From b6f6069b99871381ab7a503302f7e1c81ad1c874 Mon Sep 17 00:00:00 2001
From: Henrik Brix Andersen <hebad@vestas.com>
Date: Fri, 14 Jan 2022 15:17:32 +0100
Subject: [PATCH] drivers: can: stm32: add support for disabling automatic
 retransmissions

Add support for disabling automatic retransmission of CAN frames
(similar to CAN "one-shot" mode in the Linux kernel).

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
---
 drivers/can/can_stm32.c            | 6 ++++++
 drivers/can/can_stm32.h            | 1 +
 dts/bindings/can/st,stm32-can.yaml | 8 ++++++++
 3 files changed, 15 insertions(+)

diff --git a/drivers/can/can_stm32.c b/drivers/can/can_stm32.c
index 6a19b78c8c1..7f71eaa992c 100644
--- a/drivers/can/can_stm32.c
+++ b/drivers/can/can_stm32.c
@@ -489,6 +489,10 @@ static int can_stm32_init(const struct device *dev)
 #ifdef CONFIG_CAN_AUTO_BUS_OFF_RECOVERY
 	can->MCR |= CAN_MCR_ABOM;
 #endif
+	if (cfg->one_shot) {
+		can->MCR |= CAN_MCR_NART;
+	}
+
 	timing.sjw = cfg->sjw;
 	if (cfg->sample_point && USE_SP_ALGO) {
 		ret = can_calc_timing(dev, &timing, cfg->bus_speed,
@@ -1148,6 +1152,7 @@ static const struct can_stm32_config can_stm32_cfg_1 = {
 	.prop_ts1 = DT_PROP_OR(DT_NODELABEL(can1), prop_seg, 0) +
 		    DT_PROP_OR(DT_NODELABEL(can1), phase_seg1, 0),
 	.ts2 = DT_PROP_OR(DT_NODELABEL(can1), phase_seg2, 0),
+	.one_shot = DT_PROP(DT_NODELABEL(can1), one_shot),
 	.pclken = {
 		.enr = DT_CLOCKS_CELL(DT_NODELABEL(can1), bits),
 		.bus = DT_CLOCKS_CELL(DT_NODELABEL(can1), bus),
@@ -1245,6 +1250,7 @@ static const struct can_stm32_config can_stm32_cfg_2 = {
 	.prop_ts1 = DT_PROP_OR(DT_NODELABEL(can2), prop_seg, 0) +
 		    DT_PROP_OR(DT_NODELABEL(can2), phase_seg1, 0),
 	.ts2 = DT_PROP_OR(DT_NODELABEL(can2), phase_seg2, 0),
+	.one_shot = DT_PROP(DT_NODELABEL(can2), one_shot),
 	.pclken = {
 		.enr = DT_CLOCKS_CELL(DT_NODELABEL(can2), bits),
 		.bus = DT_CLOCKS_CELL(DT_NODELABEL(can2), bus),
diff --git a/drivers/can/can_stm32.h b/drivers/can/can_stm32.h
index 5e83dedab87..a90b9d5c68c 100644
--- a/drivers/can/can_stm32.h
+++ b/drivers/can/can_stm32.h
@@ -76,6 +76,7 @@ struct can_stm32_config {
 	uint8_t sjw;
 	uint8_t prop_ts1;
 	uint8_t ts2;
+	bool one_shot;
 	struct stm32_pclken pclken;
 	void (*config_irq)(CAN_TypeDef *can);
 	const struct pinctrl_dev_config *pcfg;
diff --git a/dts/bindings/can/st,stm32-can.yaml b/dts/bindings/can/st,stm32-can.yaml
index 623733dcd0b..7462ec3a510 100644
--- a/dts/bindings/can/st,stm32-can.yaml
+++ b/dts/bindings/can/st,stm32-can.yaml
@@ -20,6 +20,14 @@ properties:
     pinctrl-names:
       required: true
 
+    one-shot:
+      type: boolean
+      required: false
+      description: |
+        Disable automatic retransmissions. A CAN frame will only be transmitted
+        once, independently of the transmission result (successful, error, or
+        arbitration lost).
+
     master-can-reg:
       type: int
       required: false