From: Nikita Edward Baruzdin Date: Fri, 11 Jul 2014 12:13:20 +0000 (+0400) Subject: can: sja1000: Add support for CAN_CTRLMODE_LOOPBACK X-Git-Tag: firefly_0821_release~176^2~3474^2~160^2~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=dcf9e152670ea74dec24ec9ad57c495e631edba9;p=firefly-linux-kernel-4.4.55.git can: sja1000: Add support for CAN_CTRLMODE_LOOPBACK This adds support for hardware loopback in SJA1000 by utilising its self reception request (SRR) feature. Upon SRR the message is transmitted and received simultaneously, meaning you can't have hardware loopback without actually sending a message to the CAN bus in case of SJA1000. Signed-off-by: Nikita Edward Baruzdin Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index f31499a32d7d..45400d9aeedb 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -278,6 +278,7 @@ static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb, uint8_t dlc; canid_t id; uint8_t dreg; + u8 cmd_reg_val = 0x00; int i; if (can_dropped_invalid_skb(dev, skb)) @@ -312,9 +313,14 @@ static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb, can_put_echo_skb(skb, dev, 0); if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) - sja1000_write_cmdreg(priv, CMD_TR | CMD_AT); + cmd_reg_val |= CMD_AT; + + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) + cmd_reg_val |= CMD_SRR; else - sja1000_write_cmdreg(priv, CMD_TR); + cmd_reg_val |= CMD_TR; + + sja1000_write_cmdreg(priv, cmd_reg_val); return NETDEV_TX_OK; } @@ -622,9 +628,11 @@ struct net_device *alloc_sja1000dev(int sizeof_priv) priv->can.do_set_bittiming = sja1000_set_bittiming; priv->can.do_set_mode = sja1000_set_mode; priv->can.do_get_berr_counter = sja1000_get_berr_counter; - priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | - CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_LISTENONLY | - CAN_CTRLMODE_ONE_SHOT; + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | + CAN_CTRLMODE_LISTENONLY | + CAN_CTRLMODE_3_SAMPLES | + CAN_CTRLMODE_ONE_SHOT | + CAN_CTRLMODE_BERR_REPORTING; spin_lock_init(&priv->cmdreg_lock);