From 8d58790b832e13d6006d842037732304af357c3c Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 19 Sep 2016 21:34:01 +0200 Subject: [PATCH] net: can: ifi: Configure transmitter delay Configure the transmitter delay register at +0x1c to correctly handle the CAN FD bitrate switch (BRS). This moves the SSP (secondary sample point) to a proper offset, so that the TDC mechanism works and won't generate error frames on the CAN link. Signed-off-by: Marek Vasut Cc: Marc Kleine-Budde Cc: Mark Rutland Cc: Oliver Hartkopp Cc: Wolfgang Grandegger Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/ifi_canfd/ifi_canfd.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c index 2d1d22e..368bb07 100644 --- a/drivers/net/can/ifi_canfd/ifi_canfd.c +++ b/drivers/net/can/ifi_canfd/ifi_canfd.c @@ -81,6 +81,10 @@ #define IFI_CANFD_TIME_SET_TIMEA_4_12_6_6 BIT(15) #define IFI_CANFD_TDELAY 0x1c +#define IFI_CANFD_TDELAY_DEFAULT 0xb +#define IFI_CANFD_TDELAY_MASK 0x3fff +#define IFI_CANFD_TDELAY_ABS BIT(14) +#define IFI_CANFD_TDELAY_EN BIT(15) #define IFI_CANFD_ERROR 0x20 #define IFI_CANFD_ERROR_TX_OFFSET 0 @@ -641,7 +645,7 @@ static void ifi_canfd_set_bittiming(struct net_device *ndev) struct ifi_canfd_priv *priv = netdev_priv(ndev); const struct can_bittiming *bt = &priv->can.bittiming; const struct can_bittiming *dbt = &priv->can.data_bittiming; - u16 brp, sjw, tseg1, tseg2; + u16 brp, sjw, tseg1, tseg2, tdc; /* Configure bit timing */ brp = bt->brp - 2; @@ -664,6 +668,11 @@ static void ifi_canfd_set_bittiming(struct net_device *ndev) (brp << IFI_CANFD_TIME_PRESCALE_OFF) | (sjw << IFI_CANFD_TIME_SJW_OFF_7_9_8_8), priv->base + IFI_CANFD_FTIME); + + /* Configure transmitter delay */ + tdc = (dbt->brp * (dbt->phase_seg1 + 1)) & IFI_CANFD_TDELAY_MASK; + writel(IFI_CANFD_TDELAY_EN | IFI_CANFD_TDELAY_ABS | tdc, + priv->base + IFI_CANFD_TDELAY); } static void ifi_canfd_set_filter(struct net_device *ndev, const u32 id, -- 2.7.4