can: bittiming: replace CAN units with the generic ones from linux/units.h

In [1], we introduced a set of units in linux/can/bittiming.h. Since
then, generic SI prefixes were added to linux/units.h in [2]. Those
new prefixes can perfectly replace CAN specific ones.

This patch replaces all occurrences of the CAN units with their
corresponding prefix (from linux/units) and the unit (as a comment)
according to below table.

 CAN units	SI metric prefix (from linux/units) + unit (as a comment)
 ------------------------------------------------------------------------
 CAN_KBPS	KILO /* BPS */
 CAN_MBPS	MEGA /* BPS */
 CAM_MHZ	MEGA /* Hz */

The definition are then removed from linux/can/bittiming.h

[1] commit 1d775076 ("can: bittiming: add CAN_KBPS, CAN_MBPS and
CAN_MHZ macros")

[2] commit 26471d4a ("units: Add SI metric prefix definitions")

Link: https://lore.kernel.org/all/20211124014536.782550-1-mailhol.vincent@wanadoo.frSuggested-by: Jimmy Assarsson <extja@kvaser.com>
Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/dev/bittiming.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
  */
 
+#include <linux/units.h>
 #include <linux/can/dev.h>
 
 #ifdef CONFIG_CAN_CALC_BITTIMING
@@ -81,9 +82,9 @@ int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	if (bt->sample_point) {
 		sample_point_nominal = bt->sample_point;
 	} else {
-		if (bt->bitrate > 800 * CAN_KBPS)
+		if (bt->bitrate > 800 * KILO /* BPS */)
 			sample_point_nominal = 750;
-		else if (bt->bitrate > 500 * CAN_KBPS)
+		else if (bt->bitrate > 500 * KILO /* BPS */)
 			sample_point_nominal = 800;
 		else
 			sample_point_nominal = 875;

drivers/net/can/usb/etas_es58x/es581_4.c

@@ -10,6 +10,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/units.h>
 #include <asm/unaligned.h>
 
 #include "es58x_core.h"
@@ -469,8 +470,8 @@ const struct es58x_parameters es581_4_param = {
 	.bittiming_const = &es581_4_bittiming_const,
 	.data_bittiming_const = NULL,
 	.tdc_const = NULL,
-	.bitrate_max = 1 * CAN_MBPS,
-	.clock = {.freq = 50 * CAN_MHZ},
+	.bitrate_max = 1 * MEGA /* BPS */,
+	.clock = {.freq = 50 * MEGA /* Hz */},
 	.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC,
 	.tx_start_of_frame = 0xAFAF,
 	.rx_start_of_frame = 0xFAFA,

drivers/net/can/usb/etas_es58x/es58x_fd.c

@@ -12,6 +12,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/units.h>
 #include <asm/unaligned.h>
 
 #include "es58x_core.h"
@@ -522,8 +523,8 @@ const struct es58x_parameters es58x_fd_param = {
 	 * Mbps work in an optimal environment but are not recommended
 	 * for production environment.
 	 */
-	.bitrate_max = 8 * CAN_MBPS,
-	.clock = {.freq = 80 * CAN_MHZ},
+	.bitrate_max = 8 * MEGA /* BPS */,
+	.clock = {.freq = 80 * MEGA /* Hz */},
 	.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY |
 	    CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO |
 	    CAN_CTRLMODE_CC_LEN8_DLC | CAN_CTRLMODE_TDC_AUTO,

include/linux/can/bittiming.h

@@ -12,13 +12,6 @@
 #define CAN_SYNC_SEG 1
 
 
-/* Kilobits and Megabits per second */
-#define CAN_KBPS 1000UL
-#define CAN_MBPS 1000000UL
-
-/* Megahertz */
-#define CAN_MHZ 1000000UL
-
 #define CAN_CTRLMODE_TDC_MASK					\
 	(CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_TDC_MANUAL)