drivers: can: check timing parameters

Check the requested CAN timing parameters against the min/max values
supported by the driver and return an error if they are out of range.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>

drivers/can/can_common.c

@@ -250,6 +250,41 @@ static uint16_t sample_point_for_bitrate(uint32_t bitrate)
 	return sample_pnt;
 }
 
+static int check_timing_in_range(const struct can_timing *timing,
+				 const struct can_timing *min,
+				 const struct can_timing *max)
+{
+	if (timing->sjw != CAN_SJW_NO_CHANGE &&
+	    !IN_RANGE(timing->sjw, min->sjw, max->sjw)) {
+		return -ENOTSUP;
+	}
+
+	if (!IN_RANGE(timing->prop_seg, min->prop_seg, max->prop_seg) ||
+	    !IN_RANGE(timing->phase_seg1, min->phase_seg1, max->phase_seg1) ||
+	    !IN_RANGE(timing->phase_seg2, min->phase_seg2, max->phase_seg2) ||
+	    !IN_RANGE(timing->prescaler, min->prescaler, max->prescaler)) {
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+int z_impl_can_set_timing(const struct device *dev,
+			  const struct can_timing *timing)
+{
+	const struct can_driver_api *api = (const struct can_driver_api *)dev->api;
+	const struct can_timing *min = can_get_timing_min(dev);
+	const struct can_timing *max = can_get_timing_max(dev);
+	int err;
+
+	err = check_timing_in_range(timing, min, max);
+	if (err != 0) {
+		return err;
+	}
+
+	return api->set_timing(dev, timing);
+}
+
 int z_impl_can_set_bitrate(const struct device *dev, uint32_t bitrate)
 {
 	struct can_timing timing;
@@ -285,6 +320,26 @@ int z_impl_can_set_bitrate(const struct device *dev, uint32_t bitrate)
 }
 
 #ifdef CONFIG_CAN_FD_MODE
+int z_impl_can_set_timing_data(const struct device *dev,
+			       const struct can_timing *timing_data)
+{
+	const struct can_driver_api *api = (const struct can_driver_api *)dev->api;
+	const struct can_timing *min = can_get_timing_data_min(dev);
+	const struct can_timing *max = can_get_timing_data_max(dev);
+	int err;
+
+	if (api->set_timing_data == NULL) {
+		return -ENOSYS;
+	}
+
+	err = check_timing_in_range(timing_data, min, max);
+	if (err != 0) {
+		return err;
+	}
+
+	return api->set_timing_data(dev, timing_data);
+}
+
 int z_impl_can_set_bitrate_data(const struct device *dev, uint32_t bitrate_data)
 {
 	struct can_timing timing_data;

include/zephyr/drivers/can.h

@@ -234,6 +234,11 @@ struct can_bus_err_cnt {
 	uint8_t rx_err_cnt;
 };
 
+/** Synchronization Jump Width (SJW) value to indicate that the SJW should not
+ * be changed by the timing calculation.
+ */
+#define CAN_SJW_NO_CHANGE 0
+
 /**
  * @brief CAN bus timing structure
  *
@@ -868,25 +873,12 @@ __syscall int can_calc_timing_data(const struct device *dev, struct can_timing *
  * @retval 0 If successful.
  * @retval -EBUSY if the CAN controller is not in stopped state.
  * @retval -EIO General input/output error, failed to configure device.
+ * @retval -ENOTSUP if the timing parameters are not supported by the driver.
  * @retval -ENOSYS if CAN-FD support is not implemented by the driver.
  */
 __syscall int can_set_timing_data(const struct device *dev,
 				  const struct can_timing *timing_data);
 
-#ifdef CONFIG_CAN_FD_MODE
-static inline int z_impl_can_set_timing_data(const struct device *dev,
-					     const struct can_timing *timing_data)
-{
-	const struct can_driver_api *api = (const struct can_driver_api *)dev->api;
-
-	if (api->set_timing_data == NULL) {
-		return -ENOSYS;
-	}
-
-	return api->set_timing_data(dev, timing_data);
-}
-#endif /* CONFIG_CAN_FD_MODE */
-
 /**
  * @brief Set the bitrate for the data phase of the CAN-FD controller
  *
@@ -936,11 +928,6 @@ __syscall int can_set_bitrate_data(const struct device *dev, uint32_t bitrate_da
 int can_calc_prescaler(const struct device *dev, struct can_timing *timing,
 		       uint32_t bitrate);
 
-/** Synchronization Jump Width (SJW) value to indicate that the SJW should not
- * be changed by the timing calculation.
- */
-#define CAN_SJW_NO_CHANGE 0
-
 /**
  * @brief Configure the bus timing of a CAN controller.
  *
@@ -953,19 +940,12 @@ int can_calc_prescaler(const struct device *dev, struct can_timing *timing,
  *
  * @retval 0 If successful.
  * @retval -EBUSY if the CAN controller is not in stopped state.
+ * @retval -ENOTSUP if the timing parameters are not supported by the driver.
  * @retval -EIO General input/output error, failed to configure device.
  */
 __syscall int can_set_timing(const struct device *dev,
 			     const struct can_timing *timing);
 
-static inline int z_impl_can_set_timing(const struct device *dev,
-					const struct can_timing *timing)
-{
-	const struct can_driver_api *api = (const struct can_driver_api *)dev->api;
-
-	return api->set_timing(dev, timing);
-}
-
 /**
  * @brief Get the supported modes of the CAN controller
  *