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

Rob Herring
2016-03-18T21:07:29Z

On Tue, Mar 15, 2016 at 09:48:14AM +0000, Ramesh Shanmugasundaram wrote:
> 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 <ramesh.shanmugasundaram@bp.renesas.com>
> ---
> Hi All,
>
> Thanks for the review comments.
>
> This updated patch is based on linux-can-next tag (linux-can-next-for-4.6-20160310).
>
> This patch depends on
>
> [RFC] [PATCH v3] can: fix handling of unmodifiable configuration options
> (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)
> * Used new can subsystem api to set static configuration & removed check in rcar_canfd_start (as suggested by Oliver H)
> (Refer: http://comments.gmane.org/gmane.linux.can/9126 &
> https://www.mail-archive.com/linux-renesas-soc@vger.kernel.org/msg01867.html)
> * Clubbed Renesas controller drivers to driver/net/can/rcar dir (as suggested by Oliver H)
> * Updated commit message
>
> Changes since v1:
> * Removed testmodes & debugfs code (suggested by Oliver H)
> * Fixed tx path race issue by introducing lock (suggested by Marc K)
> * Removed __maybe_unused attribute of rcar_canfd_of_table
> ---
> .../devicetree/bindings/net/can/rcar_canfd.txt | 89 ++

Acked-by: Rob Herring <robh@kernel.org>

> drivers/net/can/Kconfig | 11 +-
> drivers/net/can/Makefile | 2 +-
> drivers/net/can/rcar/Kconfig | 19 +
> drivers/net/can/rcar/Makefile | 6 +
> drivers/net/can/{ => rcar}/rcar_can.c | 0
> drivers/net/can/rcar/rcar_canfd.c | 1614 ++++++++++++++++++++
> 7 files changed, 1730 insertions(+), 11 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/net/can/rcar_canfd.txt
> create mode 100644 drivers/net/can/rcar/Kconfig
> create mode 100644 drivers/net/can/rcar/Makefile
> rename drivers/net/can/{ => rcar}/rcar_can.c (100%)
> create mode 100644 drivers/net/can/rcar/rcar_canfd.c