Re: [PATCH v3] ARM: dts: at91: sama5d2: add m_can nodes
From: Alexandre Belloni
Date: Mon May 15 2017 - 05:44:36 EST
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
--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com