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authorJoachim Eastwood <manabian@gmail.com>2012-10-28 18:31:07 +0000
committerJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>2012-11-19 07:51:08 +0800
commit454c46df83945602f1cbc86efcfd063c6945d869 (patch)
tree4c358a73f3163dbf28caf2932a86daf37165119e
parent35ed3c7a3dda78e9dd0c75a31290b27520e4a99b (diff)
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ARM: AT91: Add DT support to AT91RM9200 System Timer
Based on AT91 PIT DT patch from Jean-Christophe PLAGNIOL-VILLARD. Signed-off-by: Joachim Eastwood <manabian@gmail.com> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
-rw-r--r--Documentation/devicetree/bindings/arm/atmel-at91.txt6
-rw-r--r--arch/arm/mach-at91/at91rm9200_time.c63
2 files changed, 67 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
index ecc81e368715..8adc9a8d6be9 100644
--- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -7,6 +7,12 @@ PIT Timer required properties:
- interrupts: Should contain interrupt for the PIT which is the IRQ line
shared across all System Controller members.
+System Timer (ST) required properties:
+- compatible: Should be "atmel,at91rm9200-st"
+- reg: Should contain registers location and length
+- interrupts: Should contain interrupt for the ST which is the IRQ line
+ shared across all System Controller members.
+
TC/TCLIB Timer required properties:
- compatible: Should be "atmel,<chip>-pit".
<chip> can be "at91rm9200" or "at91sam9x5"
diff --git a/arch/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
index aaa443b48c91..cafe98836c8a 100644
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ b/arch/arm/mach-at91/at91rm9200_time.c
@@ -24,6 +24,9 @@
#include <linux/irq.h>
#include <linux/clockchips.h>
#include <linux/export.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <asm/mach/time.h>
@@ -91,7 +94,8 @@ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
static struct irqaction at91rm9200_timer_irq = {
.name = "at91_tick",
.flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
- .handler = at91rm9200_timer_interrupt
+ .handler = at91rm9200_timer_interrupt,
+ .irq = NR_IRQS_LEGACY + AT91_ID_SYS,
};
static cycle_t read_clk32k(struct clocksource *cs)
@@ -179,8 +183,60 @@ static struct clock_event_device clkevt = {
void __iomem *at91_st_base;
EXPORT_SYMBOL_GPL(at91_st_base);
+#ifdef CONFIG_OF
+static struct of_device_id at91rm9200_st_timer_ids[] = {
+ { .compatible = "atmel,at91rm9200-st" },
+ { /* sentinel */ }
+};
+
+static int __init of_at91rm9200_st_init(void)
+{
+ struct device_node *np;
+ int ret;
+
+ np = of_find_matching_node(NULL, at91rm9200_st_timer_ids);
+ if (!np)
+ goto err;
+
+ at91_st_base = of_iomap(np, 0);
+ if (!at91_st_base)
+ goto node_err;
+
+ /* Get the interrupts property */
+ ret = irq_of_parse_and_map(np, 0);
+ if (!ret)
+ goto ioremap_err;
+ at91rm9200_timer_irq.irq = ret;
+
+ of_node_put(np);
+
+ return 0;
+
+ioremap_err:
+ iounmap(at91_st_base);
+node_err:
+ of_node_put(np);
+err:
+ return -EINVAL;
+}
+#else
+static int __init of_at91rm9200_st_init(void)
+{
+ return -EINVAL;
+}
+#endif
+
void __init at91rm9200_ioremap_st(u32 addr)
{
+#ifdef CONFIG_OF
+ struct device_node *np;
+
+ np = of_find_matching_node(NULL, at91rm9200_st_timer_ids);
+ if (np) {
+ of_node_put(np);
+ return;
+ }
+#endif
at91_st_base = ioremap(addr, 256);
if (!at91_st_base)
panic("Impossible to ioremap ST\n");
@@ -191,13 +247,16 @@ void __init at91rm9200_ioremap_st(u32 addr)
*/
void __init at91rm9200_timer_init(void)
{
+ /* For device tree enabled device: initialize here */
+ of_at91rm9200_st_init();
+
/* Disable all timer interrupts, and clear any pending ones */
at91_st_write(AT91_ST_IDR,
AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
at91_st_read(AT91_ST_SR);
/* Make IRQs happen for the system timer */
- setup_irq(NR_IRQS_LEGACY + AT91_ID_SYS, &at91rm9200_timer_irq);
+ setup_irq(at91rm9200_timer_irq.irq, &at91rm9200_timer_irq);
/* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
* directly for the clocksource and all clockevents, after adjusting