[PATCH 2/3] can: rcar_canfd: Add support for Bus-Off recovery mode selection
From: Biju
Date: Fri Apr 03 2026 - 05:56:38 EST
From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
The CAN-FD IP supports the below Bus-Off recovery modes:
1) ISO11898-1 compliant
2) Entry to Channel Halt mode automatically at bus-off entry
3) Entry to Channel Halt mode automatically at bus-off end
4) Entry to Channel Halt mode (in bus-off state) by program request
Add support for Bus-Off recovery mode selection via the
renesas,bus-off-recovery-mode device tree property. If the property is
absent, it defaults to RCANFD_CCTR_BOM_BENTRY (entry to Channel Halt mode
automatically at bus-off entry) for backward compatibility.
Replace the individual BOM (Bus-Off Recovery Mode) bit definitions with a
single GENMASK-based macro RCANFD_CCTR_BOM and use FIELD_PREP to set the
BOM field in the channel control register.
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
drivers/net/can/rcar/rcar_canfd.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index eaf8cac78038..1d6d667b8816 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -114,10 +114,7 @@
/* RSCFDnCFDCmCTR / RSCFDnCmCTR */
#define RCANFD_CCTR_CTME BIT(24)
#define RCANFD_CCTR_ERRD BIT(23)
-#define RCANFD_CCTR_BOM_MASK (0x3 << 21)
-#define RCANFD_CCTR_BOM_ISO (0x0 << 21)
-#define RCANFD_CCTR_BOM_BENTRY (0x1 << 21)
-#define RCANFD_CCTR_BOM_BEND (0x2 << 21)
+#define RCANFD_CCTR_BOM GENMASK(22, 21)
#define RCANFD_CCTR_TDCVFIE BIT(19)
#define RCANFD_CCTR_SOCOIE BIT(18)
#define RCANFD_CCTR_EOCOIE BIT(17)
@@ -135,6 +132,7 @@
#define RCANFD_CCTR_CHDMC_COPM (0x0)
#define RCANFD_CCTR_CHDMC_CRESET (0x1)
#define RCANFD_CCTR_CHDMC_CHLT (0x2)
+#define RCANFD_CCTR_BOM_BENTRY (1)
/* RSCFDnCFDCmSTS / RSCFDnCmSTS */
#define RCANFD_CSTS_COMSTS BIT(7)
@@ -470,6 +468,7 @@ struct rcar_canfd_global {
struct clk *can_clk; /* fCAN clock */
struct clk *clk_ram; /* Clock RAM */
unsigned long channels_mask; /* Enabled channels mask */
+ u32 bom; /* Bus-Off recovery mode */
bool extclk; /* CANFD or Ext clock */
bool fdmode; /* CAN FD or Classical CAN only mode */
bool fd_only_mode; /* FD-Only mode for CAN-FD */
@@ -891,8 +890,7 @@ static void rcar_canfd_configure_controller(struct rcar_canfd_global *gpriv)
rcar_canfd_set_bit(gpriv->base, RCANFD_CCTR(ch),
RCANFD_CCTR_ERRD);
rcar_canfd_update_bit(gpriv->base, RCANFD_CCTR(ch),
- RCANFD_CCTR_BOM_MASK,
- RCANFD_CCTR_BOM_BENTRY);
+ RCANFD_CCTR_BOM, gpriv->bom);
}
}
@@ -2110,6 +2108,7 @@ static int rcar_canfd_probe(struct platform_device *pdev)
bool fdmode = true; /* CAN FD only mode - default */
char name[9] = "channelX";
u32 ch, fcan_freq;
+ u32 prop;
int i;
info = of_device_get_match_data(dev);
@@ -2169,6 +2168,11 @@ static int rcar_canfd_probe(struct platform_device *pdev)
if (of_property_read_bool(dev->of_node, "renesas,fd-only"))
gpriv->fd_only_mode = true; /* FD-Only mode for CAN-FD */
+ if (of_property_read_u32(dev->of_node, "renesas,bus-off-recovery-mode", &prop) < 0)
+ prop = RCANFD_CCTR_BOM_BENTRY; /* default */
+
+ gpriv->bom = FIELD_PREP(RCANFD_CCTR_BOM, prop);
+
gpriv->rstc1 = devm_reset_control_get_optional_exclusive(dev, "rstp_n");
if (IS_ERR(gpriv->rstc1))
return dev_err_probe(dev, PTR_ERR(gpriv->rstc1),
--
2.43.0