/*
* Intel Wireless WiMAX Connection 2400m over USB
* Notification handling
*
*
* Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*
*
* Intel Corporation <linux-wimax@intel.com>
* Yanir Lubetkin <yanirx.lubetkin@intel.com>
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
* - Initial implementation
*
*
* The notification endpoint is active when the device is not in boot
* mode; in here we just read and get notifications; based on those,
* we act to either reinitialize the device after a reboot or to
* submit a RX request.
*
* ROADMAP
*
* i2400mu_usb_notification_setup()
*
* i2400mu_usb_notification_release()
*
* i2400mu_usb_notification_cb() Called when a URB is ready
* i2400mu_notif_grok()
* i2400m_is_boot_barker()
* i2400m_dev_reset_handle()
* i2400mu_rx_kick()
*/
#include <linux/usb.h>
#include <linux/slab.h>
#include "i2400m-usb.h"
#define D_SUBMODULE notif
#include "usb-debug-levels.h"
static const
__le32 i2400m_ZERO_BARKER[4] = { 0, 0, 0, 0 };
/*
* Process a received notification
*
* In normal operation mode, we can only receive two types of payloads
* on the notification endpoint:
*
* - a reboot barker, we do a bootstrap (the device has reseted).
*
* - a block of zeroes: there is pending data in the IN endpoint
*/
static
int i2400mu_notification_grok(struct i2400mu *i2400mu, const void *buf,
size_t buf_len)
{
int ret;
struct device *dev = &i2400mu->usb_iface->dev;
struct i2400m *i2400m = &i2400mu->i2400m;
d_fnstart(4, dev, "(i2400m %p buf %p buf_len %zu)\n",
i2400mu, buf, buf_len);
ret = -EIO;
if (buf_len < sizeof(i2400m_ZERO_BARKER))
/* Not a bug, just ignore */
goto error_bad_size;
ret = 0;
if (!memcmp(i2400m_ZERO_BARKER, buf, sizeof(i2400m_ZERO_BARKER))) {
i2400mu_rx_kick(i2400mu);
goto out;
}
ret = i2400m_is_boot_barker(i2400m, buf, buf_len);
if (unlikely(ret >= 0))
ret = i2400m_dev_reset_handle(i2400m, "device rebooted");
else /* Unknown or unexpected data in the notif message */
i2400m_unknown_barker(i2400m, buf, buf_len);
error_bad_size:
out:
d_fnend(4, dev, "(i2400m %p buf %p buf_len %zu) = %d\n",
i2400mu, buf, buf_len, ret);
return ret;
}
/*
* URB callback for the notification endpoint
*
* @urb: the urb received from the notification endpoint
*
* This function will just process the USB side of the transaction,
* checking everything is fine, pass the processing to
* i2400m_notification_grok() and resubmit the URB.
*/
static
void i2400mu_notification_cb(struct urb *urb)
{
int ret;
struct i2400mu *i2400mu = urb->context;
struct device *dev = &i2400mu->usb_iface->dev;
d_fnstart(4, dev, "(urb %p status %d actual_length %d)\n",
urb, urb->status, urb->actual_length);
ret = urb->status;
switch (ret) {
case 0:
ret = i2400mu_notification_grok(i2400mu, urb->transfer_buffer,
urb->actual_length);
if (ret == -EIO && edc_inc(&i2400mu->urb_edc, EDC_MAX_ERRORS,
EDC_ERROR_TIMEFRAME))
goto error_exceeded;
if (ret == -ENOMEM) /* uff...power cycle? shutdown? */
goto error_exceeded;
break;
case -EINVAL: /* while removing driver */
case -ENODEV: /* dev disconnect ... */
case -ENOENT: /* ditto */
case -ESHUTDOWN: /* URB killed */
case -ECONNRESET: /* disconnection */
goto out; /* Notify around */
default: /* Some error? */
if (edc_inc(&i2400mu->urb_edc,
EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
goto error_exceeded;
dev_err(dev, "notification: URB error %d, retrying\n",
urb->status);
}
usb_mark_last_busy(i2400mu->usb_dev);
ret = usb_submit_urb(i2400mu->notif_urb, GFP_ATOMIC);
switch (ret) {
case 0:
case -EINVAL: /* while removing driver */
case -ENODEV: /* dev disconnect ... */
case -ENOENT: /* ditto */
case -ESHUTDOWN: /* URB killed */
case -ECONNRESET: /* disconnection */
break; /* just ignore */
default: /* Some error? */
dev_err(dev, "notification: cannot submit URB: %d\n", ret);
goto error_submit;
}
d_fnend(4, dev, "(urb %p status %d actual_length %d) = void\n",
urb, urb->status, urb->actual_length);
return;
error_exceeded:
dev_err(dev, "maximum errors in notification URB exceeded; "
"resetting device\n");
error_submit:
usb_queue_reset_device(i2400mu->usb_iface);
out:
d_fnend(4, dev, "(urb %p status %d actual_length %d) = void\n",
urb, urb->status, urb->actual_length);
return;
}
/*
* setup the notification endpoint
*
* @i2400m: device descriptor
*
* This procedure prepares the notification urb and handler for receiving
* unsolicited barkers from the device.
*/
int i2400mu_notification_setup(struct i2400mu *i2400mu)
{
struct device *dev = &i2400mu->usb_iface->dev;
int usb_pipe, ret = 0;
struct usb_endpoint_descriptor *epd;
char *buf;
d_fnstart(4, dev, "(i2400m %p)\n", i2400mu);
buf = kmalloc(I2400MU_MAX_NOTIFICATION_LEN, GFP_KERNEL | GFP_DMA);
if (buf == NULL) {
dev_err(dev, "notification: buffer allocation failed\n");
ret = -ENOMEM;
goto error_buf_alloc;
}
i2400mu->notif_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!i2400mu->notif_urb) {
ret = -ENOMEM;
dev_err(dev, "notification: cannot allocate URB\n");
goto error_alloc_urb;
}
epd = usb_get_epd(i2400mu->usb_iface,
i2400mu->endpoint_cfg.notification);
usb_pipe = usb_rcvintpipe(i2400mu->usb_dev, epd->bEndpointAddress);
usb_fill_int_urb(i2400mu->notif_urb, i2400mu->usb_dev, usb_pipe,
buf, I2400MU_MAX_NOTIFICATION_LEN,
i2400mu_notification_cb, i2400mu, epd->bInterval);
ret = usb_submit_urb(i2400mu->notif_urb, GFP_KERNEL);
if (ret != 0) {
dev_err(dev, "notification: cannot submit URB: %d\n", ret);
goto error_submit;
}
d_fnend(4, dev, "(i2400m %p) = %d\n", i2400mu, ret);
return ret;
error_submit:
usb_free_urb(i2400mu->notif_urb);
error_alloc_urb:
kfree(buf);
error_buf_alloc:
d_fnend(4, dev, "(i2400m %p) = %d\n", i2400mu, ret);
return ret;
}
/*
* Tear down of the notification mechanism
*
* @i2400m: device descriptor
*
* Kill the interrupt endpoint urb, free any allocated resources.
*
* We need to check if we have done it before as for example,
* _suspend() call this; if after a suspend() we get a _disconnect()
* (as the case is when hibernating), nothing bad happens.
*/
void i2400mu_notification_release(struct i2400mu *i2400mu)
{
struct device *dev = &i2400mu->usb_iface->dev;
d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
if (i2400mu->notif_urb != NULL) {
usb_kill_urb(i2400mu->notif_urb);
kfree(i2400mu->notif_urb->transfer_buffer);
usb_free_urb(i2400mu->notif_urb);
i2400mu->notif_urb = NULL;
}
d_fnend(4, dev, "(i2400mu %p)\n", i2400mu);
}
