diff options
Diffstat (limited to 'drivers/net/can/c_can/c_can.c')
| -rw-r--r-- | drivers/net/can/c_can/c_can.c | 349 |
1 files changed, 199 insertions, 150 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 951bfede8f3d..a5c8dcfa8357 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -114,6 +114,14 @@ IF_COMM_CONTROL | IF_COMM_TXRQST | \ IF_COMM_DATAA | IF_COMM_DATAB) +/* For the low buffers we clear the interrupt bit, but keep newdat */ +#define IF_COMM_RCV_LOW (IF_COMM_MASK | IF_COMM_ARB | \ + IF_COMM_CONTROL | IF_COMM_CLR_INT_PND | \ + IF_COMM_DATAA | IF_COMM_DATAB) + +/* For the high buffers we clear the interrupt bit and newdat */ +#define IF_COMM_RCV_HIGH (IF_COMM_RCV_LOW | IF_COMM_TXRQST) + /* IFx arbitration */ #define IF_ARB_MSGVAL BIT(15) #define IF_ARB_MSGXTD BIT(14) @@ -122,7 +130,6 @@ /* IFx message control */ #define IF_MCONT_NEWDAT BIT(15) #define IF_MCONT_MSGLST BIT(14) -#define IF_MCONT_CLR_MSGLST (0 << 14) #define IF_MCONT_INTPND BIT(13) #define IF_MCONT_UMASK BIT(12) #define IF_MCONT_TXIE BIT(11) @@ -133,31 +140,10 @@ #define IF_MCONT_DLC_MASK 0xf /* - * IFx register masks: - * allow easy operation on 16-bit registers when the - * argument is 32-bit instead + * Use IF1 for RX and IF2 for TX */ -#define IFX_WRITE_LOW_16BIT(x) ((x) & 0xFFFF) -#define IFX_WRITE_HIGH_16BIT(x) (((x) & 0xFFFF0000) >> 16) - -/* message object split */ -#define C_CAN_NO_OF_OBJECTS 32 -#define C_CAN_MSG_OBJ_RX_NUM 16 -#define C_CAN_MSG_OBJ_TX_NUM 16 - -#define C_CAN_MSG_OBJ_RX_FIRST 1 -#define C_CAN_MSG_OBJ_RX_LAST (C_CAN_MSG_OBJ_RX_FIRST + \ - C_CAN_MSG_OBJ_RX_NUM - 1) - -#define C_CAN_MSG_OBJ_TX_FIRST (C_CAN_MSG_OBJ_RX_LAST + 1) -#define C_CAN_MSG_OBJ_TX_LAST (C_CAN_MSG_OBJ_TX_FIRST + \ - C_CAN_MSG_OBJ_TX_NUM - 1) - -#define C_CAN_MSG_OBJ_RX_SPLIT 9 -#define C_CAN_MSG_RX_LOW_LAST (C_CAN_MSG_OBJ_RX_SPLIT - 1) - -#define C_CAN_NEXT_MSG_OBJ_MASK (C_CAN_MSG_OBJ_TX_NUM - 1) -#define RECEIVE_OBJECT_BITS 0x0000ffff +#define IF_RX 0 +#define IF_TX 1 /* status interrupt */ #define STATUS_INTERRUPT 0x8000 @@ -246,10 +232,9 @@ static inline int get_tx_next_msg_obj(const struct c_can_priv *priv) C_CAN_MSG_OBJ_TX_FIRST; } -static inline int get_tx_echo_msg_obj(const struct c_can_priv *priv) +static inline int get_tx_echo_msg_obj(int txecho) { - return (priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) + - C_CAN_MSG_OBJ_TX_FIRST; + return (txecho & C_CAN_NEXT_MSG_OBJ_MASK) + C_CAN_MSG_OBJ_TX_FIRST; } static u32 c_can_read_reg32(struct c_can_priv *priv, enum reg index) @@ -366,18 +351,6 @@ static void c_can_write_msg_object(struct net_device *dev, c_can_object_put(dev, iface, objno, IF_COMM_ALL); } -static inline void c_can_mark_rx_msg_obj(struct net_device *dev, - int iface, int ctrl_mask, - int obj) -{ - struct c_can_priv *priv = netdev_priv(dev); - - priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), - ctrl_mask & ~(IF_MCONT_MSGLST | IF_MCONT_INTPND)); - c_can_object_put(dev, iface, obj, IF_COMM_CONTROL); - -} - static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev, int iface, int ctrl_mask) @@ -387,45 +360,27 @@ static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev, for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_MSG_RX_LOW_LAST; i++) { priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), - ctrl_mask & ~(IF_MCONT_MSGLST | - IF_MCONT_INTPND | IF_MCONT_NEWDAT)); + ctrl_mask & ~IF_MCONT_NEWDAT); c_can_object_put(dev, iface, i, IF_COMM_CONTROL); } } -static inline void c_can_activate_rx_msg_obj(struct net_device *dev, - int iface, int ctrl_mask, - int obj) -{ - struct c_can_priv *priv = netdev_priv(dev); - - priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), - ctrl_mask & ~(IF_MCONT_MSGLST | - IF_MCONT_INTPND | IF_MCONT_NEWDAT)); - c_can_object_put(dev, iface, obj, IF_COMM_CONTROL); -} - -static void c_can_handle_lost_msg_obj(struct net_device *dev, - int iface, int objno) +static int c_can_handle_lost_msg_obj(struct net_device *dev, + int iface, int objno, u32 ctrl) { - struct c_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; - struct sk_buff *skb; + struct c_can_priv *priv = netdev_priv(dev); struct can_frame *frame; + struct sk_buff *skb; - netdev_err(dev, "msg lost in buffer %d\n", objno); - - c_can_object_get(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST); - - priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), - IF_MCONT_CLR_MSGLST); - - c_can_object_put(dev, 0, objno, IF_COMM_CONTROL); + ctrl &= ~(IF_MCONT_MSGLST | IF_MCONT_INTPND | IF_MCONT_NEWDAT); + priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl); + c_can_object_put(dev, iface, objno, IF_COMM_CONTROL); /* create an error msg */ skb = alloc_can_err_skb(dev, &frame); if (unlikely(!skb)) - return; + return 0; frame->can_id |= CAN_ERR_CRTL; frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; @@ -433,6 +388,7 @@ static void c_can_handle_lost_msg_obj(struct net_device *dev, stats->rx_over_errors++; netif_receive_skb(skb); + return 1; } static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl) @@ -477,9 +433,6 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl) stats->rx_packets++; stats->rx_bytes += frame->can_dlc; - - can_led_event(dev, CAN_LED_EVENT_RX); - return 0; } @@ -548,10 +501,12 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, if (can_dropped_invalid_skb(dev, skb)) return NETDEV_TX_OK; + spin_lock_bh(&priv->xmit_lock); msg_obj_no = get_tx_next_msg_obj(priv); /* prepare message object for transmission */ - c_can_write_msg_object(dev, 0, frame, msg_obj_no); + c_can_write_msg_object(dev, IF_TX, frame, msg_obj_no); + priv->dlc[msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST] = frame->can_dlc; can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); /* @@ -562,10 +517,26 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, if (c_can_is_next_tx_obj_busy(priv, get_tx_next_msg_obj(priv)) || (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0) netif_stop_queue(dev); + spin_unlock_bh(&priv->xmit_lock); return NETDEV_TX_OK; } +static int c_can_wait_for_ctrl_init(struct net_device *dev, + struct c_can_priv *priv, u32 init) +{ + int retry = 0; + + while (init != (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_INIT)) { + udelay(10); + if (retry++ > 1000) { + netdev_err(dev, "CCTRL: set CONTROL_INIT failed\n"); + return -EIO; + } + } + return 0; +} + static int c_can_set_bittiming(struct net_device *dev) { unsigned int reg_btr, reg_brpe, ctrl_save; @@ -573,6 +544,7 @@ static int c_can_set_bittiming(struct net_device *dev) u32 ten_bit_brp; struct c_can_priv *priv = netdev_priv(dev); const struct can_bittiming *bt = &priv->can.bittiming; + int res; /* c_can provides a 6-bit brp and 4-bit brpe fields */ ten_bit_brp = bt->brp - 1; @@ -590,13 +562,17 @@ static int c_can_set_bittiming(struct net_device *dev) "setting BTR=%04x BRPE=%04x\n", reg_btr, reg_brpe); ctrl_save = priv->read_reg(priv, C_CAN_CTRL_REG); - priv->write_reg(priv, C_CAN_CTRL_REG, - ctrl_save | CONTROL_CCE | CONTROL_INIT); + ctrl_save &= ~CONTROL_INIT; + priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_CCE | CONTROL_INIT); + res = c_can_wait_for_ctrl_init(dev, priv, CONTROL_INIT); + if (res) + return res; + priv->write_reg(priv, C_CAN_BTR_REG, reg_btr); priv->write_reg(priv, C_CAN_BRPEXT_REG, reg_brpe); priv->write_reg(priv, C_CAN_CTRL_REG, ctrl_save); - return 0; + return c_can_wait_for_ctrl_init(dev, priv, 0); } /* @@ -614,14 +590,14 @@ static void c_can_configure_msg_objects(struct net_device *dev) /* first invalidate all message objects */ for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_NO_OF_OBJECTS; i++) - c_can_inval_msg_object(dev, 0, i); + c_can_inval_msg_object(dev, IF_RX, i); /* setup receive message objects */ for (i = C_CAN_MSG_OBJ_RX_FIRST; i < C_CAN_MSG_OBJ_RX_LAST; i++) - c_can_setup_receive_object(dev, 0, i, 0, 0, + c_can_setup_receive_object(dev, IF_RX, i, 0, 0, (IF_MCONT_RXIE | IF_MCONT_UMASK) & ~IF_MCONT_EOB); - c_can_setup_receive_object(dev, 0, C_CAN_MSG_OBJ_RX_LAST, 0, 0, + c_can_setup_receive_object(dev, IF_RX, C_CAN_MSG_OBJ_RX_LAST, 0, 0, IF_MCONT_EOB | IF_MCONT_RXIE | IF_MCONT_UMASK); } @@ -631,7 +607,7 @@ static void c_can_configure_msg_objects(struct net_device *dev) * - set operating mode * - configure message objects */ -static void c_can_chip_config(struct net_device *dev) +static int c_can_chip_config(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); @@ -668,15 +644,18 @@ static void c_can_chip_config(struct net_device *dev) priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED); /* set bittiming params */ - c_can_set_bittiming(dev); + return c_can_set_bittiming(dev); } -static void c_can_start(struct net_device *dev) +static int c_can_start(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); + int err; /* basic c_can configuration */ - c_can_chip_config(dev); + err = c_can_chip_config(dev); + if (err) + return err; priv->can.state = CAN_STATE_ERROR_ACTIVE; @@ -685,6 +664,8 @@ static void c_can_start(struct net_device *dev) /* enable status change, error and module interrupts */ c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS); + + return 0; } static void c_can_stop(struct net_device *dev) @@ -700,9 +681,13 @@ static void c_can_stop(struct net_device *dev) static int c_can_set_mode(struct net_device *dev, enum can_mode mode) { + int err; + switch (mode) { case CAN_MODE_START: - c_can_start(dev); + err = c_can_start(dev); + if (err) + return err; netif_wake_queue(dev); break; default: @@ -740,8 +725,6 @@ static int c_can_get_berr_counter(const struct net_device *dev, } /* - * theory of operation: - * * priv->tx_echo holds the number of the oldest can_frame put for * transmission into the hardware, but not yet ACKed by the CAN tx * complete IRQ. @@ -752,33 +735,113 @@ static int c_can_get_berr_counter(const struct net_device *dev, */ static void c_can_do_tx(struct net_device *dev) { - u32 val; - u32 msg_obj_no; struct c_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; + u32 val, obj, pkts = 0, bytes = 0; - for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { - msg_obj_no = get_tx_echo_msg_obj(priv); + spin_lock_bh(&priv->xmit_lock); + + for (; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) { + obj = get_tx_echo_msg_obj(priv->tx_echo); val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG); - if (!(val & (1 << (msg_obj_no - 1)))) { - can_get_echo_skb(dev, - msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST); - c_can_object_get(dev, 0, msg_obj_no, IF_COMM_ALL); - stats->tx_bytes += priv->read_reg(priv, - C_CAN_IFACE(MSGCTRL_REG, 0)) - & IF_MCONT_DLC_MASK; - stats->tx_packets++; - can_led_event(dev, CAN_LED_EVENT_TX); - c_can_inval_msg_object(dev, 0, msg_obj_no); - } else { + + if (val & (1 << (obj - 1))) break; - } + + can_get_echo_skb(dev, obj - C_CAN_MSG_OBJ_TX_FIRST); + bytes += priv->dlc[obj - C_CAN_MSG_OBJ_TX_FIRST]; + pkts++; + c_can_inval_msg_object(dev, IF_TX, obj); } /* restart queue if wrap-up or if queue stalled on last pkt */ if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) || ((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0)) netif_wake_queue(dev); + + spin_unlock_bh(&priv->xmit_lock); + + if (pkts) { + stats->tx_bytes += bytes; + stats->tx_packets += pkts; + can_led_event(dev, CAN_LED_EVENT_TX); + } +} + +/* + * If we have a gap in the pending bits, that means we either + * raced with the hardware or failed to readout all upper + * objects in the last run due to quota limit. + */ +static u32 c_can_adjust_pending(u32 pend) +{ + u32 weight, lasts; + + if (pend == RECEIVE_OBJECT_BITS) + return pend; + + /* + * If the last set bit is larger than the number of pending + * bits we have a gap. + */ + weight = hweight32(pend); + lasts = fls(pend); + + /* If the bits are linear, nothing to do */ + if (lasts == weight) + return pend; + + /* + * Find the first set bit after the gap. We walk backwards + * from the last set bit. + */ + for (lasts--; pend & (1 << (lasts - 1)); lasts--); + + return pend & ~((1 << lasts) - 1); +} + +static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv, + u32 pend, int quota) +{ + u32 pkts = 0, ctrl, obj, mcmd; + + while ((obj = ffs(pend)) && quota > 0) { + pend &= ~BIT(obj - 1); + + mcmd = obj < C_CAN_MSG_RX_LOW_LAST ? + IF_COMM_RCV_LOW : IF_COMM_RCV_HIGH; + + c_can_object_get(dev, IF_RX, obj, mcmd); + ctrl = priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, IF_RX)); + + if (ctrl & IF_MCONT_MSGLST) { + int n = c_can_handle_lost_msg_obj(dev, IF_RX, obj, ctrl); + + pkts += n; + quota -= n; + continue; + } + + /* + * This really should not happen, but this covers some + * odd HW behaviour. Do not remove that unless you + * want to brick your machine. + */ + if (!(ctrl & IF_MCONT_NEWDAT)) + continue; + + /* read the data from the message object */ + c_can_read_msg_object(dev, IF_RX, ctrl); + + if (obj == C_CAN_MSG_RX_LOW_LAST) + /* activate all lower message objects */ + c_can_activate_all_lower_rx_msg_obj(dev, IF_RX, ctrl); + + pkts++; + quota--; + } + + return pkts; } /* @@ -805,10 +868,8 @@ static void c_can_do_tx(struct net_device *dev) */ static int c_can_do_rx_poll(struct net_device *dev, int quota) { - u32 num_rx_pkts = 0; - unsigned int msg_obj, msg_ctrl_save; struct c_can_priv *priv = netdev_priv(dev); - u16 val; + u32 pkts = 0, pend = 0, toread, n; /* * It is faster to read only one 16bit register. This is only possible @@ -817,49 +878,31 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota) BUILD_BUG_ON_MSG(C_CAN_MSG_OBJ_RX_LAST > 16, "Implementation does not support more message objects than 16"); - while (quota > 0 && (val = priv->read_reg(priv, C_CAN_INTPND1_REG))) { - while ((msg_obj = ffs(val)) && quota > 0) { - val &= ~BIT(msg_obj - 1); - - c_can_object_get(dev, 0, msg_obj, IF_COMM_ALL & - ~IF_COMM_TXRQST); - msg_ctrl_save = priv->read_reg(priv, - C_CAN_IFACE(MSGCTRL_REG, 0)); - - if (msg_ctrl_save & IF_MCONT_MSGLST) { - c_can_handle_lost_msg_obj(dev, 0, msg_obj); - num_rx_pkts++; - quota--; - continue; - } - - if (msg_ctrl_save & IF_MCONT_EOB) - return num_rx_pkts; - - if (!(msg_ctrl_save & IF_MCONT_NEWDAT)) - continue; - - /* read the data from the message object */ - c_can_read_msg_object(dev, 0, msg_ctrl_save); - - if (msg_obj < C_CAN_MSG_RX_LOW_LAST) - c_can_mark_rx_msg_obj(dev, 0, - msg_ctrl_save, msg_obj); - else if (msg_obj > C_CAN_MSG_RX_LOW_LAST) - /* activate this msg obj */ - c_can_activate_rx_msg_obj(dev, 0, - msg_ctrl_save, msg_obj); - else if (msg_obj == C_CAN_MSG_RX_LOW_LAST) - /* activate all lower message objects */ - c_can_activate_all_lower_rx_msg_obj(dev, - 0, msg_ctrl_save); - - num_rx_pkts++; - quota--; + while (quota > 0) { + if (!pend) { + pend = priv->read_reg(priv, C_CAN_INTPND1_REG); + if (!pend) + break; + /* + * If the pending field has a gap, handle the + * bits above the gap first. + */ + toread = c_can_adjust_pending(pend); + } else { + toread = pend; } + /* Remove the bits from pend */ + pend &= ~toread; + /* Read the objects */ + n = c_can_read_objects(dev, priv, toread, quota); + pkts += n; + quota -= n; } - return num_rx_pkts; + if (pkts) + can_led_event(dev, CAN_LED_EVENT_RX); + + return pkts; } static inline int c_can_has_and_handle_berr(struct c_can_priv *priv) @@ -1133,17 +1176,20 @@ static int c_can_open(struct net_device *dev) goto exit_irq_fail; } - napi_enable(&priv->napi); + /* start the c_can controller */ + err = c_can_start(dev); + if (err) + goto exit_start_fail; can_led_event(dev, CAN_LED_EVENT_OPEN); - /* start the c_can controller */ - c_can_start(dev); - + napi_enable(&priv->napi); netif_start_queue(dev); return 0; +exit_start_fail: + free_irq(dev->irq, dev); exit_irq_fail: close_candev(dev); exit_open_fail: @@ -1180,6 +1226,7 @@ struct net_device *alloc_c_can_dev(void) return NULL; priv = netdev_priv(dev); + spin_lock_init(&priv->xmit_lock); netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT); priv->dev = dev; @@ -1260,15 +1307,16 @@ int c_can_power_up(struct net_device *dev) if (time_after(jiffies, time_out)) return -ETIMEDOUT; - c_can_start(dev); - - return 0; + return c_can_start(dev); } EXPORT_SYMBOL_GPL(c_can_power_up); #endif void free_c_can_dev(struct net_device *dev) { + struct c_can_priv *priv = netdev_priv(dev); + + netif_napi_del(&priv->napi); free_candev(dev); } EXPORT_SYMBOL_GPL(free_c_can_dev); @@ -1277,6 +1325,7 @@ static const struct net_device_ops c_can_netdev_ops = { .ndo_open = c_can_open, .ndo_stop = c_can_close, .ndo_start_xmit = c_can_start_xmit, + .ndo_change_mtu = can_change_mtu, }; int register_c_can_dev(struct net_device *dev) |