1 /*********************************************************************
5 * Description: IrLAP QoS parameter negotiation
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>
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>
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.
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.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
31 ********************************************************************/
33 #include <linux/config.h>
34 #include <asm/byteorder.h>
36 #include <net/irda/irda.h>
37 #include <net/irda/parameters.h>
38 #include <net/irda/qos.h>
39 #include <net/irda/irlap.h>
42 * Maximum values of the baud rate we negociate 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...
47 int sysctl_max_baud_rate = 16000000;
49 * Maximum value of the lap disconnect timer we negociate 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 longuer or shorter in case of link failure.
52 * Remember that the threshold time (early warning) is fixed to 3s...
54 int sysctl_max_noreply_time = 12;
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).
63 unsigned sysctl_min_tx_turn_time = 10;
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.
78 unsigned sysctl_max_tx_data_size = 2042;
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.
84 unsigned sysctl_max_tx_window = 7;
86 static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get);
87 static int irlap_param_link_disconnect(void *instance, irda_param_t *parm,
89 static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
91 static int irlap_param_data_size(void *instance, irda_param_t *param, int get);
92 static int irlap_param_window_size(void *instance, irda_param_t *param,
94 static int irlap_param_additional_bofs(void *instance, irda_param_t *parm,
96 static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
99 static __u32 min_turn_times[] = { 10000, 5000, 1000, 500, 100, 50, 10, 0 }; /* us */
100 static __u32 baud_rates[] = { 2400, 9600, 19200, 38400, 57600, 115200, 576000,
101 1152000, 4000000, 16000000 }; /* bps */
102 static __u32 data_sizes[] = { 64, 128, 256, 512, 1024, 2048 }; /* bytes */
103 static __u32 add_bofs[] = { 48, 24, 12, 5, 3, 2, 1, 0 }; /* bytes */
104 static __u32 max_turn_times[] = { 500, 250, 100, 50 }; /* ms */
105 static __u32 link_disc_times[] = { 3, 8, 12, 16, 20, 25, 30, 40 }; /* secs */
107 static __u32 max_line_capacities[10][4] = {
108 /* 500 ms 250 ms 100 ms 50 ms (max turn time) */
109 { 100, 0, 0, 0 }, /* 2400 bps */
110 { 400, 0, 0, 0 }, /* 9600 bps */
111 { 800, 0, 0, 0 }, /* 19200 bps */
112 { 1600, 0, 0, 0 }, /* 38400 bps */
113 { 2360, 0, 0, 0 }, /* 57600 bps */
114 { 4800, 2400, 960, 480 }, /* 115200 bps */
115 { 28800, 11520, 5760, 2880 }, /* 576000 bps */
116 { 57600, 28800, 11520, 5760 }, /* 1152000 bps */
117 { 200000, 100000, 40000, 20000 }, /* 4000000 bps */
118 { 800000, 400000, 160000, 80000 }, /* 16000000 bps */
121 static pi_minor_info_t pi_minor_call_table_type_0[] = {
123 /* 01 */{ irlap_param_baud_rate, PV_INTEGER | PV_LITTLE_ENDIAN },
130 /* 08 */{ irlap_param_link_disconnect, PV_INT_8_BITS }
133 static pi_minor_info_t pi_minor_call_table_type_1[] = {
136 /* 82 */{ irlap_param_max_turn_time, PV_INT_8_BITS },
137 /* 83 */{ irlap_param_data_size, PV_INT_8_BITS },
138 /* 84 */{ irlap_param_window_size, PV_INT_8_BITS },
139 /* 85 */{ irlap_param_additional_bofs, PV_INT_8_BITS },
140 /* 86 */{ irlap_param_min_turn_time, PV_INT_8_BITS },
143 static pi_major_info_t pi_major_call_table[] = {
144 { pi_minor_call_table_type_0, 9 },
145 { pi_minor_call_table_type_1, 7 },
148 static pi_param_info_t irlap_param_info = { pi_major_call_table, 2, 0x7f, 7 };
150 /* ---------------------- LOCAL SUBROUTINES ---------------------- */
151 /* Note : we start with a bunch of local subroutines.
152 * As the compiler is "one pass", this is the only way to get them to
157 * Function value_index (value, array, size)
159 * Returns the index to the value in the specified array
161 static inline int value_index(__u32 value, __u32 *array, int size)
165 for (i=0; i < size; i++)
166 if (array[i] == value)
172 * Function index_value (index, array)
174 * Returns value to index in array, easy!
177 static inline __u32 index_value(int index, __u32 *array)
183 * Function msb_index (word)
185 * Returns index to most significant bit (MSB) in word
188 static int msb_index (__u16 word)
191 int index = 15; /* Current MSB */
193 /* Check for buggy peers.
194 * Note : there is a small probability that it could be us, but I
195 * would expect driver authors to catch that pretty early and be
196 * able to check precisely what's going on. If a end user sees this,
197 * it's very likely the peer. - Jean II */
199 WARNING("%s(), Detected buggy peer, adjust null PV to 0x1!\n",
201 /* The only safe choice (we don't know the array size) */
207 break; /* Found it! */
215 * Function value_lower_bits (value, array)
217 * Returns a bit field marking all possibility lower than value.
219 static inline int value_lower_bits(__u32 value, __u32 *array, int size, __u16 *field)
225 for (i=0; i < size; i++) {
226 /* Add the current value to the bit field, shift mask */
230 if (array[i] >= value)
233 /* Send back a valid index */
235 i = size - 1; /* Last item */
241 * Function value_highest_bit (value, array)
243 * Returns a bit field marking the highest possibility lower than value.
245 static inline int value_highest_bit(__u32 value, __u32 *array, int size, __u16 *field)
251 for (i=0; i < size; i++) {
253 if (array[i] <= value)
258 /* Set the current value to the bit field */
260 /* Send back a valid index */
262 i = size - 1; /* Last item */
267 /* -------------------------- MAIN CALLS -------------------------- */
270 * Function irda_qos_compute_intersection (qos, new)
272 * Compute the intersection of the old QoS capabilities with new ones
275 void irda_qos_compute_intersection(struct qos_info *qos, struct qos_info *new)
277 ASSERT(qos != NULL, return;);
278 ASSERT(new != NULL, return;);
281 qos->baud_rate.bits &= new->baud_rate.bits;
282 qos->window_size.bits &= new->window_size.bits;
283 qos->min_turn_time.bits &= new->min_turn_time.bits;
284 qos->max_turn_time.bits &= new->max_turn_time.bits;
285 qos->data_size.bits &= new->data_size.bits;
286 qos->link_disc_time.bits &= new->link_disc_time.bits;
287 qos->additional_bofs.bits &= new->additional_bofs.bits;
289 irda_qos_bits_to_value(qos);
293 * Function irda_init_max_qos_capabilies (qos)
295 * The purpose of this function is for layers and drivers to be able to
296 * set the maximum QoS possible and then "and in" their own limitations
299 void irda_init_max_qos_capabilies(struct qos_info *qos)
303 * These are the maximum supported values as specified on pages
307 /* Use sysctl to set some configurable values... */
308 /* Set configured max speed */
309 i = value_lower_bits(sysctl_max_baud_rate, baud_rates, 10,
310 &qos->baud_rate.bits);
311 sysctl_max_baud_rate = index_value(i, baud_rates);
313 /* Set configured max disc time */
314 i = value_lower_bits(sysctl_max_noreply_time, link_disc_times, 8,
315 &qos->link_disc_time.bits);
316 sysctl_max_noreply_time = index_value(i, link_disc_times);
318 /* LSB is first byte, MSB is second byte */
319 qos->baud_rate.bits &= 0x03ff;
321 qos->window_size.bits = 0x7f;
322 qos->min_turn_time.bits = 0xff;
323 qos->max_turn_time.bits = 0x0f;
324 qos->data_size.bits = 0x3f;
325 qos->link_disc_time.bits &= 0xff;
326 qos->additional_bofs.bits = 0xff;
328 EXPORT_SYMBOL(irda_init_max_qos_capabilies);
331 * Function irlap_adjust_qos_settings (qos)
333 * Adjust QoS settings in case some values are not possible to use because
336 void irlap_adjust_qos_settings(struct qos_info *qos)
341 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
344 * Make sure the mintt is sensible.
345 * Main culprit : Ericsson T39. - Jean II
347 if (sysctl_min_tx_turn_time > qos->min_turn_time.value) {
350 WARNING("%s(), Detected buggy peer, adjust mtt to %dus!\n",
351 __FUNCTION__, sysctl_min_tx_turn_time);
353 /* We don't really need bits, but easier this way */
354 i = value_highest_bit(sysctl_min_tx_turn_time, min_turn_times,
355 8, &qos->min_turn_time.bits);
356 sysctl_min_tx_turn_time = index_value(i, min_turn_times);
357 qos->min_turn_time.value = sysctl_min_tx_turn_time;
361 * Not allowed to use a max turn time less than 500 ms if the baudrate
362 * is less than 115200
364 if ((qos->baud_rate.value < 115200) &&
365 (qos->max_turn_time.value < 500))
368 "%s(), adjusting max turn time from %d to 500 ms\n",
369 __FUNCTION__, qos->max_turn_time.value);
370 qos->max_turn_time.value = 500;
374 * The data size must be adjusted according to the baud rate and max
377 index = value_index(qos->data_size.value, data_sizes, 6);
378 line_capacity = irlap_max_line_capacity(qos->baud_rate.value,
379 qos->max_turn_time.value);
381 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
382 while ((qos->data_size.value > line_capacity) && (index > 0)) {
383 qos->data_size.value = data_sizes[index--];
384 IRDA_DEBUG(2, "%s(), reducing data size to %d\n",
385 __FUNCTION__, qos->data_size.value);
387 #else /* Use method described in section 6.6.11 of IrLAP */
388 while (irlap_requested_line_capacity(qos) > line_capacity) {
389 ASSERT(index != 0, return;);
391 /* Must be able to send at least one frame */
392 if (qos->window_size.value > 1) {
393 qos->window_size.value--;
394 IRDA_DEBUG(2, "%s(), reducing window size to %d\n",
395 __FUNCTION__, qos->window_size.value);
396 } else if (index > 1) {
397 qos->data_size.value = data_sizes[index--];
398 IRDA_DEBUG(2, "%s(), reducing data size to %d\n",
399 __FUNCTION__, qos->data_size.value);
401 WARNING("%s(), nothing more we can do!\n",
405 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
407 * Fix tx data size according to user limits - Jean II
409 if (qos->data_size.value > sysctl_max_tx_data_size)
410 /* Allow non discrete adjustement to avoid loosing capacity */
411 qos->data_size.value = sysctl_max_tx_data_size;
413 * Override Tx window if user request it. - Jean II
415 if (qos->window_size.value > sysctl_max_tx_window)
416 qos->window_size.value = sysctl_max_tx_window;
420 * Function irlap_negotiate (qos_device, qos_session, skb)
422 * Negotiate QoS values, not really that much negotiation :-)
423 * We just set the QoS capabilities for the peer station
426 int irlap_qos_negotiate(struct irlap_cb *self, struct sk_buff *skb)
430 ret = irda_param_extract_all(self, skb->data, skb->len,
433 /* Convert the negotiated bits to values */
434 irda_qos_bits_to_value(&self->qos_tx);
435 irda_qos_bits_to_value(&self->qos_rx);
437 irlap_adjust_qos_settings(&self->qos_tx);
439 IRDA_DEBUG(2, "Setting BAUD_RATE to %d bps.\n",
440 self->qos_tx.baud_rate.value);
441 IRDA_DEBUG(2, "Setting DATA_SIZE to %d bytes\n",
442 self->qos_tx.data_size.value);
443 IRDA_DEBUG(2, "Setting WINDOW_SIZE to %d\n",
444 self->qos_tx.window_size.value);
445 IRDA_DEBUG(2, "Setting XBOFS to %d\n",
446 self->qos_tx.additional_bofs.value);
447 IRDA_DEBUG(2, "Setting MAX_TURN_TIME to %d ms.\n",
448 self->qos_tx.max_turn_time.value);
449 IRDA_DEBUG(2, "Setting MIN_TURN_TIME to %d usecs.\n",
450 self->qos_tx.min_turn_time.value);
451 IRDA_DEBUG(2, "Setting LINK_DISC to %d secs.\n",
452 self->qos_tx.link_disc_time.value);
457 * Function irlap_insert_negotiation_params (qos, fp)
459 * Insert QoS negotiaion pararameters into frame
462 int irlap_insert_qos_negotiation_params(struct irlap_cb *self,
467 /* Insert data rate */
468 ret = irda_param_insert(self, PI_BAUD_RATE, skb->tail,
469 skb_tailroom(skb), &irlap_param_info);
474 /* Insert max turnaround time */
475 ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb->tail,
476 skb_tailroom(skb), &irlap_param_info);
481 /* Insert data size */
482 ret = irda_param_insert(self, PI_DATA_SIZE, skb->tail,
483 skb_tailroom(skb), &irlap_param_info);
488 /* Insert window size */
489 ret = irda_param_insert(self, PI_WINDOW_SIZE, skb->tail,
490 skb_tailroom(skb), &irlap_param_info);
495 /* Insert additional BOFs */
496 ret = irda_param_insert(self, PI_ADD_BOFS, skb->tail,
497 skb_tailroom(skb), &irlap_param_info);
502 /* Insert minimum turnaround time */
503 ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb->tail,
504 skb_tailroom(skb), &irlap_param_info);
509 /* Insert link disconnect/threshold time */
510 ret = irda_param_insert(self, PI_LINK_DISC, skb->tail,
511 skb_tailroom(skb), &irlap_param_info);
520 * Function irlap_param_baud_rate (instance, param, get)
522 * Negotiate data-rate
525 static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get)
529 struct irlap_cb *self = (struct irlap_cb *) instance;
531 ASSERT(self != NULL, return -1;);
532 ASSERT(self->magic == LAP_MAGIC, return -1;);
535 param->pv.i = self->qos_rx.baud_rate.bits;
536 IRDA_DEBUG(2, "%s(), baud rate = 0x%02x\n",
537 __FUNCTION__, param->pv.i);
540 * Stations must agree on baud rate, so calculate
543 IRDA_DEBUG(2, "Requested BAUD_RATE: 0x%04x\n", (__u16) param->pv.i);
544 final = (__u16) param->pv.i & self->qos_rx.baud_rate.bits;
546 IRDA_DEBUG(2, "Final BAUD_RATE: 0x%04x\n", final);
547 self->qos_tx.baud_rate.bits = final;
548 self->qos_rx.baud_rate.bits = final;
555 * Function irlap_param_link_disconnect (instance, param, get)
557 * Negotiate link disconnect/threshold time.
560 static int irlap_param_link_disconnect(void *instance, irda_param_t *param,
565 struct irlap_cb *self = (struct irlap_cb *) instance;
567 ASSERT(self != NULL, return -1;);
568 ASSERT(self->magic == LAP_MAGIC, return -1;);
571 param->pv.i = self->qos_rx.link_disc_time.bits;
574 * Stations must agree on link disconnect/threshold
577 IRDA_DEBUG(2, "LINK_DISC: %02x\n", (__u8) param->pv.i);
578 final = (__u8) param->pv.i & self->qos_rx.link_disc_time.bits;
580 IRDA_DEBUG(2, "Final LINK_DISC: %02x\n", final);
581 self->qos_tx.link_disc_time.bits = final;
582 self->qos_rx.link_disc_time.bits = final;
588 * Function irlap_param_max_turn_time (instance, param, get)
590 * Negotiate the maximum turnaround time. This is a type 1 parameter and
591 * will be negotiated independently for each station
594 static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
597 struct irlap_cb *self = (struct irlap_cb *) instance;
599 ASSERT(self != NULL, return -1;);
600 ASSERT(self->magic == LAP_MAGIC, return -1;);
603 param->pv.i = self->qos_rx.max_turn_time.bits;
605 self->qos_tx.max_turn_time.bits = (__u8) param->pv.i;
611 * Function irlap_param_data_size (instance, param, get)
613 * Negotiate the data size. This is a type 1 parameter and
614 * will be negotiated independently for each station
617 static int irlap_param_data_size(void *instance, irda_param_t *param, int get)
619 struct irlap_cb *self = (struct irlap_cb *) instance;
621 ASSERT(self != NULL, return -1;);
622 ASSERT(self->magic == LAP_MAGIC, return -1;);
625 param->pv.i = self->qos_rx.data_size.bits;
627 self->qos_tx.data_size.bits = (__u8) param->pv.i;
633 * Function irlap_param_window_size (instance, param, get)
635 * Negotiate the window size. This is a type 1 parameter and
636 * will be negotiated independently for each station
639 static int irlap_param_window_size(void *instance, irda_param_t *param,
642 struct irlap_cb *self = (struct irlap_cb *) instance;
644 ASSERT(self != NULL, return -1;);
645 ASSERT(self->magic == LAP_MAGIC, return -1;);
648 param->pv.i = self->qos_rx.window_size.bits;
650 self->qos_tx.window_size.bits = (__u8) param->pv.i;
656 * Function irlap_param_additional_bofs (instance, param, get)
658 * Negotiate additional BOF characters. This is a type 1 parameter and
659 * will be negotiated independently for each station.
661 static int irlap_param_additional_bofs(void *instance, irda_param_t *param, int get)
663 struct irlap_cb *self = (struct irlap_cb *) instance;
665 ASSERT(self != NULL, return -1;);
666 ASSERT(self->magic == LAP_MAGIC, return -1;);
669 param->pv.i = self->qos_rx.additional_bofs.bits;
671 self->qos_tx.additional_bofs.bits = (__u8) param->pv.i;
677 * Function irlap_param_min_turn_time (instance, param, get)
679 * Negotiate the minimum turn around time. This is a type 1 parameter and
680 * will be negotiated independently for each station
682 static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
685 struct irlap_cb *self = (struct irlap_cb *) instance;
687 ASSERT(self != NULL, return -1;);
688 ASSERT(self->magic == LAP_MAGIC, return -1;);
691 param->pv.i = self->qos_rx.min_turn_time.bits;
693 self->qos_tx.min_turn_time.bits = (__u8) param->pv.i;
699 * Function irlap_max_line_capacity (speed, max_turn_time, min_turn_time)
701 * Calculate the maximum line capacity
704 __u32 irlap_max_line_capacity(__u32 speed, __u32 max_turn_time)
709 IRDA_DEBUG(2, "%s(), speed=%d, max_turn_time=%d\n",
710 __FUNCTION__, speed, max_turn_time);
712 i = value_index(speed, baud_rates, 10);
713 j = value_index(max_turn_time, max_turn_times, 4);
715 ASSERT(((i >=0) && (i <10)), return 0;);
716 ASSERT(((j >=0) && (j <4)), return 0;);
718 line_capacity = max_line_capacities[i][j];
720 IRDA_DEBUG(2, "%s(), line capacity=%d bytes\n",
721 __FUNCTION__, line_capacity);
723 return line_capacity;
726 __u32 irlap_requested_line_capacity(struct qos_info *qos)
727 { __u32 line_capacity;
729 line_capacity = qos->window_size.value *
730 (qos->data_size.value + 6 + qos->additional_bofs.value) +
731 irlap_min_turn_time_in_bytes(qos->baud_rate.value,
732 qos->min_turn_time.value);
734 IRDA_DEBUG(2, "%s(), requested line capacity=%d\n",
735 __FUNCTION__, line_capacity);
737 return line_capacity;
740 void irda_qos_bits_to_value(struct qos_info *qos)
744 ASSERT(qos != NULL, return;);
746 index = msb_index(qos->baud_rate.bits);
747 qos->baud_rate.value = baud_rates[index];
749 index = msb_index(qos->data_size.bits);
750 qos->data_size.value = data_sizes[index];
752 index = msb_index(qos->window_size.bits);
753 qos->window_size.value = index+1;
755 index = msb_index(qos->min_turn_time.bits);
756 qos->min_turn_time.value = min_turn_times[index];
758 index = msb_index(qos->max_turn_time.bits);
759 qos->max_turn_time.value = max_turn_times[index];
761 index = msb_index(qos->link_disc_time.bits);
762 qos->link_disc_time.value = link_disc_times[index];
764 index = msb_index(qos->additional_bofs.bits);
765 qos->additional_bofs.value = add_bofs[index];
767 EXPORT_SYMBOL(irda_qos_bits_to_value);