Merge tag 'linux-can-next-for-4.11-20170124' of...

Merge tag 'linux-can-next-for-4.11-20170124' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2017-01-24

this is a pull request of 4 patches for net-next/master.

The first patch by Oliver Hartkopp adds a netlink API to configure the
interface termination of a CAN card. The next two patches are by me and
add a netlink API to query and configure CAN interfaces that only
support fixed bitrates. The last patch by Colin Ian King simplifies the
return path in the softing_cs driver's softingcs_probe() function.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/can/dev.c

@@ -279,25 +279,45 @@ static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	return 0;
 }
 
+/* Checks the validity of predefined bitrate settings */
+static int can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
+				const u32 *bitrate_const,
+				const unsigned int bitrate_const_cnt)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	unsigned int i;
+
+	for (i = 0; i < bitrate_const_cnt; i++) {
+		if (bt->bitrate == bitrate_const[i])
+			break;
+	}
+
+	if (i >= priv->bitrate_const_cnt)
+		return -EINVAL;
+
+	return 0;
+}
+
 static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
-			     const struct can_bittiming_const *btc)
+			     const struct can_bittiming_const *btc,
+			     const u32 *bitrate_const,
+			     const unsigned int bitrate_const_cnt)
 {
 	int err;
 
-	/* Check if the CAN device has bit-timing parameters */
-	if (!btc)
-		return -EOPNOTSUPP;
-
 	/*
 	 * Depending on the given can_bittiming parameter structure the CAN
 	 * timing parameters are calculated based on the provided bitrate OR
 	 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 	 * provided directly which are then checked and fixed up.
 	 */
-	if (!bt->tq && bt->bitrate)
+	if (!bt->tq && bt->bitrate && btc)
 		err = can_calc_bittiming(dev, bt, btc);
-	else if (bt->tq && !bt->bitrate)
+	else if (bt->tq && !bt->bitrate && btc)
 		err = can_fixup_bittiming(dev, bt, btc);
+	else if (!bt->tq && bt->bitrate && bitrate_const)
+		err = can_validate_bitrate(dev, bt, bitrate_const,
+					   bitrate_const_cnt);
 	else
 		err = -EINVAL;
 
@@ -872,8 +892,20 @@ static int can_changelink(struct net_device *dev,
 		/* Do not allow changing bittiming while running */
 		if (dev->flags & IFF_UP)
 			return -EBUSY;
+
+		/* Calculate bittiming parameters based on
+		 * bittiming_const if set, otherwise pass bitrate
+		 * directly via do_set_bitrate(). Bail out if neither
+		 * is given.
+		 */
+		if (!priv->bittiming_const && !priv->do_set_bittiming)
+			return -EOPNOTSUPP;
+
 		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
-		err = can_get_bittiming(dev, &bt, priv->bittiming_const);
+		err = can_get_bittiming(dev, &bt,
+					priv->bittiming_const,
+					priv->bitrate_const,
+					priv->bitrate_const_cnt);
 		if (err)
 			return err;
 		memcpy(&priv->bittiming, &bt, sizeof(bt));
@@ -943,9 +975,21 @@ static int can_changelink(struct net_device *dev,
 		/* Do not allow changing bittiming while running */
 		if (dev->flags & IFF_UP)
 			return -EBUSY;
+
+		/* Calculate bittiming parameters based on
+		 * data_bittiming_const if set, otherwise pass bitrate
+		 * directly via do_set_bitrate(). Bail out if neither
+		 * is given.
+		 */
+		if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
+			return -EOPNOTSUPP;
+
 		memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
 		       sizeof(dbt));
-		err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const);
+		err = can_get_bittiming(dev, &dbt,
+					priv->data_bittiming_const,
+					priv->data_bitrate_const,
+					priv->data_bitrate_const_cnt);
 		if (err)
 			return err;
 		memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
@@ -958,6 +1002,30 @@ static int can_changelink(struct net_device *dev,
 		}
 	}
 
+	if (data[IFLA_CAN_TERMINATION]) {
+		const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
+		const unsigned int num_term = priv->termination_const_cnt;
+		unsigned int i;
+
+		if (!priv->do_set_termination)
+			return -EOPNOTSUPP;
+
+		/* check whether given value is supported by the interface */
+		for (i = 0; i < num_term; i++) {
+			if (termval == priv->termination_const[i])
+				break;
+		}
+		if (i >= num_term)
+			return -EINVAL;
+
+		/* Finally, set the termination value */
+		err = priv->do_set_termination(dev, termval);
+		if (err)
+			return err;
+
+		priv->termination = termval;
+	}
+
 	return 0;
 }
 
@@ -980,6 +1048,17 @@ static size_t can_get_size(const struct net_device *dev)
 		size += nla_total_size(sizeof(struct can_bittiming));
 	if (priv->data_bittiming_const)				/* IFLA_CAN_DATA_BITTIMING_CONST */
 		size += nla_total_size(sizeof(struct can_bittiming_const));
+	if (priv->termination_const) {
+		size += nla_total_size(sizeof(priv->termination));		/* IFLA_CAN_TERMINATION */
+		size += nla_total_size(sizeof(*priv->termination_const) *	/* IFLA_CAN_TERMINATION_CONST */
+				       priv->termination_const_cnt);
+	}
+	if (priv->bitrate_const)				/* IFLA_CAN_BITRATE_CONST */
+		size += nla_total_size(sizeof(*priv->bitrate_const) *
+				       priv->bitrate_const_cnt);
+	if (priv->data_bitrate_const)				/* IFLA_CAN_DATA_BITRATE_CONST */
+		size += nla_total_size(sizeof(*priv->data_bitrate_const) *
+				       priv->data_bitrate_const_cnt);
 
 	return size;
 }
@@ -1018,7 +1097,28 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	    (priv->data_bittiming_const &&
 	     nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
 		     sizeof(*priv->data_bittiming_const),
-		     priv->data_bittiming_const)))
+		     priv->data_bittiming_const)) ||
+
+	    (priv->termination_const &&
+	     (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
+	      nla_put(skb, IFLA_CAN_TERMINATION_CONST,
+		      sizeof(*priv->termination_const) *
+		      priv->termination_const_cnt,
+		      priv->termination_const))) ||
+
+	    (priv->bitrate_const &&
+	     nla_put(skb, IFLA_CAN_BITRATE_CONST,
+		     sizeof(*priv->bitrate_const) *
+		     priv->bitrate_const_cnt,
+		     priv->bitrate_const)) ||
+
+	    (priv->data_bitrate_const &&
+	     nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
+		     sizeof(*priv->data_bitrate_const) *
+		     priv->data_bitrate_const_cnt,
+		     priv->data_bitrate_const))
+	    )
+
 		return -EMSGSIZE;
 
 	return 0;
@@ -1073,6 +1173,22 @@ static struct rtnl_link_ops can_link_ops __read_mostly = {
  */
 int register_candev(struct net_device *dev)
 {
+	struct can_priv *priv = netdev_priv(dev);
+
+	/* Ensure termination_const, termination_const_cnt and
+	 * do_set_termination consistency. All must be either set or
+	 * unset.
+	 */
+	if ((!priv->termination_const != !priv->termination_const_cnt) ||
+	    (!priv->termination_const != !priv->do_set_termination))
+		return -EINVAL;
+
+	if (!priv->bitrate_const != !priv->bitrate_const_cnt)
+		return -EINVAL;
+
+	if (!priv->data_bitrate_const != !priv->data_bitrate_const_cnt)
+		return -EINVAL;
+
 	dev->rtnl_link_ops = &can_link_ops;
 	return register_netdev(dev);
 }

drivers/net/can/softing/softing_cs.c

@@ -310,7 +310,7 @@ static int softingcs_probe(struct pcmcia_device *pcmcia)
 pcmcia_failed:
 	pcmcia_disable_device(pcmcia);
 	pcmcia->priv = NULL;
-	return ret ?: -ENODEV;
+	return ret;
 }
 
 static const struct pcmcia_device_id softingcs_ids[] = {

include/linux/can/dev.h

@@ -38,6 +38,13 @@ struct can_priv {
 	struct can_bittiming bittiming, data_bittiming;
 	const struct can_bittiming_const *bittiming_const,
 		*data_bittiming_const;
+	const u16 *termination_const;
+	unsigned int termination_const_cnt;
+	u16 termination;
+	const u32 *bitrate_const;
+	unsigned int bitrate_const_cnt;
+	const u32 *data_bitrate_const;
+	unsigned int data_bitrate_const_cnt;
 	struct can_clock clock;
 
 	enum can_state state;
@@ -53,6 +60,7 @@ struct can_priv {
 	int (*do_set_bittiming)(struct net_device *dev);
 	int (*do_set_data_bittiming)(struct net_device *dev);
 	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
+	int (*do_set_termination)(struct net_device *dev, u16 term);
 	int (*do_get_state)(const struct net_device *dev,
 			    enum can_state *state);
 	int (*do_get_berr_counter)(const struct net_device *dev,

include/uapi/linux/can/netlink.h

@@ -127,9 +127,16 @@ enum {
 	IFLA_CAN_BERR_COUNTER,
 	IFLA_CAN_DATA_BITTIMING,
 	IFLA_CAN_DATA_BITTIMING_CONST,
+	IFLA_CAN_TERMINATION,
+	IFLA_CAN_TERMINATION_CONST,
+	IFLA_CAN_BITRATE_CONST,
+	IFLA_CAN_DATA_BITRATE_CONST,
 	__IFLA_CAN_MAX
 };
 
 #define IFLA_CAN_MAX	(__IFLA_CAN_MAX - 1)
 
+/* u16 termination range: 1..65535 Ohms */
+#define CAN_TERMINATION_DISABLED 0
+
 #endif /* !_UAPI_CAN_NETLINK_H */