RE: [PATCH v3] ARM: dts: at91: sama5d2: add m_can nodes

[Wenyou.Yang]

Hi Alexandre,

> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni@xxxxxxxxxxxxxxxxxx]
> Sent: 2017年5月15日 17:44
> To: Wenyou Yang - A41535 <Wenyou.Yang@xxxxxxxxxxxxx>
> Cc: Nicolas Ferre - M43238 <Nicolas.Ferre@xxxxxxxxxxxxx>; Rob Herring
> <robh+dt@xxxxxxxxxx>; Pawel Moll <pawel.moll@xxxxxxx>; Mark Rutland
> <mark.rutland@xxxxxxx>; Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>; Kumar
> Gala <galak@xxxxxxxxxxxxxx>; Russell King <linux@xxxxxxxxxxxxxxxx>; linux-
> kernel@xxxxxxxxxxxxxxx; linux-can@xxxxxxxxxxxxxxx; Oliver Hartkopp
> <socketcan@xxxxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx; Quentin Schulz
> <quentin.schulz@xxxxxxxxxxxxxxxxxx>; Wenyou Yang - A41535
> <Wenyou.Yang@xxxxxxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3] ARM: dts: at91: sama5d2: add m_can nodes
> 
> On 24/04/2017 at 09:12:17 +0800, Wenyou Yang wrote:
> > Add nodes to support the Controller Area Network(M_CAN) on SAMA5D2.
> > The version of M_CAN IP core is 3.1.0 (CREL = 0x31040730).
> >
> > As said in SAMA5D2 datasheet, the CAN clock is recommended to use
> > frequencies of 20, 40 or 80 MHz. To achieve these frequencies, PMC
> > GCLK3 must select the UPLLCK(480 MHz) as source clock and divide by
> > 24, 12, or 6. So, the "assigned-clock-rates" property has three
> > options: 20000000, 40000000, and 80000000.
> > The "assigned-clock-parents" property should be referred to utmi
> > fixedly.
> >
> > The MSBs [bits 31:16] of the CAN Message RAM for CAN0 and CAN1 are
> > default configured in 0x00200000. To avoid conflict with SRAM map for
> > PM, change them to 0x00210000 in the AT91Bootstrap via setting the CAN
> > Memories Address-based Register(SFR_CAN) of SFR.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> > Tested-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
> > ---
> > The patch is tested on SAMA5D2 Xplained and based on the patch set,
> > 1. [PATCH v4 1/7] can: m_can: Disabled Interrupt Line 1
> >     http://marc.info/?l=linux-can&m=149165343604033&w=2
> >
> > Changes in v3:
> >  - Add Tested-by tag.
> >  - Change the number of Rx Rx Buffers, Tx Buffers and Tx Event FIFO
> >    to maximum.
> >
> > Changes in v2:
> >  - Configures 10 TX Event FIFO elements and 10 TX Buffers/FIFO slots,
> >    because the TXE FIFO is needed to be configured.
> >  - Configure the offset of Message RAM for CAN1 followed from CAN0's.
> >
> >  arch/arm/boot/dts/at91-sama5d2_xplained.dts | 24 +++++++++++++
> >  arch/arm/boot/dts/sama5d2.dtsi              | 56
> +++++++++++++++++++++++++++++
> >  2 files changed, 80 insertions(+)
> >
> 
> It didn't apply cleanly, can you please verify
> https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git/log/?h=at91-dt

Verified, it works. 

Thank you for your effort.


BTW, it will be better take the patch to add the config.
[PATCH v2] ARM: at91/defconfig: add MCAN driver to sama5_defconfig
I just submitted.

> 
> --
> Alexandre Belloni, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com


Best Regards,
Wenyou Yang