[PATCH v4] ARM: at91: pit add DT support
Rob Herring
robherring2 at gmail.com
Fri Jan 6 10:47:37 EST 2012
On 01/06/2012 10:20 AM, Nicolas Ferre wrote:
> From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
>
> Retreive registers address and IRQ from device tree entry. Fall back
> to built-in values if an error occurs.
>
> 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>
> Reviewed-by: Jamie Iles <jamie at jamieiles.com>
> Acked-by: Rob Herring <rob.herring at calxeda.com>
> ---
> 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 | 5 ++
> arch/arm/boot/dts/at91sam9g45.dtsi | 6 ++
> arch/arm/mach-at91/at91sam926x_time.c | 60 ++++++++++++++++++--
> 4 files changed, 73 insertions(+), 6 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 ea942b5..e10842a 100644
> --- a/arch/arm/boot/dts/at91sam9g20.dtsi
> +++ b/arch/arm/boot/dts/at91sam9g20.dtsi
> @@ -57,6 +57,11 @@
> 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";
> diff --git a/arch/arm/boot/dts/at91sam9g45.dtsi b/arch/arm/boot/dts/at91sam9g45.dtsi
> index ebc9617..28a678f 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..802fea3 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 timer_ids[] = {
> + { .compatible = "atmel,at91sam9260-pit" },
> + { /* sentinel */ }
> +};
> +
> +static int __init of_at91sam926x_pit_init(void)
> +{
> + struct device_node *np;
> + int ret;
> +
> + np = of_find_matching_node(NULL, 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
> +static int __init of_at91sam926x_pit_init(void)
> +{
> + return -EINVAL;
> +}
> +#endif
> +
> /*
> * Set up both clocksource and clockevent support.
> */
> @@ -177,7 +224,7 @@ 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);
> @@ -193,10 +240,11 @@ static void at91sam926x_pit_suspend(void)
>
> void __init at91sam926x_ioremap_pit(u32 addr)
> {
> - pit_base_addr = ioremap(addr, 16);
> -
> - if (!pit_base_addr)
> - panic("Impossible to ioremap PIT\n");
> + if (of_at91sam926x_pit_init() < 0) {
> + pit_base_addr = ioremap(addr, 16);
> + if (!pit_base_addr)
> + panic("Impossible to ioremap PIT\n");
> + }
This is not what I meant. I meant call either at91sam926x_ioremap_pit or
of_at91sam926x_pit_init. Don't nest the calls and keep the OF and non-OF
init somewhat separate. The fact that you are passing in the physical
address and then ignoring it for the OF case is what I have issue with.
Rob
> }
>
> struct sys_timer at91sam926x_timer = {
More information about the linux-arm-kernel
mailing list