can: dev: move bittiming related code into seperate file

This patch moves the bittiming related code of the CAN device infrastructure
into a separate file.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 44 insertions, 0 deletions

diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h
new file mode 100644
index 000000000000..707575c668f4
--- /dev/null
+++ b/include/linux/can/bittiming.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2020 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ */
+
+#ifndef _CAN_BITTIMING_H
+#define _CAN_BITTIMING_H
+
+#include <linux/netdevice.h>
+#include <linux/can/netlink.h>
+
+#define CAN_SYNC_SEG 1
+
+#ifdef CONFIG_CAN_CALC_BITTIMING
+int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		       const struct can_bittiming_const *btc);
+#else /* !CONFIG_CAN_CALC_BITTIMING */
+static inline int
+can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		   const struct can_bittiming_const *btc)
+{
+	netdev_err(dev, "bit-timing calculation not available\n");
+	return -EINVAL;
+}
+#endif /* CONFIG_CAN_CALC_BITTIMING */
+
+int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		      const struct can_bittiming_const *btc,
+		      const u32 *bitrate_const,
+		      const unsigned int bitrate_const_cnt);
+
+/*
+ * can_bit_time() - Duration of one bit
+ *
+ * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
+ * additional information.
+ *
+ * Return: the number of time quanta in one bit.
+ */
+static inline unsigned int can_bit_time(const struct can_bittiming *bt)
+{
+	return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
+}
+
+#endif /* !_CAN_BITTIMING_H */