivers/net/usb/huawei_cdc_ncm.c new file mode 100644 index 0000000..2e76c87 --- /dev/null +++ b/drivers/net/usb/huawei_cdc_ncm.c @@ -0,0 +1,239 @@ +/* + * huawei_cdc_ncm.c - handles hawei-style NCM devices. + * Copyright (C) Enrico Mioso <mrkiko.rs@gmail.com> + * This driver handles devices resembling the CDC NCM standard, but + * encapsulating another protocl inside it. An example are some Huawei modems. + * This code is based on the original cdc_ncm implementation, that is: + * 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/netdevice.h> +#include <linux/ethtool.h> +#include <linux/if_vlan.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> + +/* Specific driver data */ +struct huawei_cdc_ncm_state { + struct cdc_ncm_ctx *ctx; + atomic_t pmcount; + struct usb_driver *subdriver; + struct usb_interface *control; + struct usb_interface *data; +}; + +static int huawei_cdc_ncm_manage_power(struct usbnet *usbnet_dev, int on) +{ + struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; + int rv = 0; + + if ((on && atomic_add_return(1, &drvstate->pmcount) == 1) || (!on && atomic_dec_and_test(&drvstate->pmcount))) { + rv = usb_autopm_get_interface(usbnet_dev->intf); + if (rv < 0) + goto err; + usbnet_dev->intf->needs_remote_wakeup = on; + usb_autopm_put_interface(usbnet_dev->intf); + } +err: + return rv; +} + +static int huawei_cdc_ncm_wdm_manage_power(struct usb_interface *intf, int status) +{ + struct usbnet *usbnet_dev = usb_get_intfdata(intf); + + /* can be called while disconnecting */ + if (!usbnet_dev) + return 0; + + return huawei_cdc_ncm_manage_power(usbnet_dev, status); +} + + +/* Bind our driver to needed interfaces. Heavily inspired by cdc_mbim.c one! */ +static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev, struct usb_interface *intf) { + + /* Some general use variables */ + struct cdc_ncm_ctx *ctx; + struct usb_driver *subdriver = ERR_PTR(-ENODEV); + int ret = -ENODEV; + struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; + + /* Actually binds us to the device: use standard ncm function */ + ret = cdc_ncm_bind_common(usbnet_dev, intf, 1); /* altsetting should be 1 */ + + /* Did the ncm bind function fail? */ + if (ret) + goto err; + + /* Let cdc data ctx pointer point to our state structure */ + ctx = drvstate->ctx; + + if (usbnet_dev->status) + subdriver = usb_cdc_wdm_register(ctx->control, &usbnet_dev->status->desc, 4096, huawei_cdc_ncm_wdm_manage_power); /* a smarter way to calculate that constant? */ + if (IS_ERR(subdriver)) { + ret = PTR_ERR(subdriver); + cdc_ncm_unbind(usbnet_dev, intf); + goto err; + } + + /* Prevent usbnet from using the status descriptor */ + usbnet_dev->status = NULL; + + drvstate->subdriver = subdriver; + + /* FIXME: should we handle the vlan header in some way? */ + /* FIXME2: in my opinion we also could not do ARP, hoping somebody can help... */ +err: + return ret; /* ret = -ENODEV if not changed in the meanwhile */ +} + +static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev, struct usb_interface *intf) { + struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; + struct cdc_ncm_ctx *ctx = drvstate->ctx; + + /* Bye cdc-wdm! And see you soon! :) */ + if (drvstate->subdriver && drvstate->subdriver->disconnect) + drvstate->subdriver->disconnect(ctx->control); + drvstate->subdriver = NULL; + + /* Unbind from both control and data interface */ + cdc_ncm_unbind(usbnet_dev, intf); +} + +/* Suspend function - the logic has been taken from cdc_mbim.c directly. */ +static int huawei_cdc_ncm_suspend(struct usb_interface *intf, pm_message_t message) +{ + int ret = 0; + struct usbnet *usbnet_dev = usb_get_intfdata(intf); + struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; + struct cdc_ncm_ctx *ctx = drvstate->ctx; + + if (ctx == NULL) { + ret = -1; + goto error; + } + + /* + * Both usbnet_suspend() and subdriver->suspend() MUST return 0 + * in system sleep context, otherwise, the resume callback has + * to recover device from previous suspend failure. + */ + ret = usbnet_suspend(intf, message); + if (ret < 0) + goto error; + + if (intf == ctx->control && drvstate->subdriver && drvstate->subdriver->suspend) + ret = drvstate->subdriver->suspend(intf, message); + if (ret < 0) + usbnet_resume(intf); + +error: + return ret; +} + +/* Resume function - logic took completely from huawei_cdc.c */ +static int huawei_cdc_ncm_resume(struct usb_interface *intf) +{ + int ret = 0; + struct usbnet *usbnet_dev = usb_get_intfdata(intf); + struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; + struct cdc_ncm_ctx *ctx = drvstate->ctx; + bool callsub = (intf == ctx->control && drvstate->subdriver && drvstate->subdriver->resume); /* should we call subdriver's resume? ? */ + + if (callsub) + ret = drvstate->subdriver->resume(intf); + if (ret < 0) + goto err; + ret = usbnet_resume(intf); + if (ret < 0 && callsub && drvstate->subdriver->suspend) + drvstate->subdriver->suspend(intf, PMSG_SUSPEND); +err: + return ret; +} + + +/* General driver informations, exposed partly to modutils */ +static const struct driver_info huawei_cdc_ncm_info = { + .description = "Huawei-style CDC NCM", + .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN, + .bind = huawei_cdc_ncm_bind, + .unbind = huawei_cdc_ncm_unbind, + .manage_power = huawei_cdc_ncm_manage_power, + /* NCM RX and TX fixup functions work properly on these devices */ + .rx_fixup = cdc_ncm_rx_fixup, + .tx_fixup = cdc_ncm_tx_fixup, +}; + +static const struct usb_device_id huawei_cdc_ncm_devs[] = { + /* The correct NCM handling will be implemented. For now, only my dongle + will be handled. + */ + { USB_DEVICE_INTERFACE_NUMBER(0x12d1, 0x1506, 1), \ + .driver_info = (unsigned long)&huawei_cdc_ncm_info, + }, + + { + /* Terminating entry */ + }, +}; +/* Expose table in module info */ +MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs); + + +/* USB driver struct - used by USB stack */ +static struct usb_driver huawei_cdc_ncm_driver = { + .name = "huawei_cdc_ncm", + .id_table = huawei_cdc_ncm_devs, + .probe = usbnet_probe, + .disconnect = usbnet_disconnect, + .suspend = huawei_cdc_ncm_suspend, + .resume = huawei_cdc_ncm_resume, + .reset_resume = huawei_cdc_ncm_resume, + .supports_autosuspend = 1, + .disable_hub_initiated_lpm = 1, +}; +module_usb_driver(huawei_cdc_ncm_driver); +MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>"); +MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support"); +MODULE_LICENSE("GPL");

[RFC,3/3] huawei_cdc_ncm base skeleton

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