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authorYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>2007-10-22 19:43:15 +0900
committerRalf Baechle <ralf@linux-mips.org>2007-10-22 22:09:00 +0100
commit1097c6ac33defae6cf501b7919c23faf240601f0 (patch)
tree326fdeb21a0b0b67a569e74117c63d74620a0fb2 /arch/mips/kernel/cevt-gt641xx.c
parentd04533650f64fe3367e180f3e488d92205152cd3 (diff)
[MIPS] time: Add GT641xx timer0 clockevent driver
And make use of it for Cobalt. A few others such as the Malta could make use of it as well. Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/cevt-gt641xx.c')
-rw-r--r--arch/mips/kernel/cevt-gt641xx.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/arch/mips/kernel/cevt-gt641xx.c b/arch/mips/kernel/cevt-gt641xx.c
new file mode 100644
index 00000000000..4c651b2680f
--- /dev/null
+++ b/arch/mips/kernel/cevt-gt641xx.c
@@ -0,0 +1,144 @@
+/*
+ * GT641xx clockevent routines.
+ *
+ * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/clockchips.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+
+#include <asm/gt64120.h>
+#include <asm/time.h>
+
+#include <irq.h>
+
+static DEFINE_SPINLOCK(gt641xx_timer_lock);
+static unsigned int gt641xx_base_clock;
+
+void gt641xx_set_base_clock(unsigned int clock)
+{
+ gt641xx_base_clock = clock;
+}
+
+int gt641xx_timer0_state(void)
+{
+ if (GT_READ(GT_TC0_OFS))
+ return 0;
+
+ GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
+ GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK);
+
+ return 1;
+}
+
+static int gt641xx_timer0_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ unsigned long flags;
+ u32 ctrl;
+
+ spin_lock_irqsave(&gt641xx_timer_lock, flags);
+
+ ctrl = GT_READ(GT_TC_CONTROL_OFS);
+ ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
+ ctrl |= GT_TC_CONTROL_ENTC0_MSK;
+
+ GT_WRITE(GT_TC0_OFS, delta);
+ GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
+
+ spin_unlock_irqrestore(&gt641xx_timer_lock, flags);
+
+ return 0;
+}
+
+static void gt641xx_timer0_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ unsigned long flags;
+ u32 ctrl;
+
+ spin_lock_irqsave(&gt641xx_timer_lock, flags);
+
+ ctrl = GT_READ(GT_TC_CONTROL_OFS);
+ ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ ctrl |= GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK;
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ ctrl |= GT_TC_CONTROL_ENTC0_MSK;
+ break;
+ default:
+ break;
+ }
+
+ GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
+
+ spin_unlock_irqrestore(&gt641xx_timer_lock, flags);
+}
+
+static void gt641xx_timer0_event_handler(struct clock_event_device *dev)
+{
+}
+
+static struct clock_event_device gt641xx_timer0_clockevent = {
+ .name = "gt641xx-timer0",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .cpumask = CPU_MASK_CPU0,
+ .irq = GT641XX_TIMER0_IRQ,
+ .set_next_event = gt641xx_timer0_set_next_event,
+ .set_mode = gt641xx_timer0_set_mode,
+ .event_handler = gt641xx_timer0_event_handler,
+};
+
+static irqreturn_t gt641xx_timer0_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *cd = &gt641xx_timer0_clockevent;
+
+ cd->event_handler(cd);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction gt641xx_timer0_irqaction = {
+ .handler = gt641xx_timer0_interrupt,
+ .flags = IRQF_DISABLED | IRQF_PERCPU,
+ .name = "gt641xx_timer0",
+};
+
+static int __init gt641xx_timer0_clockevent_init(void)
+{
+ struct clock_event_device *cd;
+
+ if (!gt641xx_base_clock)
+ return 0;
+
+ GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
+
+ cd = &gt641xx_timer0_clockevent;
+ cd->rating = 200 + gt641xx_base_clock / 10000000;
+ cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
+ cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
+ clockevent_set_clock(cd, gt641xx_base_clock);
+
+ clockevents_register_device(&gt641xx_timer0_clockevent);
+
+ return setup_irq(GT641XX_TIMER0_IRQ, &gt641xx_timer0_irqaction);
+}
+arch_initcall(gt641xx_timer0_clockevent_init);