3 files changed, 129 insertions, 38 deletions

diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 311d8564d611..e3d840b81357 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -15,6 +15,7 @@
 #include <linux/can/dev.h>
 #include <linux/can/skb.h>
 #include <linux/can/led.h>
+#include <linux/gpio/consumer.h>
 #include <linux/of.h>
 
 #define MOD_DESC "CAN device driver interface"
@@ -400,10 +401,69 @@ void close_candev(struct net_device *dev)
 }
 EXPORT_SYMBOL_GPL(close_candev);
 
+static int can_set_termination(struct net_device *ndev, u16 term)
+{
+	struct can_priv *priv = netdev_priv(ndev);
+	int set;
+
+	if (term == priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED])
+		set = 1;
+	else
+		set = 0;
+
+	gpiod_set_value(priv->termination_gpio, set);
+
+	return 0;
+}
+
+static int can_get_termination(struct net_device *ndev)
+{
+	struct can_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
+	struct gpio_desc *gpio;
+	u32 term;
+	int ret;
+
+	/* Disabling termination by default is the safe choice: Else if many
+	 * bus participants enable it, no communication is possible at all.
+	 */
+	gpio = devm_gpiod_get_optional(dev, "termination", GPIOD_OUT_LOW);
+	if (IS_ERR(gpio))
+		return dev_err_probe(dev, PTR_ERR(gpio),
+				     "Cannot get termination-gpios\n");
+
+	if (!gpio)
+		return 0;
+
+	ret = device_property_read_u32(dev, "termination-ohms", &term);
+	if (ret) {
+		netdev_err(ndev, "Cannot get termination-ohms: %pe\n",
+			   ERR_PTR(ret));
+		return ret;
+	}
+
+	if (term > U16_MAX) {
+		netdev_err(ndev, "Invalid termination-ohms value (%u > %u)\n",
+			   term, U16_MAX);
+		return -EINVAL;
+	}
+
+	priv->termination_const_cnt = ARRAY_SIZE(priv->termination_gpio_ohms);
+	priv->termination_const = priv->termination_gpio_ohms;
+	priv->termination_gpio = gpio;
+	priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_DISABLED] =
+		CAN_TERMINATION_DISABLED;
+	priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED] = term;
+	priv->do_set_termination = can_set_termination;
+
+	return 0;
+}
+
 /* Register the CAN network device */
 int register_candev(struct net_device *dev)
 {
 	struct can_priv *priv = netdev_priv(dev);
+	int err;
 
 	/* Ensure termination_const, termination_const_cnt and
 	 * do_set_termination consistency. All must be either set or
@@ -419,6 +479,12 @@ int register_candev(struct net_device *dev)
 	if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
 		return -EINVAL;
 
+	if (!priv->termination_const) {
+		err = can_get_termination(dev);
+		if (err)
+			return err;
+	}
+
 	dev->rtnl_link_ops = &can_link_ops;
 	netif_carrier_off(dev);
 
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index e38c2566aff4..80425636049d 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -47,7 +47,7 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[],
 	}
 
 	if (data[IFLA_CAN_DATA_BITTIMING]) {
-		if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
+		if (!is_can_fd)
 			return -EOPNOTSUPP;
 	}
 
@@ -116,7 +116,7 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 		maskedflags = cm->flags & cm->mask;
 
 		/* check whether provided bits are allowed to be passed */
-		if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
+		if (maskedflags & ~(priv->ctrlmode_supported | ctrlstatic))
 			return -EOPNOTSUPP;
 
 		/* do not check for static fd-non-iso if 'fd' is disabled */
@@ -132,10 +132,13 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 		priv->ctrlmode |= maskedflags;
 
 		/* CAN_CTRLMODE_FD can only be set when driver supports FD */
-		if (priv->ctrlmode & CAN_CTRLMODE_FD)
+		if (priv->ctrlmode & CAN_CTRLMODE_FD) {
 			dev->mtu = CANFD_MTU;
-		else
+		} else {
 			dev->mtu = CAN_MTU;
+			memset(&priv->data_bittiming, 0,
+			       sizeof(priv->data_bittiming));
+		}
 	}
 
 	if (data[IFLA_CAN_RESTART_MS]) {
diff --git a/drivers/net/can/dev/rx-offload.c b/drivers/net/can/dev/rx-offload.c
index ab2c1543786c..37b0cc65237b 100644
--- a/drivers/net/can/dev/rx-offload.c
+++ b/drivers/net/can/dev/rx-offload.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2014      Protonic Holland,
  *                         David Jander
- * Copyright (C) 2014-2017 Pengutronix,
+ * Copyright (C) 2014-2021 Pengutronix,
  *                         Marc Kleine-Budde <kernel@pengutronix.de>
  */
 
@@ -174,10 +174,8 @@ can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
 int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload,
 					 u64 pending)
 {
-	struct sk_buff_head skb_queue;
 	unsigned int i;
-
-	__skb_queue_head_init(&skb_queue);
+	int received = 0;
 
 	for (i = offload->mb_first;
 	     can_rx_offload_le(offload, i, offload->mb_last);
@@ -191,26 +189,12 @@ int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload,
 		if (IS_ERR_OR_NULL(skb))
 			continue;
 
-		__skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare);
-	}
-
-	if (!skb_queue_empty(&skb_queue)) {
-		unsigned long flags;
-		u32 queue_len;
-
-		spin_lock_irqsave(&offload->skb_queue.lock, flags);
-		skb_queue_splice_tail(&skb_queue, &offload->skb_queue);
-		spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
-
-		queue_len = skb_queue_len(&offload->skb_queue);
-		if (queue_len > offload->skb_queue_len_max / 8)
-			netdev_dbg(offload->dev, "%s: queue_len=%d\n",
-				   __func__, queue_len);
-
-		can_rx_offload_schedule(offload);
+		__skb_queue_add_sort(&offload->skb_irq_queue, skb,
+				     can_rx_offload_compare);
+		received++;
 	}
 
-	return skb_queue_len(&skb_queue);
+	return received;
 }
 EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_timestamp);
 
@@ -226,13 +210,10 @@ int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload)
 		if (!skb)
 			break;
 
-		skb_queue_tail(&offload->skb_queue, skb);
+		__skb_queue_tail(&offload->skb_irq_queue, skb);
 		received++;
 	}
 
-	if (received)
-		can_rx_offload_schedule(offload);
-
 	return received;
 }
 EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_fifo);
@@ -241,7 +222,6 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 				struct sk_buff *skb, u32 timestamp)
 {
 	struct can_rx_offload_cb *cb;
-	unsigned long flags;
 
 	if (skb_queue_len(&offload->skb_queue) >
 	    offload->skb_queue_len_max) {
@@ -252,11 +232,8 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 	cb = can_rx_offload_get_cb(skb);
 	cb->timestamp = timestamp;
 
-	spin_lock_irqsave(&offload->skb_queue.lock, flags);
-	__skb_queue_add_sort(&offload->skb_queue, skb, can_rx_offload_compare);
-	spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
-
-	can_rx_offload_schedule(offload);
+	__skb_queue_add_sort(&offload->skb_irq_queue, skb,
+			     can_rx_offload_compare);
 
 	return 0;
 }
@@ -295,13 +272,56 @@ int can_rx_offload_queue_tail(struct can_rx_offload *offload,
 		return -ENOBUFS;
 	}
 
-	skb_queue_tail(&offload->skb_queue, skb);
-	can_rx_offload_schedule(offload);
+	__skb_queue_tail(&offload->skb_irq_queue, skb);
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(can_rx_offload_queue_tail);
 
+void can_rx_offload_irq_finish(struct can_rx_offload *offload)
+{
+	unsigned long flags;
+	int queue_len;
+
+	if (skb_queue_empty_lockless(&offload->skb_irq_queue))
+		return;
+
+	spin_lock_irqsave(&offload->skb_queue.lock, flags);
+	skb_queue_splice_tail_init(&offload->skb_irq_queue, &offload->skb_queue);
+	spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
+
+	queue_len = skb_queue_len(&offload->skb_queue);
+	if (queue_len > offload->skb_queue_len_max / 8)
+		netdev_dbg(offload->dev, "%s: queue_len=%d\n",
+			   __func__, queue_len);
+
+	napi_schedule(&offload->napi);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_irq_finish);
+
+void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload)
+{
+	unsigned long flags;
+	int queue_len;
+
+	if (skb_queue_empty_lockless(&offload->skb_irq_queue))
+		return;
+
+	spin_lock_irqsave(&offload->skb_queue.lock, flags);
+	skb_queue_splice_tail_init(&offload->skb_irq_queue, &offload->skb_queue);
+	spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
+
+	queue_len = skb_queue_len(&offload->skb_queue);
+	if (queue_len > offload->skb_queue_len_max / 8)
+		netdev_dbg(offload->dev, "%s: queue_len=%d\n",
+			   __func__, queue_len);
+
+	local_bh_disable();
+	napi_schedule(&offload->napi);
+	local_bh_enable();
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_threaded_irq_finish);
+
 static int can_rx_offload_init_queue(struct net_device *dev,
 				     struct can_rx_offload *offload,
 				     unsigned int weight)
@@ -312,6 +332,7 @@ static int can_rx_offload_init_queue(struct net_device *dev,
 	offload->skb_queue_len_max = 2 << fls(weight);
 	offload->skb_queue_len_max *= 4;
 	skb_queue_head_init(&offload->skb_queue);
+	__skb_queue_head_init(&offload->skb_irq_queue);
 
 	netif_napi_add(dev, &offload->napi, can_rx_offload_napi_poll, weight);
 
@@ -373,5 +394,6 @@ void can_rx_offload_del(struct can_rx_offload *offload)
 {
 	netif_napi_del(&offload->napi);
 	skb_queue_purge(&offload->skb_queue);
+	__skb_queue_purge(&offload->skb_irq_queue);
 }
 EXPORT_SYMBOL_GPL(can_rx_offload_del);