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authorDavid S. Miller <davem@davemloft.net>2013-11-04 19:59:44 -0500
committerDavid S. Miller <davem@davemloft.net>2013-11-04 19:59:44 -0500
commit13521a57974635384db51d65135cc0267c6ae771 (patch)
tree7efbad661e4cdbb5e469dcb7c64e5b35ddc0266a
parent9f9843a751d0a2057f9f3d313886e7e5e6ebaac9 (diff)
parent26896fd98130cdda73b19c75849a0d25cb850cb8 (diff)
Merge branch 'for-davem' of git://gitorious.org/linux-can/linux-can-next
Marc Kleine-Budde says: ==================== here's a pull request for net-next. It includes a patch by Oliver Hartkopp et al. that adds documentation for the broadcast manager to Documentation/networking/can.txt. Three patches by me that clean up the netlink handling code in the CAN core. And another patch that removes a not needed function from the ti_hecc driver. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--Documentation/networking/can.txt217
-rw-r--r--drivers/net/can/dev.c67
-rw-r--r--drivers/net/can/ti_hecc.c10
3 files changed, 249 insertions, 45 deletions
diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
index 820f55344edc..4c072414eadb 100644
--- a/Documentation/networking/can.txt
+++ b/Documentation/networking/can.txt
@@ -25,6 +25,12 @@ This file contains
4.1.5 RAW socket option CAN_RAW_FD_FRAMES
4.1.6 RAW socket returned message flags
4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
+ 4.2.1 Broadcast Manager operations
+ 4.2.2 Broadcast Manager message flags
+ 4.2.3 Broadcast Manager transmission timers
+ 4.2.4 Broadcast Manager message sequence transmission
+ 4.2.5 Broadcast Manager receive filter timers
+ 4.2.6 Broadcast Manager multiplex message receive filter
4.3 connected transport protocols (SOCK_SEQPACKET)
4.4 unconnected transport protocols (SOCK_DGRAM)
@@ -593,6 +599,217 @@ solution for a couple of reasons:
In order to receive such messages, CAN_RAW_RECV_OWN_MSGS must be set.
4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
+
+ The Broadcast Manager protocol provides a command based configuration
+ interface to filter and send (e.g. cyclic) CAN messages in kernel space.
+
+ Receive filters can be used to down sample frequent messages; detect events
+ such as message contents changes, packet length changes, and do time-out
+ monitoring of received messages.
+
+ Periodic transmission tasks of CAN frames or a sequence of CAN frames can be
+ created and modified at runtime; both the message content and the two
+ possible transmit intervals can be altered.
+
+ A BCM socket is not intended for sending individual CAN frames using the
+ struct can_frame as known from the CAN_RAW socket. Instead a special BCM
+ configuration message is defined. The basic BCM configuration message used
+ to communicate with the broadcast manager and the available operations are
+ defined in the linux/can/bcm.h include. The BCM message consists of a
+ message header with a command ('opcode') followed by zero or more CAN frames.
+ The broadcast manager sends responses to user space in the same form:
+
+ struct bcm_msg_head {
+ __u32 opcode; /* command */
+ __u32 flags; /* special flags */
+ __u32 count; /* run 'count' times with ival1 */
+ struct timeval ival1, ival2; /* count and subsequent interval */
+ canid_t can_id; /* unique can_id for task */
+ __u32 nframes; /* number of can_frames following */
+ struct can_frame frames[0];
+ };
+
+ The aligned payload 'frames' uses the same basic CAN frame structure defined
+ at the beginning of section 4 and in the include/linux/can.h include. All
+ messages to the broadcast manager from user space have this structure.
+
+ Note a CAN_BCM socket must be connected instead of bound after socket
+ creation (example without error checking):
+
+ int s;
+ struct sockaddr_can addr;
+ struct ifreq ifr;
+
+ s = socket(PF_CAN, SOCK_DGRAM, CAN_BCM);
+
+ strcpy(ifr.ifr_name, "can0");
+ ioctl(s, SIOCGIFINDEX, &ifr);
+
+ addr.can_family = AF_CAN;
+ addr.can_ifindex = ifr.ifr_ifindex;
+
+ connect(s, (struct sockaddr *)&addr, sizeof(addr))
+
+ (..)
+
+ The broadcast manager socket is able to handle any number of in flight
+ transmissions or receive filters concurrently. The different RX/TX jobs are
+ distinguished by the unique can_id in each BCM message. However additional
+ CAN_BCM sockets are recommended to communicate on multiple CAN interfaces.
+ When the broadcast manager socket is bound to 'any' CAN interface (=> the
+ interface index is set to zero) the configured receive filters apply to any
+ CAN interface unless the sendto() syscall is used to overrule the 'any' CAN
+ interface index. When using recvfrom() instead of read() to retrieve BCM
+ socket messages the originating CAN interface is provided in can_ifindex.
+
+ 4.2.1 Broadcast Manager operations
+
+ The opcode defines the operation for the broadcast manager to carry out,
+ or details the broadcast managers response to several events, including
+ user requests.
+
+ Transmit Operations (user space to broadcast manager):
+
+ TX_SETUP: Create (cyclic) transmission task.
+
+ TX_DELETE: Remove (cyclic) transmission task, requires only can_id.
+
+ TX_READ: Read properties of (cyclic) transmission task for can_id.
+
+ TX_SEND: Send one CAN frame.
+
+ Transmit Responses (broadcast manager to user space):
+
+ TX_STATUS: Reply to TX_READ request (transmission task configuration).
+
+ TX_EXPIRED: Notification when counter finishes sending at initial interval
+ 'ival1'. Requires the TX_COUNTEVT flag to be set at TX_SETUP.
+
+ Receive Operations (user space to broadcast manager):
+
+ RX_SETUP: Create RX content filter subscription.
+
+ RX_DELETE: Remove RX content filter subscription, requires only can_id.
+
+ RX_READ: Read properties of RX content filter subscription for can_id.
+
+ Receive Responses (broadcast manager to user space):
+
+ RX_STATUS: Reply to RX_READ request (filter task configuration).
+
+ RX_TIMEOUT: Cyclic message is detected to be absent (timer ival1 expired).
+
+ RX_CHANGED: BCM message with updated CAN frame (detected content change).
+ Sent on first message received or on receipt of revised CAN messages.
+
+ 4.2.2 Broadcast Manager message flags
+
+ When sending a message to the broadcast manager the 'flags' element may
+ contain the following flag definitions which influence the behaviour:
+
+ SETTIMER: Set the values of ival1, ival2 and count
+
+ STARTTIMER: Start the timer with the actual values of ival1, ival2
+ and count. Starting the timer leads simultaneously to emit a CAN frame.
+
+ TX_COUNTEVT: Create the message TX_EXPIRED when count expires
+
+ TX_ANNOUNCE: A change of data by the process is emitted immediately.
+
+ TX_CP_CAN_ID: Copies the can_id from the message header to each
+ subsequent frame in frames. This is intended as usage simplification. For
+ TX tasks the unique can_id from the message header may differ from the
+ can_id(s) stored for transmission in the subsequent struct can_frame(s).
+
+ RX_FILTER_ID: Filter by can_id alone, no frames required (nframes=0).
+
+ RX_CHECK_DLC: A change of the DLC leads to an RX_CHANGED.
+
+ RX_NO_AUTOTIMER: Prevent automatically starting the timeout monitor.
+
+ RX_ANNOUNCE_RESUME: If passed at RX_SETUP and a receive timeout occured, a
+ RX_CHANGED message will be generated when the (cyclic) receive restarts.
+
+ TX_RESET_MULTI_IDX: Reset the index for the multiple frame transmission.
+
+ RX_RTR_FRAME: Send reply for RTR-request (placed in op->frames[0]).
+
+ 4.2.3 Broadcast Manager transmission timers
+
+ Periodic transmission configurations may use up to two interval timers.
+ In this case the BCM sends a number of messages ('count') at an interval
+ 'ival1', then continuing to send at another given interval 'ival2'. When
+ only one timer is needed 'count' is set to zero and only 'ival2' is used.
+ When SET_TIMER and START_TIMER flag were set the timers are activated.
+ The timer values can be altered at runtime when only SET_TIMER is set.
+
+ 4.2.4 Broadcast Manager message sequence transmission
+
+ Up to 256 CAN frames can be transmitted in a sequence in the case of a cyclic
+ TX task configuration. The number of CAN frames is provided in the 'nframes'
+ element of the BCM message head. The defined number of CAN frames are added
+ as array to the TX_SETUP BCM configuration message.
+
+ /* create a struct to set up a sequence of four CAN frames */
+ struct {
+ struct bcm_msg_head msg_head;
+ struct can_frame frame[4];
+ } mytxmsg;
+
+ (..)
+ mytxmsg.nframes = 4;
+ (..)
+
+ write(s, &mytxmsg, sizeof(mytxmsg));
+
+ With every transmission the index in the array of CAN frames is increased
+ and set to zero at index overflow.
+
+ 4.2.5 Broadcast Manager receive filter timers
+
+ The timer values ival1 or ival2 may be set to non-zero values at RX_SETUP.
+ When the SET_TIMER flag is set the timers are enabled:
+
+ ival1: Send RX_TIMEOUT when a received message is not received again within
+ the given time. When START_TIMER is set at RX_SETUP the timeout detection
+ is activated directly - even without a former CAN frame reception.
+
+ ival2: Throttle the received message rate down to the value of ival2. This
+ is useful to reduce messages for the application when the signal inside the
+ CAN frame is stateless as state changes within the ival2 periode may get
+ lost.
+
+ 4.2.6 Broadcast Manager multiplex message receive filter
+
+ To filter for content changes in multiplex message sequences an array of more
+ than one CAN frames can be passed in a RX_SETUP configuration message. The
+ data bytes of the first CAN frame contain the mask of relevant bits that
+ have to match in the subsequent CAN frames with the received CAN frame.
+ If one of the subsequent CAN frames is matching the bits in that frame data
+ mark the relevant content to be compared with the previous received content.
+ Up to 257 CAN frames (multiplex filter bit mask CAN frame plus 256 CAN
+ filters) can be added as array to the TX_SETUP BCM configuration message.
+
+ /* usually used to clear CAN frame data[] - beware of endian problems! */
+ #define U64_DATA(p) (*(unsigned long long*)(p)->data)
+
+ struct {
+ struct bcm_msg_head msg_head;
+ struct can_frame frame[5];
+ } msg;
+
+ msg.msg_head.opcode = RX_SETUP;
+ msg.msg_head.can_id = 0x42;
+ msg.msg_head.flags = 0;
+ msg.msg_head.nframes = 5;
+ U64_DATA(&msg.frame[0]) = 0xFF00000000000000ULL; /* MUX mask */
+ U64_DATA(&msg.frame[1]) = 0x01000000000000FFULL; /* data mask (MUX 0x01) */
+ U64_DATA(&msg.frame[2]) = 0x0200FFFF000000FFULL; /* data mask (MUX 0x02) */
+ U64_DATA(&msg.frame[3]) = 0x330000FFFFFF0003ULL; /* data mask (MUX 0x33) */
+ U64_DATA(&msg.frame[4]) = 0x4F07FC0FF0000000ULL; /* data mask (MUX 0x4F) */
+
+ write(s, &msg, sizeof(msg));
+
4.3 connected transport protocols (SOCK_SEQPACKET)
4.4 unconnected transport protocols (SOCK_DGRAM)
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 1870c4731a57..bda1888cae9a 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -645,19 +645,6 @@ static int can_changelink(struct net_device *dev,
/* We need synchronization with dev->stop() */
ASSERT_RTNL();
- if (data[IFLA_CAN_CTRLMODE]) {
- struct can_ctrlmode *cm;
-
- /* Do not allow changing controller mode while running */
- if (dev->flags & IFF_UP)
- return -EBUSY;
- cm = nla_data(data[IFLA_CAN_CTRLMODE]);
- if (cm->flags & ~priv->ctrlmode_supported)
- return -EOPNOTSUPP;
- priv->ctrlmode &= ~cm->mask;
- priv->ctrlmode |= cm->flags;
- }
-
if (data[IFLA_CAN_BITTIMING]) {
struct can_bittiming bt;
@@ -680,6 +667,19 @@ static int can_changelink(struct net_device *dev,
}
}
+ if (data[IFLA_CAN_CTRLMODE]) {
+ struct can_ctrlmode *cm;
+
+ /* Do not allow changing controller mode while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+ cm = nla_data(data[IFLA_CAN_CTRLMODE]);
+ if (cm->flags & ~priv->ctrlmode_supported)
+ return -EOPNOTSUPP;
+ priv->ctrlmode &= ~cm->mask;
+ priv->ctrlmode |= cm->flags;
+ }
+
if (data[IFLA_CAN_RESTART_MS]) {
/* Do not allow changing restart delay while running */
if (dev->flags & IFF_UP)
@@ -702,17 +702,17 @@ static int can_changelink(struct net_device *dev,
static size_t can_get_size(const struct net_device *dev)
{
struct can_priv *priv = netdev_priv(dev);
- size_t size;
-
- size = nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
- size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
- size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
- size += nla_total_size(sizeof(struct can_bittiming)); /* IFLA_CAN_BITTIMING */
- size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
- if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
- size += nla_total_size(sizeof(struct can_berr_counter));
- if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
+ size_t size = 0;
+
+ size += nla_total_size(sizeof(struct can_bittiming)); /* IFLA_CAN_BITTIMING */
+ if (priv->bittiming_const) /* IFLA_CAN_BITTIMING_CONST */
size += nla_total_size(sizeof(struct can_bittiming_const));
+ size += nla_total_size(sizeof(struct can_clock)); /* IFLA_CAN_CLOCK */
+ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_STATE */
+ size += nla_total_size(sizeof(struct can_ctrlmode)); /* IFLA_CAN_CTRLMODE */
+ size += nla_total_size(sizeof(u32)); /* IFLA_CAN_RESTART_MS */
+ if (priv->do_get_berr_counter) /* IFLA_CAN_BERR_COUNTER */
+ size += nla_total_size(sizeof(struct can_berr_counter));
return size;
}
@@ -726,23 +726,20 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
if (priv->do_get_state)
priv->do_get_state(dev, &state);
- if (nla_put_u32(skb, IFLA_CAN_STATE, state) ||
- nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
- nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
- nla_put(skb, IFLA_CAN_BITTIMING,
+ if (nla_put(skb, IFLA_CAN_BITTIMING,
sizeof(priv->bittiming), &priv->bittiming) ||
+ (priv->bittiming_const &&
+ nla_put(skb, IFLA_CAN_BITTIMING_CONST,
+ sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
nla_put(skb, IFLA_CAN_CLOCK, sizeof(cm), &priv->clock) ||
+ nla_put_u32(skb, IFLA_CAN_STATE, state) ||
+ nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
+ nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
(priv->do_get_berr_counter &&
!priv->do_get_berr_counter(dev, &bec) &&
- nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
- (priv->bittiming_const &&
- nla_put(skb, IFLA_CAN_BITTIMING_CONST,
- sizeof(*priv->bittiming_const), priv->bittiming_const)))
- goto nla_put_failure;
+ nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)))
+ return -EMSGSIZE;
return 0;
-
-nla_put_failure:
- return -EMSGSIZE;
}
static size_t can_get_xstats_size(const struct net_device *dev)
diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
index beb5ef834f0f..60d95b44d0f7 100644
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -286,15 +286,6 @@ static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask)
return (hecc_read(priv, reg) & bit_mask) ? 1 : 0;
}
-static int ti_hecc_get_state(const struct net_device *ndev,
- enum can_state *state)
-{
- struct ti_hecc_priv *priv = netdev_priv(ndev);
-
- *state = priv->can.state;
- return 0;
-}
-
static int ti_hecc_set_btc(struct ti_hecc_priv *priv)
{
struct can_bittiming *bit_timing = &priv->can.bittiming;
@@ -940,7 +931,6 @@ static int ti_hecc_probe(struct platform_device *pdev)
priv->can.bittiming_const = &ti_hecc_bittiming_const;
priv->can.do_set_mode = ti_hecc_do_set_mode;
- priv->can.do_get_state = ti_hecc_get_state;
priv->can.do_get_berr_counter = ti_hecc_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;