[U-Boot] [PATCH 3/4] arm: Support new Xilinx Zynq platform

Tue Aug 14 19:11:36 CEST 2012

On 08/14/2012 06:41 PM, Joe Hershberger wrote:
> Hi Michal,
>
> On Tue, Aug 14, 2012 at 11:28 AM, Michal Simek <monstr at monstr.eu> wrote:
>> On 08/14/2012 05:36 PM, Joe Hershberger wrote:
>>>
>>> Hi Michal,
>>>
>>> On Tue, Aug 14, 2012 at 6:42 AM, Michal Simek <monstr at monstr.eu> wrote:
>>>>
>>>> Add timer driver.
>>>>
>>>> Signed-off-by: Michal Simek <monstr at monstr.eu>
>>>> ---
>>>>    arch/arm/cpu/armv7/zynq/Makefile |   48 ++++++++++++
>>>>    arch/arm/cpu/armv7/zynq/timer.c  |  151
>>>> ++++++++++++++++++++++++++++++++++++++
>>>>    2 files changed, 199 insertions(+), 0 deletions(-)
>>>>    create mode 100644 arch/arm/cpu/armv7/zynq/Makefile
>>>>    create mode 100644 arch/arm/cpu/armv7/zynq/timer.c
>>>>
>>>> diff --git a/arch/arm/cpu/armv7/zynq/Makefile
>>>> b/arch/arm/cpu/armv7/zynq/Makefile
>>>> new file mode 100644
>>>> index 0000000..814c1d4
>>>> --- /dev/null
>>>> +++ b/arch/arm/cpu/armv7/zynq/Makefile
>>>> @@ -0,0 +1,48 @@
>>>> +#
>>>> +# (C) Copyright 2000-2003
>>>> +# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
>>>> +#
>>>> +# (C) Copyright 2008
>>>> +# Guennadi Liakhovetki, DENX Software Engineering, <lg at denx.de>
>>>> +#
>>>> +# See file CREDITS for list of people who contributed to this
>>>> +# project.
>>>> +#
>>>> +# 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, write to the Free Software
>>>> +# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
>>>> +# MA 02111-1307 USA
>>>> +#
>>>> +
>>>> +include $(TOPDIR)/config.mk
>>>> +
>>>> +LIB    = $(obj)lib$(SOC).o
>>>> +
>>>
>>>
>>> You should include the lowlevel_init.o here instead of in the board.
>>
>>
>> Probably make sense.
>>
>>
>>
>>>
>>>> +COBJS  = timer.o
>>>> +
>>>
>>>
>>> Preferably emulate the Makefile in arch/arm/cpu/armv7/tegra2/.  By
>>> that I mean use COBJS-y instead of COBJS directly.  This is more
>>> forward looking to allow for features to be disabled in the future.
>>
>>
>> no problem with that.
>>
>>
>>>
>>>> +SRCS   := $(SOBJS:.o=.S) $(COBJS:.o=.c)
>>>> +OBJS   := $(addprefix $(obj),$(SOBJS) $(COBJS))
>>>> +
>>>> +all:   $(obj).depend $(LIB)
>>>> +
>>>> +$(LIB): $(OBJS)
>>>> +       $(call cmd_link_o_target, $(OBJS))
>>>> +
>>>>
>>>> +#########################################################################
>>>> +
>>>> +# defines $(obj).depend target
>>>> +include $(SRCTREE)/rules.mk
>>>> +
>>>> +sinclude $(obj).depend
>>>> +
>>>>
>>>> +#########################################################################
>>>> diff --git a/arch/arm/cpu/armv7/zynq/timer.c
>>>> b/arch/arm/cpu/armv7/zynq/timer.c
>>>> new file mode 100644
>>>> index 0000000..d79da97
>>>> --- /dev/null
>>>> +++ b/arch/arm/cpu/armv7/zynq/timer.c
>>>> @@ -0,0 +1,151 @@
>>>> +/*
>>>> + * Copyright (C) 2012 Michal Simek <monstr at monstr.eu>
>>>> + * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
>>>> + *
>>>> + * (C) Copyright 2008
>>>> + * Guennadi Liakhovetki, DENX Software Engineering, <lg at denx.de>
>>>> + *
>>>> + * (C) Copyright 2004
>>>> + * Philippe Robin, ARM Ltd. <philippe.robin at arm.com>
>>>> + *
>>>> + * (C) Copyright 2002-2004
>>>> + * Gary Jennejohn, DENX Software Engineering, <gj at denx.de>
>>>> + *
>>>> + * (C) Copyright 2003
>>>> + * Texas Instruments <www.ti.com>
>>>> + *
>>>> + * (C) Copyright 2002
>>>> + * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
>>>> + * Marius Groeger <mgroeger at sysgo.de>
>>>> + *
>>>> + * (C) Copyright 2002
>>>> + * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
>>>> + * Alex Zuepke <azu at sysgo.de>
>>>> + *
>>>> + * See file CREDITS for list of people who contributed to this
>>>> + * project.
>>>> + *
>>>> + * 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, write to the Free Software
>>>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
>>>> + * MA 02111-1307 USA
>>>> + */
>>>> +
>>>> +#include <common.h>
>>>> +#include <div64.h>
>>>> +#include <asm/io.h>
>>>> +
>>>> +DECLARE_GLOBAL_DATA_PTR;
>>>> +
>>>> +struct scu_timer {
>>>> +       u32 load; /* Timer Load Register */
>>>> +       u32 counter; /* Timer Counter Register */
>>>> +       u32 control; /* Timer Control Register */
>>>> +};
>>>
>>>
>>> You are using the timer in the ARM Cortex A9 core.  This is not
>>> Zynq-specific in any way.  It should be made available in a different
>>> place.  Probably in arch/arm/lib.  It should be stripped on any "XSCU"
>>> references.  Use ARM names instead.
>>
>>
>>
>> Based on this I can't see the reason why XSCU should be stripped.
>> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407f/BABDEAGJ.html
>>
>> It is SCU private timer. Agree that we can remove X prefix.
>>
>>
>> I don't think that arch/arm/lib is the proper location for that.
>> I am not arm specialist to say that this timer is available in all arm
>> families
>> to be in lib folder.
>
> I'm not sure that it is available on more than armv7 (like
> arch/arm/lib/cache-pl310.c).  If it is only available in armv7, then
> it can go in arch/arm/cpu/armv7/.

For me was just safer to use it in zynq folder because I am not familiar with others ARMs.
+ I see that other armv7 cpus uses own timer drivers.

Any input from arm custodian will be helpful.

Thanks,
Michal
-- 
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian