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 allows to add these one-shot and loopback functions to the
driver when the embedded firmware allows it.
Signed-off-by: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
---
drivers/net/can/usb/peak_usb/pcan_usb.c | 50 +++++++++++++++++++++++--
1 file changed, 46 insertions(+), 4 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c
index 9f3e16684e28..4c86cf58eac3 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb.c
@@ -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 +959,16 @@ 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;
+ }
+
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,
--
2.25.1
