/* huawei_cdc_ncm.c - handles Huawei devices using the CDC NCM protocol as
* transport layer.
* Copyright (C) 2013 Enrico Mioso <mrkiko.rs@gmail.com>
*
*
* ABSTRACT:
* This driver handles devices resembling the CDC NCM standard, but
* encapsulating another protocol inside it. An example are some Huawei 3G
* devices, exposing an embedded AT channel where you can set up the NCM
* connection.
* This code has been heavily inspired by the cdc_mbim.c driver, which is
* Copyright (c) 2012 Smith Micro Software, Inc.
* Copyright (c) 2012 Bjørn Mork <bjorn@mork.no>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*/
#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>
/* 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;
if ((on && atomic_add_return(1, &drvstate->pmcount) == 1) ||
(!on && atomic_dec_and_test(&drvstate->pmcount))) {
rv = usb_autopm_get_interface(usbnet_dev->intf);
usbnet_dev->intf->needs_remote_wakeup = on;
if (!rv)
usb_autopm_put_interface(usbnet_dev->intf);
}
return 0;
}
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);
}
static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
struct usb_interface *intf)
{
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;
int drvflags = 0;
/* altsetting should always be 1 for NCM devices - so we hard-coded
* it here. Some huawei devices will need the NDP part of the NCM package to
* be at the end of the frame.
*/
drvflags |= CDC_NCM_FLAG_NDP_TO_END;
/* Additionally, it has been reported that some Huawei E3372H devices, with
* firmware version 21.318.01.00.541, come out of reset in NTB32 format mode, hence
* needing to be set to the NTB16 one again.
*/
drvflags |= CDC_NCM_FLAG_RESET_NTB16;
ret = cdc_ncm_bind_common(usbnet_dev, intf, 1, drvflags);
if (ret)
goto err;
ctx = drvstate->ctx;
if (usbnet_dev->status)
/* The wMaxCommand buffer must be big enough to hold
* any message from the modem. Experience has shown
* that some replies are more than 256 bytes long
*/
subdriver = usb_cdc_wdm_register(ctx->control,
&usbnet_dev->status->desc,
1024, /* wMaxCommand */
huawei_cdc_ncm_wdm_manage_power);
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;
err:
return ret;
}
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;
if (drvstate->subdriver && drvstate->subdriver->disconnect)
drvstate->subdriver->disconnect(ctx->control);
drvstate->subdriver = NULL;
cdc_ncm_unbind(usbnet_dev, intf);
}
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 = -ENODEV;
goto error;
}
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;
}
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;
bool callsub;
struct cdc_ncm_ctx *ctx = drvstate->ctx;
/* should we call subdriver's resume function? */
callsub =
(intf == ctx->control &&
drvstate->subdriver &&
drvstate->subdriver->resume);
if (callsub)
ret = drvstate->subdriver->resume(intf);
if (ret < 0)
goto err;
ret = usbnet_resume(intf);
if (ret < 0 && callsub)
drvstate->subdriver->suspend(intf, PMSG_SUSPEND);
err:
return ret;
}
static const struct driver_info huawei_cdc_ncm_info = {
.description = "Huawei CDC NCM device",
.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,
.rx_fixup = cdc_ncm_rx_fixup,
.tx_fixup = cdc_ncm_tx_fixup,
};
static const struct usb_device_id huawei_cdc_ncm_devs[] = {
/* Huawei NCM devices disguised as vendor specific */
{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16),
.driver_info = (unsigned long)&huawei_cdc_ncm_info,
},
{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46),
.driver_info = (unsigned long)&huawei_cdc_ncm_info,
},
{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76),
.driver_info = (unsigned long)&huawei_cdc_ncm_info,
},
{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x03, 0x16),
.driver_info = (unsigned long)&huawei_cdc_ncm_info,
},
/* Terminating entry */
{
},
};
MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs);
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");
