[PATCH 5/9] clocksource: dw_apb_timer: quirk for variants without EOI register

Heiko Stübner
2013-07-05T22:54:19Z

Some variants of the dw_apb_timer don't have an eoi register but instead expect a
one to be written to the int_status register at eoi time.

Signed-off-by: Ulrich Prinz <ulrich.prinz@googlemail.com>
---
drivers/clocksource/dw_apb_timer.c | 10 +++++++++-
include/linux/dw_apb_timer.h | 5 +++++
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c
index 5f80a30..23cd7c6 100644
--- a/drivers/clocksource/dw_apb_timer.c
+++ b/drivers/clocksource/dw_apb_timer.c
@@ -104,6 +104,11 @@ static void apbt_eoi(struct dw_apb_timer *timer)
apbt_readl(timer, timer->reg_eoi);
}

+static void apbt_eoi_int_status(struct dw_apb_timer *timer)
+{
+ apbt_writel(timer, 1, timer->reg_int_status);
+}
+
static irqreturn_t dw_apb_clockevent_irq(int irq, void *data)
{
struct clock_event_device *evt = data;
@@ -286,7 +291,10 @@ dw_apb_clockevent_init(int cpu, const char *name, unsigned rating,
IRQF_NOBALANCING |
IRQF_DISABLED;

- dw_ced->eoi = apbt_eoi;
+ if (quirks & APBTMR_QUIRK_NO_EOI)
+ dw_ced->eoi = apbt_eoi_int_status;
+ else
+ dw_ced->eoi = apbt_eoi;
err = setup_irq(irq, &dw_ced->irqaction);
if (err) {
pr_err("failed to request timer irq\n");
diff --git a/include/linux/dw_apb_timer.h b/include/linux/dw_apb_timer.h
index 80f6686..fbe4c6b 100644
--- a/include/linux/dw_apb_timer.h
+++ b/include/linux/dw_apb_timer.h
@@ -25,6 +25,11 @@
*/
#define APBTMR_QUIRK_64BIT_COUNTER BIT(0)

+/* The IP does not provide a end-of-interrupt register to clear pending
+ * interrupts, but requires to write a 1 to the interrupt-status register.
+ */
+#define APBTMR_QUIRK_NO_EOI BIT(1)
+
struct dw_apb_timer {
void __iomem *base;
unsigned long freq;
--
1.7.10.4