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Date: Tue, 11 Aug 2015 22:09:04 +0200
From: Hans Ulli Kroll <ulli.kroll@...glemail.com>
To: Olof Johansson <olof@...om.net>
Cc: arm@...nel.org, linux-kernel@...r.kernel.org,
Arnd Bergmann <arnd@...db.de>, Roman Yeryomin <roman@...em.lv>,
linus.walleij@...aro.org,
Hans Ulli Kroll <ulli.kroll@...glemail.com>
Subject: [PATCH 2/3] ARM:Gemini:use timer1 for clockevent
Use timer1 as clockevent timer.
The old driver uses timer2, which has some issues to setup
Signed-off-by: Hans Ulli Kroll <ulli.kroll@...glemail.com>
---
arch/arm/mach-gemini/time.c | 94 +++++++++++++++++++++++++++++----------------
1 file changed, 60 insertions(+), 34 deletions(-)
diff --git a/arch/arm/mach-gemini/time.c b/arch/arm/mach-gemini/time.c
index fd751b1..5e2b1ba 100644
--- a/arch/arm/mach-gemini/time.c
+++ b/arch/arm/mach-gemini/time.c
@@ -67,19 +67,11 @@ static int gemini_timer_set_next_event(unsigned long cycles,
{
u32 cr;
- cr = readl(TIMER_CR);
-
- /* This may be overdoing it, feel free to test without this */
- cr &= ~TIMER_2_CR_ENABLE;
- cr &= ~TIMER_2_CR_INT;
- writel(cr, TIMER_CR);
-
- /* Set next event */
- writel(cycles, TIMER_COUNT(TIMER2_BASE));
- writel(cycles, TIMER_LOAD(TIMER2_BASE));
- cr |= TIMER_2_CR_ENABLE;
- cr |= TIMER_2_CR_INT;
- writel(cr, TIMER_CR);
+ /* Setup the match register */
+ cr = readl(TIMER_COUNT(TIMER1_BASE));
+ writel(cr + cycles, TIMER_MATCH1(TIMER1_BASE));
+ if (readl(TIMER_COUNT(TIMER1_BASE)) - cr > cycles)
+ return -ETIME;
return 0;
}
@@ -92,10 +84,26 @@ static int gemini_timer_shutdown(struct clock_event_device *evt)
* Disable also for oneshot: the set_next() call will arm the timer
* instead.
*/
+ /* Stop timer and interrupt. */
cr = readl(TIMER_CR);
- cr &= ~TIMER_2_CR_ENABLE;
- cr &= ~TIMER_2_CR_INT;
+ cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
writel(cr, TIMER_CR);
+
+ /* Setup counter start from 0 */
+ writel(0, TIMER_COUNT(TIMER1_BASE));
+ writel(0, TIMER_LOAD(TIMER1_BASE));
+
+ /* enable interrupt */
+ cr = readl(TIMER_INTR_MASK);
+ cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2);
+ cr |= TIMER_1_INT_MATCH1;
+ writel(cr, TIMER_INTR_MASK);
+
+ /* start the timer */
+ cr = readl(TIMER_CR);
+ cr |= TIMER_1_CR_ENABLE;
+ writel(cr, TIMER_CR);
+
return 0;
}
@@ -104,21 +112,37 @@ static int gemini_timer_set_periodic(struct clock_event_device *evt)
u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ);
u32 cr;
+ /* Stop timer and interrupt */
+ cr = readl(TIMER_CR);
+ cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
+ writel(cr, TIMER_CR);
+
+ /* Setup timer to fire at 1/HT intervals. */
+ cr = 0xffffffff - (period - 1);
+ writel(cr, TIMER_COUNT(TIMER1_BASE));
+ writel(cr, TIMER_LOAD(TIMER1_BASE));
+
+ /* enable interrupt on overflow */
+ cr = readl(TIMER_INTR_MASK);
+ cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2);
+ cr |= TIMER_1_INT_OVERFLOW;
+ writel(cr, TIMER_INTR_MASK);
+
/* Start the timer */
- writel(period, TIMER_COUNT(TIMER2_BASE));
- writel(period, TIMER_LOAD(TIMER2_BASE));
cr = readl(TIMER_CR);
- cr |= TIMER_2_CR_ENABLE;
- cr |= TIMER_2_CR_INT;
+ cr |= TIMER_1_CR_ENABLE;
+ cr |= TIMER_1_CR_INT;
writel(cr, TIMER_CR);
+
return 0;
}
-/* Use TIMER2 as clock event */
+/* Use TIMER1 as clock event */
static struct clock_event_device gemini_clockevent = {
- .name = "TIMER2",
+ .name = "TIMER1",
/* Reasonably fast and accurate clock event */
.rating = 300,
+ .shift = 32,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = gemini_timer_set_next_event,
@@ -175,20 +199,22 @@ void __init gemini_timer_init(void)
}
/*
- * Make irqs happen for the system timer
+ * Reset the interrupt mask and status
*/
- setup_irq(IRQ_TIMER2, &gemini_timer_irq);
-
- /* Enable and use TIMER1 as clock source */
- writel(0xffffffff, TIMER_COUNT(TIMER1_BASE));
- writel(0xffffffff, TIMER_LOAD(TIMER1_BASE));
- writel(TIMER_1_CR_ENABLE, TIMER_CR);
- if (clocksource_mmio_init(TIMER_COUNT(TIMER1_BASE),
- "TIMER1", tick_rate, 300, 32,
- clocksource_mmio_readl_up))
- pr_err("timer: failed to initialize gemini clock source\n");
-
- /* Configure and register the clockevent */
+ writel(TIMER_INT_ALL_MASK, TIMER_INTR_MASK);
+ writel(0, TIMER_INTR_STATE);
+ writel(TIMER_DEFAULT_FLAGS, TIMER_CR);
+
+ /*
+ * Setup clockevent timer (interrupt-driven.)
+ */
+ writel(0, TIMER_COUNT(TIMER1_BASE));
+ writel(0, TIMER_LOAD(TIMER1_BASE));
+ writel(0, TIMER_MATCH1(TIMER1_BASE));
+ writel(0, TIMER_MATCH2(TIMER1_BASE));
+ setup_irq(IRQ_TIMER1, &gemini_timer_irq);
+ gemini_clockevent.cpumask = cpumask_of(0);
clockevents_config_and_register(&gemini_clockevent, tick_rate,
1, 0xffffffff);
+
}
--
2.4.6
--
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