drivers/net/wimax/i2400m/usb-notif.c

   1 /*
   2  * Intel Wireless WiMAX Connection 2400m over USB
   3  * Notification handling
   4  *
   5  *
   6  * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  *   * Redistributions of source code must retain the above copyright
  13  *     notice, this list of conditions and the following disclaimer.
  14  *   * Redistributions in binary form must reproduce the above copyright
  15  *     notice, this list of conditions and the following disclaimer in
  16  *     the documentation and/or other materials provided with the
  17  *     distribution.
  18  *   * Neither the name of Intel Corporation nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  25  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  26  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  28  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  32  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  *
  35  * Intel Corporation <linux-wimax@intel.com>
  36  * Yanir Lubetkin <yanirx.lubetkin@intel.com>
  37  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  38  *  - Initial implementation
  39  *
  40  *
  41  * The notification endpoint is active when the device is not in boot
  42  * mode; in here we just read and get notifications; based on those,
  43  * we act to either reinitialize the device after a reboot or to
  44  * submit a RX request.
  45  *
  46  * ROADMAP
  47  *
  48  * i2400mu_usb_notification_setup()
  49  *
  50  * i2400mu_usb_notification_release()
  51  *
  52  * i2400mu_usb_notification_cb()        Called when a URB is ready
  53  *   i2400mu_notif_grok()
  54  *     i2400m_dev_reset_handle()
  55  *     i2400mu_rx_kick()
  56  */
  57 #include <linux/usb.h>
  58 #include "i2400m-usb.h"
  59
  60
  61 #define D_SUBMODULE notif
  62 #include "usb-debug-levels.h"
  63
  64
  65 static const
  66 __le32 i2400m_ZERO_BARKER[4] = { 0, 0, 0, 0 };
  67
  68
  69 /*
  70  * Process a received notification
  71  *
  72  * In normal operation mode, we can only receive two types of payloads
  73  * on the notification endpoint:
  74  *
  75  *   - a reboot barker, we do a bootstrap (the device has reseted).
  76  *
  77  *   - a block of zeroes: there is pending data in the IN endpoint
  78  */
  79 static
  80 int i2400mu_notification_grok(struct i2400mu *i2400mu, const void *buf,
  81                                  size_t buf_len)
  82 {
  83         int ret;
  84         struct device *dev = &i2400mu->usb_iface->dev;
  85         struct i2400m *i2400m = &i2400mu->i2400m;
  86
  87         d_fnstart(4, dev, "(i2400m %p buf %p buf_len %zu)\n",
  88                   i2400mu, buf, buf_len);
  89         ret = -EIO;
  90         if (buf_len < sizeof(i2400m_NBOOT_BARKER))
  91                 /* Not a bug, just ignore */
  92                 goto error_bad_size;
  93         if (!memcmp(i2400m_NBOOT_BARKER, buf, sizeof(i2400m_NBOOT_BARKER))
  94             || !memcmp(i2400m_SBOOT_BARKER, buf, sizeof(i2400m_SBOOT_BARKER)))
  95                 ret = i2400m_dev_reset_handle(i2400m);
  96         else if (!memcmp(i2400m_ZERO_BARKER, buf, sizeof(i2400m_ZERO_BARKER))) {
  97                 i2400mu_rx_kick(i2400mu);
  98                 ret = 0;
  99         } else {        /* Unknown or unexpected data in the notif message */
 100                 char prefix[64];
 101                 ret = -EIO;
 102                 dev_err(dev, "HW BUG? Unknown/unexpected data in notification "
 103                         "message (%zu bytes)\n", buf_len);
 104                 snprintf(prefix, sizeof(prefix), "%s %s: ",
 105                          dev_driver_string(dev), dev_name(dev));
 106                 if (buf_len > 64) {
 107                         print_hex_dump(KERN_ERR, prefix, DUMP_PREFIX_OFFSET,
 108                                        8, 4, buf, 64, 0);
 109                         printk(KERN_ERR "%s... (only first 64 bytes "
 110                                "dumped)\n", prefix);
 111                 } else
 112                         print_hex_dump(KERN_ERR, prefix, DUMP_PREFIX_OFFSET,
 113                                        8, 4, buf, buf_len, 0);
 114         }
 115 error_bad_size:
 116         d_fnend(4, dev, "(i2400m %p buf %p buf_len %zu) = %d\n",
 117                 i2400mu, buf, buf_len, ret);
 118         return ret;
 119 }
 120
 121
 122 /*
 123  * URB callback for the notification endpoint
 124  *
 125  * @urb: the urb received from the notification endpoint
 126  *
 127  * This function will just process the USB side of the transaction,
 128  * checking everything is fine, pass the processing to
 129  * i2400m_notification_grok() and resubmit the URB.
 130  */
 131 static
 132 void i2400mu_notification_cb(struct urb *urb)
 133 {
 134         int ret;
 135         struct i2400mu *i2400mu = urb->context;
 136         struct device *dev = &i2400mu->usb_iface->dev;
 137
 138         d_fnstart(4, dev, "(urb %p status %d actual_length %d)\n",
 139                   urb, urb->status, urb->actual_length);
 140         ret = urb->status;
 141         switch (ret) {
 142         case 0:
 143                 ret = i2400mu_notification_grok(i2400mu, urb->transfer_buffer,
 144                                                 urb->actual_length);
 145                 if (ret == -EIO && edc_inc(&i2400mu->urb_edc, EDC_MAX_ERRORS,
 146                                            EDC_ERROR_TIMEFRAME))
 147                         goto error_exceeded;
 148                 if (ret == -ENOMEM)     /* uff...power cycle? shutdown? */
 149                         goto error_exceeded;
 150                 break;
 151         case -EINVAL:                   /* while removing driver */
 152         case -ENODEV:                   /* dev disconnect ... */
 153         case -ENOENT:                   /* ditto */
 154         case -ESHUTDOWN:                /* URB killed */
 155         case -ECONNRESET:               /* disconnection */
 156                 goto out;               /* Notify around */
 157         default:                        /* Some error? */
 158                 if (edc_inc(&i2400mu->urb_edc,
 159                             EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
 160                         goto error_exceeded;
 161                 dev_err(dev, "notification: URB error %d, retrying\n",
 162                         urb->status);
 163         }
 164         usb_mark_last_busy(i2400mu->usb_dev);
 165         ret = usb_submit_urb(i2400mu->notif_urb, GFP_ATOMIC);
 166         switch (ret) {
 167         case 0:
 168         case -EINVAL:                   /* while removing driver */
 169         case -ENODEV:                   /* dev disconnect ... */
 170         case -ENOENT:                   /* ditto */
 171         case -ESHUTDOWN:                /* URB killed */
 172         case -ECONNRESET:               /* disconnection */
 173                 break;                  /* just ignore */
 174         default:                        /* Some error? */
 175                 dev_err(dev, "notification: cannot submit URB: %d\n", ret);
 176                 goto error_submit;
 177         }
 178         d_fnend(4, dev, "(urb %p status %d actual_length %d) = void\n",
 179                 urb, urb->status, urb->actual_length);
 180         return;
 181
 182 error_exceeded:
 183         dev_err(dev, "maximum errors in notification URB exceeded; "
 184                 "resetting device\n");
 185 error_submit:
 186         usb_queue_reset_device(i2400mu->usb_iface);
 187 out:
 188         d_fnend(4, dev, "(urb %p status %d actual_length %d) = void\n",
 189                 urb, urb->status, urb->actual_length);
 190         return;
 191 }
 192
 193
 194 /*
 195  * setup the notification endpoint
 196  *
 197  * @i2400m: device descriptor
 198  *
 199  * This procedure prepares the notification urb and handler for receiving
 200  * unsolicited barkers from the device.
 201  */
 202 int i2400mu_notification_setup(struct i2400mu *i2400mu)
 203 {
 204         struct device *dev = &i2400mu->usb_iface->dev;
 205         int usb_pipe, ret = 0;
 206         struct usb_endpoint_descriptor *epd;
 207         char *buf;
 208
 209         d_fnstart(4, dev, "(i2400m %p)\n", i2400mu);
 210         buf = kmalloc(I2400MU_MAX_NOTIFICATION_LEN, GFP_KERNEL | GFP_DMA);
 211         if (buf == NULL) {
 212                 dev_err(dev, "notification: buffer allocation failed\n");
 213                 ret = -ENOMEM;
 214                 goto error_buf_alloc;
 215         }
 216
 217         i2400mu->notif_urb = usb_alloc_urb(0, GFP_KERNEL);
 218         if (!i2400mu->notif_urb) {
 219                 ret = -ENOMEM;
 220                 dev_err(dev, "notification: cannot allocate URB\n");
 221                 goto error_alloc_urb;
 222         }
 223         epd = usb_get_epd(i2400mu->usb_iface, I2400MU_EP_NOTIFICATION);
 224         usb_pipe = usb_rcvintpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 225         usb_fill_int_urb(i2400mu->notif_urb, i2400mu->usb_dev, usb_pipe,
 226                          buf, I2400MU_MAX_NOTIFICATION_LEN,
 227                          i2400mu_notification_cb, i2400mu, epd->bInterval);
 228         ret = usb_submit_urb(i2400mu->notif_urb, GFP_KERNEL);
 229         if (ret != 0) {
 230                 dev_err(dev, "notification: cannot submit URB: %d\n", ret);
 231                 goto error_submit;
 232         }
 233         d_fnend(4, dev, "(i2400m %p) = %d\n", i2400mu, ret);
 234         return ret;
 235
 236 error_submit:
 237         usb_free_urb(i2400mu->notif_urb);
 238 error_alloc_urb:
 239         kfree(buf);
 240 error_buf_alloc:
 241         d_fnend(4, dev, "(i2400m %p) = %d\n", i2400mu, ret);
 242         return ret;
 243 }
 244
 245
 246 /*
 247  * Tear down of the notification mechanism
 248  *
 249  * @i2400m: device descriptor
 250  *
 251  * Kill the interrupt endpoint urb, free any allocated resources.
 252  *
 253  * We need to check if we have done it before as for example,
 254  * _suspend() call this; if after a suspend() we get a _disconnect()
 255  * (as the case is when hibernating), nothing bad happens.
 256  */
 257 void i2400mu_notification_release(struct i2400mu *i2400mu)
 258 {
 259         struct device *dev = &i2400mu->usb_iface->dev;
 260
 261         d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
 262         if (i2400mu->notif_urb != NULL) {
 263                 usb_kill_urb(i2400mu->notif_urb);
 264                 kfree(i2400mu->notif_urb->transfer_buffer);
 265                 usb_free_urb(i2400mu->notif_urb);
 266                 i2400mu->notif_urb = NULL;
 267         }
 268         d_fnend(4, dev, "(i2400mu %p)\n", i2400mu);
 269 }