path: root/drivers/net/can/dev/dev.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
 * Copyright (C) 2006 Andrey Volkov, Varma Electronics
 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/workqueue.h>
#include <linux/can.h>
#include <linux/can/can-ml.h>
#include <linux/can/dev.h>
#include <linux/can/skb.h>
#include <linux/can/netlink.h>
#include <linux/can/led.h>
#include <linux/of.h>
#include <net/rtnetlink.h>

#define MOD_DESC "CAN device driver interface"

MODULE_DESCRIPTION(MOD_DESC);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");

/* CAN DLC to real data length conversion helpers */

static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
			     8, 12, 16, 20, 24, 32, 48, 64};

/* get data length from raw data length code (DLC) */
u8 can_fd_dlc2len(u8 dlc)
{
	return dlc2len[dlc & 0x0F];
}
EXPORT_SYMBOL_GPL(can_fd_dlc2len);

static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,		/* 0 - 8 */
			     9, 9, 9, 9,			/* 9 - 12 */
			     10, 10, 10, 10,			/* 13 - 16 */
			     11, 11, 11, 11,			/* 17 - 20 */
			     12, 12, 12, 12,			/* 21 - 24 */
			     13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
			     14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
			     14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
			     15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
			     15, 15, 15, 15, 15, 15, 15, 15};	/* 57 - 64 */

/* map the sanitized data length to an appropriate data length code */
u8 can_fd_len2dlc(u8 len)
{
	if (unlikely(len > 64))
		return 0xF;

	return len2dlc[len];
}
EXPORT_SYMBOL_GPL(can_fd_len2dlc);

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;
	}
}

static const char *can_get_state_str(const enum can_state state)
{
	switch (state) {
	case CAN_STATE_ERROR_ACTIVE:
		return "Error Active";
	case CAN_STATE_ERROR_WARNING:
		return "Error Warning";
	case CAN_STATE_ERROR_PASSIVE:
		return "Error Passive";
	case CAN_STATE_BUS_OFF:
		return "Bus Off";
	case CAN_STATE_STOPPED:
		return "Stopped";
	case CAN_STATE_SLEEPING:
		return "Sleeping";
	default:
		return "<unknown>";
	}

	return "<unknown>";
}

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, "Controller changed from %s State (%d) into %s State (%d).\n",
		   can_get_state_str(priv->state), priv->state,
		   can_get_state_str(new_state), 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 |=