drivers/can: add shared_irq support to can_stm32fd driver

This commit adds shared_irq support to can_stm32fd driver, such that
two can instances can be used on stm32g0.

Additinally to the necessary code changes, bindings are added to
st,stm32-fdacn.yaml,
and the SHARED_IRQ is automatically enabled in KConfig if the can
devices define a shared-irqs phandle-array.

Signed-off-by: Thomas Stranger <[email protected]>

Author: str4t0m

drivers/can/can_stm32fd.c

@@ -10,6 +10,7 @@
 #include <stm32_ll_rcc.h>
 #include "can_stm32fd.h"
 #include <pinmux/pinmux_stm32.h>
+#include <shared_irq.h>
 
 #include <logging/log.h>
 LOG_MODULE_DECLARE(can_driver, CONFIG_CAN_LOG_LEVEL);
@@ -208,18 +209,22 @@ static const struct can_driver_api can_api_funcs = {
 #endif
 };
 
+/*
+ * If a shared-irq with matching name exists and has status okay use the
+ * shared-irq driver, otherwise, connect to normal IRQ.
+ */
 #define CAN_STM32FD_IRQ_CFG_FUNCTION(inst)                                     \
 static void config_can_##inst##_irq(void)                                      \
 {                                                                              \
 	LOG_DBG("Enable CAN" #inst " IRQ");                                    \
-	IRQ_CONNECT(DT_INST_IRQ_BY_NAME(inst, line_0, irq),                    \
-		    DT_INST_IRQ_BY_NAME(inst, line_0, priority),               \
-		    can_stm32fd_line_0_isr, DEVICE_DT_INST_GET(inst), 0);      \
-	irq_enable(DT_INST_IRQ_BY_NAME(inst, line_0, irq));                    \
-	IRQ_CONNECT(DT_INST_IRQ_BY_NAME(inst, line_1, irq),                    \
-		    DT_INST_IRQ_BY_NAME(inst, line_1, priority),               \
-		    can_stm32fd_line_1_isr, DEVICE_DT_INST_GET(inst), 0);      \
-	irq_enable(DT_INST_IRQ_BY_NAME(inst, line_1, irq));                    \
+	SHARED_IRQ_CONNECT_IRQ_BY_NAME_COND(DT_DRV_INST(inst), line_0,         \
+						 can_stm32fd_line_0_isr,       \
+						 DEVICE_DT_INST_GET(inst), 0); \
+	SHARED_IRQ_CONNECT_IRQ_BY_NAME_COND(DT_DRV_INST(inst), line_1,         \
+						 can_stm32fd_line_1_isr,       \
+						 DEVICE_DT_INST_GET(inst), 0); \
+	SHARED_IRQ_ENABLE_BY_NAME_COND(DT_DRV_INST(inst), line_0);             \
+	SHARED_IRQ_ENABLE_BY_NAME_COND(DT_DRV_INST(inst), line_1);             \
 }
 
 #ifdef CONFIG_CAN_FD_MODE

dts/bindings/can/st,stm32-fdcan.yaml

@@ -14,3 +14,22 @@ properties:
 
         For example the can1 would be
            pinctrl-0 = <&fdcan1_rx_pa11 &fdcan1_tx_pa12>;
+
+    shared-irq-names:
+      type: string-array
+      required: false
+      description: |
+        Name of each shared-irq in shared-irqs.
+        Required if shared-irqs are used and interrupts are chosen by name.
+
+    shared-irqs:
+      type: phandle-array
+      required: false
+      description: |
+        To avoid interrupt conflicts shared-irq nodes can be referenced.
+        In case the referenced shared_irq phandles have status okay the driver
+        registers the isr with the shared_irq instance instead of connecting to
+        the irq.
+
+        Example for stm32g0 would be
+              shared-irqs = <&shared_irq21 &shared_irq22>;