From: Geert Uytterhoeven Date: Wed, 11 Jun 2025 15:37:39 +0000 (+0200) Subject: can: rcar_canfd: Add support for Transceiver Delay Compensation X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=586d5eecdf1479b9ab861ab16438ba236fb2f383;p=thirdparty%2Flinux.git can: rcar_canfd: Add support for Transceiver Delay Compensation The Renesas CAN-FD hardware block supports configuring Transceiver Delay Compensation, and reading back the Transceiver Delay Compensation Result, which is needed to support high transfer rates like 8 Mbps. The Secondary Sample Point is either the measured delay plus the configured offset, or just the configured offset. Fix the existing RCANFD_FDCFG_TDCO() macro for the intended use case (writing instead of reading the field). Add register definition bits for the Channel n CAN-FD Status Register. Signed-off-by: Geert Uytterhoeven Reviewed-by: Vincent Mailhol Link: https://patch.msgid.link/69db727d5f728d679ba691d20854e7d963d0f323.1749655315.git.geert+renesas@glider.be Signed-off-by: Marc Kleine-Budde --- diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c index 3340ae75bbecd..1e559c0ff0389 100644 --- a/drivers/net/can/rcar/rcar_canfd.c +++ b/drivers/net/can/rcar/rcar_canfd.c @@ -191,9 +191,19 @@ /* RSCFDnCFDCmFDCFG */ #define RCANFD_GEN4_FDCFG_CLOE BIT(30) #define RCANFD_GEN4_FDCFG_FDOE BIT(28) +#define RCANFD_FDCFG_TDCO GENMASK(23, 16) #define RCANFD_FDCFG_TDCE BIT(9) #define RCANFD_FDCFG_TDCOC BIT(8) -#define RCANFD_FDCFG_TDCO(x) (((x) & 0x7f) >> 16) + +/* RSCFDnCFDCmFDSTS */ +#define RCANFD_FDSTS_SOC GENMASK(31, 24) +#define RCANFD_FDSTS_EOC GENMASK(23, 16) +#define RCANFD_GEN4_FDSTS_TDCVF BIT(15) +#define RCANFD_GEN4_FDSTS_PNSTS GENMASK(13, 12) +#define RCANFD_FDSTS_SOCO BIT(9) +#define RCANFD_FDSTS_EOCO BIT(8) +#define RCANFD_FDSTS_TDCVF BIT(7) +#define RCANFD_FDSTS_TDCR GENMASK(7, 0) /* RSCFDnCFDRFCCx */ #define RCANFD_RFCC_RFIM BIT(12) @@ -520,6 +530,7 @@ struct rcar_canfd_shift_data { struct rcar_canfd_hw_info { const struct can_bittiming_const *nom_bittiming; const struct can_bittiming_const *data_bittiming; + const struct can_tdc_const *tdc_const; const struct rcar_canfd_regs *regs; const struct rcar_canfd_shift_data *sh; u8 rnc_field_width; @@ -627,6 +638,25 @@ static const struct can_bittiming_const rcar_canfd_bittiming_const = { .brp_inc = 1, }; +/* CAN FD Transmission Delay Compensation constants */ +static const struct can_tdc_const rcar_canfd_gen3_tdc_const = { + .tdcv_min = 1, + .tdcv_max = 128, + .tdco_min = 1, + .tdco_max = 128, + .tdcf_min = 0, /* Filter window not supported */ + .tdcf_max = 0, +}; + +static const struct can_tdc_const rcar_canfd_gen4_tdc_const = { + .tdcv_min = 1, + .tdcv_max = 256, + .tdco_min = 1, + .tdco_max = 256, + .tdcf_min = 0, /* Filter window not supported */ + .tdcf_max = 0, +}; + static const struct rcar_canfd_regs rcar_gen3_regs = { .rfcc = 0x00b8, .cfcc = 0x0118, @@ -672,6 +702,7 @@ static const struct rcar_canfd_shift_data rcar_gen4_shift_data = { static const struct rcar_canfd_hw_info rcar_gen3_hw_info = { .nom_bittiming = &rcar_canfd_gen3_nom_bittiming_const, .data_bittiming = &rcar_canfd_gen3_data_bittiming_const, + .tdc_const = &rcar_canfd_gen3_tdc_const, .regs = &rcar_gen3_regs, .sh = &rcar_gen3_shift_data, .rnc_field_width = 8, @@ -688,6 +719,7 @@ static const struct rcar_canfd_hw_info rcar_gen3_hw_info = { static const struct rcar_canfd_hw_info rcar_gen4_hw_info = { .nom_bittiming = &rcar_canfd_gen4_nom_bittiming_const, .data_bittiming = &rcar_canfd_gen4_data_bittiming_const, + .tdc_const = &rcar_canfd_gen4_tdc_const, .regs = &rcar_gen4_regs, .sh = &rcar_gen4_shift_data, .rnc_field_width = 16, @@ -704,6 +736,7 @@ static const struct rcar_canfd_hw_info rcar_gen4_hw_info = { static const struct rcar_canfd_hw_info rzg2l_hw_info = { .nom_bittiming = &rcar_canfd_gen3_nom_bittiming_const, .data_bittiming = &rcar_canfd_gen3_data_bittiming_const, + .tdc_const = &rcar_canfd_gen3_tdc_const, .regs = &rcar_gen3_regs, .sh = &rcar_gen3_shift_data, .rnc_field_width = 8, @@ -720,6 +753,7 @@ static const struct rcar_canfd_hw_info rzg2l_hw_info = { static const struct rcar_canfd_hw_info r9a09g047_hw_info = { .nom_bittiming = &rcar_canfd_gen4_nom_bittiming_const, .data_bittiming = &rcar_canfd_gen4_data_bittiming_const, + .tdc_const = &rcar_canfd_gen4_tdc_const, .regs = &rcar_gen4_regs, .sh = &rcar_gen4_shift_data, .rnc_field_width = 16, @@ -1460,12 +1494,15 @@ static irqreturn_t rcar_canfd_channel_interrupt(int irq, void *dev_id) static void rcar_canfd_set_bittiming(struct net_device *ndev) { + u32 mask = RCANFD_FDCFG_TDCO | RCANFD_FDCFG_TDCE | RCANFD_FDCFG_TDCOC; struct rcar_canfd_channel *priv = netdev_priv(ndev); struct rcar_canfd_global *gpriv = priv->gpriv; const struct can_bittiming *bt = &priv->can.bittiming; const struct can_bittiming *dbt = &priv->can.fd.data_bittiming; + const struct can_tdc_const *tdc_const = priv->can.fd.tdc_const; + const struct can_tdc *tdc = &priv->can.fd.tdc; + u32 cfg, tdcmode = 0, tdco = 0; u16 brp, sjw, tseg1, tseg2; - u32 cfg; u32 ch = priv->channel; /* Nominal bit timing settings */ @@ -1497,6 +1534,20 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev) RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2)); rcar_canfd_write(priv->base, rcar_canfd_f_dcfg(gpriv, ch), cfg); + + /* Transceiver Delay Compensation */ + if (priv->can.ctrlmode & CAN_CTRLMODE_TDC_AUTO) { + /* TDC enabled, measured + offset */ + tdcmode = RCANFD_FDCFG_TDCE; + tdco = tdc->tdco - 1; + } else if (priv->can.ctrlmode & CAN_CTRLMODE_TDC_MANUAL) { + /* TDC enabled, offset only */ + tdcmode = RCANFD_FDCFG_TDCE | RCANFD_FDCFG_TDCOC; + tdco = min(tdc->tdcv + tdc->tdco, tdc_const->tdco_max) - 1; + } + + rcar_canfd_update_bit(gpriv->base, rcar_canfd_f_cfdcfg(gpriv, ch), mask, + tdcmode | FIELD_PREP(RCANFD_FDCFG_TDCO, tdco)); } static int rcar_canfd_start(struct net_device *ndev) @@ -1807,6 +1858,29 @@ static int rcar_canfd_rx_poll(struct napi_struct *napi, int quota) return num_pkts; } +static unsigned int rcar_canfd_get_tdcr(struct rcar_canfd_global *gpriv, + unsigned int ch) +{ + u32 sts = rcar_canfd_read(gpriv->base, rcar_canfd_f_cfdsts(gpriv, ch)); + u32 tdcr = FIELD_GET(RCANFD_FDSTS_TDCR, sts); + + return tdcr & (gpriv->info->tdc_const->tdcv_max - 1); +} + +static int rcar_canfd_get_auto_tdcv(const struct net_device *ndev, u32 *tdcv) +{ + struct rcar_canfd_channel *priv = netdev_priv(ndev); + u32 tdco = priv->can.fd.tdc.tdco; + u32 tdcr; + + /* Transceiver Delay Compensation Result */ + tdcr = rcar_canfd_get_tdcr(priv->gpriv, priv->channel) + 1; + + *tdcv = tdcr < tdco ? 0 : tdcr - tdco; + + return 0; +} + static int rcar_canfd_do_set_mode(struct net_device *ndev, enum can_mode mode) { int err; @@ -1929,12 +2003,17 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch, if (gpriv->fdmode) { priv->can.bittiming_const = gpriv->info->nom_bittiming; priv->can.fd.data_bittiming_const = gpriv->info->data_bittiming; + priv->can.fd.tdc_const = gpriv->info->tdc_const; /* Controller starts in CAN FD only mode */ err = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD); if (err) goto fail; - priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING; + + priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING | + CAN_CTRLMODE_TDC_AUTO | + CAN_CTRLMODE_TDC_MANUAL; + priv->can.fd.do_get_auto_tdcv = rcar_canfd_get_auto_tdcv; } else { /* Controller starts in Classical CAN only mode */ priv->can.bittiming_const = &rcar_canfd_bittiming_const;