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 <geert+renesas@xxxxxxxxx>
---
drivers/net/can/rcar/rcar_canfd.c | 80 +++++++++++++++++++++++++++++--
1 file changed, 77 insertions(+), 3 deletions(-)
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 7b6bb67ed6f76f14..a9c5b4ac040bdc0a 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_PNSTS GENMASK(13, 12)
+#define RCANFD_FDSTS_SOCO BIT(9)
+#define RCANFD_FDSTS_EOCO BIT(8)
+#define RCANFD_FDSTS_TDCR(gpriv, x) ((x) & ((gpriv)->info->tdc_const->tdcv_max - 1))
+#define RCANFD_FDSTS_TDCVF(gpriv) \
+ ((gpriv)->info->tdc_const->tdcv_max > 128 ? BIT(15) : BIT(7))
/* RSCFDnCFDRFCCx */
#define RCANFD_RFCC_RFIM BIT(12)
@@ -527,6 +537,7 @@ 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;
@@ -634,6 +645,25 @@ 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,
@@ -679,6 +709,7 @@ 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,
@@ -695,6 +726,7 @@ 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,
@@ -711,6 +743,7 @@ 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,
@@ -727,6 +760,7 @@ 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,
@@ -1436,12 +1470,15 @@ 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 */
@@ -1477,6 +1514,22 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
rcar_canfd_write(priv->base, RCANFD_F_DCFG(gpriv, ch), cfg);
netdev_dbg(ndev, "drate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
brp, sjw, tseg1, tseg2);
+
+ /* Transceiver Delay Compensation */
+ if (priv->can.ctrlmode & CAN_CTRLMODE_TDC_AUTO) {
+ /* TDC enabled, measured + offset */
+ tdcmode = RCANFD_FDCFG_TDCE;
+ tdco = tdc->tdco - 1;
+ netdev_dbg(ndev, "tdc: auto %u\n", tdco);
+ } 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;
+ netdev_dbg(ndev, "tdc: manual %u\n", tdco);
+ }
+
+ rcar_canfd_update_bit(gpriv->base, RCANFD_F_CFDCFG(gpriv, ch), mask,
+ tdcmode | FIELD_PREP(RCANFD_FDCFG_TDCO, tdco));
}
static int rcar_canfd_start(struct net_device *ndev)
@@ -1787,6 +1840,22 @@ static int rcar_canfd_rx_poll(struct napi_struct *napi, int quota)
return num_pkts;
}
+static int rcar_canfd_get_auto_tdcv(const struct net_device *ndev, u32 *tdcv)
+{
+ struct rcar_canfd_channel *priv = netdev_priv(ndev);
+ struct rcar_canfd_global *gpriv = priv->gpriv;
+ u32 sts = rcar_canfd_read(priv->base, RCANFD_F_CFDSTS(gpriv, priv->channel));
+ u32 tdco = priv->can.fd.tdc.tdco;
+ u32 tdcr;
+
+ /* Transceiver Delay Compensation Result */
+ tdcr = RCANFD_FDSTS_TDCR(gpriv, sts) + 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;
@@ -1909,12 +1978,17 @@ 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;
--
2.43.0
