Initial import

1 files changed, 176 insertions, 0 deletions

diff --git a/arch/mips/alchemy/common/time.c b/arch/mips/alchemy/common/time.c
new file mode 100644
index 000000000..50e17e13c
--- /dev/null
+++ b/arch/mips/alchemy/common/time.c
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2008-2009 Manuel Lauss <manuel.lauss@gmail.com>
+ *
+ * Previous incarnations were:
+ * Copyright (C) 2001, 2006, 2008 MontaVista Software, <source@mvista.com>
+ * Copied and modified Carsten Langgaard's time.c
+ *
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ * ########################################################################
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ * ########################################################################
+ *
+ * Clocksource/event using the 32.768kHz-clocked Counter1 ('RTC' in the
+ * databooks).  Firmware/Board init code must enable the counters in the
+ * counter control register, otherwise the CP0 counter clocksource/event
+ * will be installed instead (and use of 'wait' instruction is prohibited).
+ */
+
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+
+#include <asm/idle.h>
+#include <asm/processor.h>
+#include <asm/time.h>
+#include <asm/mach-au1x00/au1000.h>
+
+/* 32kHz clock enabled and detected */
+#define CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
+
+static cycle_t au1x_counter1_read(struct clocksource *cs)
+{
+	return alchemy_rdsys(AU1000_SYS_RTCREAD);
+}
+
+static struct clocksource au1x_counter1_clocksource = {
+	.name		= "alchemy-counter1",
+	.read		= au1x_counter1_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.rating		= 1500,
+};
+
+static int au1x_rtcmatch2_set_next_event(unsigned long delta,
+					 struct clock_event_device *cd)
+{
+	delta += alchemy_rdsys(AU1000_SYS_RTCREAD);
+	/* wait for register access */
+	while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M21)
+		;
+	alchemy_wrsys(delta, AU1000_SYS_RTCMATCH2);
+
+	return 0;
+}
+
+static void au1x_rtcmatch2_set_mode(enum clock_event_mode mode,
+				    struct clock_event_device *cd)
+{
+}
+
+static irqreturn_t au1x_rtcmatch2_irq(int irq, void *dev_id)
+{
+	struct clock_event_device *cd = dev_id;
+	cd->event_handler(cd);
+	return IRQ_HANDLED;
+}
+
+static struct clock_event_device au1x_rtcmatch2_clockdev = {
+	.name		= "rtcmatch2",
+	.features	= CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 1500,
+	.set_next_event = au1x_rtcmatch2_set_next_event,
+	.set_mode	= au1x_rtcmatch2_set_mode,
+	.cpumask	= cpu_all_mask,
+};
+
+static struct irqaction au1x_rtcmatch2_irqaction = {
+	.handler	= au1x_rtcmatch2_irq,
+	.flags		= IRQF_TIMER,
+	.name		= "timer",
+	.dev_id		= &au1x_rtcmatch2_clockdev,
+};
+
+static int __init alchemy_time_init(unsigned int m2int)
+{
+	struct clock_event_device *cd = &au1x_rtcmatch2_clockdev;
+	unsigned long t;
+
+	au1x_rtcmatch2_clockdev.irq = m2int;
+
+	/* Check if firmware (YAMON, ...) has enabled 32kHz and clock
+	 * has been detected.  If so install the rtcmatch2 clocksource,
+	 * otherwise don't bother.  Note that both bits being set is by
+	 * no means a definite guarantee that the counters actually work
+	 * (the 32S bit seems to be stuck set to 1 once a single clock-
+	 * edge is detected, hence the timeouts).
+	 */
+	if (CNTR_OK != (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & CNTR_OK))
+		goto cntr_err;
+
+	/*
+	 * setup counter 1 (RTC) to tick at full speed
+	 */
+	t = 0xffffff;
+	while ((alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_T1S) && --t)
+		asm volatile ("nop");
+	if (!t)
+		goto cntr_err;
+
+	alchemy_wrsys(0, AU1000_SYS_RTCTRIM);	/* 32.768 kHz */
+
+	t = 0xffffff;
+	while ((alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_C1S) && --t)
+		asm volatile ("nop");
+	if (!t)
+		goto cntr_err;
+	alchemy_wrsys(0, AU1000_SYS_RTCWRITE);
+
+	t = 0xffffff;
+	while ((alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_C1S) && --t)
+		asm volatile ("nop");
+	if (!t)
+		goto cntr_err;
+
+	/* register counter1 clocksource and event device */
+	clocksource_register_hz(&au1x_counter1_clocksource, 32768);
+
+	cd->shift = 32;
+	cd->mult = div_sc(32768, NSEC_PER_SEC, cd->shift);
+	cd->max_delta_ns = clockevent_delta2ns(0xffffffff, cd);
+	cd->min_delta_ns = clockevent_delta2ns(9, cd);	/* ~0.28ms */
+	clockevents_register_device(cd);
+	setup_irq(m2int, &au1x_rtcmatch2_irqaction);
+
+	printk(KERN_INFO "Alchemy clocksource installed\n");
+
+	return 0;
+
+cntr_err:
+	return -1;
+}
+
+static int alchemy_m2inttab[] __initdata = {
+	AU1000_RTC_MATCH2_INT,
+	AU1500_RTC_MATCH2_INT,
+	AU1100_RTC_MATCH2_INT,
+	AU1550_RTC_MATCH2_INT,
+	AU1200_RTC_MATCH2_INT,
+	AU1300_RTC_MATCH2_INT,
+};
+
+void __init plat_time_init(void)
+{
+	int t;
+
+	t = alchemy_get_cputype();
+	if (t == ALCHEMY_CPU_UNKNOWN ||
+	    alchemy_time_init(alchemy_m2inttab[t]))
+		cpu_wait = NULL;	/* wait doesn't work with r4k timer */
+}