Subject: Re: [PATCH v6] can: xilinx CAN controller support

From: Michal Simek <[email-masked]>
Date: Thu, 27 Mar 2014 15:14:46 +0100

Hi Kedar,

On 03/26/2014 06:26 AM, Kedareswara rao Appana wrote:
> This patch adds xilinx CAN controller support.
> This driver supports both ZYNQ CANPS and Soft IP
> AXI CAN controller.
> 
> Signed-off-by: Kedareswara rao Appana <[email-masked]>
> ---
> This patch is rebased on the 3.14 rc8 kernel
> Chnages for v6:
> - Updated the driver with review comments.
> - Used the clock names specified in the IP data sheet.
> - Updated the devicetree bindings doc as per Rob suggestion.
> Changes for v5:
> - Updated the driver with the review comments.
> - Remove the check for the tx fifo full interrupt condition
>   form Tx interrupt routine as we are checking it in the _xmit
>   routine.
> - Clearing the txok interrupt in the tx interrupt routine for
>   every Tx can frame.
> Changes for v4:
> - Added check for the tx fifo full interrupt condition in
>   Tx interrupt routine.
> - Added be iohelper functions.
> - Moved the clock enable/disable to probe/remove because of
>   Added big endian support for AXI CAN controller case(reading
>   a register during probe for that we need to enable clock).
> Changes for v3:
> - Updated the driver with the review comments.
> - Modified the tranmit logic as per Marc suggestion.
> - Enabling the clock when the interface is up to reduce the
>   Power consumption.
> Changes for v2:
> - Updated with the review comments.
> - Removed the unnecessary debug prints.
> - include tx,rx fifo depths in ZYNQ CANPS case also.
> ---
>  .../devicetree/bindings/net/can/xilinx_can.txt     |   44 +
>  drivers/net/can/Kconfig                            |    7 +
>  drivers/net/can/Makefile                           |    1 +
>  drivers/net/can/xilinx_can.c                       | 1179 ++++++++++++++++++++
>  4 files changed, 1231 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/net/can/xilinx_can.txt
>  create mode 100644 drivers/net/can/xilinx_can.c
> 
> diff --git a/Documentation/devicetree/bindings/net/can/xilinx_can.txt b/Documentation/devicetree/bindings/net/can/xilinx_can.txt
> new file mode 100644
> index 0000000..4646396
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/can/xilinx_can.txt
> @@ -0,0 +1,44 @@
> +Xilinx Axi CAN/Zynq CANPS controller Device Tree Bindings
> +---------------------------------------------------------
> +
> +Required properties:
> +- compatible		: Should be "xlnx,zynq-can-1.00.a" for Zynq CAN

We should do one more change and better now than later.
Please use just "xlnx,zynq-can-1.0" compatible string here.

> +			  controllers and "xlnx,axi-can-1.00.a" for Axi CAN
> +			  controllers.
> +- reg			: Physical base address and size of the Axi CAN/Zynq
> +			  CANPS registers map.
> +- interrupts		: Property with a value describing the interrupt
> +			  number.
> +- interrupt-parent	: Must be core interrupt controller
> +- clock-names		: List of input clock names - "can_clk", "pclk"
> +			  (For CANPS), "can_clk" , "s_axi_aclk"(For AXI CAN)
> +			  (See clock bindings for details).
> +- clocks		: Clock phandles (see clock bindings for details).
> +- tx-fifo-depth		: Can Tx fifo depth.
> +- rx-fifo-depth		: Can Rx fifo depth.
> +
> +
> +Example:
> +
> +For Zynq CANPS Dts file:
> +	zynq_can_0: can@e0008000 {
> +			compatible = "xlnx,zynq-can-1.00.a";

the same here.

> +			clocks = <&clkc 19>, <&clkc 36>;
> +			clock-names = "can_clk", "pclk";
> +			reg = <0xe0008000 0x1000>;
> +			interrupts = <0 28 4>;
> +			interrupt-parent = <&intc>;
> +			tx-fifo-depth = <0x40>;
> +			rx-fifo-depth = <0x40>;
> +		};
> +For Axi CAN Dts file:
> +	axi_can_0: axi-can@40000000 {
> +			compatible = "xlnx,axi-can-1.00.a";
> +			clocks = <&clkc 0>;
> +			clock-names = "can_clk","s_axi_aclk" ;
> +			reg = <0x40000000 0x10000>;
> +			interrupt-parent = <&intc>;
> +			interrupts = <0 59 1>;
> +			tx-fifo-depth = <0x40>;
> +			rx-fifo-depth = <0x40>;
> +		};

I don't know which thread I discussed this with Rob but please send this binding
separately out of this and copy [email-masked] for this patch.
They should give us ACK on device-tree binding.

> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
> index 9e7d95d..9049884 100644
> --- a/drivers/net/can/Kconfig
> +++ b/drivers/net/can/Kconfig
> @@ -125,6 +125,13 @@ config CAN_GRCAN
>  	  endian syntheses of the cores would need some modifications on
>  	  the hardware level to work.
>  
> +config CAN_XILINXCAN
> +	tristate "Xilinx CAN"
> +	depends on ARCH_ZYNQ || MICROBLAZE || COMPILE_TEST
> +	depends on COMMON_CLK && HAS_IOMEM
> +	---help---
> +	  Xilinx CAN driver. This driver supports both soft AXI CAN IP and
> +	  Zynq CANPS IP.
>  source "drivers/net/can/mscan/Kconfig"
>  
>  source "drivers/net/can/sja1000/Kconfig"
> diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
> index c744039..0b8e11e 100644
> --- a/drivers/net/can/Makefile
> +++ b/drivers/net/can/Makefile
> @@ -25,5 +25,6 @@ obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o
>  obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan.o
>  obj-$(CONFIG_PCH_CAN)		+= pch_can.o
>  obj-$(CONFIG_CAN_GRCAN)		+= grcan.o
> +obj-$(CONFIG_CAN_XILINXCAN)	+= xilinx_can.o
>  
>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
> new file mode 100644
> index 0000000..3bb289c
> --- /dev/null
> +++ b/drivers/net/can/xilinx_can.c
> @@ -0,0 +1,1179 @@
> +/* Xilinx CAN device driver
> + *
> + * Copyright (C) 2012 - 2014 Xilinx, Inc.
> + * Copyright (C) 2009 PetaLogix. All rights reserved.
> + *
> + * Description:
> + * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.

Please remove this paragraph. Some testing tools reports this
as a problematic part.

<snip>

> +/* Match table for OF platform binding */
> +static struct of_device_id xcan_of_match[] = {
> +	{ .compatible = "xlnx,zynq-can-1.00.a", },

And here also xlnx,zynq-can-1.0

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform