Include CANFD TX support with the legacy CAN support, enabling
support for extended data payloads to provide higher bit rates.
Signed-off-by: Arun Muthusamy <arun.muthusamy@gaisler.com>
---
drivers/net/can/grcan.c | 117 +++++++++++++++++++++++++++++-----------
1 file changed, 87 insertions(+), 30 deletions(-)
diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index 4c56861e21d7..94af34fbd1fd 100644
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -174,6 +174,7 @@ struct grcan_registers {
#define GRCAN_IRQ_DEFAULT (GRCAN_IRQ_RX | GRCAN_IRQ_TX | GRCAN_IRQ_ERRORS)
#define GRCAN_MSG_SIZE 16
+#define GRCAN_CLASSIC_DATA_SIZE 8
#define GRCAN_MSG_IDE 0x80000000
#define GRCAN_MSG_RTR 0x40000000
@@ -195,6 +196,10 @@ struct grcan_registers {
#define GRCAN_MSG_OFF 0x00000002
#define GRCAN_MSG_PASS 0x00000001
+#define GRCAN_MSG_EID_MASK GENMASK(28, 0)
+#define GRCAN_MSG_BID_MASK GENMASK(28, 18)
+#define GRCAN_MSG_DLC_MASK GENMASK(31, 28)
+
#define GRCAN_BUFFER_ALIGNMENT 1024
#define GRCAN_DEFAULT_BUFFER_SIZE 1024
#define GRCAN_VALID_TR_SIZE_MASK 0x001fffc0
@@ -227,6 +232,9 @@ struct grcan_registers {
#define GRCANFD_FDBTR_PS2_BIT 5
#define GRCANFD_FDBTR_SJW_BIT 0
+#define GRCAN_TX_BRS BIT(25)
+#define GRCAN_TX_FDF BIT(26)
+
/* Hardware capabilities */
struct grcan_hwcap {
/* CAN-FD capable, indicates GRCANFD IP.
@@ -434,6 +442,12 @@ grcan_msg_header_at(struct grcan_dma_buffer *dbuf, u32 offset)
return (struct grcan_msg_header *)((u8 *)dbuf->buf + offset);
}
+static inline struct grcan_msg_fragment *
+grcan_msg_frag_at(struct grcan_dma_buffer *dbuf, u32 offset)
+{
+ return (struct grcan_msg_fragment *)((u8 *)dbuf->buf + offset);
+}
+
/* Configuration parameters that can be set via module parameters */
static struct grcan_device_config grcan_module_config =
GRCAN_DEFAULT_DEVICE_CONFIG;
@@ -1227,6 +1241,14 @@ static void grcan_transmit_catch_up(struct net_device *dev)
spin_unlock_irqrestore(&priv->lock, flags);
}
+static int grcan_numbds(int len)
+{
+ if (len <= GRCAN_CLASSIC_DATA_SIZE)
+ return 1;
+
+ return 1 + DIV_ROUND_UP(len - GRCAN_CLASSIC_DATA_SIZE, GRCAN_MSG_SIZE);
+}
+
static int grcan_receive(struct net_device *dev, int budget)
{
struct grcan_priv *priv = netdev_priv(dev);
@@ -1413,15 +1435,24 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct grcan_priv *priv = netdev_priv(dev);
- struct grcan_registers __iomem *regs = priv->regs;
+ struct grcan_registers __iomem *regs;
+ u32 eff, rtr, dlc, tmp, err, can_id;
struct grcan_dma *dma = &priv->dma;
- struct can_frame *cf = (struct can_frame *)skb->data;
- struct grcan_msg_header *hdr;
+ u32 bds, copy_len, payload_offset;
u32 id, txwr, txrd, space, txctrl;
- int slotindex;
- u32 rtr, eff, dlc, tmp, err;
+ struct grcan_msg_fragment *frag;
+ struct grcan_msg_header *hdr;
+ struct canfd_frame *cfd;
+ struct can_frame *cf;
unsigned long flags;
- u32 oneshotmode = priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT;
+ u32 oneshotmode;
+ int slotindex;
+ u8 *payload;
+ u8 len;
+ int i;
+
+ regs = priv->regs;
+ oneshotmode = priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT;
if (can_dev_dropped_skb(dev, skb))
return NETDEV_TX_OK;
@@ -1432,6 +1463,18 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *skb,
if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
return NETDEV_TX_BUSY;
+ cfd = (struct canfd_frame *)skb->data;
+ len = cfd->len;
+ can_id = cfd->can_id;
+ payload = cfd->data;
+
+ if (can_is_canfd_skb(skb)) {
+ dlc = can_fd_len2dlc(len);
+ } else {
+ cf = (struct can_frame *)skb->data;
+ dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
+ }
+
/* Reads of priv->eskbp and shut-downs of the queue needs to
* be atomic towards the updates to priv->eskbp and wake-ups
* of the queue in the interrupt handler.
@@ -1442,40 +1485,55 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *skb,
space = grcan_txspace(dma->tx.size, txwr, priv->eskbp);
slotindex = txwr / GRCAN_MSG_SIZE;
+ bds = grcan_numbds(len);
- if (unlikely(space == 1))
+ if (unlikely(space < bds)) {
netif_stop_queue(dev);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return NETDEV_TX_BUSY;
+ }
spin_unlock_irqrestore(&priv->lock, flags);
/* End of critical section*/
- /* This should never happen. If circular buffer is full, the
- * netif_stop_queue should have been stopped already.
- */
- if (unlikely(!space)) {
- netdev_err(dev, "No buffer space, but queue is non-stopped.\n");
- return NETDEV_TX_BUSY;
- }
-
hdr = grcan_msg_header_at(&dma->tx, txwr);
memset(hdr, 0, sizeof(*hdr));
- /* Convert and write CAN message to DMA buffer */
- eff = cf->can_id & CAN_EFF_FLAG;
- rtr = cf->can_id & CAN_RTR_FLAG;
- id = cf->can_id & (eff ? CAN_EFF_MASK : CAN_SFF_MASK);
- dlc = cf->len;
- if (eff)
- tmp = (id << GRCAN_MSG_EID_BIT) & GRCAN_MSG_EID;
- else
- tmp = (id << GRCAN_MSG_BID_BIT) & GRCAN_MSG_BID;
+ eff = can_id & CAN_EFF_FLAG;
+ rtr = can_id & CAN_RTR_FLAG;
+ id = can_id & (eff ? CAN_EFF_MASK : CAN_SFF_MASK);
+
+ tmp = eff ? FIELD_PREP(GRCAN_MSG_EID_MASK, id)
+ : FIELD_PREP(GRCAN_MSG_BID_MASK, id);
+
+ hdr->id = (eff ? GRCAN_MSG_IDE : 0) |
+ (rtr ? GRCAN_MSG_RTR : 0) |
+ tmp;
- hdr->id = (eff ? GRCAN_MSG_IDE : 0) | (rtr ? GRCAN_MSG_RTR : 0) | tmp;
+ hdr->ctrl = FIELD_PREP(GRCAN_MSG_DLC_MASK, dlc);
+
+ if (can_is_canfd_skb(skb)) {
+ hdr->ctrl |= GRCAN_TX_FDF;
+ if (cfd->flags & CANFD_BRS)
+ hdr->ctrl |= GRCAN_TX_BRS;
+ }
- hdr->ctrl = ((dlc << GRCAN_MSG_DLC_BIT) & GRCAN_MSG_DLC);
+ copy_len = min_t(u32, len, CAN_MAX_DLEN);
+ memcpy(hdr->data, payload, copy_len);
+ payload_offset = copy_len;
- if (dlc > 0)
- memcpy(hdr->data, cf->data, min_t(u32, cf->len, CAN_MAX_DLEN));
+ txwr = grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size);
+
+ for (i = 1; i < bds; i++) {
+ frag = grcan_msg_frag_at(&dma->tx, txwr);
+
+ memset(frag, 0, sizeof(*frag));
+ copy_len = min_t(u32, (u32)len - payload_offset, (u32)GRCAN_MSG_SIZE);
+ memcpy(frag->data, payload + payload_offset, copy_len);
+ payload_offset += copy_len;
+
+ txwr = grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size);
+ }
/* Checking that channel has not been disabled. These cases
* should never happen
@@ -1517,8 +1575,7 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *skb,
wmb();
/* Update write pointer to start transmission */
- grcan_write_reg(®s->txwr,
- grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size));
+ grcan_write_reg(®s->txwr, txwr);
return NETDEV_TX_OK;
}
--
2.51.0