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

Joe Hershberger
2012-08-14T15:36:18Z

Hi Michal,

On Tue, Aug 14, 2012 at 6:42 AM, Michal Simek <monstr@monstr.eu> wrote:
> Add timer driver.
>
> Signed-off-by: Michal Simek <monstr@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@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@monstr.eu>
> + * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
> + *
> + * (C) Copyright 2008
> + * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
> + *
> + * (C) Copyright 2004
> + * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
> + *
> + * (C) Copyright 2002-2004
> + * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
> + *
> + * (C) Copyright 2003
> + * Texas Instruments <www.ti.com>
> + *
> + * (C) Copyright 2002
> + * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
> + * Marius Groeger <mgroeger@sysgo.de>
> + *
> + * (C) Copyright 2002
> + * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
> + * Alex Zuepke <azu@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
>
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