From d8e0364364d333feb4564bb7d7d983182b34427e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 10 Jan 2012 22:15:45 +0000 Subject: [PATCH] ARM: smp_twd: add device tree support Add bindings to support DT discovery of the ARM Timer Watchdog (aka TWD). Only the timer side is converted by this patch. Acked-by: Rob Herring Signed-off-by: Marc Zyngier --- Documentation/devicetree/bindings/arm/twd.txt | 48 ++++++++++++ arch/arm/include/asm/smp_twd.h | 8 ++ arch/arm/kernel/smp_twd.c | 77 +++++++++++++++---- 3 files changed, 120 insertions(+), 13 deletions(-) create mode 100644 Documentation/devicetree/bindings/arm/twd.txt diff --git a/Documentation/devicetree/bindings/arm/twd.txt b/Documentation/devicetree/bindings/arm/twd.txt new file mode 100644 index 000000000000..75b8610939fa --- /dev/null +++ b/Documentation/devicetree/bindings/arm/twd.txt @@ -0,0 +1,48 @@ +* ARM Timer Watchdog + +ARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core +Timer-Watchdog (aka TWD), which provides both a per-cpu local timer +and watchdog. + +The TWD is usually attached to a GIC to deliver its two per-processor +interrupts. + +** Timer node required properties: + +- compatible : Should be one of: + "arm,cortex-a9-twd-timer" + "arm,cortex-a5-twd-timer" + "arm,arm11mp-twd-timer" + +- interrupts : One interrupt to each core + +- reg : Specify the base address and the size of the TWD timer + register window. + +Example: + + twd-timer@2c000600 { + compatible = "arm,arm11mp-twd-timer""; + reg = <0x2c000600 0x20>; + interrupts = <1 13 0xf01>; + }; + +** Watchdog node properties: + +- compatible : Should be one of: + "arm,cortex-a9-twd-wdt" + "arm,cortex-a5-twd-wdt" + "arm,arm11mp-twd-wdt" + +- interrupts : One interrupt to each core + +- reg : Specify the base address and the size of the TWD watchdog + register window. + +Example: + + twd-watchdog@2c000620 { + compatible = "arm,arm11mp-twd-wdt"; + reg = <0x2c000620 0x20>; + interrupts = <1 14 0xf01>; + }; diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h index 16c89b793f90..8047e6e580b6 100644 --- a/arch/arm/include/asm/smp_twd.h +++ b/arch/arm/include/asm/smp_twd.h @@ -40,4 +40,12 @@ struct twd_local_timer name __initdata = { \ int twd_local_timer_register(struct twd_local_timer *); +#ifdef CONFIG_HAVE_ARM_TWD +void twd_local_timer_of_register(void); +#else +static inline void twd_local_timer_of_register(void) +{ +} +#endif + #endif diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index 18c55f1e4e48..761826c628b1 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -20,6 +20,8 @@ #include #include #include +#include +#include #include #include @@ -284,37 +286,86 @@ static struct local_timer_ops twd_lt_ops __cpuinitdata = { .stop = twd_timer_stop, }; -int __init twd_local_timer_register(struct twd_local_timer *tlt) +static int __init twd_local_timer_common_register(void) { int err; - if (twd_base || twd_evt) - return -EBUSY; - - twd_ppi = tlt->res[1].start; - twd_evt = alloc_percpu(struct clock_event_device *); - twd_base = ioremap(tlt->res[0].start, resource_size(&tlt->res[0])); - if (!twd_base || !twd_evt) { + if (!twd_evt) { err = -ENOMEM; - goto out; + goto out_free; } err = request_percpu_irq(twd_ppi, twd_handler, "twd", twd_evt); if (err) { pr_err("twd: can't register interrupt %d (%d)\n", twd_ppi, err); - goto out; + goto out_free; } err = local_timer_register(&twd_lt_ops); if (err) - goto out; + goto out_irq; return 0; -out: +out_irq: + free_percpu_irq(twd_ppi, twd_evt); +out_free: iounmap(twd_base); + twd_base = NULL; free_percpu(twd_evt); - twd_base = twd_evt = NULL; + return err; } + +int __init twd_local_timer_register(struct twd_local_timer *tlt) +{ + if (twd_base || twd_evt) + return -EBUSY; + + twd_ppi = tlt->res[1].start; + + twd_base = ioremap(tlt->res[0].start, resource_size(&tlt->res[0])); + if (!twd_base) + return -ENOMEM; + + return twd_local_timer_common_register(); +} + +#ifdef CONFIG_OF +const static struct of_device_id twd_of_match[] __initconst = { + { .compatible = "arm,cortex-a9-twd-timer", }, + { .compatible = "arm,cortex-a5-twd-timer", }, + { .compatible = "arm,arm11mp-twd-timer", }, + { }, +}; + +void __init twd_local_timer_of_register(void) +{ + struct device_node *np; + int err; + + np = of_find_matching_node(NULL, twd_of_match); + if (!np) { + err = -ENODEV; + goto out; + } + + twd_ppi = irq_of_parse_and_map(np, 0); + if (!twd_ppi) { + err = -EINVAL; + goto out; + } + + twd_base = of_iomap(np, 0); + if (!twd_base) { + err = -ENOMEM; + goto out; + } + + err = twd_local_timer_common_register(); + +out: + WARN(err, "twd_local_timer_of_register failed (%d)\n", err); +} +#endif -- 2.20.1