Commit 3a793949 authored by Stephane Grosjean's avatar Stephane Grosjean Committed by Marc Kleine-Budde
Browse files

can: peak_usb: PCAN-USB: add support of loopback and one-shot mode 

The CAN - USB PCAN-USB interface is able to generate one-shot frames
as well as loopback frames that it transmits starting from version 4.1
of its firmware.

This patch adds support for the one-shot and loopback functionality to
the driver, that can be activated if the embedded firmware allows it.
If the driver detects that the PCAN-USB device runs an old firmware
(< 4.1) it prints a message suggesting to contact
<support@peak-system.com> for a possible firmware update.

Link: https://lore.kernel.org/r/20210625130931.27438-3-s.grosjean@peak-system.com


Signed-off-by: default avatarStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 1d0214a0

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

+49 −4
Original line number Diff line number Diff line
@@ -73,6 +73,10 @@ 
#define PCAN_USB_STATUSLEN_RTR		(1 << 4)

#define PCAN_USB_STATUSLEN_DLC		(0xf)



/* PCAN-USB 4.1 CAN Id tx extended flags */

#define PCAN_USB_TX_SRR			0x01	/* SJA1000 SRR command */

#define PCAN_USB_TX_AT			0x02	/* SJA1000 AT command */



/* PCAN-USB error flags */

#define PCAN_USB_ERROR_TXFULL		0x01

#define PCAN_USB_ERROR_RXQOVR		0x02
@@ -705,6 +709,7 @@ static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len) 
	struct sk_buff *skb;

	struct can_frame *cf;

	struct skb_shared_hwtstamps *hwts;

	u32 can_id_flags;



	skb = alloc_can_skb(mc->netdev, &cf);

	if (!skb)
@@ -714,13 +719,15 @@ static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len) 
		if ((mc->ptr + 4) > mc->end)

			goto decode_failed;



		cf->can_id = get_unaligned_le32(mc->ptr) >> 3 | CAN_EFF_FLAG;

		can_id_flags = get_unaligned_le32(mc->ptr);

		cf->can_id = can_id_flags >> 3 | CAN_EFF_FLAG;

		mc->ptr += 4;

	} else {

		if ((mc->ptr + 2) > mc->end)

			goto decode_failed;



		cf->can_id = get_unaligned_le16(mc->ptr) >> 5;

		can_id_flags = get_unaligned_le16(mc->ptr);

		cf->can_id = can_id_flags >> 5;

		mc->ptr += 2;

	}
@@ -743,6 +750,10 @@ static int pcan_usb_decode_data(struct pcan_usb_msg_context *mc, u8 status_len) 


		memcpy(cf->data, mc->ptr, cf->len);

		mc->ptr += rec_len;



		/* Ignore next byte (client private id) if SRR bit is set */

		if (can_id_flags & PCAN_USB_TX_SRR)

			mc->ptr++;

	}



	/* convert timestamp into kernel time */
@@ -820,6 +831,7 @@ static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb, 
	struct net_device *netdev = dev->netdev;

	struct net_device_stats *stats = &netdev->stats;

	struct can_frame *cf = (struct can_frame *)skb->data;

	u32 can_id_flags = cf->can_id & CAN_ERR_MASK;

	u8 *pc;



	obuf[0] = 2;
@@ -838,12 +850,28 @@ static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb, 
		*pc |= PCAN_USB_STATUSLEN_EXT_ID;

		pc++;



		put_unaligned_le32((cf->can_id & CAN_ERR_MASK) << 3, pc);

		can_id_flags <<= 3;



		if (dev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)

			can_id_flags |= PCAN_USB_TX_SRR;



		if (dev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)

			can_id_flags |= PCAN_USB_TX_AT;



		put_unaligned_le32(can_id_flags, pc);

		pc += 4;

	} else {

		pc++;



		put_unaligned_le16((cf->can_id & CAN_ERR_MASK) << 5, pc);

		can_id_flags <<= 5;



		if (dev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)

			can_id_flags |= PCAN_USB_TX_SRR;



		if (dev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)

			can_id_flags |= PCAN_USB_TX_AT;



		put_unaligned_le16(can_id_flags, pc);

		pc += 2;

	}
@@ -853,6 +881,10 @@ static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb, 
		pc += cf->len;

	}



	/* SRR bit needs a writer id (useless here) */

	if (can_id_flags & PCAN_USB_TX_SRR)

		*pc++ = 0x80;



	obuf[(*size)-1] = (u8)(stats->tx_packets & 0xff);



	return 0;
@@ -927,6 +959,19 @@ static int pcan_usb_init(struct peak_usb_device *dev) 
		return err;

	}



	/* Since rev 4.1, PCAN-USB is able to make single-shot as well as

	 * looped back frames.

	 */

	if (dev->device_rev >= 41) {

		struct can_priv *priv = netdev_priv(dev->netdev);



		priv->ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT |

					    CAN_CTRLMODE_LOOPBACK;

	} else {

		dev_info(dev->netdev->dev.parent,

			 "Firmware update available. Please contact support@peak-system.com\n");

	}



	dev_info(dev->netdev->dev.parent,

		 "PEAK-System %s adapter hwrev %u serial %08X (%u channel)\n",

		 pcan_usb.name, dev->device_rev, serial_number,