linux/net/irda/qos.c
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   1/*********************************************************************
   2 *
   3 * Filename:      qos.c
   4 * Version:       1.0
   5 * Description:   IrLAP QoS parameter negotiation
   6 * Status:        Stable
   7 * Author:        Dag Brattli <dagb@cs.uit.no>
   8 * Created at:    Tue Sep  9 00:00:26 1997
   9 * Modified at:   Sun Jan 30 14:29:16 2000
  10 * Modified by:   Dag Brattli <dagb@cs.uit.no>
  11 *
  12 *     Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
  13 *     All Rights Reserved.
  14 *     Copyright (c) 2000-2001 Jean Tourrilhes <jt@hpl.hp.com>
  15 *
  16 *     This program is free software; you can redistribute it and/or
  17 *     modify it under the terms of the GNU General Public License as
  18 *     published by the Free Software Foundation; either version 2 of
  19 *     the License, or (at your option) any later version.
  20 *
  21 *     This program is distributed in the hope that it will be useful,
  22 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  24 *     GNU General Public License for more details.
  25 *
  26 *     You should have received a copy of the GNU General Public License
  27 *     along with this program; if not, see <http://www.gnu.org/licenses/>.
  28 *
  29 ********************************************************************/
  30
  31#include <linux/export.h>
  32
  33#include <asm/byteorder.h>
  34
  35#include <net/irda/irda.h>
  36#include <net/irda/parameters.h>
  37#include <net/irda/qos.h>
  38#include <net/irda/irlap.h>
  39#include <net/irda/irlap_frame.h>
  40
  41/*
  42 * Maximum values of the baud rate we negotiate with the other end.
  43 * Most often, you don't have to change that, because Linux-IrDA will
  44 * use the maximum offered by the link layer, which usually works fine.
  45 * In some very rare cases, you may want to limit it to lower speeds...
  46 */
  47int sysctl_max_baud_rate = 16000000;
  48/*
  49 * Maximum value of the lap disconnect timer we negotiate with the other end.
  50 * Most often, the value below represent the best compromise, but some user
  51 * may want to keep the LAP alive longer or shorter in case of link failure.
  52 * Remember that the threshold time (early warning) is fixed to 3s...
  53 */
  54int sysctl_max_noreply_time = 12;
  55/*
  56 * Minimum turn time to be applied before transmitting to the peer.
  57 * Nonzero values (usec) are used as lower limit to the per-connection
  58 * mtt value which was announced by the other end during negotiation.
  59 * Might be helpful if the peer device provides too short mtt.
  60 * Default is 10us which means using the unmodified value given by the
  61 * peer except if it's 0 (0 is likely a bug in the other stack).
  62 */
  63unsigned int sysctl_min_tx_turn_time = 10;
  64/*
  65 * Maximum data size to be used in transmission in payload of LAP frame.
  66 * There is a bit of confusion in the IrDA spec :
  67 * The LAP spec defines the payload of a LAP frame (I field) to be
  68 * 2048 bytes max (IrLAP 1.1, chapt 6.6.5, p40).
  69 * On the other hand, the PHY mention frames of 2048 bytes max (IrPHY
  70 * 1.2, chapt 5.3.2.1, p41). But, this number includes the LAP header
  71 * (2 bytes), and CRC (32 bits at 4 Mb/s). So, for the I field (LAP
  72 * payload), that's only 2042 bytes. Oups !
  73 * My nsc-ircc hardware has troubles receiving 2048 bytes frames at 4 Mb/s,
  74 * so adjust to 2042... I don't know if this bug applies only for 2048
  75 * bytes frames or all negotiated frame sizes, but you can use the sysctl
  76 * to play with this value anyway.
  77 * Jean II */
  78unsigned int sysctl_max_tx_data_size = 2042;
  79/*
  80 * Maximum transmit window, i.e. number of LAP frames between turn-around.
  81 * This allow to override what the peer told us. Some peers are buggy and
  82 * don't always support what they tell us.
  83 * Jean II */
  84unsigned int sysctl_max_tx_window = 7;
  85
  86static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get);
  87static int irlap_param_link_disconnect(void *instance, irda_param_t *parm,
  88                                       int get);
  89static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
  90                                     int get);
  91static int irlap_param_data_size(void *instance, irda_param_t *param, int get);
  92static int irlap_param_window_size(void *instance, irda_param_t *param,
  93                                   int get);
  94static int irlap_param_additional_bofs(void *instance, irda_param_t *parm,
  95                                       int get);
  96static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
  97                                     int get);
  98
  99#ifndef CONFIG_IRDA_DYNAMIC_WINDOW
 100static __u32 irlap_requested_line_capacity(struct qos_info *qos);
 101#endif
 102
 103static __u32 min_turn_times[]  = { 10000, 5000, 1000, 500, 100, 50, 10, 0 }; /* us */
 104static __u32 baud_rates[]      = { 2400, 9600, 19200, 38400, 57600, 115200, 576000,
 105                                   1152000, 4000000, 16000000 };           /* bps */
 106static __u32 data_sizes[]      = { 64, 128, 256, 512, 1024, 2048 };        /* bytes */
 107static __u32 add_bofs[]        = { 48, 24, 12, 5, 3, 2, 1, 0 };            /* bytes */
 108static __u32 max_turn_times[]  = { 500, 250, 100, 50 };                    /* ms */
 109static __u32 link_disc_times[] = { 3, 8, 12, 16, 20, 25, 30, 40 };         /* secs */
 110
 111static __u32 max_line_capacities[10][4] = {
 112       /* 500 ms     250 ms  100 ms  50 ms (max turn time) */
 113        {    100,      0,      0,     0 }, /*     2400 bps */
 114        {    400,      0,      0,     0 }, /*     9600 bps */
 115        {    800,      0,      0,     0 }, /*    19200 bps */
 116        {   1600,      0,      0,     0 }, /*    38400 bps */
 117        {   2360,      0,      0,     0 }, /*    57600 bps */
 118        {   4800,   2400,    960,   480 }, /*   115200 bps */
 119        {  28800,  11520,   5760,  2880 }, /*   576000 bps */
 120        {  57600,  28800,  11520,  5760 }, /*  1152000 bps */
 121        { 200000, 100000,  40000, 20000 }, /*  4000000 bps */
 122        { 800000, 400000, 160000, 80000 }, /* 16000000 bps */
 123};
 124
 125static const pi_minor_info_t pi_minor_call_table_type_0[] = {
 126        { NULL, 0 },
 127/* 01 */{ irlap_param_baud_rate,       PV_INTEGER | PV_LITTLE_ENDIAN },
 128        { NULL, 0 },
 129        { NULL, 0 },
 130        { NULL, 0 },
 131        { NULL, 0 },
 132        { NULL, 0 },
 133        { NULL, 0 },
 134/* 08 */{ irlap_param_link_disconnect, PV_INT_8_BITS }
 135};
 136
 137static const pi_minor_info_t pi_minor_call_table_type_1[] = {
 138        { NULL, 0 },
 139        { NULL, 0 },
 140/* 82 */{ irlap_param_max_turn_time,   PV_INT_8_BITS },
 141/* 83 */{ irlap_param_data_size,       PV_INT_8_BITS },
 142/* 84 */{ irlap_param_window_size,     PV_INT_8_BITS },
 143/* 85 */{ irlap_param_additional_bofs, PV_INT_8_BITS },
 144/* 86 */{ irlap_param_min_turn_time,   PV_INT_8_BITS },
 145};
 146
 147static const pi_major_info_t pi_major_call_table[] = {
 148        { pi_minor_call_table_type_0, 9 },
 149        { pi_minor_call_table_type_1, 7 },
 150};
 151
 152static pi_param_info_t irlap_param_info = { pi_major_call_table, 2, 0x7f, 7 };
 153
 154/* ---------------------- LOCAL SUBROUTINES ---------------------- */
 155/* Note : we start with a bunch of local subroutines.
 156 * As the compiler is "one pass", this is the only way to get them to
 157 * inline properly...
 158 * Jean II
 159 */
 160/*
 161 * Function value_index (value, array, size)
 162 *
 163 *    Returns the index to the value in the specified array
 164 */
 165static inline int value_index(__u32 value, __u32 *array, int size)
 166{
 167        int i;
 168
 169        for (i=0; i < size; i++)
 170                if (array[i] == value)
 171                        break;
 172        return i;
 173}
 174
 175/*
 176 * Function index_value (index, array)
 177 *
 178 *    Returns value to index in array, easy!
 179 *
 180 */
 181static inline __u32 index_value(int index, __u32 *array)
 182{
 183        return array[index];
 184}
 185
 186/*
 187 * Function msb_index (word)
 188 *
 189 *    Returns index to most significant bit (MSB) in word
 190 *
 191 */
 192static int msb_index (__u16 word)
 193{
 194        __u16 msb = 0x8000;
 195        int index = 15;   /* Current MSB */
 196
 197        /* Check for buggy peers.
 198         * Note : there is a small probability that it could be us, but I
 199         * would expect driver authors to catch that pretty early and be
 200         * able to check precisely what's going on. If a end user sees this,
 201         * it's very likely the peer. - Jean II */
 202        if (word == 0) {
 203                net_warn_ratelimited("%s(), Detected buggy peer, adjust null PV to 0x1!\n",
 204                                     __func__);
 205                /* The only safe choice (we don't know the array size) */
 206                word = 0x1;
 207        }
 208
 209        while (msb) {
 210                if (word & msb)
 211                        break;   /* Found it! */
 212                msb >>=1;
 213                index--;
 214        }
 215        return index;
 216}
 217
 218/*
 219 * Function value_lower_bits (value, array)
 220 *
 221 *    Returns a bit field marking all possibility lower than value.
 222 */
 223static inline int value_lower_bits(__u32 value, __u32 *array, int size, __u16 *field)
 224{
 225        int     i;
 226        __u16   mask = 0x1;
 227        __u16   result = 0x0;
 228
 229        for (i=0; i < size; i++) {
 230                /* Add the current value to the bit field, shift mask */
 231                result |= mask;
 232                mask <<= 1;
 233                /* Finished ? */
 234                if (array[i] >= value)
 235                        break;
 236        }
 237        /* Send back a valid index */
 238        if(i >= size)
 239          i = size - 1; /* Last item */
 240        *field = result;
 241        return i;
 242}
 243
 244/*
 245 * Function value_highest_bit (value, array)
 246 *
 247 *    Returns a bit field marking the highest possibility lower than value.
 248 */
 249static inline int value_highest_bit(__u32 value, __u32 *array, int size, __u16 *field)
 250{
 251        int     i;
 252        __u16   mask = 0x1;
 253        __u16   result = 0x0;
 254
 255        for (i=0; i < size; i++) {
 256                /* Finished ? */
 257                if (array[i] <= value)
 258                        break;
 259                /* Shift mask */
 260                mask <<= 1;
 261        }
 262        /* Set the current value to the bit field */
 263        result |= mask;
 264        /* Send back a valid index */
 265        if(i >= size)
 266          i = size - 1; /* Last item */
 267        *field = result;
 268        return i;
 269}
 270
 271/* -------------------------- MAIN CALLS -------------------------- */
 272
 273/*
 274 * Function irda_qos_compute_intersection (qos, new)
 275 *
 276 *    Compute the intersection of the old QoS capabilities with new ones
 277 *
 278 */
 279void irda_qos_compute_intersection(struct qos_info *qos, struct qos_info *new)
 280{
 281        IRDA_ASSERT(qos != NULL, return;);
 282        IRDA_ASSERT(new != NULL, return;);
 283
 284        /* Apply */
 285        qos->baud_rate.bits       &= new->baud_rate.bits;
 286        qos->window_size.bits     &= new->window_size.bits;
 287        qos->min_turn_time.bits   &= new->min_turn_time.bits;
 288        qos->max_turn_time.bits   &= new->max_turn_time.bits;
 289        qos->data_size.bits       &= new->data_size.bits;
 290        qos->link_disc_time.bits  &= new->link_disc_time.bits;
 291        qos->additional_bofs.bits &= new->additional_bofs.bits;
 292
 293        irda_qos_bits_to_value(qos);
 294}
 295
 296/*
 297 * Function irda_init_max_qos_capabilies (qos)
 298 *
 299 *    The purpose of this function is for layers and drivers to be able to
 300 *    set the maximum QoS possible and then "and in" their own limitations
 301 *
 302 */
 303void irda_init_max_qos_capabilies(struct qos_info *qos)
 304{
 305        int i;
 306        /*
 307         *  These are the maximum supported values as specified on pages
 308         *  39-43 in IrLAP
 309         */
 310
 311        /* Use sysctl to set some configurable values... */
 312        /* Set configured max speed */
 313        i = value_lower_bits(sysctl_max_baud_rate, baud_rates, 10,
 314                             &qos->baud_rate.bits);
 315        sysctl_max_baud_rate = index_value(i, baud_rates);
 316
 317        /* Set configured max disc time */
 318        i = value_lower_bits(sysctl_max_noreply_time, link_disc_times, 8,
 319                             &qos->link_disc_time.bits);
 320        sysctl_max_noreply_time = index_value(i, link_disc_times);
 321
 322        /* LSB is first byte, MSB is second byte */
 323        qos->baud_rate.bits    &= 0x03ff;
 324
 325        qos->window_size.bits     = 0x7f;
 326        qos->min_turn_time.bits   = 0xff;
 327        qos->max_turn_time.bits   = 0x0f;
 328        qos->data_size.bits       = 0x3f;
 329        qos->link_disc_time.bits &= 0xff;
 330        qos->additional_bofs.bits = 0xff;
 331}
 332EXPORT_SYMBOL(irda_init_max_qos_capabilies);
 333
 334/*
 335 * Function irlap_adjust_qos_settings (qos)
 336 *
 337 *     Adjust QoS settings in case some values are not possible to use because
 338 *     of other settings
 339 */
 340static void irlap_adjust_qos_settings(struct qos_info *qos)
 341{
 342        __u32 line_capacity;
 343        int index;
 344
 345        /*
 346         * Make sure the mintt is sensible.
 347         * Main culprit : Ericsson T39. - Jean II
 348         */
 349        if (sysctl_min_tx_turn_time > qos->min_turn_time.value) {
 350                int i;
 351
 352                net_warn_ratelimited("%s(), Detected buggy peer, adjust mtt to %dus!\n",
 353                                     __func__, sysctl_min_tx_turn_time);
 354
 355                /* We don't really need bits, but easier this way */
 356                i = value_highest_bit(sysctl_min_tx_turn_time, min_turn_times,
 357                                      8, &qos->min_turn_time.bits);
 358                sysctl_min_tx_turn_time = index_value(i, min_turn_times);
 359                qos->min_turn_time.value = sysctl_min_tx_turn_time;
 360        }
 361
 362        /*
 363         * Not allowed to use a max turn time less than 500 ms if the baudrate
 364         * is less than 115200
 365         */
 366        if ((qos->baud_rate.value < 115200) &&
 367            (qos->max_turn_time.value < 500))
 368        {
 369                pr_debug("%s(), adjusting max turn time from %d to 500 ms\n",
 370                         __func__, qos->max_turn_time.value);
 371                qos->max_turn_time.value = 500;
 372        }
 373
 374        /*
 375         * The data size must be adjusted according to the baud rate and max
 376         * turn time
 377         */
 378        index = value_index(qos->data_size.value, data_sizes, 6);
 379        line_capacity = irlap_max_line_capacity(qos->baud_rate.value,
 380                                                qos->max_turn_time.value);
 381
 382#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
 383        while ((qos->data_size.value > line_capacity) && (index > 0)) {
 384                qos->data_size.value = data_sizes[index--];
 385                pr_debug("%s(), reducing data size to %d\n",
 386                         __func__, qos->data_size.value);
 387        }
 388#else /* Use method described in section 6.6.11 of IrLAP */
 389        while (irlap_requested_line_capacity(qos) > line_capacity) {
 390                IRDA_ASSERT(index != 0, return;);
 391
 392                /* Must be able to send at least one frame */
 393                if (qos->window_size.value > 1) {
 394                        qos->window_size.value--;
 395                        pr_debug("%s(), reducing window size to %d\n",
 396                                 __func__, qos->window_size.value);
 397                } else if (index > 1) {
 398                        qos->data_size.value = data_sizes[index--];
 399                        pr_debug("%s(), reducing data size to %d\n",
 400                                 __func__, qos->data_size.value);
 401                } else {
 402                        net_warn_ratelimited("%s(), nothing more we can do!\n",
 403                                             __func__);
 404                }
 405        }
 406#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
 407        /*
 408         * Fix tx data size according to user limits - Jean II
 409         */
 410        if (qos->data_size.value > sysctl_max_tx_data_size)
 411                /* Allow non discrete adjustement to avoid losing capacity */
 412                qos->data_size.value = sysctl_max_tx_data_size;
 413        /*
 414         * Override Tx window if user request it. - Jean II
 415         */
 416        if (qos->window_size.value > sysctl_max_tx_window)
 417                qos->window_size.value = sysctl_max_tx_window;
 418}
 419
 420/*
 421 * Function irlap_negotiate (qos_device, qos_session, skb)
 422 *
 423 *    Negotiate QoS values, not really that much negotiation :-)
 424 *    We just set the QoS capabilities for the peer station
 425 *
 426 */
 427int irlap_qos_negotiate(struct irlap_cb *self, struct sk_buff *skb)
 428{
 429        int ret;
 430
 431        ret = irda_param_extract_all(self, skb->data, skb->len,
 432                                     &irlap_param_info);
 433
 434        /* Convert the negotiated bits to values */
 435        irda_qos_bits_to_value(&self->qos_tx);
 436        irda_qos_bits_to_value(&self->qos_rx);
 437
 438        irlap_adjust_qos_settings(&self->qos_tx);
 439
 440        pr_debug("Setting BAUD_RATE to %d bps.\n",
 441                 self->qos_tx.baud_rate.value);
 442        pr_debug("Setting DATA_SIZE to %d bytes\n",
 443                 self->qos_tx.data_size.value);
 444        pr_debug("Setting WINDOW_SIZE to %d\n",
 445                 self->qos_tx.window_size.value);
 446        pr_debug("Setting XBOFS to %d\n",
 447                 self->qos_tx.additional_bofs.value);
 448        pr_debug("Setting MAX_TURN_TIME to %d ms.\n",
 449                 self->qos_tx.max_turn_time.value);
 450        pr_debug("Setting MIN_TURN_TIME to %d usecs.\n",
 451                 self->qos_tx.min_turn_time.value);
 452        pr_debug("Setting LINK_DISC to %d secs.\n",
 453                 self->qos_tx.link_disc_time.value);
 454        return ret;
 455}
 456
 457/*
 458 * Function irlap_insert_negotiation_params (qos, fp)
 459 *
 460 *    Insert QoS negotiaion pararameters into frame
 461 *
 462 */
 463int irlap_insert_qos_negotiation_params(struct irlap_cb *self,
 464                                        struct sk_buff *skb)
 465{
 466        int ret;
 467
 468        /* Insert data rate */
 469        ret = irda_param_insert(self, PI_BAUD_RATE, skb_tail_pointer(skb),
 470                                skb_tailroom(skb), &irlap_param_info);
 471        if (ret < 0)
 472                return ret;
 473        skb_put(skb, ret);
 474
 475        /* Insert max turnaround time */
 476        ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb_tail_pointer(skb),
 477                                skb_tailroom(skb), &irlap_param_info);
 478        if (ret < 0)
 479                return ret;
 480        skb_put(skb, ret);
 481
 482        /* Insert data size */
 483        ret = irda_param_insert(self, PI_DATA_SIZE, skb_tail_pointer(skb),
 484                                skb_tailroom(skb), &irlap_param_info);
 485        if (ret < 0)
 486                return ret;
 487        skb_put(skb, ret);
 488
 489        /* Insert window size */
 490        ret = irda_param_insert(self, PI_WINDOW_SIZE, skb_tail_pointer(skb),
 491                                skb_tailroom(skb), &irlap_param_info);
 492        if (ret < 0)
 493                return ret;
 494        skb_put(skb, ret);
 495
 496        /* Insert additional BOFs */
 497        ret = irda_param_insert(self, PI_ADD_BOFS, skb_tail_pointer(skb),
 498                                skb_tailroom(skb), &irlap_param_info);
 499        if (ret < 0)
 500                return ret;
 501        skb_put(skb, ret);
 502
 503        /* Insert minimum turnaround time */
 504        ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb_tail_pointer(skb),
 505                                skb_tailroom(skb), &irlap_param_info);
 506        if (ret < 0)
 507                return ret;
 508        skb_put(skb, ret);
 509
 510        /* Insert link disconnect/threshold time */
 511        ret = irda_param_insert(self, PI_LINK_DISC, skb_tail_pointer(skb),
 512                                skb_tailroom(skb), &irlap_param_info);
 513        if (ret < 0)
 514                return ret;
 515        skb_put(skb, ret);
 516
 517        return 0;
 518}
 519
 520/*
 521 * Function irlap_param_baud_rate (instance, param, get)
 522 *
 523 *    Negotiate data-rate
 524 *
 525 */
 526static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get)
 527{
 528        __u16 final;
 529
 530        struct irlap_cb *self = (struct irlap_cb *) instance;
 531
 532        IRDA_ASSERT(self != NULL, return -1;);
 533        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 534
 535        if (get) {
 536                param->pv.i = self->qos_rx.baud_rate.bits;
 537                pr_debug("%s(), baud rate = 0x%02x\n",
 538                         __func__, param->pv.i);
 539        } else {
 540                /*
 541                 *  Stations must agree on baud rate, so calculate
 542                 *  intersection
 543                 */
 544                pr_debug("Requested BAUD_RATE: 0x%04x\n", (__u16)param->pv.i);
 545                final = (__u16) param->pv.i & self->qos_rx.baud_rate.bits;
 546
 547                pr_debug("Final BAUD_RATE: 0x%04x\n", final);
 548                self->qos_tx.baud_rate.bits = final;
 549                self->qos_rx.baud_rate.bits = final;
 550        }
 551
 552        return 0;
 553}
 554
 555/*
 556 * Function irlap_param_link_disconnect (instance, param, get)
 557 *
 558 *    Negotiate link disconnect/threshold time.
 559 *
 560 */
 561static int irlap_param_link_disconnect(void *instance, irda_param_t *param,
 562                                       int get)
 563{
 564        __u16 final;
 565
 566        struct irlap_cb *self = (struct irlap_cb *) instance;
 567
 568        IRDA_ASSERT(self != NULL, return -1;);
 569        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 570
 571        if (get)
 572                param->pv.i = self->qos_rx.link_disc_time.bits;
 573        else {
 574                /*
 575                 *  Stations must agree on link disconnect/threshold
 576                 *  time.
 577                 */
 578                pr_debug("LINK_DISC: %02x\n", (__u8)param->pv.i);
 579                final = (__u8) param->pv.i & self->qos_rx.link_disc_time.bits;
 580
 581                pr_debug("Final LINK_DISC: %02x\n", final);
 582                self->qos_tx.link_disc_time.bits = final;
 583                self->qos_rx.link_disc_time.bits = final;
 584        }
 585        return 0;
 586}
 587
 588/*
 589 * Function irlap_param_max_turn_time (instance, param, get)
 590 *
 591 *    Negotiate the maximum turnaround time. This is a type 1 parameter and
 592 *    will be negotiated independently for each station
 593 *
 594 */
 595static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
 596                                     int get)
 597{
 598        struct irlap_cb *self = (struct irlap_cb *) instance;
 599
 600        IRDA_ASSERT(self != NULL, return -1;);
 601        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 602
 603        if (get)
 604                param->pv.i = self->qos_rx.max_turn_time.bits;
 605        else
 606                self->qos_tx.max_turn_time.bits = (__u8) param->pv.i;
 607
 608        return 0;
 609}
 610
 611/*
 612 * Function irlap_param_data_size (instance, param, get)
 613 *
 614 *    Negotiate the data size. This is a type 1 parameter and
 615 *    will be negotiated independently for each station
 616 *
 617 */
 618static int irlap_param_data_size(void *instance, irda_param_t *param, int get)
 619{
 620        struct irlap_cb *self = (struct irlap_cb *) instance;
 621
 622        IRDA_ASSERT(self != NULL, return -1;);
 623        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 624
 625        if (get)
 626                param->pv.i = self->qos_rx.data_size.bits;
 627        else
 628                self->qos_tx.data_size.bits = (__u8) param->pv.i;
 629
 630        return 0;
 631}
 632
 633/*
 634 * Function irlap_param_window_size (instance, param, get)
 635 *
 636 *    Negotiate the window size. This is a type 1 parameter and
 637 *    will be negotiated independently for each station
 638 *
 639 */
 640static int irlap_param_window_size(void *instance, irda_param_t *param,
 641                                   int get)
 642{
 643        struct irlap_cb *self = (struct irlap_cb *) instance;
 644
 645        IRDA_ASSERT(self != NULL, return -1;);
 646        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 647
 648        if (get)
 649                param->pv.i = self->qos_rx.window_size.bits;
 650        else
 651                self->qos_tx.window_size.bits = (__u8) param->pv.i;
 652
 653        return 0;
 654}
 655
 656/*
 657 * Function irlap_param_additional_bofs (instance, param, get)
 658 *
 659 *    Negotiate additional BOF characters. This is a type 1 parameter and
 660 *    will be negotiated independently for each station.
 661 */
 662static int irlap_param_additional_bofs(void *instance, irda_param_t *param, int get)
 663{
 664        struct irlap_cb *self = (struct irlap_cb *) instance;
 665
 666        IRDA_ASSERT(self != NULL, return -1;);
 667        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 668
 669        if (get)
 670                param->pv.i = self->qos_rx.additional_bofs.bits;
 671        else
 672                self->qos_tx.additional_bofs.bits = (__u8) param->pv.i;
 673
 674        return 0;
 675}
 676
 677/*
 678 * Function irlap_param_min_turn_time (instance, param, get)
 679 *
 680 *    Negotiate the minimum turn around time. This is a type 1 parameter and
 681 *    will be negotiated independently for each station
 682 */
 683static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
 684                                     int get)
 685{
 686        struct irlap_cb *self = (struct irlap_cb *) instance;
 687
 688        IRDA_ASSERT(self != NULL, return -1;);
 689        IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
 690
 691        if (get)
 692                param->pv.i = self->qos_rx.min_turn_time.bits;
 693        else
 694                self->qos_tx.min_turn_time.bits = (__u8) param->pv.i;
 695
 696        return 0;
 697}
 698
 699/*
 700 * Function irlap_max_line_capacity (speed, max_turn_time, min_turn_time)
 701 *
 702 *    Calculate the maximum line capacity
 703 *
 704 */
 705__u32 irlap_max_line_capacity(__u32 speed, __u32 max_turn_time)
 706{
 707        __u32 line_capacity;
 708        int i,j;
 709
 710        pr_debug("%s(), speed=%d, max_turn_time=%d\n",
 711                 __func__, speed, max_turn_time);
 712
 713        i = value_index(speed, baud_rates, 10);
 714        j = value_index(max_turn_time, max_turn_times, 4);
 715
 716        IRDA_ASSERT(((i >=0) && (i <10)), return 0;);
 717        IRDA_ASSERT(((j >=0) && (j <4)), return 0;);
 718
 719        line_capacity = max_line_capacities[i][j];
 720
 721        pr_debug("%s(), line capacity=%d bytes\n",
 722                 __func__, line_capacity);
 723
 724        return line_capacity;
 725}
 726
 727#ifndef CONFIG_IRDA_DYNAMIC_WINDOW
 728static __u32 irlap_requested_line_capacity(struct qos_info *qos)
 729{
 730        __u32 line_capacity;
 731
 732        line_capacity = qos->window_size.value *
 733                (qos->data_size.value + 6 + qos->additional_bofs.value) +
 734                irlap_min_turn_time_in_bytes(qos->baud_rate.value,
 735                                             qos->min_turn_time.value);
 736
 737        pr_debug("%s(), requested line capacity=%d\n",
 738                 __func__, line_capacity);
 739
 740        return line_capacity;
 741}
 742#endif
 743
 744void irda_qos_bits_to_value(struct qos_info *qos)
 745{
 746        int index;
 747
 748        IRDA_ASSERT(qos != NULL, return;);
 749
 750        index = msb_index(qos->baud_rate.bits);
 751        qos->baud_rate.value = baud_rates[index];
 752
 753        index = msb_index(qos->data_size.bits);
 754        qos->data_size.value = data_sizes[index];
 755
 756        index = msb_index(qos->window_size.bits);
 757        qos->window_size.value = index+1;
 758
 759        index = msb_index(qos->min_turn_time.bits);
 760        qos->min_turn_time.value = min_turn_times[index];
 761
 762        index = msb_index(qos->max_turn_time.bits);
 763        qos->max_turn_time.value = max_turn_times[index];
 764
 765        index = msb_index(qos->link_disc_time.bits);
 766        qos->link_disc_time.value = link_disc_times[index];
 767
 768        index = msb_index(qos->additional_bofs.bits);
 769        qos->additional_bofs.value = add_bofs[index];
 770}
 771EXPORT_SYMBOL(irda_qos_bits_to_value);
 772