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

Ramesh Shanmugasundaram
2016-03-15T14:26:03Z

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:
> > 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)
>
> 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