can: usb: etas_es58X: add support for ETAS ES58X CAN USB interfaces

This driver supports the ES581.4, ES582.1 and ES584.1 interfaces from
ETAS GmbH (https://www.etas.com/en/products/es58x.php).

Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
--

*Warning*: this patch is based on the testing branch of linux-can-next:
https://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git/log/?h=testing

Changes in v6 (2020-11-15):
  - Rebase the patch on the testing branch of linux-can-next.
  - Rename the helper functions according latest changes
    (e.g. can_cc_get_len() -> can_cc_dlc2len())
  - Fix comments of enum es58x_physical_layer and enum
    es58x_sync_edge.

Changes in v5 (2020-11-07):
  - Add support for DLC greater than 8.
  - All other patches from the previous series were either accepted or
    dismissed. As such, this is not a serie any more but a single
    patch.

Changes in v4 (2020-10-17):
  - Remove struct es58x_abstracted_can_frame.
    branch is already done inside net/can/af_can.c#can_send().
  - Fix formating (spaces, comment style).
  - Transform macros into static inline functions when possible.
  - Fix the ctrlmode_supported flags in es581_4.c and removed
    misleading comments in enum es58x_samples_per_bit.
  - Rename enums according to the type.
  - Remove function es58x_can_put_echo_skb().
Reference: https://lkml.org/lkml/2020/10/10/53

Changes in v3 (2020-10-03):
  - Remove all the calls to likely() and unlikely().
Reference: https://lkml.org/lkml/2020/9/30/995

Changes in v2 (2020-09-30):
  - Fixed -W1 warnings (v1 was tested with GCC -WExtra but not with -W1).

v1 (2020-09-27):
 - First release

drivers/net/can/usb/Kconfig

@@ -20,6 +20,15 @@ config CAN_ESD_USB2
 	  This driver supports the CAN-USB/2 interface
 	  from esd electronic system design gmbh (http://www.esd.eu).
 
+config CAN_ETAS_ES58X
+	tristate "ETAS ES58X CAN/USB interfaces"
+	help
+	  This driver supports the ES581.4, ES582.1 and ES584.1 interfaces
+	  from ETAS GmbH (https://www.etas.com/en/products/es58x.php).
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called etas_es58x.
+
 config CAN_GS_USB
 	tristate "Geschwister Schneider UG interfaces"
 	help

drivers/net/can/usb/Makefile

@@ -6,6 +6,7 @@
 obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
 obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
 obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
+obj-$(CONFIG_CAN_ETAS_ES58X) += etas_es58x/
 obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
 obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb/
 obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o

drivers/net/can/usb/etas_es58x/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_CAN_ETAS_ES58X) += etas_es58x.o
+etas_es58x-y = es58x_core.o es581_4.o es58x_fd.o