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

Joe Hershberger joe.hershberger at gmail.com
Tue Aug 14 17:36:18 CEST 2012


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.

> +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.

> +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.

> +
> +static struct scu_timer *timer_base = CONFIG_XPSS_SCUTIMER_BASEADDR;
> +
> +#define XSCUTIMER_CONTROL_PRESCALER_MASK       0x0000FF00 /* Prescaler */
> +#define XSCUTIMER_CONTROL_PRESCALER_SHIFT      8
> +#define XSCUTIMER_CONTROL_AUTO_RELOAD_MASK     0x00000002 /* Auto-reload */
> +#define XSCUTIMER_CONTROL_ENABLE_MASK          0x00000001 /* Timer enable */
> +
> +#define TIMER_LOAD_VAL 0xFFFFFFFF
> +#define TIMER_PRESCALE 255
> +#define TIMER_TICK_HZ  (CONFIG_CPU_FREQ_HZ / 2 / TIMER_PRESCALE)
> +
> +int timer_init(void)
> +{
> +       u32 val;
> +
> +       /* Load the timer counter register */
> +       writel(0xFFFFFFFF, &timer_base->counter);
> +
> +       /* Start the A9Timer device */
> +       val = readl(&timer_base->control);
> +       /* Enable Auto reload mode */
> +       val |= XSCUTIMER_CONTROL_AUTO_RELOAD_MASK;
> +       /* Clear prescaler control bits */
> +       val &= ~XSCUTIMER_CONTROL_PRESCALER_MASK;
> +       /* Set prescaler value */
> +       val |= (TIMER_PRESCALE << XSCUTIMER_CONTROL_PRESCALER_SHIFT);
> +       /* Enable the decrementer */
> +       val |= XSCUTIMER_CONTROL_ENABLE_MASK;
> +       writel(val, &timer_base->control);
> +
> +       /* Reset time */
> +       gd->lastinc = readl(&timer_base->counter) /
> +                                       (TIMER_TICK_HZ / CONFIG_SYS_HZ);
> +       gd->tbl = 0;
> +
> +       return 0;
> +}
> +
> +/*
> + * This function is derived from PowerPC code (read timebase as long long).
> + * On ARM it just returns the timer value.
> + */
> +ulong get_timer_masked(void)
> +{
> +       ulong now;
> +
> +       now = readl(&timer_base->counter) / (TIMER_TICK_HZ / CONFIG_SYS_HZ);
> +
> +       if (gd->lastinc >= now) {
> +               /* Normal mode */
> +               gd->tbl += gd->lastinc - now;
> +       } else {
> +               /* We have an overflow ... */
> +               gd->tbl += gd->lastinc + TIMER_LOAD_VAL - now;
> +       }
> +       gd->lastinc = now;
> +
> +       return gd->tbl;
> +}
> +
> +void __udelay(unsigned long usec)
> +{
> +       unsigned long long tmp;
> +       ulong tmo;
> +
> +       tmo = usec / (1000000 / CONFIG_SYS_HZ);
> +       tmp = get_ticks() + tmo; /* Get current timestamp */
> +
> +       while (get_ticks() < tmp) { /* Loop till event */
> +                /* NOP */;
> +       }
> +}
> +
> +/* Timer without interrupts */
> +ulong get_timer(ulong base)
> +{
> +       return get_timer_masked() - base;
> +}
> +
> +/*
> + * This function is derived from PowerPC code (read timebase as long long).
> + * On ARM it just returns the timer value.
> + */
> +unsigned long long get_ticks(void)
> +{
> +       return get_timer(0);
> +}
> +
> +/*
> + * This function is derived from PowerPC code (timebase clock frequency).
> + * On ARM it returns the number of timer ticks per second.
> + */
> +ulong get_tbclk(void)
> +{
> +       return CONFIG_SYS_HZ;
> +}
> --
> 1.7.0.4
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot


More information about the U-Boot mailing list