[ARM] 4331/3: Support for Micrel/Kendin KS8695 processor

Add core support for the Kendin/Micrel KS8695 processor family.

It is an ARM922-T based SoC with integrated USART, 4-port Ethernet
Switch, WAN Ethernet port, and optional PCI Host bridge, etc.
 http://www.micrel.com/page.do?page=product-info/sys_on_chip.jsp

This patch is based on earlier patches from Lennert Buytenhek, Ben
Dooks and Greg Ungerer posted to the arm-linux-kernel mailing list in
March 2006;  and Micrel's 2.6.9 port.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 114 insertions, 0 deletions

diff --git a/arch/arm/mach-ks8695/time.c b/arch/arm/mach-ks8695/time.c
new file mode 100644
index 000000000000..d2c86e4a72eb
--- /dev/null
+++ b/arch/arm/mach-ks8695/time.c
@@ -0,0 +1,114 @@
+/*
+ * arch/arm/mach-ks8695/time.c
+ *
+ * Copyright (C) 2006 Ben Dooks <ben@simtec.co.uk>
+ * Copyright (C) 2006 Simtec Electronics
+ *
+ * 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/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+
+#include <asm/io.h>
+#include <asm/mach/time.h>
+
+#include <asm/arch/regs-timer.h>
+#include <asm/arch/regs-irq.h>
+
+#include "generic.h"
+
+/*
+ * Returns number of ms since last clock interrupt.  Note that interrupts
+ * will have been disabled by do_gettimeoffset()
+ */
+static unsigned long ks8695_gettimeoffset (void)
+{
+	unsigned long elapsed, tick2, intpending;
+
+	/*
+	 * Get the current number of ticks.  Note that there is a race
+	 * condition between us reading the timer and checking for an
+	 * interrupt.  We solve this by ensuring that the counter has not
+	 * reloaded between our two reads.
+	 */
+	elapsed = __raw_readl(KS8695_TMR_VA + KS8695_T1TC) + __raw_readl(KS8695_TMR_VA + KS8695_T1PD);
+	do {
+		tick2 = elapsed;
+		intpending = __raw_readl(KS8695_IRQ_VA + KS8695_INTST) & (1 << KS8695_IRQ_TIMER1);
+		elapsed = __raw_readl(KS8695_TMR_VA + KS8695_T1TC) + __raw_readl(KS8695_TMR_VA + KS8695_T1PD);
+	} while (elapsed > tick2);
+
+	/* Convert to number of ticks expired (not remaining) */
+	elapsed = (CLOCK_TICK_RATE / HZ) - elapsed;
+
+	/* Is interrupt pending?  If so, then timer has been reloaded already. */
+	if (intpending)
+		elapsed += (CLOCK_TICK_RATE / HZ);
+
+	/* Convert ticks to usecs */
+	return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH;
+}
+
+/*
+ * IRQ handler for the timer.
+ */
+static irqreturn_t ks8695_timer_interrupt(int irq, void *dev_id)
+{
+	write_seqlock(&xtime_lock);
+	timer_tick();
+	write_sequnlock(&xtime_lock);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction ks8695_timer_irq = {
+	.name		= "ks8695_tick",
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
+	.handler	= ks8695_timer_interrupt,
+};
+
+static void ks8695_timer_setup(void)
+{
+	unsigned long tmout = CLOCK_TICK_RATE / HZ;
+	unsigned long tmcon;
+
+	/* disable timer1 */
+	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
+	__raw_writel(tmcon & ~TMCON_T1EN, KS8695_TMR_VA + KS8695_TMCON);
+
+	__raw_writel(tmout / 2, KS8695_TMR_VA + KS8695_T1TC);
+	__raw_writel(tmout / 2, KS8695_TMR_VA + KS8695_T1PD);
+
+	/* re-enable timer1 */
+	__raw_writel(tmcon | TMCON_T1EN, KS8695_TMR_VA + KS8695_TMCON);
+}
+
+static void __init ks8695_timer_init (void)
+{
+	ks8695_timer_setup();
+
+	/* Enable timer interrupts */
+	setup_irq(KS8695_IRQ_TIMER1, &ks8695_timer_irq);
+}
+
+struct sys_timer ks8695_timer = {
+	.init		= ks8695_timer_init,
+	.offset		= ks8695_gettimeoffset,
+	.resume		= ks8695_timer_setup,
+};