From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: [PATCH] net: can: ifi: Configure transmitter delay Date: Mon, 19 Sep 2016 21:34:01 +0200 Message-ID: <20160919193401.8320-1-marex@denx.de> Return-path: Received: from mail-out.m-online.net ([212.18.0.9]:46147 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752105AbcISTeP (ORCPT ); Mon, 19 Sep 2016 15:34:15 -0400 Sender: linux-can-owner@vger.kernel.org List-ID: To: linux-can@vger.kernel.org Cc: Marek Vasut , Marc Kleine-Budde , Mark Rutland , Oliver Hartkopp , Wolfgang Grandegger 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 --- 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, -- 2.9.3