drivers/net/wimax/i2400m/i2400m-usb.h

   1 /*
   2  * Intel Wireless WiMAX Connection 2400m
   3  * USB-specific i2400m driver definitions
   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  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  37  * Yanir Lubetkin <yanirx.lubetkin@intel.com>
  38  *  - Initial implementation
  39  *
  40  *
  41  * This driver implements the bus-specific part of the i2400m for
  42  * USB. Check i2400m.h for a generic driver description.
  43  *
  44  * ARCHITECTURE
  45  *
  46  * This driver listens to notifications sent from the notification
  47  * endpoint (in usb-notif.c); when data is ready to read, the code in
  48  * there schedules a read from the device (usb-rx.c) and then passes
  49  * the data to the generic RX code (rx.c).
  50  *
  51  * When the generic driver needs to send data (network or control), it
  52  * queues up in the TX FIFO (tx.c) and that will notify the driver
  53  * through the i2400m->bus_tx_kick() callback
  54  * (usb-tx.c:i2400mu_bus_tx_kick) which will send the items in the
  55  * FIFO queue.
  56  *
  57  * This driver, as well, implements the USB-specific ops for the generic
  58  * driver to be able to setup/teardown communication with the device
  59  * [i2400m_bus_dev_start() and i2400m_bus_dev_stop()], reseting the
  60  * device [i2400m_bus_reset()] and performing firmware upload
  61  * [i2400m_bus_bm_cmd() and i2400_bus_bm_wait_for_ack()].
  62  */
  63
  64 #ifndef __I2400M_USB_H__
  65 #define __I2400M_USB_H__
  66
  67 #include "i2400m.h"
  68 #include <linux/kthread.h>
  69
  70
  71 /*
  72  * Error Density Count: cheapo error density (over time) counter
  73  *
  74  * Originally by Reinette Chatre <reinette.chatre@intel.com>
  75  *
  76  * Embed an 'struct edc' somewhere. Each time there is a soft or
  77  * retryable error, call edc_inc() and check if the error top
  78  * watermark has been reached.
  79  */
  80 enum {
  81         EDC_MAX_ERRORS = 10,
  82         EDC_ERROR_TIMEFRAME = HZ,
  83 };
  84
  85 /* error density counter */
  86 struct edc {
  87         unsigned long timestart;
  88         u16 errorcount;
  89 };
  90
  91 static inline void edc_init(struct edc *edc)
  92 {
  93         edc->timestart = jiffies;
  94 }
  95
  96 /**
  97  * edc_inc - report a soft error and check if we are over the watermark
  98  *
  99  * @edc: pointer to error density counter.
 100  * @max_err: maximum number of errors we can accept over the timeframe
 101  * @timeframe: lenght of the timeframe (in jiffies).
 102  *
 103  * Returns: !0 1 if maximum acceptable errors per timeframe has been
 104  *     exceeded. 0 otherwise.
 105  *
 106  * This is way to determine if the number of acceptable errors per time
 107  * period has been exceeded. It is not accurate as there are cases in which
 108  * this scheme will not work, for example if there are periodic occurences
 109  * of errors that straddle updates to the start time. This scheme is
 110  * sufficient for our usage.
 111  *
 112  * To use, embed a 'struct edc' somewhere, initialize it with
 113  * edc_init() and when an error hits:
 114  *
 115  * if (do_something_fails_with_a_soft_error) {
 116  *        if (edc_inc(&my->edc, MAX_ERRORS, MAX_TIMEFRAME))
 117  *                 Ops, hard error, do something about it
 118  *        else
 119  *                 Retry or ignore, depending on whatever
 120  * }
 121  */
 122 static inline int edc_inc(struct edc *edc, u16 max_err, u16 timeframe)
 123 {
 124         unsigned long now;
 125
 126         now = jiffies;
 127         if (now - edc->timestart > timeframe) {
 128                 edc->errorcount = 1;
 129                 edc->timestart = now;
 130         } else if (++edc->errorcount > max_err) {
 131                 edc->errorcount = 0;
 132                 edc->timestart = now;
 133                 return 1;
 134         }
 135         return 0;
 136 }
 137
 138 /* Host-Device interface for USB */
 139 enum {
 140         I2400MU_MAX_NOTIFICATION_LEN = 256,
 141         I2400MU_BLK_SIZE = 16,
 142         I2400MU_PL_SIZE_MAX = 0x3EFF,
 143
 144         /* Endpoints */
 145         I2400MU_EP_BULK_OUT = 0,
 146         I2400MU_EP_NOTIFICATION,
 147         I2400MU_EP_RESET_COLD,
 148         I2400MU_EP_BULK_IN,
 149 };
 150
 151
 152 /**
 153  * struct i2400mu - descriptor for a USB connected i2400m
 154  *
 155  * @i2400m: bus-generic i2400m implementation; has to be first (see
 156  *     it's documentation in i2400m.h).
 157  *
 158  * @usb_dev: pointer to our USB device
 159  *
 160  * @usb_iface: pointer to our USB interface
 161  *
 162  * @urb_edc: error density counter; used to keep a density-on-time tab
 163  *     on how many soft (retryable or ignorable) errors we get. If we
 164  *     go over the threshold, we consider the bus transport is failing
 165  *     too much and reset.
 166  *
 167  * @notif_urb: URB for receiving notifications from the device.
 168  *
 169  * @tx_kthread: thread we use for data TX. We use a thread because in
 170  *     order to do deep power saving and put the device to sleep, we
 171  *     need to call usb_autopm_*() [blocking functions].
 172  *
 173  * @tx_wq: waitqueue for the TX kthread to sleep when there is no data
 174  *     to be sent; when more data is available, it is woken up by
 175  *     i2400mu_bus_tx_kick().
 176  *
 177  * @rx_kthread: thread we use for data RX. We use a thread because in
 178  *     order to do deep power saving and put the device to sleep, we
 179  *     need to call usb_autopm_*() [blocking functions].
 180  *
 181  * @rx_wq: waitqueue for the RX kthread to sleep when there is no data
 182  *     to receive. When data is available, it is woken up by
 183  *     usb-notif.c:i2400mu_notification_grok().
 184  *
 185  * @rx_pending_count: number of rx-data-ready notifications that were
 186  *     still not handled by the RX kthread.
 187  *
 188  * @rx_size: current RX buffer size that is being used.
 189  *
 190  * @rx_size_acc: accumulator of the sizes of the previous read
 191  *     transactions.
 192  *
 193  * @rx_size_cnt: number of read transactions accumulated in
 194  *     @rx_size_acc.
 195  *
 196  * @do_autopm: disable(0)/enable(>0) calling the
 197  *     usb_autopm_get/put_interface() barriers when executing
 198  *     commands. See doc in i2400mu_suspend() for more information.
 199  *
 200  * @rx_size_auto_shrink: if true, the rx_size is shrinked
 201  *     automatically based on the average size of the received
 202  *     transactions. This allows the receive code to allocate smaller
 203  *     chunks of memory and thus reduce pressure on the memory
 204  *     allocator by not wasting so much space. By default it is
 205  *     enabled.
 206  *
 207  * @debugfs_dentry: hookup for debugfs files.
 208  *     These have to be in a separate directory, a child of
 209  *     (wimax_dev->debugfs_dentry) so they can be removed when the
 210  *     module unloads, as we don't keep each dentry.
 211  */
 212 struct i2400mu {
 213         struct i2400m i2400m;           /* FIRST! See doc */
 214
 215         struct usb_device *usb_dev;
 216         struct usb_interface *usb_iface;
 217         struct edc urb_edc;             /* Error density counter */
 218
 219         struct urb *notif_urb;
 220         struct task_struct *tx_kthread;
 221         wait_queue_head_t tx_wq;
 222
 223         struct task_struct *rx_kthread;
 224         wait_queue_head_t rx_wq;
 225         atomic_t rx_pending_count;
 226         size_t rx_size, rx_size_acc, rx_size_cnt;
 227         atomic_t do_autopm;
 228         u8 rx_size_auto_shrink;
 229
 230         struct dentry *debugfs_dentry;
 231 };
 232
 233
 234 static inline
 235 void i2400mu_init(struct i2400mu *i2400mu)
 236 {
 237         i2400m_init(&i2400mu->i2400m);
 238         edc_init(&i2400mu->urb_edc);
 239         init_waitqueue_head(&i2400mu->tx_wq);
 240         atomic_set(&i2400mu->rx_pending_count, 0);
 241         init_waitqueue_head(&i2400mu->rx_wq);
 242         i2400mu->rx_size = PAGE_SIZE - sizeof(struct skb_shared_info);
 243         atomic_set(&i2400mu->do_autopm, 1);
 244         i2400mu->rx_size_auto_shrink = 1;
 245 }
 246
 247 extern int i2400mu_notification_setup(struct i2400mu *);
 248 extern void i2400mu_notification_release(struct i2400mu *);
 249
 250 extern int i2400mu_rx_setup(struct i2400mu *);
 251 extern void i2400mu_rx_release(struct i2400mu *);
 252 extern void i2400mu_rx_kick(struct i2400mu *);
 253
 254 extern int i2400mu_tx_setup(struct i2400mu *);
 255 extern void i2400mu_tx_release(struct i2400mu *);
 256 extern void i2400mu_bus_tx_kick(struct i2400m *);
 257
 258 extern ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *,
 259                                        const struct i2400m_bootrom_header *,
 260                                        size_t, int);
 261 extern ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *,
 262                                            struct i2400m_bootrom_header *,
 263                                            size_t);
 264 #endif /* #ifndef __I2400M_USB_H__ */