/*
|
* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
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* Copyright (C) 2006 Andrey Volkov, Varma Electronics
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* Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the version 2 of the GNU General Public License
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* as published by the Free Software Foundation
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
|
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/workqueue.h>
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#include <linux/can.h>
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#include <linux/can/dev.h>
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#include <linux/can/skb.h>
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#include <linux/can/netlink.h>
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#include <linux/can/led.h>
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#include <linux/of.h>
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#include <net/rtnetlink.h>
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#define MOD_DESC "CAN device driver interface"
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MODULE_DESCRIPTION(MOD_DESC);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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/* CAN DLC to real data length conversion helpers */
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static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
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8, 12, 16, 20, 24, 32, 48, 64};
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/* get data length from can_dlc with sanitized can_dlc */
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u8 can_dlc2len(u8 can_dlc)
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{
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return dlc2len[can_dlc & 0x0F];
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}
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EXPORT_SYMBOL_GPL(can_dlc2len);
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static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */
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9, 9, 9, 9, /* 9 - 12 */
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10, 10, 10, 10, /* 13 - 16 */
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11, 11, 11, 11, /* 17 - 20 */
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12, 12, 12, 12, /* 21 - 24 */
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13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */
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14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */
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14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */
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15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */
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15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */
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/* map the sanitized data length to an appropriate data length code */
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u8 can_len2dlc(u8 len)
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{
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if (unlikely(len > 64))
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return 0xF;
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return len2dlc[len];
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}
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EXPORT_SYMBOL_GPL(can_len2dlc);
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#ifdef CONFIG_CAN_CALC_BITTIMING
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#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
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#define CAN_CALC_SYNC_SEG 1
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/*
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* Bit-timing calculation derived from:
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*
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* Code based on LinCAN sources and H8S2638 project
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* Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
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* Copyright 2005 Stanislav Marek
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* email: pisa@cmp.felk.cvut.cz
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*
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* Calculates proper bit-timing parameters for a specified bit-rate
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* and sample-point, which can then be used to set the bit-timing
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* registers of the CAN controller. You can find more information
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* in the header file linux/can/netlink.h.
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*/
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static int can_update_sample_point(const struct can_bittiming_const *btc,
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unsigned int sample_point_nominal, unsigned int tseg,
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unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
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unsigned int *sample_point_error_ptr)
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{
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unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
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unsigned int sample_point, best_sample_point = 0;
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unsigned int tseg1, tseg2;
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int i;
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for (i = 0; i <= 1; i++) {
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tseg2 = tseg + CAN_CALC_SYNC_SEG - (sample_point_nominal * (tseg + CAN_CALC_SYNC_SEG)) / 1000 - i;
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tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
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tseg1 = tseg - tseg2;
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if (tseg1 > btc->tseg1_max) {
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tseg1 = btc->tseg1_max;
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tseg2 = tseg - tseg1;
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}
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sample_point = 1000 * (tseg + CAN_CALC_SYNC_SEG - tseg2) / (tseg + CAN_CALC_SYNC_SEG);
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sample_point_error = abs(sample_point_nominal - sample_point);
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if ((sample_point <= sample_point_nominal) && (sample_point_error < best_sample_point_error)) {
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best_sample_point = sample_point;
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best_sample_point_error = sample_point_error;
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*tseg1_ptr = tseg1;
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*tseg2_ptr = tseg2;
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}
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}
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if (sample_point_error_ptr)
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*sample_point_error_ptr = best_sample_point_error;
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return best_sample_point;
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}
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static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
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const struct can_bittiming_const *btc)
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{
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struct can_priv *priv = netdev_priv(dev);
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unsigned int bitrate; /* current bitrate */
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unsigned int bitrate_error; /* difference between current and nominal value */
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unsigned int best_bitrate_error = UINT_MAX;
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unsigned int sample_point_error; /* difference between current and nominal value */
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unsigned int best_sample_point_error = UINT_MAX;
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unsigned int sample_point_nominal; /* nominal sample point */
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unsigned int best_tseg = 0; /* current best value for tseg */
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unsigned int best_brp = 0; /* current best value for brp */
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unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
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u64 v64;
|
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/* Use CiA recommended sample points */
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if (bt->sample_point) {
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sample_point_nominal = bt->sample_point;
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} else {
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if (bt->bitrate > 800000)
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sample_point_nominal = 750;
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else if (bt->bitrate > 500000)
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sample_point_nominal = 800;
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else
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sample_point_nominal = 875;
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}
|
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/* tseg even = round down, odd = round up */
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for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
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tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
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tsegall = CAN_CALC_SYNC_SEG + tseg / 2;
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/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
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brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
|
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/* choose brp step which is possible in system */
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brp = (brp / btc->brp_inc) * btc->brp_inc;
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if ((brp < btc->brp_min) || (brp > btc->brp_max))
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continue;
|
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bitrate = priv->clock.freq / (brp * tsegall);
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bitrate_error = abs(bt->bitrate - bitrate);
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/* tseg brp biterror */
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if (bitrate_error > best_bitrate_error)
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continue;
|
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/* reset sample point error if we have a better bitrate */
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if (bitrate_error < best_bitrate_error)
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best_sample_point_error = UINT_MAX;
|
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can_update_sample_point(btc, sample_point_nominal, tseg / 2, &tseg1, &tseg2, &sample_point_error);
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if (sample_point_error > best_sample_point_error)
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continue;
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best_sample_point_error = sample_point_error;
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best_bitrate_error = bitrate_error;
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best_tseg = tseg / 2;
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best_brp = brp;
|
|
if (bitrate_error == 0 && sample_point_error == 0)
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break;
|
}
|
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if (best_bitrate_error) {
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/* Error in one-tenth of a percent */
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v64 = (u64)best_bitrate_error * 1000;
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do_div(v64, bt->bitrate);
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bitrate_error = (u32)v64;
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if (bitrate_error > CAN_CALC_MAX_ERROR) {
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netdev_err(dev,
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"bitrate error %d.%d%% too high\n",
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bitrate_error / 10, bitrate_error % 10);
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return -EDOM;
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}
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netdev_warn(dev, "bitrate error %d.%d%%\n",
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bitrate_error / 10, bitrate_error % 10);
|
}
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/* real sample point */
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bt->sample_point = can_update_sample_point(btc, sample_point_nominal, best_tseg,
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&tseg1, &tseg2, NULL);
|
|
v64 = (u64)best_brp * 1000 * 1000 * 1000;
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do_div(v64, priv->clock.freq);
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bt->tq = (u32)v64;
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bt->prop_seg = tseg1 / 2;
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bt->phase_seg1 = tseg1 - bt->prop_seg;
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bt->phase_seg2 = tseg2;
|
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/* check for sjw user settings */
|
if (!bt->sjw || !btc->sjw_max) {
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bt->sjw = 1;
|
} else {
|
/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
|
if (bt->sjw > btc->sjw_max)
|
bt->sjw = btc->sjw_max;
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/* bt->sjw must not be higher than tseg2 */
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if (tseg2 < bt->sjw)
|
bt->sjw = tseg2;
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}
|
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bt->brp = best_brp;
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/* real bitrate */
|
bt->bitrate = priv->clock.freq / (bt->brp * (CAN_CALC_SYNC_SEG + tseg1 + tseg2));
|
|
return 0;
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}
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#else /* !CONFIG_CAN_CALC_BITTIMING */
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static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
|
const struct can_bittiming_const *btc)
|
{
|
netdev_err(dev, "bit-timing calculation not available\n");
|
return -EINVAL;
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}
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#endif /* CONFIG_CAN_CALC_BITTIMING */
|
|
/*
|
* Checks the validity of the specified bit-timing parameters prop_seg,
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* phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
|
* prescaler value brp. You can find more information in the header
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* file linux/can/netlink.h.
|
*/
|
static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
|
const struct can_bittiming_const *btc)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
int tseg1, alltseg;
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u64 brp64;
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|
tseg1 = bt->prop_seg + bt->phase_seg1;
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if (!bt->sjw)
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bt->sjw = 1;
|
if (bt->sjw > btc->sjw_max ||
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tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
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bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
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return -ERANGE;
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|
brp64 = (u64)priv->clock.freq * (u64)bt->tq;
|
if (btc->brp_inc > 1)
|
do_div(brp64, btc->brp_inc);
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brp64 += 500000000UL - 1;
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do_div(brp64, 1000000000UL); /* the practicable BRP */
|
if (btc->brp_inc > 1)
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brp64 *= btc->brp_inc;
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bt->brp = (u32)brp64;
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|
if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
|
return -EINVAL;
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|
alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
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bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
|
bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
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|
return 0;
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}
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/* Checks the validity of predefined bitrate settings */
|
static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
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const u32 *bitrate_const,
|
const unsigned int bitrate_const_cnt)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
unsigned int i;
|
|
for (i = 0; i < bitrate_const_cnt; i++) {
|
if (bt->bitrate == bitrate_const[i])
|
break;
|
}
|
|
if (i >= priv->bitrate_const_cnt)
|
return -EINVAL;
|
|
return 0;
|
}
|
|
static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
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const struct can_bittiming_const *btc,
|
const u32 *bitrate_const,
|
const unsigned int bitrate_const_cnt)
|
{
|
int err;
|
|
/*
|
* Depending on the given can_bittiming parameter structure the CAN
|
* timing parameters are calculated based on the provided bitrate OR
|
* alternatively the CAN timing parameters (tq, prop_seg, etc.) are
|
* provided directly which are then checked and fixed up.
|
*/
|
if (!bt->tq && bt->bitrate && btc)
|
err = can_calc_bittiming(dev, bt, btc);
|
else if (bt->tq && !bt->bitrate && btc)
|
err = can_fixup_bittiming(dev, bt, btc);
|
else if (!bt->tq && bt->bitrate && bitrate_const)
|
err = can_validate_bitrate(dev, bt, bitrate_const,
|
bitrate_const_cnt);
|
else
|
err = -EINVAL;
|
|
return err;
|
}
|
|
static void can_update_state_error_stats(struct net_device *dev,
|
enum can_state new_state)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
if (new_state <= priv->state)
|
return;
|
|
switch (new_state) {
|
case CAN_STATE_ERROR_WARNING:
|
priv->can_stats.error_warning++;
|
break;
|
case CAN_STATE_ERROR_PASSIVE:
|
priv->can_stats.error_passive++;
|
break;
|
case CAN_STATE_BUS_OFF:
|
priv->can_stats.bus_off++;
|
break;
|
default:
|
break;
|
}
|
}
|
|
static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
|
{
|
switch (state) {
|
case CAN_STATE_ERROR_ACTIVE:
|
return CAN_ERR_CRTL_ACTIVE;
|
case CAN_STATE_ERROR_WARNING:
|
return CAN_ERR_CRTL_TX_WARNING;
|
case CAN_STATE_ERROR_PASSIVE:
|
return CAN_ERR_CRTL_TX_PASSIVE;
|
default:
|
return 0;
|
}
|
}
|
|
static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
|
{
|
switch (state) {
|
case CAN_STATE_ERROR_ACTIVE:
|
return CAN_ERR_CRTL_ACTIVE;
|
case CAN_STATE_ERROR_WARNING:
|
return CAN_ERR_CRTL_RX_WARNING;
|
case CAN_STATE_ERROR_PASSIVE:
|
return CAN_ERR_CRTL_RX_PASSIVE;
|
default:
|
return 0;
|
}
|
}
|
|
void can_change_state(struct net_device *dev, struct can_frame *cf,
|
enum can_state tx_state, enum can_state rx_state)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
enum can_state new_state = max(tx_state, rx_state);
|
|
if (unlikely(new_state == priv->state)) {
|
netdev_warn(dev, "%s: oops, state did not change", __func__);
|
return;
|
}
|
|
netdev_dbg(dev, "New error state: %d\n", new_state);
|
|
can_update_state_error_stats(dev, new_state);
|
priv->state = new_state;
|
|
if (!cf)
|
return;
|
|
if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
|
cf->can_id |= CAN_ERR_BUSOFF;
|
return;
|
}
|
|
cf->can_id |= CAN_ERR_CRTL;
|
cf->data[1] |= tx_state >= rx_state ?
|
can_tx_state_to_frame(dev, tx_state) : 0;
|
cf->data[1] |= tx_state <= rx_state ?
|
can_rx_state_to_frame(dev, rx_state) : 0;
|
}
|
EXPORT_SYMBOL_GPL(can_change_state);
|
|
/*
|
* Local echo of CAN messages
|
*
|
* CAN network devices *should* support a local echo functionality
|
* (see Documentation/networking/can.rst). To test the handling of CAN
|
* interfaces that do not support the local echo both driver types are
|
* implemented. In the case that the driver does not support the echo
|
* the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
|
* to perform the echo as a fallback solution.
|
*/
|
static void can_flush_echo_skb(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
struct net_device_stats *stats = &dev->stats;
|
int i;
|
|
for (i = 0; i < priv->echo_skb_max; i++) {
|
if (priv->echo_skb[i]) {
|
kfree_skb(priv->echo_skb[i]);
|
priv->echo_skb[i] = NULL;
|
stats->tx_dropped++;
|
stats->tx_aborted_errors++;
|
}
|
}
|
}
|
|
/*
|
* Put the skb on the stack to be looped backed locally lateron
|
*
|
* The function is typically called in the start_xmit function
|
* of the device driver. The driver must protect access to
|
* priv->echo_skb, if necessary.
|
*/
|
void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
|
unsigned int idx)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
BUG_ON(idx >= priv->echo_skb_max);
|
|
/* check flag whether this packet has to be looped back */
|
if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
|
(skb->protocol != htons(ETH_P_CAN) &&
|
skb->protocol != htons(ETH_P_CANFD))) {
|
kfree_skb(skb);
|
return;
|
}
|
|
if (!priv->echo_skb[idx]) {
|
|
skb = can_create_echo_skb(skb);
|
if (!skb)
|
return;
|
|
/* make settings for echo to reduce code in irq context */
|
skb->pkt_type = PACKET_BROADCAST;
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
skb->dev = dev;
|
|
/* save this skb for tx interrupt echo handling */
|
priv->echo_skb[idx] = skb;
|
} else {
|
/* locking problem with netif_stop_queue() ?? */
|
netdev_err(dev, "%s: BUG! echo_skb is occupied!\n", __func__);
|
kfree_skb(skb);
|
}
|
}
|
EXPORT_SYMBOL_GPL(can_put_echo_skb);
|
|
struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
if (idx >= priv->echo_skb_max) {
|
netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
|
__func__, idx, priv->echo_skb_max);
|
return NULL;
|
}
|
|
if (priv->echo_skb[idx]) {
|
/* Using "struct canfd_frame::len" for the frame
|
* length is supported on both CAN and CANFD frames.
|
*/
|
struct sk_buff *skb = priv->echo_skb[idx];
|
struct canfd_frame *cf = (struct canfd_frame *)skb->data;
|
|
/* get the real payload length for netdev statistics */
|
if (cf->can_id & CAN_RTR_FLAG)
|
*len_ptr = 0;
|
else
|
*len_ptr = cf->len;
|
|
priv->echo_skb[idx] = NULL;
|
|
return skb;
|
}
|
|
return NULL;
|
}
|
|
/*
|
* Get the skb from the stack and loop it back locally
|
*
|
* The function is typically called when the TX done interrupt
|
* is handled in the device driver. The driver must protect
|
* access to priv->echo_skb, if necessary.
|
*/
|
unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
|
{
|
struct sk_buff *skb;
|
u8 len;
|
|
skb = __can_get_echo_skb(dev, idx, &len);
|
if (!skb)
|
return 0;
|
|
skb_get(skb);
|
if (netif_rx(skb) == NET_RX_SUCCESS)
|
dev_consume_skb_any(skb);
|
else
|
dev_kfree_skb_any(skb);
|
|
return len;
|
}
|
EXPORT_SYMBOL_GPL(can_get_echo_skb);
|
|
/*
|
* Remove the skb from the stack and free it.
|
*
|
* The function is typically called when TX failed.
|
*/
|
void can_free_echo_skb(struct net_device *dev, unsigned int idx)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
BUG_ON(idx >= priv->echo_skb_max);
|
|
if (priv->echo_skb[idx]) {
|
dev_kfree_skb_any(priv->echo_skb[idx]);
|
priv->echo_skb[idx] = NULL;
|
}
|
}
|
EXPORT_SYMBOL_GPL(can_free_echo_skb);
|
|
/*
|
* CAN device restart for bus-off recovery
|
*/
|
static void can_restart(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
struct net_device_stats *stats = &dev->stats;
|
struct sk_buff *skb;
|
struct can_frame *cf;
|
int err;
|
|
BUG_ON(netif_carrier_ok(dev));
|
|
/*
|
* No synchronization needed because the device is bus-off and
|
* no messages can come in or go out.
|
*/
|
can_flush_echo_skb(dev);
|
|
/* send restart message upstream */
|
skb = alloc_can_err_skb(dev, &cf);
|
if (skb == NULL) {
|
err = -ENOMEM;
|
goto restart;
|
}
|
cf->can_id |= CAN_ERR_RESTARTED;
|
|
stats->rx_packets++;
|
stats->rx_bytes += cf->can_dlc;
|
|
netif_rx_ni(skb);
|
|
restart:
|
netdev_dbg(dev, "restarted\n");
|
priv->can_stats.restarts++;
|
|
/* Now restart the device */
|
err = priv->do_set_mode(dev, CAN_MODE_START);
|
|
netif_carrier_on(dev);
|
if (err)
|
netdev_err(dev, "Error %d during restart", err);
|
}
|
|
static void can_restart_work(struct work_struct *work)
|
{
|
struct delayed_work *dwork = to_delayed_work(work);
|
struct can_priv *priv = container_of(dwork, struct can_priv, restart_work);
|
|
can_restart(priv->dev);
|
}
|
|
int can_restart_now(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
/*
|
* A manual restart is only permitted if automatic restart is
|
* disabled and the device is in the bus-off state
|
*/
|
if (priv->restart_ms)
|
return -EINVAL;
|
if (priv->state != CAN_STATE_BUS_OFF)
|
return -EBUSY;
|
|
cancel_delayed_work_sync(&priv->restart_work);
|
can_restart(dev);
|
|
return 0;
|
}
|
|
/*
|
* CAN bus-off
|
*
|
* This functions should be called when the device goes bus-off to
|
* tell the netif layer that no more packets can be sent or received.
|
* If enabled, a timer is started to trigger bus-off recovery.
|
*/
|
void can_bus_off(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
netdev_info(dev, "bus-off\n");
|
|
netif_carrier_off(dev);
|
|
if (priv->restart_ms)
|
schedule_delayed_work(&priv->restart_work,
|
msecs_to_jiffies(priv->restart_ms));
|
}
|
EXPORT_SYMBOL_GPL(can_bus_off);
|
|
static void can_setup(struct net_device *dev)
|
{
|
dev->type = ARPHRD_CAN;
|
dev->mtu = CAN_MTU;
|
dev->hard_header_len = 0;
|
dev->addr_len = 0;
|
dev->tx_queue_len = 10;
|
|
/* New-style flags. */
|
dev->flags = IFF_NOARP;
|
dev->features = NETIF_F_HW_CSUM;
|
}
|
|
struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
|
{
|
struct sk_buff *skb;
|
|
skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
|
sizeof(struct can_frame));
|
if (unlikely(!skb))
|
return NULL;
|
|
skb->protocol = htons(ETH_P_CAN);
|
skb->pkt_type = PACKET_BROADCAST;
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
skb_reset_mac_header(skb);
|
skb_reset_network_header(skb);
|
skb_reset_transport_header(skb);
|
|
can_skb_reserve(skb);
|
can_skb_prv(skb)->ifindex = dev->ifindex;
|
can_skb_prv(skb)->skbcnt = 0;
|
|
*cf = skb_put_zero(skb, sizeof(struct can_frame));
|
|
return skb;
|
}
|
EXPORT_SYMBOL_GPL(alloc_can_skb);
|
|
struct sk_buff *alloc_canfd_skb(struct net_device *dev,
|
struct canfd_frame **cfd)
|
{
|
struct sk_buff *skb;
|
|
skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
|
sizeof(struct canfd_frame));
|
if (unlikely(!skb))
|
return NULL;
|
|
skb->protocol = htons(ETH_P_CANFD);
|
skb->pkt_type = PACKET_BROADCAST;
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
skb_reset_mac_header(skb);
|
skb_reset_network_header(skb);
|
skb_reset_transport_header(skb);
|
|
can_skb_reserve(skb);
|
can_skb_prv(skb)->ifindex = dev->ifindex;
|
can_skb_prv(skb)->skbcnt = 0;
|
|
*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
|
|
return skb;
|
}
|
EXPORT_SYMBOL_GPL(alloc_canfd_skb);
|
|
struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
|
{
|
struct sk_buff *skb;
|
|
skb = alloc_can_skb(dev, cf);
|
if (unlikely(!skb))
|
return NULL;
|
|
(*cf)->can_id = CAN_ERR_FLAG;
|
(*cf)->can_dlc = CAN_ERR_DLC;
|
|
return skb;
|
}
|
EXPORT_SYMBOL_GPL(alloc_can_err_skb);
|
|
/*
|
* Allocate and setup space for the CAN network device
|
*/
|
struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
|
unsigned int txqs, unsigned int rxqs)
|
{
|
struct net_device *dev;
|
struct can_priv *priv;
|
int size;
|
|
if (echo_skb_max)
|
size = ALIGN(sizeof_priv, sizeof(struct sk_buff *)) +
|
echo_skb_max * sizeof(struct sk_buff *);
|
else
|
size = sizeof_priv;
|
|
dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
|
txqs, rxqs);
|
if (!dev)
|
return NULL;
|
|
priv = netdev_priv(dev);
|
priv->dev = dev;
|
|
if (echo_skb_max) {
|
priv->echo_skb_max = echo_skb_max;
|
priv->echo_skb = (void *)priv +
|
ALIGN(sizeof_priv, sizeof(struct sk_buff *));
|
}
|
|
priv->state = CAN_STATE_STOPPED;
|
|
INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
|
|
return dev;
|
}
|
EXPORT_SYMBOL_GPL(alloc_candev_mqs);
|
|
/*
|
* Free space of the CAN network device
|
*/
|
void free_candev(struct net_device *dev)
|
{
|
free_netdev(dev);
|
}
|
EXPORT_SYMBOL_GPL(free_candev);
|
|
/*
|
* changing MTU and control mode for CAN/CANFD devices
|
*/
|
int can_change_mtu(struct net_device *dev, int new_mtu)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
/* Do not allow changing the MTU while running */
|
if (dev->flags & IFF_UP)
|
return -EBUSY;
|
|
/* allow change of MTU according to the CANFD ability of the device */
|
switch (new_mtu) {
|
case CAN_MTU:
|
/* 'CANFD-only' controllers can not switch to CAN_MTU */
|
if (priv->ctrlmode_static & CAN_CTRLMODE_FD)
|
return -EINVAL;
|
|
priv->ctrlmode &= ~CAN_CTRLMODE_FD;
|
break;
|
|
case CANFD_MTU:
|
/* check for potential CANFD ability */
|
if (!(priv->ctrlmode_supported & CAN_CTRLMODE_FD) &&
|
!(priv->ctrlmode_static & CAN_CTRLMODE_FD))
|
return -EINVAL;
|
|
priv->ctrlmode |= CAN_CTRLMODE_FD;
|
break;
|
|
default:
|
return -EINVAL;
|
}
|
|
dev->mtu = new_mtu;
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(can_change_mtu);
|
|
/*
|
* Common open function when the device gets opened.
|
*
|
* This function should be called in the open function of the device
|
* driver.
|
*/
|
int open_candev(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
if (!priv->bittiming.bitrate) {
|
netdev_err(dev, "bit-timing not yet defined\n");
|
return -EINVAL;
|
}
|
|
/* For CAN FD the data bitrate has to be >= the arbitration bitrate */
|
if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
|
(!priv->data_bittiming.bitrate ||
|
(priv->data_bittiming.bitrate < priv->bittiming.bitrate))) {
|
netdev_err(dev, "incorrect/missing data bit-timing\n");
|
return -EINVAL;
|
}
|
|
/* Switch carrier on if device was stopped while in bus-off state */
|
if (!netif_carrier_ok(dev))
|
netif_carrier_on(dev);
|
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(open_candev);
|
|
#ifdef CONFIG_OF
|
/* Common function that can be used to understand the limitation of
|
* a transceiver when it provides no means to determine these limitations
|
* at runtime.
|
*/
|
void of_can_transceiver(struct net_device *dev)
|
{
|
struct device_node *dn;
|
struct can_priv *priv = netdev_priv(dev);
|
struct device_node *np = dev->dev.parent->of_node;
|
int ret;
|
|
dn = of_get_child_by_name(np, "can-transceiver");
|
if (!dn)
|
return;
|
|
ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
|
of_node_put(dn);
|
if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
|
netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
|
}
|
EXPORT_SYMBOL_GPL(of_can_transceiver);
|
#endif
|
|
/*
|
* Common close function for cleanup before the device gets closed.
|
*
|
* This function should be called in the close function of the device
|
* driver.
|
*/
|
void close_candev(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
cancel_delayed_work_sync(&priv->restart_work);
|
can_flush_echo_skb(dev);
|
}
|
EXPORT_SYMBOL_GPL(close_candev);
|
|
/*
|
* CAN netlink interface
|
*/
|
static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
|
[IFLA_CAN_STATE] = { .type = NLA_U32 },
|
[IFLA_CAN_CTRLMODE] = { .len = sizeof(struct can_ctrlmode) },
|
[IFLA_CAN_RESTART_MS] = { .type = NLA_U32 },
|
[IFLA_CAN_RESTART] = { .type = NLA_U32 },
|
[IFLA_CAN_BITTIMING] = { .len = sizeof(struct can_bittiming) },
|
[IFLA_CAN_BITTIMING_CONST]
|
= { .len = sizeof(struct can_bittiming_const) },
|
[IFLA_CAN_CLOCK] = { .len = sizeof(struct can_clock) },
|
[IFLA_CAN_BERR_COUNTER] = { .len = sizeof(struct can_berr_counter) },
|
[IFLA_CAN_DATA_BITTIMING]
|
= { .len = sizeof(struct can_bittiming) },
|
[IFLA_CAN_DATA_BITTIMING_CONST]
|
= { .len = sizeof(struct can_bittiming_const) },
|
[IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
|
};
|
|
static int can_validate(struct nlattr *tb[], struct nlattr *data[],
|
struct netlink_ext_ack *extack)
|
{
|
bool is_can_fd = false;
|
|
/* Make sure that valid CAN FD configurations always consist of
|
* - nominal/arbitration bittiming
|
* - data bittiming
|
* - control mode with CAN_CTRLMODE_FD set
|
*/
|
|
if (!data)
|
return 0;
|
|
if (data[IFLA_CAN_CTRLMODE]) {
|
struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
|
|
is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
|
}
|
|
if (is_can_fd) {
|
if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
|
return -EOPNOTSUPP;
|
}
|
|
if (data[IFLA_CAN_DATA_BITTIMING]) {
|
if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
|
return -EOPNOTSUPP;
|
}
|
|
return 0;
|
}
|
|
static int can_changelink(struct net_device *dev, struct nlattr *tb[],
|
struct nlattr *data[],
|
struct netlink_ext_ack *extack)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
int err;
|
|
/* We need synchronization with dev->stop() */
|
ASSERT_RTNL();
|
|
if (data[IFLA_CAN_BITTIMING]) {
|
struct can_bittiming bt;
|
|
/* Do not allow changing bittiming while running */
|
if (dev->flags & IFF_UP)
|
return -EBUSY;
|
|
/* Calculate bittiming parameters based on
|
* bittiming_const if set, otherwise pass bitrate
|
* directly via do_set_bitrate(). Bail out if neither
|
* is given.
|
*/
|
if (!priv->bittiming_const && !priv->do_set_bittiming)
|
return -EOPNOTSUPP;
|
|
memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
|
err = can_get_bittiming(dev, &bt,
|
priv->bittiming_const,
|
priv->bitrate_const,
|
priv->bitrate_const_cnt);
|
if (err)
|
return err;
|
|
if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
|
netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
|
priv->bitrate_max);
|
return -EINVAL;
|
}
|
|
memcpy(&priv->bittiming, &bt, sizeof(bt));
|
|
if (priv->do_set_bittiming) {
|
/* Finally, set the bit-timing registers */
|
err = priv->do_set_bittiming(dev);
|
if (err)
|
return err;
|
}
|
}
|
|
if (data[IFLA_CAN_CTRLMODE]) {
|
struct can_ctrlmode *cm;
|
u32 ctrlstatic;
|
u32 maskedflags;
|
|
/* Do not allow changing controller mode while running */
|
if (dev->flags & IFF_UP)
|
return -EBUSY;
|
cm = nla_data(data[IFLA_CAN_CTRLMODE]);
|
ctrlstatic = priv->ctrlmode_static;
|
maskedflags = cm->flags & cm->mask;
|
|
/* check whether provided bits are allowed to be passed */
|
if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
|
return -EOPNOTSUPP;
|
|
/* do not check for static fd-non-iso if 'fd' is disabled */
|
if (!(maskedflags & CAN_CTRLMODE_FD))
|
ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
|
|
/* make sure static options are provided by configuration */
|
if ((maskedflags & ctrlstatic) != ctrlstatic)
|
return -EOPNOTSUPP;
|
|
/* clear bits to be modified and copy the flag values */
|
priv->ctrlmode &= ~cm->mask;
|
priv->ctrlmode |= maskedflags;
|
|
/* CAN_CTRLMODE_FD can only be set when driver supports FD */
|
if (priv->ctrlmode & CAN_CTRLMODE_FD)
|
dev->mtu = CANFD_MTU;
|
else
|
dev->mtu = CAN_MTU;
|
}
|
|
if (data[IFLA_CAN_RESTART_MS]) {
|
/* Do not allow changing restart delay while running */
|
if (dev->flags & IFF_UP)
|
return -EBUSY;
|
priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
|
}
|
|
if (data[IFLA_CAN_RESTART]) {
|
/* Do not allow a restart while not running */
|
if (!(dev->flags & IFF_UP))
|
return -EINVAL;
|
err = can_restart_now(dev);
|
if (err)
|
return err;
|
}
|
|
if (data[IFLA_CAN_DATA_BITTIMING]) {
|
struct can_bittiming dbt;
|
|
/* Do not allow changing bittiming while running */
|
if (dev->flags & IFF_UP)
|
return -EBUSY;
|
|
/* Calculate bittiming parameters based on
|
* data_bittiming_const if set, otherwise pass bitrate
|
* directly via do_set_bitrate(). Bail out if neither
|
* is given.
|
*/
|
if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
|
return -EOPNOTSUPP;
|
|
memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
|
sizeof(dbt));
|
err = can_get_bittiming(dev, &dbt,
|
priv->data_bittiming_const,
|
priv->data_bitrate_const,
|
priv->data_bitrate_const_cnt);
|
if (err)
|
return err;
|
|
if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
|
netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
|
priv->bitrate_max);
|
return -EINVAL;
|
}
|
|
memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
|
|
if (priv->do_set_data_bittiming) {
|
/* Finally, set the bit-timing registers */
|
err = priv->do_set_data_bittiming(dev);
|
if (err)
|
return err;
|
}
|
}
|
|
if (data[IFLA_CAN_TERMINATION]) {
|
const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
|
const unsigned int num_term = priv->termination_const_cnt;
|
unsigned int i;
|
|
if (!priv->do_set_termination)
|
return -EOPNOTSUPP;
|
|
/* check whether given value is supported by the interface */
|
for (i = 0; i < num_term; i++) {
|
if (termval == priv->termination_const[i])
|
break;
|
}
|
if (i >= num_term)
|
return -EINVAL;
|
|
/* Finally, set the termination value */
|
err = priv->do_set_termination(dev, termval);
|
if (err)
|
return err;
|
|
priv->termination = termval;
|
}
|
|
return 0;
|
}
|
|
static size_t can_get_size(const struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
size_t size = 0;
|
|
if (priv->bittiming.bitrate) /* IFLA_CAN_BITTIMING */
|
size += nla_total_size(sizeof(struct can_bittiming));
|
if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
|
size += nla_total_size(sizeof(struct can_bittiming_const));
|
size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
|
size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
|
size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
|
size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
|
if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
|
size += nla_total_size(sizeof(struct can_berr_counter));
|
if (priv->data_bittiming.bitrate) /* IFLA_CAN_DATA_BITTIMING */
|
size += nla_total_size(sizeof(struct can_bittiming));
|
if (priv->data_bittiming_const) /* IFLA_CAN_DATA_BITTIMING_CONST */
|
size += nla_total_size(sizeof(struct can_bittiming_const));
|
if (priv->termination_const) {
|
size += nla_total_size(sizeof(priv->termination)); /* IFLA_CAN_TERMINATION */
|
size += nla_total_size(sizeof(*priv->termination_const) * /* IFLA_CAN_TERMINATION_CONST */
|
priv->termination_const_cnt);
|
}
|
if (priv->bitrate_const) /* IFLA_CAN_BITRATE_CONST */
|
size += nla_total_size(sizeof(*priv->bitrate_const) *
|
priv->bitrate_const_cnt);
|
if (priv->data_bitrate_const) /* IFLA_CAN_DATA_BITRATE_CONST */
|
size += nla_total_size(sizeof(*priv->data_bitrate_const) *
|
priv->data_bitrate_const_cnt);
|
size += sizeof(priv->bitrate_max); /* IFLA_CAN_BITRATE_MAX */
|
|
return size;
|
}
|
|
static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
struct can_ctrlmode cm = {.flags = priv->ctrlmode};
|
struct can_berr_counter bec = { };
|
enum can_state state = priv->state;
|
|
if (priv->do_get_state)
|
priv->do_get_state(dev, &state);
|
|
if ((priv->bittiming.bitrate &&
|
nla_put(skb, IFLA_CAN_BITTIMING,
|
sizeof(priv->bittiming), &priv->bittiming)) ||
|
|
(priv->bittiming_const &&
|
nla_put(skb, IFLA_CAN_BITTIMING_CONST,
|
sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
|
|
nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
|
nla_put_u32(skb, IFLA_CAN_STATE, state) ||
|
nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
|
nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
|
|
(priv->do_get_berr_counter &&
|
!priv->do_get_berr_counter(dev, &bec) &&
|
nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
|
|
(priv->data_bittiming.bitrate &&
|
nla_put(skb, IFLA_CAN_DATA_BITTIMING,
|
sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
|
|
(priv->data_bittiming_const &&
|
nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
|
sizeof(*priv->data_bittiming_const),
|
priv->data_bittiming_const)) ||
|
|
(priv->termination_const &&
|
(nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
|
nla_put(skb, IFLA_CAN_TERMINATION_CONST,
|
sizeof(*priv->termination_const) *
|
priv->termination_const_cnt,
|
priv->termination_const))) ||
|
|
(priv->bitrate_const &&
|
nla_put(skb, IFLA_CAN_BITRATE_CONST,
|
sizeof(*priv->bitrate_const) *
|
priv->bitrate_const_cnt,
|
priv->bitrate_const)) ||
|
|
(priv->data_bitrate_const &&
|
nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
|
sizeof(*priv->data_bitrate_const) *
|
priv->data_bitrate_const_cnt,
|
priv->data_bitrate_const)) ||
|
|
(nla_put(skb, IFLA_CAN_BITRATE_MAX,
|
sizeof(priv->bitrate_max),
|
&priv->bitrate_max))
|
)
|
|
return -EMSGSIZE;
|
|
return 0;
|
}
|
|
static size_t can_get_xstats_size(const struct net_device *dev)
|
{
|
return sizeof(struct can_device_stats);
|
}
|
|
static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
if (nla_put(skb, IFLA_INFO_XSTATS,
|
sizeof(priv->can_stats), &priv->can_stats))
|
goto nla_put_failure;
|
return 0;
|
|
nla_put_failure:
|
return -EMSGSIZE;
|
}
|
|
static int can_newlink(struct net *src_net, struct net_device *dev,
|
struct nlattr *tb[], struct nlattr *data[],
|
struct netlink_ext_ack *extack)
|
{
|
return -EOPNOTSUPP;
|
}
|
|
static void can_dellink(struct net_device *dev, struct list_head *head)
|
{
|
return;
|
}
|
|
static struct rtnl_link_ops can_link_ops __read_mostly = {
|
.kind = "can",
|
.maxtype = IFLA_CAN_MAX,
|
.policy = can_policy,
|
.setup = can_setup,
|
.validate = can_validate,
|
.newlink = can_newlink,
|
.changelink = can_changelink,
|
.dellink = can_dellink,
|
.get_size = can_get_size,
|
.fill_info = can_fill_info,
|
.get_xstats_size = can_get_xstats_size,
|
.fill_xstats = can_fill_xstats,
|
};
|
|
/*
|
* Register the CAN network device
|
*/
|
int register_candev(struct net_device *dev)
|
{
|
struct can_priv *priv = netdev_priv(dev);
|
|
/* Ensure termination_const, termination_const_cnt and
|
* do_set_termination consistency. All must be either set or
|
* unset.
|
*/
|
if ((!priv->termination_const != !priv->termination_const_cnt) ||
|
(!priv->termination_const != !priv->do_set_termination))
|
return -EINVAL;
|
|
if (!priv->bitrate_const != !priv->bitrate_const_cnt)
|
return -EINVAL;
|
|
if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
|
return -EINVAL;
|
|
dev->rtnl_link_ops = &can_link_ops;
|
netif_carrier_off(dev);
|
|
return register_netdev(dev);
|
}
|
EXPORT_SYMBOL_GPL(register_candev);
|
|
/*
|
* Unregister the CAN network device
|
*/
|
void unregister_candev(struct net_device *dev)
|
{
|
unregister_netdev(dev);
|
}
|
EXPORT_SYMBOL_GPL(unregister_candev);
|
|
/*
|
* Test if a network device is a candev based device
|
* and return the can_priv* if so.
|
*/
|
struct can_priv *safe_candev_priv(struct net_device *dev)
|
{
|
if ((dev->type != ARPHRD_CAN) || (dev->rtnl_link_ops != &can_link_ops))
|
return NULL;
|
|
return netdev_priv(dev);
|
}
|
EXPORT_SYMBOL_GPL(safe_candev_priv);
|
|
static __init int can_dev_init(void)
|
{
|
int err;
|
|
can_led_notifier_init();
|
|
err = rtnl_link_register(&can_link_ops);
|
if (!err)
|
printk(KERN_INFO MOD_DESC "\n");
|
|
return err;
|
}
|
module_init(can_dev_init);
|
|
static __exit void can_dev_exit(void)
|
{
|
rtnl_link_unregister(&can_link_ops);
|
|
can_led_notifier_exit();
|
}
|
module_exit(can_dev_exit);
|
|
MODULE_ALIAS_RTNL_LINK("can");
|
