arm: timer and interrupt init rework

actually the timer init use the interrupt_init as init callback
which make the interrupt and timer implementation difficult to follow

so now rename it as int timer_init(void) and use interrupt_init for interrupt

btw also remane the corresponding file to the functionnality implemented

as ixp arch implement two timer - one based on interrupt - so all the timer
related code is moved to timer.c

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

1 files changed, 177 insertions, 0 deletions

diff --git a/cpu/arm1176/s3c64xx/timer.c b/cpu/arm1176/s3c64xx/timer.c
new file mode 100644
index 0000000..22a5b77
--- /dev/null
+++ b/cpu/arm1176/s3c64xx/timer.c
@@ -0,0 +1,177 @@
+/*
+ * (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>
+ *
+ * (C) Copyright 2002-2004
+ * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+ *
+ * (C) Copyright 2004
+ * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
+ *
+ * (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 <common.h>
+#include <asm/proc-armv/ptrace.h>
+#include <s3c6400.h>
+#include <div64.h>
+
+static ulong timer_load_val;
+
+#define PRESCALER	167
+
+static s3c64xx_timers *s3c64xx_get_base_timers(void)
+{
+	return (s3c64xx_timers *)ELFIN_TIMER_BASE;
+}
+
+/* macro to read the 16 bit timer */
+static inline ulong read_timer(void)
+{
+	s3c64xx_timers *const timers = s3c64xx_get_base_timers();
+
+	return timers->TCNTO4;
+}
+
+/* Internal tick units */
+/* Last decremneter snapshot */
+static unsigned long lastdec;
+/* Monotonic incrementing timer */
+static unsigned long long timestamp;
+
+int timer_init(void)
+{
+	s3c64xx_timers *const timers = s3c64xx_get_base_timers();
+
+	/* use PWM Timer 4 because it has no output */
+	/*
+	 * We use the following scheme for the timer:
+	 * Prescaler is hard fixed at 167, divider at 1/4.
+	 * This gives at PCLK frequency 66MHz approx. 10us ticks
+	 * The timer is set to wrap after 100s, at 66MHz this obviously
+	 * happens after 10,000,000 ticks. A long variable can thus
+	 * keep values up to 40,000s, i.e., 11 hours. This should be
+	 * enough for most uses:-) Possible optimizations: select a
+	 * binary-friendly frequency, e.g., 1ms / 128. Also calculate
+	 * the prescaler automatically for other PCLK frequencies.
+	 */
+	timers->TCFG0 = PRESCALER << 8;
+	if (timer_load_val == 0) {
+		timer_load_val = get_PCLK() / PRESCALER * (100 / 4); /* 100s */
+		timers->TCFG1 = (timers->TCFG1 & ~0xf0000) | 0x20000;
+	}
+
+	/* load value for 10 ms timeout */
+	lastdec = timers->TCNTB4 = timer_load_val;
+	/* auto load, manual update of Timer 4 */
+	timers->TCON = (timers->TCON & ~0x00700000) | TCON_4_AUTO |
+		TCON_4_UPDATE;
+
+	/* auto load, start Timer 4 */
+	timers->TCON = (timers->TCON & ~0x00700000) | TCON_4_AUTO | COUNT_4_ON;
+	timestamp = 0;
+
+	return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+
+/*
+ * 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)
+{
+	ulong now = read_timer();
+
+	if (lastdec >= now) {
+		/* normal mode */
+		timestamp += lastdec - now;
+	} else {
+		/* we have an overflow ... */
+		timestamp += lastdec + timer_load_val - now;
+	}
+	lastdec = now;
+
+	return timestamp;
+}
+
+/*
+ * 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)
+{
+	/* We overrun in 100s */
+	return (ulong)(timer_load_val / 100);
+}
+
+void reset_timer_masked(void)
+{
+	/* reset time */
+	lastdec = read_timer();
+	timestamp = 0;
+}
+
+void reset_timer(void)
+{
+	reset_timer_masked();
+}
+
+ulong get_timer_masked(void)
+{
+	unsigned long long res = get_ticks();
+	do_div (res, (timer_load_val / (100 * CONFIG_SYS_HZ)));
+	return res;
+}
+
+ulong get_timer(ulong base)
+{
+	return get_timer_masked() - base;
+}
+
+void set_timer(ulong t)
+{
+	timestamp = t * (timer_load_val / (100 * CONFIG_SYS_HZ));
+}
+
+void udelay(unsigned long usec)
+{
+	unsigned long long tmp;
+	ulong tmo;
+
+	tmo = (usec + 9) / 10;
+	tmp = get_ticks() + tmo;	/* get current timestamp */
+
+	while (get_ticks() < tmp)/* loop till event */
+		 /*NOP*/;
+}