Hi Marc,

Subject: Re: [PATCH v3] can: rcar_canfd: Add Renesas R-Car CAN FD driver

On 03/15/2016 10:48 AM, Ramesh Shanmugasundaram wrote:

quoted

This patch adds support for the CAN FD controller found in Renesas
R-Car SoCs. The controller operates in CAN FD only mode by default.

CAN FD mode supports both Classical CAN & CAN FD frame formats. The
controller supports ISO 11898-1:2015 CAN FD format only.

This controller supports two channels and the driver can enable either
or both of the channels.

Driver uses Rx FIFOs (one per channel) for reception & Common FIFOs
(one per channel) for transmission. Rx filter rules are configured to
the minimum (one per channel) and it accepts Standard, Extended, Data
& Remote Frame combinations.

Note: There are few documentation errors in R-Car Gen3 Hardware User
Manual v0.5E with respect to CAN FD controller. They are listed below:

1. CAN FD interrupt numbers 29 & 30 are listed as per channel
interrupts. However, they are common to both channels (i.e.) they are
global and channel interrupts respectively.

2. CANFD clock is derived from PLL1. This is not documented.

3. CANFD clock is further divided by (1/2) within the CAN FD controller.
This is not documented.

4. The minimum value of NTSEG1 in RSCFDnCFDCmNCFG register is 2 Tq. It
is specified 4 Tq in the manual.

5. The maximum number of message RAM area the controller can use is
3584 bytes. It is specified 10752 bytes in the manual.

Signed-off-by: Ramesh Shanmugasundaram
[off-list ref]
---
Hi All,

   Thanks for the review comments.

   This updated patch is based on linux-can-next tag (linux-can-next-

for-4.6-20160310).

quoted

   This patch depends on

   [RFC] [PATCH v3] can: fix handling of unmodifiable configuration

options

quoted

   (http://comments.gmane.org/gmane.linux.can/9126)

Changes since v2:
	* Rebased to latest tag (linux-can-next-for-4.6-20160310)
	* Cleaned up leftover debugfs code (Thanks Oliver H)
	* Revised devicetree documentation text (as suggested by Rob H)
	  (https://www.mail-archive.com/linux-renesas-

soc@vger.kernel.org/msg01597.html)

quoted

	* Used new can subsystem api to set static configuration & removed

check in rcar_canfd_start (as suggested by Oliver H)

quoted

	  (Refer: http://comments.gmane.org/gmane.linux.can/9126 &
	   https://www.mail-archive.com/linux-renesas-

soc@vger.kernel.org/msg01867.html)

quoted

	* Clubbed Renesas controller drivers to driver/net/can/rcar dir (as
suggested by Oliver H)

Please make moving of the existing drivers a separate patch.

OK. I'll submit new patch with CAN FD driver in new "rcar" dir and will provide a separate patch on top that will move the CAN driver to "rcar" dir.

Thanks,
Ramesh