Commit ea8b33bd authored by Stephane Grosjean's avatar Stephane Grosjean Committed by Marc Kleine-Budde
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can: pcan_usb: add support of rxerr/txerr counters 



This patch adds the support of the rx/tx errors CAN counters to the
driver of the PCAN-USB PC-CAN interface from PEAK-System GmbH.

The PCAN-USB is capable of giving back the values of the rx/tx errors
counters, to provide more details and statistics to the linux-can layer.
Getting these values allows the driver to better tune CAN_ERR_CRTL_TX_xxx
and CAN_ERR_CRTL_RX_xxx bits in case of the interface enters any
CAN_STATE_ERROR_xxx state.

Signed-off-by: default avatarStephane Grosjean <s.grosjean@peak-system.com>
Link: https://lore.kernel.org/r/20191206153803.17725-3-s.grosjean@peak-system.com


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent a8bb19df

drivers/net/can/usb/peak_usb/pcan_usb.c

+117 −16
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter"); 
#define PCAN_USB_CMD_SN		6

#define PCAN_USB_CMD_REGISTER	9

#define PCAN_USB_CMD_EXT_VCC	10

#define PCAN_USB_CMD_ERR_FR	11



/* PCAN_USB_CMD_SET_BUS number arg */

#define PCAN_USB_BUS_XCVER		2
@@ -82,6 +83,10 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter"); 
#define PCAN_USB_ERROR_QOVR		0x40

#define PCAN_USB_ERROR_TXQFULL		0x80



#define PCAN_USB_ERROR_BUS		(PCAN_USB_ERROR_BUS_LIGHT | \

					 PCAN_USB_ERROR_BUS_HEAVY | \

					 PCAN_USB_ERROR_BUS_OFF)



/* SJA1000 modes */

#define SJA1000_MODE_NORMAL		0x00

#define SJA1000_MODE_INIT		0x01
@@ -101,11 +106,25 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter"); 
#define PCAN_USB_REC_TS			4

#define PCAN_USB_REC_BUSEVT		5



/* CAN bus events notifications selection mask */

#define PCAN_USB_ERR_RXERR		0x02	/* ask for rxerr counter */

#define PCAN_USB_ERR_TXERR		0x04	/* ask for txerr counter */



/* This mask generates an usb packet each time the state of the bus changes.

 * In other words, its interest is to know which side among rx and tx is

 * responsible of the change of the bus state.

 */

#define PCAN_USB_BERR_MASK	(PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR)



/* identify bus event packets with rx/tx error counters */

#define PCAN_USB_ERR_CNT		0x80



/* private to PCAN-USB adapter */

struct pcan_usb {

	struct peak_usb_device dev;

	struct peak_time_ref time_ref;

	struct timer_list restart_timer;

	struct can_berr_counter bec;

};



/* incoming message context for decoding */
@@ -212,6 +231,16 @@ static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff) 
				 PCAN_USB_BUS_SILENT_MODE, args);

}



/* send the cmd to be notified from bus errors */

static int pcan_usb_set_err_frame(struct peak_usb_device *dev, u8 err_mask)

{

	u8 args[PCAN_USB_CMD_ARGS_LEN] = {

		[0] = err_mask,

	};



	return pcan_usb_send_cmd(dev, PCAN_USB_CMD_ERR_FR, PCAN_USB_SET, args);

}



static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)

{

	u8 args[PCAN_USB_CMD_ARGS_LEN] = {
@@ -445,7 +474,7 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n, 
			new_state = CAN_STATE_BUS_OFF;

			break;

		}

		if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {

		if (n & ~PCAN_USB_ERROR_BUS) {

			/*

			 * trick to bypass next comparison and process other

			 * errors
@@ -469,7 +498,7 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n, 
			new_state = CAN_STATE_ERROR_WARNING;

			break;

		}

		if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {

		if (n & ~PCAN_USB_ERROR_BUS) {

			/*

			 * trick to bypass next comparison and process other

			 * errors
@@ -508,29 +537,50 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n, 


	case CAN_STATE_ERROR_PASSIVE:

		cf->can_id |= CAN_ERR_CRTL;

		cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE |

		cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ?

				CAN_ERR_CRTL_TX_PASSIVE :

				CAN_ERR_CRTL_RX_PASSIVE;

		cf->data[6] = mc->pdev->bec.txerr;

		cf->data[7] = mc->pdev->bec.rxerr;



		mc->pdev->dev.can.can_stats.error_passive++;

		break;



	case CAN_STATE_ERROR_WARNING:

		cf->can_id |= CAN_ERR_CRTL;

		cf->data[1] |= CAN_ERR_CRTL_TX_WARNING |

		cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ?

				CAN_ERR_CRTL_TX_WARNING :

				CAN_ERR_CRTL_RX_WARNING;

		cf->data[6] = mc->pdev->bec.txerr;

		cf->data[7] = mc->pdev->bec.rxerr;



		mc->pdev->dev.can.can_stats.error_warning++;

		break;



	case CAN_STATE_ERROR_ACTIVE:

		cf->can_id |= CAN_ERR_CRTL;

		cf->data[1] = CAN_ERR_CRTL_ACTIVE;



		/* sync local copies of rxerr/txerr counters */

		mc->pdev->bec.txerr = 0;

		mc->pdev->bec.rxerr = 0;

		break;



	default:

		/* CAN_STATE_MAX (trick to handle other errors) */

		if (n & PCAN_USB_ERROR_TXQFULL)

			netdev_dbg(mc->netdev, "device Tx queue full)\n");



		if (n & PCAN_USB_ERROR_RXQOVR) {

			netdev_dbg(mc->netdev, "data overrun interrupt\n");

			cf->can_id |= CAN_ERR_CRTL;

			cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;

			mc->netdev->stats.rx_over_errors++;

			mc->netdev->stats.rx_errors++;

		}



		cf->data[6] = mc->pdev->bec.txerr;

		cf->data[7] = mc->pdev->bec.rxerr;



		new_state = mc->pdev->dev.can.state;

		break;
@@ -552,6 +602,30 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n, 
	return 0;

}



/* decode bus event usb packet: first byte contains rxerr while 2nd one contains

 * txerr.

 */

static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir)

{

	struct pcan_usb *pdev = mc->pdev;



	/* acccording to the content of the packet */

	switch (ir) {

	case PCAN_USB_ERR_CNT:



		/* save rx/tx error counters from in the device context */

		pdev->bec.rxerr = mc->ptr[0];

		pdev->bec.txerr = mc->ptr[1];

		break;



	default:

		/* reserved */

		break;

	}



	return 0;

}



/*

 * decode non-data usb message

 */
@@ -606,9 +680,10 @@ static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc, 
		break;



	case PCAN_USB_REC_BUSEVT:

		/* error frame/bus event */

		if (n & PCAN_USB_ERROR_TXQFULL)

			netdev_dbg(mc->netdev, "device Tx queue full)\n");

		/* bus event notifications (get rxerr/txerr) */

		err = pcan_usb_handle_bus_evt(mc, n);

		if (err)

			return err;

		break;

	default:

		netdev_err(mc->netdev, "unexpected function %u\n", f);
@@ -792,20 +867,44 @@ static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb, 
	return 0;

}



/* socket callback used to copy berr counters values received through USB */

static int pcan_usb_get_berr_counter(const struct net_device *netdev,

				     struct can_berr_counter *bec)

{

	struct peak_usb_device *dev = netdev_priv(netdev);

	struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);



	*bec = pdev->bec;



	/* must return 0 */

	return 0;

}



/*

 * start interface

 */

static int pcan_usb_start(struct peak_usb_device *dev)

{

	struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);

	int err;



	/* number of bits used in timestamps read from adapter struct */

	peak_usb_init_time_ref(&pdev->time_ref, &pcan_usb);



	pdev->bec.rxerr = 0;

	pdev->bec.txerr = 0;



	/* be notified on error counter changes (if requested by user) */

	if (dev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {

		err = pcan_usb_set_err_frame(dev, PCAN_USB_BERR_MASK);

		if (err)

			netdev_warn(dev->netdev,

				    "Asking for BERR reporting error %u\n",

				    err);

	}



	/* if revision greater than 3, can put silent mode on/off */

	if (dev->device_rev > 3) {

		int err;



		err = pcan_usb_set_silent(dev,

				dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY);

		if (err)
@@ -892,7 +991,8 @@ const struct peak_usb_adapter pcan_usb = { 
	.name = "PCAN-USB",

	.device_id = PCAN_USB_PRODUCT_ID,

	.ctrl_count = 1,

	.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,

	.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |

			      CAN_CTRLMODE_BERR_REPORTING,

	.clock = {

		.freq = PCAN_USB_CRYSTAL_HZ / 2 ,

	},
@@ -925,4 +1025,5 @@ const struct peak_usb_adapter pcan_usb = { 
	.dev_encode_msg = pcan_usb_encode_msg,

	.dev_start = pcan_usb_start,

	.dev_restart_async = pcan_usb_restart_async,

	.do_get_berr_counter = pcan_usb_get_berr_counter,

};