linux/drivers/net/wimax/i2400m/i2400m-usb.h
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   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 */
  80enum {
  81        EDC_MAX_ERRORS = 10,
  82        EDC_ERROR_TIMEFRAME = HZ,
  83};
  84
  85/* error density counter */
  86struct edc {
  87        unsigned long timestart;
  88        u16 errorcount;
  89};
  90
  91struct i2400m_endpoint_cfg {
  92        unsigned char bulk_out;
  93        unsigned char notification;
  94        unsigned char reset_cold;
  95        unsigned char bulk_in;
  96};
  97
  98static inline void edc_init(struct edc *edc)
  99{
 100        edc->timestart = jiffies;
 101}
 102
 103/**
 104 * edc_inc - report a soft error and check if we are over the watermark
 105 *
 106 * @edc: pointer to error density counter.
 107 * @max_err: maximum number of errors we can accept over the timeframe
 108 * @timeframe: length of the timeframe (in jiffies).
 109 *
 110 * Returns: !0 1 if maximum acceptable errors per timeframe has been
 111 *     exceeded. 0 otherwise.
 112 *
 113 * This is way to determine if the number of acceptable errors per time
 114 * period has been exceeded. It is not accurate as there are cases in which
 115 * this scheme will not work, for example if there are periodic occurrences
 116 * of errors that straddle updates to the start time. This scheme is
 117 * sufficient for our usage.
 118 *
 119 * To use, embed a 'struct edc' somewhere, initialize it with
 120 * edc_init() and when an error hits:
 121 *
 122 * if (do_something_fails_with_a_soft_error) {
 123 *        if (edc_inc(&my->edc, MAX_ERRORS, MAX_TIMEFRAME))
 124 *                 Ops, hard error, do something about it
 125 *        else
 126 *                 Retry or ignore, depending on whatever
 127 * }
 128 */
 129static inline int edc_inc(struct edc *edc, u16 max_err, u16 timeframe)
 130{
 131        unsigned long now;
 132
 133        now = jiffies;
 134        if (time_after(now, edc->timestart + timeframe)) {
 135                edc->errorcount = 1;
 136                edc->timestart = now;
 137        } else if (++edc->errorcount > max_err) {
 138                edc->errorcount = 0;
 139                edc->timestart = now;
 140                return 1;
 141        }
 142        return 0;
 143}
 144
 145/* Host-Device interface for USB */
 146enum {
 147        I2400M_USB_BOOT_RETRIES = 3,
 148        I2400MU_MAX_NOTIFICATION_LEN = 256,
 149        I2400MU_BLK_SIZE = 16,
 150        I2400MU_PL_SIZE_MAX = 0x3EFF,
 151
 152        /* Device IDs */
 153        USB_DEVICE_ID_I6050 = 0x0186,
 154        USB_DEVICE_ID_I6050_2 = 0x0188,
 155        USB_DEVICE_ID_I6150 = 0x07d6,
 156        USB_DEVICE_ID_I6150_2 = 0x07d7,
 157        USB_DEVICE_ID_I6150_3 = 0x07d9,
 158        USB_DEVICE_ID_I6250 = 0x0187,
 159};
 160
 161
 162/**
 163 * struct i2400mu - descriptor for a USB connected i2400m
 164 *
 165 * @i2400m: bus-generic i2400m implementation; has to be first (see
 166 *     it's documentation in i2400m.h).
 167 *
 168 * @usb_dev: pointer to our USB device
 169 *
 170 * @usb_iface: pointer to our USB interface
 171 *
 172 * @urb_edc: error density counter; used to keep a density-on-time tab
 173 *     on how many soft (retryable or ignorable) errors we get. If we
 174 *     go over the threshold, we consider the bus transport is failing
 175 *     too much and reset.
 176 *
 177 * @notif_urb: URB for receiving notifications from the device.
 178 *
 179 * @tx_kthread: thread we use for data TX. We use a thread because in
 180 *     order to do deep power saving and put the device to sleep, we
 181 *     need to call usb_autopm_*() [blocking functions].
 182 *
 183 * @tx_wq: waitqueue for the TX kthread to sleep when there is no data
 184 *     to be sent; when more data is available, it is woken up by
 185 *     i2400mu_bus_tx_kick().
 186 *
 187 * @rx_kthread: thread we use for data RX. We use a thread because in
 188 *     order to do deep power saving and put the device to sleep, we
 189 *     need to call usb_autopm_*() [blocking functions].
 190 *
 191 * @rx_wq: waitqueue for the RX kthread to sleep when there is no data
 192 *     to receive. When data is available, it is woken up by
 193 *     usb-notif.c:i2400mu_notification_grok().
 194 *
 195 * @rx_pending_count: number of rx-data-ready notifications that were
 196 *     still not handled by the RX kthread.
 197 *
 198 * @rx_size: current RX buffer size that is being used.
 199 *
 200 * @rx_size_acc: accumulator of the sizes of the previous read
 201 *     transactions.
 202 *
 203 * @rx_size_cnt: number of read transactions accumulated in
 204 *     @rx_size_acc.
 205 *
 206 * @do_autopm: disable(0)/enable(>0) calling the
 207 *     usb_autopm_get/put_interface() barriers when executing
 208 *     commands. See doc in i2400mu_suspend() for more information.
 209 *
 210 * @rx_size_auto_shrink: if true, the rx_size is shrunk
 211 *     automatically based on the average size of the received
 212 *     transactions. This allows the receive code to allocate smaller
 213 *     chunks of memory and thus reduce pressure on the memory
 214 *     allocator by not wasting so much space. By default it is
 215 *     enabled.
 216 *
 217 * @debugfs_dentry: hookup for debugfs files.
 218 *     These have to be in a separate directory, a child of
 219 *     (wimax_dev->debugfs_dentry) so they can be removed when the
 220 *     module unloads, as we don't keep each dentry.
 221 */
 222struct i2400mu {
 223        struct i2400m i2400m;           /* FIRST! See doc */
 224
 225        struct usb_device *usb_dev;
 226        struct usb_interface *usb_iface;
 227        struct edc urb_edc;             /* Error density counter */
 228        struct i2400m_endpoint_cfg endpoint_cfg;
 229
 230        struct urb *notif_urb;
 231        struct task_struct *tx_kthread;
 232        wait_queue_head_t tx_wq;
 233
 234        struct task_struct *rx_kthread;
 235        wait_queue_head_t rx_wq;
 236        atomic_t rx_pending_count;
 237        size_t rx_size, rx_size_acc, rx_size_cnt;
 238        atomic_t do_autopm;
 239        u8 rx_size_auto_shrink;
 240
 241        struct dentry *debugfs_dentry;
 242        unsigned i6050:1;       /* 1 if this is a 6050 based SKU */
 243};
 244
 245
 246static inline
 247void i2400mu_init(struct i2400mu *i2400mu)
 248{
 249        i2400m_init(&i2400mu->i2400m);
 250        edc_init(&i2400mu->urb_edc);
 251        init_waitqueue_head(&i2400mu->tx_wq);
 252        atomic_set(&i2400mu->rx_pending_count, 0);
 253        init_waitqueue_head(&i2400mu->rx_wq);
 254        i2400mu->rx_size = PAGE_SIZE - sizeof(struct skb_shared_info);
 255        atomic_set(&i2400mu->do_autopm, 1);
 256        i2400mu->rx_size_auto_shrink = 1;
 257}
 258
 259int i2400mu_notification_setup(struct i2400mu *);
 260void i2400mu_notification_release(struct i2400mu *);
 261
 262int i2400mu_rx_setup(struct i2400mu *);
 263void i2400mu_rx_release(struct i2400mu *);
 264void i2400mu_rx_kick(struct i2400mu *);
 265
 266int i2400mu_tx_setup(struct i2400mu *);
 267void i2400mu_tx_release(struct i2400mu *);
 268void i2400mu_bus_tx_kick(struct i2400m *);
 269
 270ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *,
 271                                const struct i2400m_bootrom_header *, size_t,
 272                                int);
 273ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *,
 274                                    struct i2400m_bootrom_header *, size_t);
 275#endif /* #ifndef __I2400M_USB_H__ */
 276