Commit 4de0e8ef authored by Dario Binacchi's avatar Dario Binacchi Committed by Marc Kleine-Budde
Browse files

can: slcan: add ethtool support to reset adapter errors 

This patch adds a private flag to the slcan driver to switch the
"err-rst-on-open" setting on and off.

"err-rst-on-open" on  - Reset error states on opening command

"err-rst-on-open" off - Don't reset error states on opening command
                        (default)

The setting can only be changed if the interface is down:

    ip link set dev can0 down
    ethtool --set-priv-flags can0 err-rst-on-open {off|on}
    ip link set dev can0 up

Link: https://lore.kernel.org/all/20220628163137.413025-11-dario.binacchi@amarulasolutions.com


Signed-off-by: default avatarDario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 98b12064

drivers/net/can/slcan/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,3 +4,4 @@ obj-$(CONFIG_CAN_SLCAN) += slcan.o 


slcan-objs :=

slcan-objs += slcan-core.o

slcan-objs += slcan-ethtool.o

drivers/net/can/slcan/slcan-core.c

+36 −0
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ 
#include <linux/can/dev.h>

#include <linux/can/skb.h>



#include "slcan.h"



MODULE_ALIAS_LDISC(N_SLCAN);

MODULE_DESCRIPTION("serial line CAN interface");

MODULE_LICENSE("GPL");
@@ -98,6 +100,8 @@ struct slcan { 
#define SLF_INUSE		0		/* Channel in use            */

#define SLF_ERROR		1               /* Parity, etc. error        */

#define SLF_XCMD		2               /* Command transmission      */

	unsigned long           cmd_flags;      /* Command flags             */

#define CF_ERR_RST		0               /* Reset errors on open      */

	wait_queue_head_t       xcmd_wait;      /* Wait queue for commands   */

						/* transmission              */

};
@@ -109,6 +113,28 @@ static const u32 slcan_bitrate_const[] = { 
	250000, 500000, 800000, 1000000

};



bool slcan_err_rst_on_open(struct net_device *ndev)

{

	struct slcan *sl = netdev_priv(ndev);



	return !!test_bit(CF_ERR_RST, &sl->cmd_flags);

}



int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on)

{

	struct slcan *sl = netdev_priv(ndev);



	if (netif_running(ndev))

		return -EBUSY;



	if (on)

		set_bit(CF_ERR_RST, &sl->cmd_flags);

	else

		clear_bit(CF_ERR_RST, &sl->cmd_flags);



	return 0;

}



 /************************************************************************

  *			SLCAN ENCAPSULATION FORMAT			 *

  ************************************************************************/
@@ -510,6 +536,15 @@ static int slc_open(struct net_device *dev) 
			goto cmd_transmit_failed;

		}



		if (test_bit(CF_ERR_RST, &sl->cmd_flags)) {

			err = slcan_transmit_cmd(sl, "F\r");

			if (err) {

				netdev_err(dev,

					   "failed to send error command 'F\\r'\n");

				goto cmd_transmit_failed;

			}

		}



		err = slcan_transmit_cmd(sl, "O\r");

		if (err) {

			netdev_err(dev, "failed to send open command 'O\\r'\n");
@@ -629,6 +664,7 @@ static struct slcan *slc_alloc(void) 
	snprintf(dev->name, sizeof(dev->name), "slcan%d", i);

	dev->netdev_ops = &slc_netdev_ops;

	dev->base_addr  = i;

	slcan_set_ethtool_ops(dev);

	sl = netdev_priv(dev);



	/* Initialize channel control data */

drivers/net/can/slcan/slcan-ethtool.c

0 → 100644
+65 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/* Copyright (c) 2022 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>

 *

 */



#include <linux/can/dev.h>

#include <linux/ethtool.h>

#include <linux/kernel.h>

#include <linux/netdevice.h>

#include <linux/platform_device.h>



#include "slcan.h"



static const char slcan_priv_flags_strings[][ETH_GSTRING_LEN] = {

#define SLCAN_PRIV_FLAGS_ERR_RST_ON_OPEN BIT(0)

	"err-rst-on-open",

};



static void slcan_get_strings(struct net_device *ndev, u32 stringset, u8 *data)

{

	switch (stringset) {

	case ETH_SS_PRIV_FLAGS:

		memcpy(data, slcan_priv_flags_strings,

		       sizeof(slcan_priv_flags_strings));

	}

}



static u32 slcan_get_priv_flags(struct net_device *ndev)

{

	u32 flags = 0;



	if (slcan_err_rst_on_open(ndev))

		flags |= SLCAN_PRIV_FLAGS_ERR_RST_ON_OPEN;



	return flags;

}



static int slcan_set_priv_flags(struct net_device *ndev, u32 flags)

{

	bool err_rst_op_open = !!(flags & SLCAN_PRIV_FLAGS_ERR_RST_ON_OPEN);



	return slcan_enable_err_rst_on_open(ndev, err_rst_op_open);

}



static int slcan_get_sset_count(struct net_device *netdev, int sset)

{

	switch (sset) {

	case ETH_SS_PRIV_FLAGS:

		return ARRAY_SIZE(slcan_priv_flags_strings);

	default:

		return -EOPNOTSUPP;

	}

}



static const struct ethtool_ops slcan_ethtool_ops = {

	.get_strings = slcan_get_strings,

	.get_priv_flags = slcan_get_priv_flags,

	.set_priv_flags = slcan_set_priv_flags,

	.get_sset_count = slcan_get_sset_count,

};



void slcan_set_ethtool_ops(struct net_device *netdev)

{

	netdev->ethtool_ops = &slcan_ethtool_ops;

}

drivers/net/can/slcan/slcan.h

0 → 100644
+18 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0

 * slcan.h - serial line CAN interface driver

 *

 * Copyright (C) Laurence Culhane <loz@holmes.demon.co.uk>

 * Copyright (C) Fred N. van Kempen <waltje@uwalt.nl.mugnet.org>

 * Copyright (C) Oliver Hartkopp <socketcan@hartkopp.net>

 * Copyright (C) 2022 Amarula Solutions, Dario Binacchi <dario.binacchi@amarulasolutions.com>

 *

 */



#ifndef _SLCAN_H

#define _SLCAN_H



bool slcan_err_rst_on_open(struct net_device *ndev);

int slcan_enable_err_rst_on_open(struct net_device *ndev, bool on);

void slcan_set_ethtool_ops(struct net_device *ndev);



#endif /* _SLCAN_H */