ARMV7: Add basic support for TI OMAP4

This patch adds minimum support for OMAP4. Code which can be shared
between OMAP3 and OMAP4 is placed in arch/arm/cpu/armv7/omap-common

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

1 files changed, 143 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/omap-common/timer.c b/arch/arm/cpu/armv7/omap-common/timer.c
new file mode 100644
index 0000000000..69e285ff1d
--- /dev/null
+++ b/arch/arm/cpu/armv7/omap-common/timer.c
@@ -0,0 +1,143 @@
+/*
+ * (C) Copyright 2008
+ * Texas Instruments
+ *
+ * Richard Woodruff <r-woodruff2@ti.com>
+ * Syed Moahmmed Khasim <khasim@ti.com>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <garyj@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 <common.h>
+#include <asm/io.h>
+
+static ulong timestamp;
+static ulong lastinc;
+static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
+
+/*
+ * Nothing really to do with interrupts, just starts up a counter.
+ * We run the counter with 13MHz, divided by 8, resulting in timer
+ * frequency of 1.625MHz. With 32bit counter register, counter
+ * overflows in ~44min
+ */
+
+/* 13MHz / 8 = 1.625MHz */
+#define TIMER_CLOCK	(V_SCLK / (2 << CONFIG_SYS_PTV))
+#define TIMER_LOAD_VAL	0xffffffff
+
+int timer_init(void)
+{
+	/* start the counter ticking up, reload value on overflow */
+	writel(TIMER_LOAD_VAL, &timer_base->tldr);
+	/* enable timer */
+	writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
+		&timer_base->tclr);
+
+	reset_timer_masked();	/* init the timestamp and lastinc value */
+
+	return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+void reset_timer(void)
+{
+	reset_timer_masked();
+}
+
+ulong get_timer(ulong base)
+{
+	return get_timer_masked() - base;
+}
+
+void set_timer(ulong t)
+{
+	timestamp = t;
+}
+
+/* delay x useconds */
+void __udelay(unsigned long usec)
+{
+#if defined(CONFIG_OMAP44XX)
+	/* TODO temporary hack until OMAP4 clock setup routines are present */
+	if (usec > 1000)
+		usec = usec/1000;
+#endif
+	long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
+	unsigned long now, last = readl(&timer_base->tcrr);
+
+	while (tmo > 0) {
+		now = readl(&timer_base->tcrr);
+		if (last > now) /* count up timer overflow */
+			tmo -= TIMER_LOAD_VAL - last + now;
+		else
+			tmo -= now - last;
+		last = now;
+	}
+}
+
+void reset_timer_masked(void)
+{
+	/* reset time, capture current incrementer value time */
+	lastinc = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
+	timestamp = 0;		/* start "advancing" time stamp from 0 */
+}
+
+ulong get_timer_masked(void)
+{
+	/* current tick value */
+	ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
+
+	if (now >= lastinc)	/* normal mode (non roll) */
+		/* move stamp fordward with absoulte diff ticks */
+		timestamp += (now - lastinc);
+	else	/* we have rollover of incrementer */
+		timestamp += ((TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ))
+				- lastinc) + now;
+	lastinc = now;
+	return timestamp;
+}
+
+/*
+ * 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;
+}