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 * I've had trouble trouble transmitting 2048 bytes frames with USB
74 * dongles and nsc-ircc at 4 Mb/s, so adjust to 2042... I don't know
75 * if this bug applies only for 2048 bytes frames or all negociated
76 * frame sizes, but all hardware seem to support "2048 bytes" frames.
77 * You can use the sysctl to play with this value anyway.
79 unsigned sysctl_max_tx_data_size = 2042;
81 static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get);
82 static int irlap_param_link_disconnect(void *instance, irda_param_t *parm,
84 static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
86 static int irlap_param_data_size(void *instance, irda_param_t *param, int get);
87 static int irlap_param_window_size(void *instance, irda_param_t *param,
89 static int irlap_param_additional_bofs(void *instance, irda_param_t *parm,
91 static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
94 __u32 min_turn_times[] = { 10000, 5000, 1000, 500, 100, 50, 10, 0 }; /* us */
95 __u32 baud_rates[] = { 2400, 9600, 19200, 38400, 57600, 115200, 576000,
96 1152000, 4000000, 16000000 }; /* bps */
97 __u32 data_sizes[] = { 64, 128, 256, 512, 1024, 2048 }; /* bytes */
98 __u32 add_bofs[] = { 48, 24, 12, 5, 3, 2, 1, 0 }; /* bytes */
99 __u32 max_turn_times[] = { 500, 250, 100, 50 }; /* ms */
100 __u32 link_disc_times[] = { 3, 8, 12, 16, 20, 25, 30, 40 }; /* secs */
102 __u32 max_line_capacities[10][4] = {
103 /* 500 ms 250 ms 100 ms 50 ms (max turn time) */
104 { 100, 0, 0, 0 }, /* 2400 bps */
105 { 400, 0, 0, 0 }, /* 9600 bps */
106 { 800, 0, 0, 0 }, /* 19200 bps */
107 { 1600, 0, 0, 0 }, /* 38400 bps */
108 { 2360, 0, 0, 0 }, /* 57600 bps */
109 { 4800, 2400, 960, 480 }, /* 115200 bps */
110 { 28800, 11520, 5760, 2880 }, /* 576000 bps */
111 { 57600, 28800, 11520, 5760 }, /* 1152000 bps */
112 { 200000, 100000, 40000, 20000 }, /* 4000000 bps */
113 { 800000, 400000, 160000, 80000 }, /* 16000000 bps */
116 static pi_minor_info_t pi_minor_call_table_type_0[] = {
118 /* 01 */{ irlap_param_baud_rate, PV_INTEGER | PV_LITTLE_ENDIAN },
125 /* 08 */{ irlap_param_link_disconnect, PV_INT_8_BITS }
128 static pi_minor_info_t pi_minor_call_table_type_1[] = {
131 /* 82 */{ irlap_param_max_turn_time, PV_INT_8_BITS },
132 /* 83 */{ irlap_param_data_size, PV_INT_8_BITS },
133 /* 84 */{ irlap_param_window_size, PV_INT_8_BITS },
134 /* 85 */{ irlap_param_additional_bofs, PV_INT_8_BITS },
135 /* 86 */{ irlap_param_min_turn_time, PV_INT_8_BITS },
138 static pi_major_info_t pi_major_call_table[] = {
139 { pi_minor_call_table_type_0, 9 },
140 { pi_minor_call_table_type_1, 7 },
143 static pi_param_info_t irlap_param_info = { pi_major_call_table, 2, 0x7f, 7 };
145 /* ---------------------- LOCAL SUBROUTINES ---------------------- */
146 /* Note : we start with a bunch of local subroutines.
147 * As the compiler is "one pass", this is the only way to get them to
152 * Function value_index (value, array, size)
154 * Returns the index to the value in the specified array
156 static inline int value_index(__u32 value, __u32 *array, int size)
160 for (i=0; i < size; i++)
161 if (array[i] == value)
167 * Function index_value (index, array)
169 * Returns value to index in array, easy!
172 static inline __u32 index_value(int index, __u32 *array)
178 * Function msb_index (word)
180 * Returns index to most significant bit (MSB) in word
183 int msb_index (__u16 word)
186 int index = 15; /* Current MSB */
190 break; /* Found it! */
197 static inline __u32 byte_value(__u8 byte, __u32 *array)
201 ASSERT(array != NULL, return -1;);
203 index = msb_index(byte);
205 return index_value(index, array);
209 * Function value_lower_bits (value, array)
211 * Returns a bit field marking all possibility lower than value.
213 static inline int value_lower_bits(__u32 value, __u32 *array, int size, __u16 *field)
219 for (i=0; i < size; i++) {
220 /* Add the current value to the bit field, shift mask */
224 if (array[i] >= value)
227 /* Send back a valid index */
229 i = size - 1; /* Last item */
235 * Function value_highest_bit (value, array)
237 * Returns a bit field marking the highest possibility lower than value.
239 static inline int value_highest_bit(__u32 value, __u32 *array, int size, __u16 *field)
245 for (i=0; i < size; i++) {
247 if (array[i] <= value)
252 /* Set the current value to the bit field */
254 /* Send back a valid index */
256 i = size - 1; /* Last item */
261 /* -------------------------- MAIN CALLS -------------------------- */
264 * Function irda_qos_compute_intersection (qos, new)
266 * Compute the intersection of the old QoS capabilites with new ones
269 void irda_qos_compute_intersection(struct qos_info *qos, struct qos_info *new)
271 ASSERT(qos != NULL, return;);
272 ASSERT(new != NULL, return;);
275 qos->baud_rate.bits &= new->baud_rate.bits;
276 qos->window_size.bits &= new->window_size.bits;
277 qos->min_turn_time.bits &= new->min_turn_time.bits;
278 qos->max_turn_time.bits &= new->max_turn_time.bits;
279 qos->data_size.bits &= new->data_size.bits;
280 qos->link_disc_time.bits &= new->link_disc_time.bits;
281 qos->additional_bofs.bits &= new->additional_bofs.bits;
283 irda_qos_bits_to_value(qos);
287 * Function irda_init_max_qos_capabilies (qos)
289 * The purpose of this function is for layers and drivers to be able to
290 * set the maximum QoS possible and then "and in" their own limitations
293 void irda_init_max_qos_capabilies(struct qos_info *qos)
297 * These are the maximum supported values as specified on pages
301 /* Use sysctl to set some configurable values... */
302 /* Set configured max speed */
303 i = value_lower_bits(sysctl_max_baud_rate, baud_rates, 10,
304 &qos->baud_rate.bits);
305 sysctl_max_baud_rate = index_value(i, baud_rates);
307 /* Set configured max disc time */
308 i = value_lower_bits(sysctl_max_noreply_time, link_disc_times, 8,
309 &qos->link_disc_time.bits);
310 sysctl_max_noreply_time = index_value(i, link_disc_times);
312 /* LSB is first byte, MSB is second byte */
313 qos->baud_rate.bits &= 0x03ff;
315 qos->window_size.bits = 0x7f;
316 qos->min_turn_time.bits = 0xff;
317 qos->max_turn_time.bits = 0x0f;
318 qos->data_size.bits = 0x3f;
319 qos->link_disc_time.bits &= 0xff;
320 qos->additional_bofs.bits = 0xff;
324 * Function irlap_adjust_qos_settings (qos)
326 * Adjust QoS settings in case some values are not possible to use because
329 void irlap_adjust_qos_settings(struct qos_info *qos)
334 IRDA_DEBUG(2, __FUNCTION__ "()\n");
337 * Make sure the mintt is sensible.
339 if (sysctl_min_tx_turn_time > qos->min_turn_time.value) {
342 /* We don't really need bits, but easier this way */
343 i = value_highest_bit(sysctl_min_tx_turn_time, min_turn_times,
344 8, &qos->min_turn_time.bits);
345 sysctl_min_tx_turn_time = index_value(i, min_turn_times);
346 qos->min_turn_time.value = sysctl_min_tx_turn_time;
350 * Not allowed to use a max turn time less than 500 ms if the baudrate
351 * is less than 115200
353 if ((qos->baud_rate.value < 115200) &&
354 (qos->max_turn_time.value < 500))
356 IRDA_DEBUG(0, __FUNCTION__
357 "(), adjusting max turn time from %d to 500 ms\n",
358 qos->max_turn_time.value);
359 qos->max_turn_time.value = 500;
363 * The data size must be adjusted according to the baud rate and max
366 index = value_index(qos->data_size.value, data_sizes, 6);
367 line_capacity = irlap_max_line_capacity(qos->baud_rate.value,
368 qos->max_turn_time.value);
370 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
371 while ((qos->data_size.value > line_capacity) && (index > 0)) {
372 qos->data_size.value = data_sizes[index--];
373 IRDA_DEBUG(2, __FUNCTION__
374 "(), reducing data size to %d\n",
375 qos->data_size.value);
377 #else /* Use method described in section 6.6.11 of IrLAP */
378 while (irlap_requested_line_capacity(qos) > line_capacity) {
379 ASSERT(index != 0, return;);
381 /* Must be able to send at least one frame */
382 if (qos->window_size.value > 1) {
383 qos->window_size.value--;
384 IRDA_DEBUG(2, __FUNCTION__
385 "(), reducing window size to %d\n",
386 qos->window_size.value);
387 } else if (index > 1) {
388 qos->data_size.value = data_sizes[index--];
389 IRDA_DEBUG(2, __FUNCTION__
390 "(), reducing data size to %d\n",
391 qos->data_size.value);
393 WARNING(__FUNCTION__ "(), nothing more we can do!\n");
396 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
398 * Fix tx data size according to user limits - Jean II
400 if (qos->data_size.value > sysctl_max_tx_data_size)
401 /* Allow non discrete adjustement to avoid loosing capacity */
402 qos->data_size.value = sysctl_max_tx_data_size;
406 * Function irlap_negotiate (qos_device, qos_session, skb)
408 * Negotiate QoS values, not really that much negotiation :-)
409 * We just set the QoS capabilities for the peer station
412 int irlap_qos_negotiate(struct irlap_cb *self, struct sk_buff *skb)
416 ret = irda_param_extract_all(self, skb->data, skb->len,
419 /* Convert the negotiated bits to values */
420 irda_qos_bits_to_value(&self->qos_tx);
421 irda_qos_bits_to_value(&self->qos_rx);
423 irlap_adjust_qos_settings(&self->qos_tx);
425 IRDA_DEBUG(2, "Setting BAUD_RATE to %d bps.\n",
426 self->qos_tx.baud_rate.value);
427 IRDA_DEBUG(2, "Setting DATA_SIZE to %d bytes\n",
428 self->qos_tx.data_size.value);
429 IRDA_DEBUG(2, "Setting WINDOW_SIZE to %d\n",
430 self->qos_tx.window_size.value);
431 IRDA_DEBUG(2, "Setting XBOFS to %d\n",
432 self->qos_tx.additional_bofs.value);
433 IRDA_DEBUG(2, "Setting MAX_TURN_TIME to %d ms.\n",
434 self->qos_tx.max_turn_time.value);
435 IRDA_DEBUG(2, "Setting MIN_TURN_TIME to %d usecs.\n",
436 self->qos_tx.min_turn_time.value);
437 IRDA_DEBUG(2, "Setting LINK_DISC to %d secs.\n",
438 self->qos_tx.link_disc_time.value);
443 * Function irlap_insert_negotiation_params (qos, fp)
445 * Insert QoS negotiaion pararameters into frame
448 int irlap_insert_qos_negotiation_params(struct irlap_cb *self,
453 /* Insert data rate */
454 ret = irda_param_insert(self, PI_BAUD_RATE, skb->tail,
455 skb_tailroom(skb), &irlap_param_info);
460 /* Insert max turnaround time */
461 ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb->tail,
462 skb_tailroom(skb), &irlap_param_info);
467 /* Insert data size */
468 ret = irda_param_insert(self, PI_DATA_SIZE, skb->tail,
469 skb_tailroom(skb), &irlap_param_info);
474 /* Insert window size */
475 ret = irda_param_insert(self, PI_WINDOW_SIZE, skb->tail,
476 skb_tailroom(skb), &irlap_param_info);
481 /* Insert additional BOFs */
482 ret = irda_param_insert(self, PI_ADD_BOFS, skb->tail,
483 skb_tailroom(skb), &irlap_param_info);
488 /* Insert minimum turnaround time */
489 ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb->tail,
490 skb_tailroom(skb), &irlap_param_info);
495 /* Insert link disconnect/threshold time */
496 ret = irda_param_insert(self, PI_LINK_DISC, skb->tail,
497 skb_tailroom(skb), &irlap_param_info);
506 * Function irlap_param_baud_rate (instance, param, get)
508 * Negotiate data-rate
511 static int irlap_param_baud_rate(void *instance, irda_param_t *param, int get)
515 struct irlap_cb *self = (struct irlap_cb *) instance;
517 ASSERT(self != NULL, return -1;);
518 ASSERT(self->magic == LAP_MAGIC, return -1;);
521 param->pv.i = self->qos_rx.baud_rate.bits;
522 IRDA_DEBUG(2, __FUNCTION__ "(), baud rate = 0x%02x\n",
526 * Stations must agree on baud rate, so calculate
529 IRDA_DEBUG(2, "Requested BAUD_RATE: 0x%04x\n", (__u16) param->pv.i);
530 final = (__u16) param->pv.i & self->qos_rx.baud_rate.bits;
532 IRDA_DEBUG(2, "Final BAUD_RATE: 0x%04x\n", final);
533 self->qos_tx.baud_rate.bits = final;
534 self->qos_rx.baud_rate.bits = final;
541 * Function irlap_param_link_disconnect (instance, param, get)
543 * Negotiate link disconnect/threshold time.
546 static int irlap_param_link_disconnect(void *instance, irda_param_t *param,
551 struct irlap_cb *self = (struct irlap_cb *) instance;
553 ASSERT(self != NULL, return -1;);
554 ASSERT(self->magic == LAP_MAGIC, return -1;);
557 param->pv.i = self->qos_rx.link_disc_time.bits;
560 * Stations must agree on link disconnect/threshold
563 IRDA_DEBUG(2, "LINK_DISC: %02x\n", (__u8) param->pv.i);
564 final = (__u8) param->pv.i & self->qos_rx.link_disc_time.bits;
566 IRDA_DEBUG(2, "Final LINK_DISC: %02x\n", final);
567 self->qos_tx.link_disc_time.bits = final;
568 self->qos_rx.link_disc_time.bits = final;
574 * Function irlap_param_max_turn_time (instance, param, get)
576 * Negotiate the maximum turnaround time. This is a type 1 parameter and
577 * will be negotiated independently for each station
580 static int irlap_param_max_turn_time(void *instance, irda_param_t *param,
583 struct irlap_cb *self = (struct irlap_cb *) instance;
585 ASSERT(self != NULL, return -1;);
586 ASSERT(self->magic == LAP_MAGIC, return -1;);
589 param->pv.i = self->qos_rx.max_turn_time.bits;
591 self->qos_tx.max_turn_time.bits = (__u8) param->pv.i;
597 * Function irlap_param_data_size (instance, param, get)
599 * Negotiate the data size. This is a type 1 parameter and
600 * will be negotiated independently for each station
603 static int irlap_param_data_size(void *instance, irda_param_t *param, int get)
605 struct irlap_cb *self = (struct irlap_cb *) instance;
607 ASSERT(self != NULL, return -1;);
608 ASSERT(self->magic == LAP_MAGIC, return -1;);
611 param->pv.i = self->qos_rx.data_size.bits;
613 self->qos_tx.data_size.bits = (__u8) param->pv.i;
619 * Function irlap_param_window_size (instance, param, get)
621 * Negotiate the window size. This is a type 1 parameter and
622 * will be negotiated independently for each station
625 static int irlap_param_window_size(void *instance, irda_param_t *param,
628 struct irlap_cb *self = (struct irlap_cb *) instance;
630 ASSERT(self != NULL, return -1;);
631 ASSERT(self->magic == LAP_MAGIC, return -1;);
634 param->pv.i = self->qos_rx.window_size.bits;
636 self->qos_tx.window_size.bits = (__u8) param->pv.i;
642 * Function irlap_param_additional_bofs (instance, param, get)
644 * Negotiate additional BOF characters. This is a type 1 parameter and
645 * will be negotiated independently for each station.
647 static int irlap_param_additional_bofs(void *instance, irda_param_t *param, int get)
649 struct irlap_cb *self = (struct irlap_cb *) instance;
651 ASSERT(self != NULL, return -1;);
652 ASSERT(self->magic == LAP_MAGIC, return -1;);
655 param->pv.i = self->qos_rx.additional_bofs.bits;
657 self->qos_tx.additional_bofs.bits = (__u8) param->pv.i;
663 * Function irlap_param_min_turn_time (instance, param, get)
665 * Negotiate the minimum turn around time. This is a type 1 parameter and
666 * will be negotiated independently for each station
668 static int irlap_param_min_turn_time(void *instance, irda_param_t *param,
671 struct irlap_cb *self = (struct irlap_cb *) instance;
673 ASSERT(self != NULL, return -1;);
674 ASSERT(self->magic == LAP_MAGIC, return -1;);
677 param->pv.i = self->qos_rx.min_turn_time.bits;
679 self->qos_tx.min_turn_time.bits = (__u8) param->pv.i;
685 * Function irlap_max_line_capacity (speed, max_turn_time, min_turn_time)
687 * Calculate the maximum line capacity
690 __u32 irlap_max_line_capacity(__u32 speed, __u32 max_turn_time)
695 IRDA_DEBUG(2, __FUNCTION__ "(), speed=%d, max_turn_time=%d\n",
696 speed, max_turn_time);
698 i = value_index(speed, baud_rates, 10);
699 j = value_index(max_turn_time, max_turn_times, 4);
701 ASSERT(((i >=0) && (i <=10)), return 0;);
702 ASSERT(((j >=0) && (j <=4)), return 0;);
704 line_capacity = max_line_capacities[i][j];
706 IRDA_DEBUG(2, __FUNCTION__ "(), line capacity=%d bytes\n",
709 return line_capacity;
712 __u32 irlap_requested_line_capacity(struct qos_info *qos)
713 { __u32 line_capacity;
715 line_capacity = qos->window_size.value *
716 (qos->data_size.value + 6 + qos->additional_bofs.value) +
717 irlap_min_turn_time_in_bytes(qos->baud_rate.value,
718 qos->min_turn_time.value);
720 IRDA_DEBUG(2, __FUNCTION__ "(), requested line capacity=%d\n",
723 return line_capacity;
726 void irda_qos_bits_to_value(struct qos_info *qos)
730 ASSERT(qos != NULL, return;);
732 index = msb_index(qos->baud_rate.bits);
733 qos->baud_rate.value = baud_rates[index];
735 index = msb_index(qos->data_size.bits);
736 qos->data_size.value = data_sizes[index];
738 index = msb_index(qos->window_size.bits);
739 qos->window_size.value = index+1;
741 index = msb_index(qos->min_turn_time.bits);
742 qos->min_turn_time.value = min_turn_times[index];
744 index = msb_index(qos->max_turn_time.bits);
745 qos->max_turn_time.value = max_turn_times[index];
747 index = msb_index(qos->link_disc_time.bits);
748 qos->link_disc_time.value = link_disc_times[index];
750 index = msb_index(qos->additional_bofs.bits);
751 qos->additional_bofs.value = add_bofs[index];