[PATCH v5 1/2] ARM: at91: pit add DT support
Nicolas Ferre
nicolas.ferre at atmel.com
Wed Feb 22 09:32:48 EST 2012
From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
Retreive registers address and IRQ from device tree entry.
Called from at91_dt_init_irq() so that timers are up-n-running
when timers initialization will occur.
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
[nicolas.ferre at atmel.com: change error path and interrupts property handling]
Signed-off-by: Nicolas Ferre <nicolas.ferre at atmel.com>
---
Hi,
I have removed Rob's "Acked-by" and Jamie's "Reviewed-by" because I have changed
the way PIT is initialized. Do you want to put it back?
v5: - of_at91sam926x_pit_init() now called from at91sam926x_pit_init()
which is the init function of the system tick timer.
- get out of at91sam926x_ioremap_pit() if matching node found in DT.
v4: - change of_at91sam926x_pit_init() return value usage logic as
suggested by Rob Herring
- irq_of_parse_and_map() returns 0 on error: change test according to
Grant Likely note.
v3: - use irq_of_parse_and_map() for handling irq numbers specified by DT.
Correction proposed by Jamie Iles.
v2: - new specification of irq numbers in DT (due to modification of AIC code)
- new error path in of_at91sam926x_pit_init()
- fall back to built-in values if an error occurs
- use of of_property_read_u32() to get irq property
.../devicetree/bindings/arm/atmel-at91.txt | 8 +++
arch/arm/boot/dts/at91sam9g20.dtsi | 6 ++
arch/arm/boot/dts/at91sam9g45.dtsi | 6 ++
arch/arm/mach-at91/at91sam926x_time.c | 63 +++++++++++++++++++-
arch/arm/mach-at91/at91sam9x5.c | 2 -
arch/arm/mach-at91/generic.h | 1 +
6 files changed, 82 insertions(+), 4 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/atmel-at91.txt
diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
new file mode 100644
index 0000000..380f711
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
@@ -0,0 +1,8 @@
+Atmel AT91 device tree bindings.
+================================
+
+PIT Timer required properties:
+- compatible: Should be "atmel,at91sam9260-pit"
+- reg: Should contain registers location and length
+- interrupts: Should contain interrupt for the PIT which is the IRQ line
+ shared across all System Controller members.
diff --git a/arch/arm/boot/dts/at91sam9g20.dtsi b/arch/arm/boot/dts/at91sam9g20.dtsi
index 325989a..04c56c4 100644
--- a/arch/arm/boot/dts/at91sam9g20.dtsi
+++ b/arch/arm/boot/dts/at91sam9g20.dtsi
@@ -57,6 +57,12 @@
reg = <0xfffff000 0x200>;
};
+ pit: timer at fffffd30 {
+ compatible = "atmel,at91sam9260-pit";
+ reg = <0xfffffd30 0xf>;
+ interrupts = <1 4>;
+ };
+
pioA: gpio at fffff400 {
compatible = "atmel,at91rm9200-gpio";
reg = <0xfffff400 0x100>;
diff --git a/arch/arm/boot/dts/at91sam9g45.dtsi b/arch/arm/boot/dts/at91sam9g45.dtsi
index a9dbbb5..3881cab 100644
--- a/arch/arm/boot/dts/at91sam9g45.dtsi
+++ b/arch/arm/boot/dts/at91sam9g45.dtsi
@@ -58,6 +58,12 @@
reg = <0xfffff000 0x200>;
};
+ pit: timer at fffffd30 {
+ compatible = "atmel,at91sam9260-pit";
+ reg = <0xfffffd30 0xf>;
+ interrupts = <1 4>;
+ };
+
dma: dma-controller at ffffec00 {
compatible = "atmel,at91sam9g45-dma";
reg = <0xffffec00 0x200>;
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index d89ead7..8e5cc37 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -14,6 +14,9 @@
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <asm/mach/time.h>
@@ -133,7 +136,8 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
static struct irqaction at91sam926x_pit_irq = {
.name = "at91_tick",
.flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
- .handler = at91sam926x_pit_interrupt
+ .handler = at91sam926x_pit_interrupt,
+ .irq = AT91_ID_SYS,
};
static void at91sam926x_pit_reset(void)
@@ -149,6 +153,49 @@ static void at91sam926x_pit_reset(void)
pit_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
}
+#ifdef CONFIG_OF
+static struct of_device_id pit_timer_ids[] = {
+ { .compatible = "atmel,at91sam9260-pit" },
+ { /* sentinel */ }
+};
+
+int __init of_at91sam926x_pit_init(void)
+{
+ struct device_node *np;
+ int ret;
+
+ np = of_find_matching_node(NULL, pit_timer_ids);
+ if (!np)
+ goto err;
+
+ pit_base_addr = of_iomap(np, 0);
+ if (!pit_base_addr)
+ goto node_err;
+
+ /* Get the interrupts property */
+ ret = irq_of_parse_and_map(np, 0);
+ if (!ret)
+ goto ioremap_err;
+ at91sam926x_pit_irq.irq = ret;
+
+ of_node_put(np);
+
+ return 0;
+
+ioremap_err:
+ iounmap(pit_base_addr);
+node_err:
+ of_node_put(np);
+err:
+ return -EINVAL;
+}
+#else
+int __init of_at91sam926x_pit_init(void)
+{
+ return -EINVAL;
+}
+#endif
+
/*
* Set up both clocksource and clockevent support.
*/
@@ -157,6 +204,9 @@ static void __init at91sam926x_pit_init(void)
unsigned long pit_rate;
unsigned bits;
+ /* For device tree enabled device: initialize here */
+ of_at91sam926x_pit_init();
+
/*
* Use our actual MCK to figure out how many MCK/16 ticks per
* 1/HZ period (instead of a compile-time constant LATCH).
@@ -177,7 +227,7 @@ static void __init at91sam926x_pit_init(void)
clocksource_register_hz(&pit_clk, pit_rate);
/* Set up irq handler */
- setup_irq(AT91_ID_SYS, &at91sam926x_pit_irq);
+ setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
/* Set up and register clockevents */
pit_clkevt.mult = div_sc(pit_rate, NSEC_PER_SEC, pit_clkevt.shift);
@@ -193,6 +243,15 @@ static void at91sam926x_pit_suspend(void)
void __init at91sam926x_ioremap_pit(u32 addr)
{
+#if defined(CONFIG_OF)
+ struct device_node *np =
+ of_find_matching_node(NULL, pit_timer_ids);
+
+ if (np) {
+ of_node_put(np);
+ return;
+ }
+#endif
pit_base_addr = ioremap(addr, 16);
if (!pit_base_addr)
diff --git a/arch/arm/mach-at91/at91sam9x5.c b/arch/arm/mach-at91/at91sam9x5.c
index 1c3444d..3e33711 100644
--- a/arch/arm/mach-at91/at91sam9x5.c
+++ b/arch/arm/mach-at91/at91sam9x5.c
@@ -301,8 +301,6 @@ static void __init at91sam9x5_map_io(void)
static void __init at91sam9x5_ioremap_registers(void)
{
- if (of_at91sam926x_pit_init() < 0)
- panic("Impossible to find PIT\n");
}
void __init at91sam9x5_initialize(void)
diff --git a/arch/arm/mach-at91/generic.h b/arch/arm/mach-at91/generic.h
index 0726f42..c5d16e5 100644
--- a/arch/arm/mach-at91/generic.h
+++ b/arch/arm/mach-at91/generic.h
@@ -33,6 +33,7 @@ extern int __init at91_aic_of_init(struct device_node *node,
/* Timer */
struct sys_timer;
extern struct sys_timer at91rm9200_timer;
+extern int of_at91sam926x_pit_init(void);
extern void at91sam926x_ioremap_pit(u32 addr);
extern struct sys_timer at91sam926x_timer;
extern struct sys_timer at91x40_timer;
--
1.7.9
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