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authorTero Kristo <tero.kristo@nokia.com>2009-10-23 19:03:47 +0300
committerTony Lindgren <tony@atomide.com>2010-01-21 18:30:10 -0800
commit5c3db36bf68bb9f682a0188d81dc184f5e62a6e4 (patch)
treeb18b45715c6ebfd4f5e3022be441bc386b6d479d
parentb2d959173fea3e04229b2ff33473b5a031669f66 (diff)
OMAP2/3: DMTIMER: Clear pending interrupts when stopping a timer
OMAP GP timers keep running for a few cycles after they are stopped, which can cause the timer to expire and generate an interrupt. The pending interrupt will prevent e.g. OMAP from entering suspend, thus we ack it manually. Only applicable on OMAP2/3/4. Signed-off-by: Tero Kristo <tero.kristo@nokia.com> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
-rw-r--r--arch/arm/plat-omap/dmtimer.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
index 64f407ee0f4..08ccf892252 100644
--- a/arch/arm/plat-omap/dmtimer.c
+++ b/arch/arm/plat-omap/dmtimer.c
@@ -551,6 +551,19 @@ void omap_dm_timer_stop(struct omap_dm_timer *timer)
if (l & OMAP_TIMER_CTRL_ST) {
l &= ~0x1;
omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+#if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3) || \
+ defined(CONFIG_ARCH_OMAP4)
+ /* Readback to make sure write has completed */
+ omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
+ /*
+ * Wait for functional clock period x 3.5 to make sure that
+ * timer is stopped
+ */
+ udelay(3500000 / clk_get_rate(timer->fclk) + 1);
+ /* Ack possibly pending interrupt */
+ omap_dm_timer_write_reg(timer, OMAP_TIMER_STAT_REG,
+ OMAP_TIMER_INT_OVERFLOW);
+#endif
}
}
EXPORT_SYMBOL_GPL(omap_dm_timer_stop);