From nobody Fri Apr 3 03:21:43 2026 Received: from smtp-out3.simply.com (smtp-out3.simply.com [94.231.106.210]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BF31831328A; Mon, 16 Feb 2026 13:54:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=94.231.106.210 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771250044; cv=none; b=mWrF91sepHqVMhfw8yPSae4yXXdoxVPeHTpgR2b1ldu/ydKU+DnWTthGOeV0t6ppKiONn6haqc4y6SE6BmCnz+zUIiOEenBMemvCy3viSvMqvcrSmDriSpPcRclCOAZjtx5sryu00aRnlRxtSvfLrLwB3iunI7oX0fl2FsBfQqQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771250044; c=relaxed/simple; bh=eRo33dKNPrW1Rzcrh2RUObWmQwr19UJeHASiH+4hDB0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dsFlRILaAwKbOg1MbtYjuoO1E+2wTBloNnJJjMuUy84VUExc0ZBsIZ1CN04/JnfrwaH63rftQKDw3VvX7Lf1DznRI/BBRbfMLhyK2GC7fCCkZNI504o6wGGk7ybWojGJLIfVENc6stA6lXm0oEvLCmDX7GLxR8BFFybrfWObYxU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gaisler.com; spf=pass smtp.mailfrom=gaisler.com; dkim=fail (0-bit key) header.d=gaisler.com header.i=@gaisler.com header.b=ZCE0MW1Y reason="key not found in DNS"; arc=none smtp.client-ip=94.231.106.210 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gaisler.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gaisler.com Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=gaisler.com header.i=@gaisler.com header.b="ZCE0MW1Y" Received: from localhost (localhost [127.0.0.1]) by smtp.simply.com (Simply.com) with ESMTP id 4fF44c2FQJz1Fbwc; Mon, 16 Feb 2026 14:53:52 +0100 (CET) Received: from d-5xj5g74.got.gaisler.com.com (h-98-128-223-123.NA.cust.bahnhof.se [98.128.223.123]) by smtp.simply.com (Simply.com) with ESMTPA id 4fF44c0MGgz1FbwZ; Mon, 16 Feb 2026 14:53:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gaisler.com; s=simplycom2; t=1771250032; bh=mIj+Gfc6bwbkhoXJDGZOXj4xv50OW9cInGwc4zKvq4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZCE0MW1YY/QdD9K1RSzG/fUU4Y7SSj5pgdKbGjy9jDzdVblRKtVCcU5DLDincIYlc evl0IenD1hCAE9Yx1GOAQXWWnmS5FEhyY+CMWiJ3HJ/AhsDab/Rsk3Te+dtFZiv3OC kzgJQUlR/NjvDRwXEHNglVT7CXAsAfQm4D9AQoecJUrDzFYmTyKQ+6pqErC8vERMfy G8mhKfH8ZGd2n7VW4ZSBdA9+ptp1Bl3mXrPQwlNpBe77H+C7P4yDODlwVwemFtYMTv NkEQtxEXD8P8D8HwLpQsA91z8lkHFPf87n1fSIwtxbpai0HajfnNr52Ijf7k4ase62 mbT6oasln+TSQ== From: Arun Muthusamy To: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, mkl@pengutronix.de, mailhol@kernel.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-can@vger.kernel.org, Arun Muthusamy Subject: [PATCH v5 13/16] can: grcan: Add CANFD TX support alongside legacy CAN Date: Mon, 16 Feb 2026 14:53:41 +0100 Message-ID: <20260216135344.23246-14-arun.muthusamy@gaisler.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260216135344.23246-1-arun.muthusamy@gaisler.com> References: <20260216135344.23246-1-arun.muthusamy@gaisler.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- drivers/net/can/grcan.c | 111 ++++++++++++++++++++++++++++++---------- 1 file changed, 85 insertions(+), 26 deletions(-) diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c index 28fa219e1c3b..ae9f6fd4c8bf 100644 --- a/drivers/net/can/grcan.c +++ b/drivers/net/can/grcan.c @@ -196,6 +196,10 @@ struct grcan_registers { #define GRCAN_MSG_OFF 0x00000002 #define GRCAN_MSG_PASS 0x00000001 =20 +#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 @@ -228,6 +232,9 @@ struct grcan_registers { #define GRCANFD_FDBTR_PS2_BIT 5 #define GRCANFD_FDBTR_SJW_BIT 0 =20 +#define GRCAN_TX_BRS BIT(25) +#define GRCAN_TX_FDF BIT(26) + /* Hardware capabilities */ struct grcan_hwcap { /* CAN-FD capable, indicates GRCANFD IP. @@ -1222,6 +1229,19 @@ static void grcan_transmit_catch_up(struct net_devic= e *dev) spin_unlock_irqrestore(&priv->lock, flags); } =20 +static int grcan_numbds(int len) +{ + if (len <=3D GRCAN_CLASSIC_DATA_SIZE) + return 1; + + return 1 + DIV_ROUND_UP(len - GRCAN_CLASSIC_DATA_SIZE, GRCAN_MSG_SIZE); +} + +static inline union grcan_msg_slot *grcan_tx_msg_slot(struct grcan_dma *dm= a, u32 off) +{ + return (union grcan_msg_slot *)((u8 *)dma->tx.msg_slot + off); +} + static int grcan_receive(struct net_device *dev, int budget) { struct grcan_priv *priv =3D netdev_priv(dev); @@ -1404,15 +1424,23 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff = *skb, struct net_device *dev) { struct grcan_priv *priv =3D netdev_priv(dev); - struct grcan_registers __iomem *regs =3D priv->regs; + struct grcan_registers __iomem *regs; + u32 eff, rtr, dlc, tmp, err, can_id; struct grcan_dma *dma =3D &priv->dma; - struct can_frame *cf =3D (struct can_frame *)skb->data; + u32 bds, copy_len, payload_offset; u32 id, txwr, txrd, space, txctrl; - int slotindex; - u32 *slot; - u32 rtr, eff, dlc, tmp, err; + union grcan_msg_slot *msg; + struct canfd_frame *cfd; + struct can_frame *cf; unsigned long flags; - u32 oneshotmode =3D priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT; + u32 oneshotmode; + int slotindex; + u8 *payload; + u8 len; + int i; + + regs =3D priv->regs; + oneshotmode =3D priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT; =20 if (can_dev_dropped_skb(dev, skb)) return NETDEV_TX_OK; @@ -1423,6 +1451,18 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *= skb, if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) return NETDEV_TX_BUSY; =20 + cfd =3D (struct canfd_frame *)skb->data; + len =3D cfd->len; + can_id =3D cfd->can_id; + payload =3D cfd->data; + + if (can_is_canfd_skb(skb)) { + dlc =3D can_fd_len2dlc(len); + } else { + cf =3D (struct can_frame *)skb->data; + dlc =3D 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. @@ -1433,7 +1473,7 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *s= kb, space =3D grcan_txspace(dma->tx.size, txwr, priv->eskbp); =20 slotindex =3D txwr / GRCAN_MSG_SIZE; - slot =3D (u32 *)((u8 *)dma->tx.msg_slot + txwr); + bds =3D grcan_numbds(len); =20 if (unlikely(space =3D=3D 1)) netif_stop_queue(dev); @@ -1449,24 +1489,44 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff = *skb, return NETDEV_TX_BUSY; } =20 - /* Convert and write CAN message to DMA buffer */ - eff =3D cf->can_id & CAN_EFF_FLAG; - rtr =3D cf->can_id & CAN_RTR_FLAG; - id =3D cf->can_id & (eff ? CAN_EFF_MASK : CAN_SFF_MASK); - dlc =3D cf->len; - if (eff) - tmp =3D (id << GRCAN_MSG_EID_BIT) & GRCAN_MSG_EID; - else - tmp =3D (id << GRCAN_MSG_BID_BIT) & GRCAN_MSG_BID; - slot[0] =3D (eff ? GRCAN_MSG_IDE : 0) | (rtr ? GRCAN_MSG_RTR : 0) | tmp; + msg =3D grcan_tx_msg_slot(dma, txwr); + memset(msg, 0, sizeof(*msg)); + + eff =3D can_id & CAN_EFF_FLAG; + rtr =3D can_id & CAN_RTR_FLAG; + id =3D can_id & (eff ? CAN_EFF_MASK : CAN_SFF_MASK); + + tmp =3D eff ? FIELD_PREP(GRCAN_MSG_EID_MASK, id) + : FIELD_PREP(GRCAN_MSG_BID_MASK, id); + + msg->header.id =3D (eff ? GRCAN_MSG_IDE : 0) | + (rtr ? GRCAN_MSG_RTR : 0) | + tmp; =20 - slot[1] =3D ((dlc << GRCAN_MSG_DLC_BIT) & GRCAN_MSG_DLC); - slot[2] =3D 0; - slot[3] =3D 0; - if (dlc > 0) - memcpy(&slot[2], cf->data, sizeof(u32)); - if (dlc > 4) - memcpy(&slot[3], cf->data + 4, sizeof(u32)); + msg->header.ctrl =3D FIELD_PREP(GRCAN_MSG_DLC_MASK, dlc); + + if (can_is_canfd_skb(skb)) { + msg->header.ctrl |=3D GRCAN_TX_FDF; + if (cfd->flags & CANFD_BRS) + msg->header.ctrl |=3D GRCAN_TX_BRS; + } + + copy_len =3D min_t(u32, len, GRCAN_CLASSIC_DATA_SIZE); + memcpy(msg->header.data, payload, copy_len); + payload_offset =3D copy_len; + + txwr =3D grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size); + + for (i =3D 1; i < bds; i++) { + msg =3D grcan_tx_msg_slot(dma, txwr); + + memset(msg, 0, sizeof(*msg)); + copy_len =3D min_t(u32, (u32)len - payload_offset, (u32)GRCAN_MSG_SIZE); + memcpy(msg->frags.data, payload + payload_offset, copy_len); + payload_offset +=3D copy_len; + + txwr =3D grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size); + } =20 /* Checking that channel has not been disabled. These cases * should never happen @@ -1508,8 +1568,7 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *s= kb, wmb(); =20 /* 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); =20 return NETDEV_TX_OK; } --=20 2.51.0