[ARM] 4533/1: AT91x40 timer support

Support for the timers in the Atmel AT91x40 family of CPUs.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-at91/at91x40_time.c

+/*
+ * arch/arm/mach-at91/at91x40_time.c
+ *
+ * (C) Copyright 2007, Greg Ungerer <gerg@snapgear.com>
+ *
+ * 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 <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/time.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/mach/time.h>
+#include <asm/arch/at91_tc.h>
+
+/*
+ *	3 counter/timer units present.
+ */
+#define	AT91_TC_CLK0BASE	0
+#define	AT91_TC_CLK1BASE	0x40
+#define	AT91_TC_CLK2BASE	0x80
+
+static unsigned long at91x40_gettimeoffset(void)
+{
+	return (at91_sys_read(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_CV) * 1000000 / (AT91X40_MASTER_CLOCK / 128));
+}
+
+static irqreturn_t at91x40_timer_interrupt(int irq, void *dev_id)
+{
+	at91_sys_read(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_SR);
+	timer_tick();
+	return IRQ_HANDLED;
+}
+
+static struct irqaction at91x40_timer_irq = {
+	.name		= "at91_tick",
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
+	.handler	= at91x40_timer_interrupt
+};
+
+void __init at91x40_timer_init(void)
+{
+	unsigned int v;
+
+	at91_sys_write(AT91_TC + AT91_TC_BCR, 0);
+	v = at91_sys_read(AT91_TC + AT91_TC_BMR);
+	v = (v & ~AT91_TC_TC1XC1S) | AT91_TC_TC1XC1S_NONE;
+	at91_sys_write(AT91_TC + AT91_TC_BMR, v);
+
+	at91_sys_write(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_CCR, AT91_TC_CLKDIS);
+	at91_sys_write(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_CMR, (AT91_TC_TIMER_CLOCK4 | AT91_TC_CPCTRG));
+	at91_sys_write(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_IDR, 0xffffffff);
+	at91_sys_write(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_RC, (AT91X40_MASTER_CLOCK / 128) / HZ - 1);
+	at91_sys_write(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_IER, (1<<4));
+
+	setup_irq(AT91X40_ID_TC1, &at91x40_timer_irq);
+
+	at91_sys_write(AT91_TC + AT91_TC_CLK1BASE + AT91_TC_CCR, (AT91_TC_SWTRG | AT91_TC_CLKEN));
+}
+
+struct sys_timer at91x40_timer = {
+	.init	= at91x40_timer_init,
+	.offset	= at91x40_gettimeoffset,
+};
+