can: CAN Network device driver and Netlink interface

The CAN network device driver interface provides a generic interface to
setup, configure and monitor CAN network devices. It exports a set of
common data structures and functions, which all real CAN network device
drivers should use. Please have a look to the SJA1000 or MSCAN driver
to understand how to use them. The name of the module is can-dev.ko.

Furthermore, it adds a Netlink interface allowing to configure the CAN
device using the program "ip" from the iproute2 utility suite.

For further information please check "Documentation/networking/can.txt"

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 184 insertions, 0 deletions

diff --git a/include/linux/can/Kbuild b/include/linux/can/Kbuild
index eff898aac02b..8cb05aae661c 100644
--- a/include/linux/can/Kbuild
+++ b/include/linux/can/Kbuild
@@ -1,3 +1,4 @@
 header-y += raw.h
 header-y += bcm.h
 header-y += error.h
+header-y += netlink.h
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
new file mode 100644
index 000000000000..4a37a56f6cdd
--- /dev/null
+++ b/include/linux/can/dev.h
@@ -0,0 +1,70 @@
+/*
+ * linux/can/dev.h
+ *
+ * Definitions for the CAN network device driver interface
+ *
+ * Copyright (C) 2006 Andrey Volkov <avolkov@varma-el.com>
+ *               Varma Electronics Oy
+ *
+ * Copyright (C) 2008 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ */
+
+#ifndef CAN_DEV_H
+#define CAN_DEV_H
+
+#include <linux/can/netlink.h>
+#include <linux/can/error.h>
+
+/*
+ * CAN mode
+ */
+enum can_mode {
+        CAN_MODE_STOP = 0,
+        CAN_MODE_START,
+        CAN_MODE_SLEEP
+};
+
+/*
+ * CAN common private data
+ */
+#define CAN_ECHO_SKB_MAX  4
+
+struct can_priv {
+        struct can_device_stats can_stats;
+
+        struct can_bittiming bittiming;
+        struct can_bittiming_const *bittiming_const;
+        struct can_clock clock;
+
+        enum can_state state;
+        u32 ctrlmode;
+
+        int restart_ms;
+        struct timer_list restart_timer;
+
+        struct sk_buff *echo_skb[CAN_ECHO_SKB_MAX];
+
+        int (*do_set_bittiming)(struct net_device *dev);
+        int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
+        int (*do_get_state)(const struct net_device *dev,
+                            enum can_state *state);
+};
+
+struct net_device *alloc_candev(int sizeof_priv);
+void free_candev(struct net_device *dev);
+
+int open_candev(struct net_device *dev);
+void close_candev(struct net_device *dev);
+
+int register_candev(struct net_device *dev);
+void unregister_candev(struct net_device *dev);
+
+int can_restart_now(struct net_device *dev);
+void can_bus_off(struct net_device *dev);
+
+void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, int idx);
+void can_get_echo_skb(struct net_device *dev, int idx);
+
+#endif /* CAN_DEV_H */
diff --git a/include/linux/can/netlink.h b/include/linux/can/netlink.h
new file mode 100644
index 000000000000..9ecbb7871c0e
--- /dev/null
+++ b/include/linux/can/netlink.h
@@ -0,0 +1,113 @@
+/*
+ * linux/can/netlink.h
+ *
+ * Definitions for the CAN netlink interface
+ *
+ * Copyright (c) 2009 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * Send feedback to <socketcan-users@lists.berlios.de>
+ *
+ */
+
+#ifndef CAN_NETLINK_H
+#define CAN_NETLINK_H
+
+#include <linux/types.h>
+
+/*
+ * CAN bit-timing parameters
+ *
+ * For futher information, please read chapter "8 BIT TIMING
+ * REQUIREMENTS" of the "Bosch CAN Specification version 2.0"
+ * at http://www.semiconductors.bosch.de/pdf/can2spec.pdf.
+ */
+struct can_bittiming {
+        __u32 bitrate;          /* Bit-rate in bits/second */
+        __u32 sample_point;     /* Sample point in one-tenth of a percent */
+        __u32 tq;               /* Time quanta (TQ) in nanoseconds */
+        __u32 prop_seg;         /* Propagation segment in TQs */
+        __u32 phase_seg1;       /* Phase buffer segment 1 in TQs */
+        __u32 phase_seg2;       /* Phase buffer segment 2 in TQs */
+        __u32 sjw;              /* Synchronisation jump width in TQs */
+        __u32 brp;              /* Bit-rate prescaler */
+};
+
+/*
+ * CAN harware-dependent bit-timing constant
+ *
+ * Used for calculating and checking bit-timing parameters
+ */
+struct can_bittiming_const {
+        char name[16];          /* Name of the CAN controller hardware */
+        __u32 tseg1_min;        /* Time segement 1 = prop_seg + phase_seg1 */
+        __u32 tseg1_max;
+        __u32 tseg2_min;        /* Time segement 2 = phase_seg2 */
+        __u32 tseg2_max;
+        __u32 sjw_max;          /* Synchronisation jump width */
+        __u32 brp_min;          /* Bit-rate prescaler */
+        __u32 brp_max;
+        __u32 brp_inc;
+};
+
+/*
+ * CAN clock parameters
+ */
+struct can_clock {
+        __u32 freq;             /* CAN system clock frequency in Hz */
+};
+
+/*
+ * CAN operational and error states
+ */
+enum can_state {
+        CAN_STATE_ERROR_ACTIVE = 0,     /* RX/TX error count < 96 */
+        CAN_STATE_ERROR_WARNING,        /* RX/TX error count < 128 */
+        CAN_STATE_ERROR_PASSIVE,        /* RX/TX error count < 256 */
+        CAN_STATE_BUS_OFF,              /* RX/TX error count >= 256 */
+        CAN_STATE_STOPPED,              /* Device is stopped */
+        CAN_STATE_SLEEPING,             /* Device is sleeping */
+        CAN_STATE_MAX
+};
+
+/*
+ * CAN controller mode
+ */
+struct can_ctrlmode {
+        __u32 mask;
+        __u32 flags;
+};
+
+#define CAN_CTRLMODE_LOOPBACK   0x1     /* Loopback mode */
+#define CAN_CTRLMODE_LISTENONLY 0x2     /* Listen-only mode */
+#define CAN_CTRLMODE_3_SAMPLES  0x4     /* Triple sampling mode */
+
+/*
+ * CAN device statistics
+ */
+struct can_device_stats {
+        __u32 bus_error;        /* Bus errors */
+        __u32 error_warning;    /* Changes to error warning state */
+        __u32 error_passive;    /* Changes to error passive state */
+        __u32 bus_off;          /* Changes to bus off state */
+        __u32 arbitration_lost; /* Arbitration lost errors */
+        __u32 restarts;         /* CAN controller re-starts */
+};
+
+/*
+ * CAN netlink interface
+ */
+enum {
+        IFLA_CAN_UNSPEC,
+        IFLA_CAN_BITTIMING,
+        IFLA_CAN_BITTIMING_CONST,
+        IFLA_CAN_CLOCK,
+        IFLA_CAN_STATE,
+        IFLA_CAN_CTRLMODE,
+        IFLA_CAN_RESTART_MS,
+        IFLA_CAN_RESTART,
+        __IFLA_CAN_MAX
+};
+
+#define IFLA_CAN_MAX    (__IFLA_CAN_MAX - 1)
+
+#endif /* CAN_NETLINK_H */