[U-Boot] [PATCH 3/4 v2] arm: Support new Xilinx Zynq platform

[Marek Vasut]

Dear Michal Simek,

[...]

> +#include <config.h>
> +#include <linux/linkage.h>
> +
> +ENTRY(lowlevel_init)
> +        mov     pc, lr
> +ENDPROC(lowlevel_init)

inline void lowlevel_init(void) {} works as well and you don't need the assembly 
file.

> diff --git a/arch/arm/cpu/armv7/zynq/timer.c
> b/arch/arm/cpu/armv7/zynq/timer.c new file mode 100644
> index 0000000..0252220
> --- /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 */
> +};
> +
> +static struct scu_timer *timer_base = CONFIG_SCUTIMER_BASEADDR;
> +
> +#define SCUTIMER_CONTROL_PRESCALER_MASK	0x0000FF00 /* Prescaler */
> +#define SCUTIMER_CONTROL_PRESCALER_SHIFT	8
> +#define SCUTIMER_CONTROL_AUTO_RELOAD_MASK	0x00000002 /* Auto-reload */
> +#define SCUTIMER_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 |= SCUTIMER_CONTROL_AUTO_RELOAD_MASK;
> +	/* Clear prescaler control bits */
> +	val &= ~SCUTIMER_CONTROL_PRESCALER_MASK;
> +	/* Set prescaler value */
> +	val |= (TIMER_PRESCALE << SCUTIMER_CONTROL_PRESCALER_SHIFT);
> +	/* Enable the decrementer */
> +	val |= SCUTIMER_CONTROL_ENABLE_MASK;
> +	writel(val, &timer_base->control);

clrsetbits_le32()

> +	/* 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;
> +}